ABG-186 DEC
Transcription
ABG-186 DEC
GENETIC VARIATION IN PREVALENCE OF STOMACH WORM (Haemonchuscontortus) IN DIFFERENT POPULATIONS OF BLACK BENGAL GOAT MS Thesis NABILA NOURIN RETEE Department of Animal Breeding and Genetics Bangladesh Agricultural University Mymensingh December (2014) GENETIC VARIATION IN PREVALENCE OF STOMACH WORM (Haemonchuscontortus) IN DIFFERENT POPULATIONS OF BLACK BENGAL GOAT A Thesis Submitted to Bangladesh Agricultural University, Mymensingh In Partial Fulfillment of the Requirements for the Degree of Master of Science in Animal Breeding and Genetics By NABILA NOURIN RETEE Roll No. 13ABGJD02M Registration No. 34379Session: 2007-08 Department of Animal Breeding and Genetics Bangladesh Agricultural University Mymensingh December (2014) GENETIC VARIATION IN PREVALENCE OF STOMACH WORM (Haemonchuscontortus) IN DIFFERENT POPULATIONS OF BLACK BENGAL GOAT A Thesis Submitted to Bangladesh Agricultural University, Mymensingh In Partial Fulfillment of the Requirements for the Degree of Master of Science in Animal Breeding and Genetics By NABILA NOURIN RETEE Appoved as to style and content by _________________________ Prof. Dr. Md. OmarFaruque Supervisor ________________________________ Prof. Dr. Md. MotaharHussainMondal Co-supervisor _________________________ Prof. Dr. Md. Omar Faruque Chairman, Defence Committee and Head, Department of Animal Breeding and Genetics December (2014) ACKNOWLEDGEMENTS The author has pleasure to express her greatest and deepest gratitude to the supreme of everything Allah, for her mercy to successfully complete the thesis work, manage each and everything soundly. The author feels it a profound privilege to expresses her deepest sense of gratitude, profound appreciation and heartfelt indebtedness to her research supervisor Professor. Dr. Md. Omar Faruque, Department of Animal Breeding and Genetics, Faculty of Animal Husbandry, Bangladesh Agricultural University, Mymensingh, for his scholarly guidance, innovative suggestions, encouragements, constant supervision, constructive criticism, affable behavior and untiring perseverance throughout the tenure of this research work and preparing manuscript of this thesis. The author wishes to express her indebtedness with heartiest gratitude to another research supervisor Professor Dr. Md.MotaharHussainMondal, Department of Parasitology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, for his outstanding inspiration, total guidance, intellectual help, valuable criticism, keen suggestions, cordial behavior throughout this research work and preparation of this manuscript. The author is also thankful to the present respectable chairmanProfessor. Dr. Md. Omar Faruque, Department of Animal Breeding and Genetics, Faculty of Animal Husbandry, Bangladesh Agricultural University, Mymensingh, for the moral support throughout this research work and benevolent inspiration as well as overall his greatest kindness. The author is also indebted and grateful to all of her honorable teachers of the Department of Animal Breeding and Genetics, Faculty of Animal Husbandry, Bangladesh Agricultural University, Mymensingh, for their valuable advice and help during the course of the study period. i The author is grateful and wants to give special thanks to the project of “Studies on the Quantitative Traits Loci (QTL) of Economic traits in Black Bengal goat” funded by SPGR program of NATP Phase –I and “Genetic variation on the control of nematodes in the small ruminant in Bangladesh” funded by IAEA (International Atomic Energy Agency, Vienna, Austria)for financial support during the research period. The author is very much thankful to the Sheikh HabiburRahman, Md. Jalaluddin, Md. Mohon Mia and all field assistants for their cordial behavior and help throughout this research work. The author says special thanks to Desha, Pervez, Manik, Juel, Mitu, Sumi, Rupa, Badhon, Moon and all of her friends and well-wishers for their constant company and encouragement during this study period. Finally, the author owes her deepest gratitude, heartfelt respects, and thanks to her beloved parents, husband, sisters Rachi and Mugdha, brother Rakin for their understanding, inspirations, moral support, kindness and blessings, forbearance and endless love to complete her study. THE AUTHOR December, 2014 ii GENETIC VARIATION IN PREVALENCE OF STOMACH WORM (Haemonchuscontortus) IN DIFFERENT POPULATIONS OF BLACK BENGAL GOAT NABILA NOURIN RETEE ABSTRACT Black Bengal goat is the only recognized breed of Livestock in Bangladesh.A number of factors viz., reduced grazing land for goat, diseases and parasite infection are limiting the production of Black Bengal goat in the country nowadays. This experiment was conducted to investigate the genetic variation in resistance to Haemonchuscontortus(a GI Nematode)in different populations of Black Bengal goat in Bangladesh. To achieve this goal, two studies were done. In study 1, 196 goats from different populations of Black Bengal goat (BBW, BBC, BBH)were studied.The prevalence of Haemonchuscontortuswas 47.52%, 46.54% and 42.85% for BBW, BBC and BBH population respectively. So, more than 50% of Black Bengal goats under natural grazing condition had noHaemonchuscontortusinfestation.The haematological values (PCV and Hb) were larger in non-infectious goats than infectious goats in all three populations. In study II, two populations of Black Bengal goat (BBC and BBH) were studied through artificial challenge trial. 5 kids of 5 months old were dewormed properly and infested with L3 larvae @5000/ kid. Thebody weight (BWT),faecal egg count(FEC), haematological values (Hb and PCV) were measured at day 0 (Day when larvae were infested artificially), day 21 (21 days after the larvae were infested artificially) and day 28 (day after the larvae were infested artificially). Only two kids of BBC had FEC at day 21 and day 28 thought it was low ranging from 50 to 200 only. On the other hands, no kids of BBH had FEC even at day 28.The studies revealed that BBH had the least prevalence and load of Haemonchuscontortusthan other two populations of Black Bengal goat in naturally grazing condition and artificial challenge trial.This supports the between population difference for resistance to Haemonchuscontortus inBlack Bengal goats.It might be topography, feeding habit or genotypic differences of threepopulations of Black Bengal goats. Further work on gene expression is needed to clarify the actual cause behind this fact. iii CONTENTS CHAPTER TITLE PAGE ACKNOWLEDGEMENTS i-ii ABSTRACT iii CONTENTS iv-v LIST OF TABLES vi LIST OF PLATES vii LIST OF FIGURES viii CHAPTER 1 INTRODUCTION 1-5 CHAPTER 2 REVIEW OF LITERATURE 6-18 Importance of Black Bengal goat in 6-7 2.1 Bangladesh 2.2 Prevalence of nematode and stomach 7-9 worm in ruminant including Black Bengal goat in Bangladesh 2.3 Haemonchuscontortus 9-10 2.4 Prevalence of Haemonchus parasite and 11-13 economic loss in ruminant including goat CHAPTER 2.5 Prevention for Haemonchuscontortus 13-16 2.6 Research on Haemonchusresistance gene 16-18 MATERIALS AND METHODS 19-29 Study-I: Study on the prevalence of 19-25 3 3.1 parasites 3.2 Study-II: Artificial challenge trial 3.3 Study-III: Identification of population resistance to Haemonchuscontortus iv 25-28 29 CONTENTS CHAPTER CHAPTER CHAPTER CHAPTER CHAPTER TITLE PAGE 4 RESULTS 30-41 4.1 Study-I: Prevalence of parasites 30-37 4.2 Study-II: Artificial challenge trial 38-41 4.3 Identification of population resistance to Haemonchuscontortus DISCUSSION CONCLUSION REFERENCES 5 6 7 v 41 42-44 45-46 47-59 LIST OF TABLES TABLE TITLE PAGE 3.1 Schedule of artificial challenge trial 26 4.2 Prevelance of Haemonchuscontortus in BBW, BBC and BBH 30 population 4.3 ANOVA table for prevalence of Haemonchuscontortus in three populations of Black Bengal goat 31 4.4 Prevalence of Haemonchuscontortusin different sex and age 32 gropus in Black Bengal goats 4.5 Faecal egg count (epg) and percent of animal affected by Haemonchuscontortus 33 4.6 Variation in PCV and Hb values among the Haemonchuscontortusinfected and non-infected goat 35 4.7 Level of significance between infectious and non-infectious goats for PCV value by t-Test 36 4.8 Level of significance between infectious and non-infectious goats for Hb value by t-Test 36 4.9 FEC, HB and PCV at and after artificial infestation of larvae (L3 @5000/kid) 38 4.10 Body weight of kids at and after artificial infestation of larvae (L3 @5000/kid) 40 vi LIST OF PLATES TABLE TITLE PAGE [ [[[ 3.1 20 Different populations of Black Bengal goat. BBW: Black Bengal goat in the western part, BBC: Black Bengal goat in the western part, BBH: Black Bengal goat in the western part, 3.2 Black Bengal goats are under natural grazing condition. A 22 represents BBW goats, B represents BBC goats and C represents BBH goats [ [[ 3.3 23 Clean canvass floor mat used for faeces collection [ [[ 3.4 28 Collection of Haemonchuscontortus wormfrom slaughtered goat’sabomasums vii LIST OF FIGURES TABLE TITLE PAGE [[[ [ 1.1 3 Dendrogram for genetic relationship of five goat populations/breeds BBW: Bangladesh west, BBC: Bangladesh central, BBH: Bangladesh Hilly, JAM: Exotic breeds, CRW: Crossbred between Black Bengal and exotic breeds [[[ [[ 2.2 [ 4.3 [[[ [[ Life cycle of Haemonchuscontortus Prevelance of Haemonchuscontortus in BBW, BBC and BBH 10 [ 31 population [[ [[ 4.4 34 Distribution of animals having different level of faecal egg count of Haemonchuscontortus [[[ [[ 4.5 37 Correlation between PCV value (%) and different level of faecal egg count of Haemonchuscontortus 4.6 37 Correlation between Hb value (gm/dl) and different level of faecal egg count of Haemonchuscontortus 4.7 Body weight of kids at different days during artificial challenge trial viii 41 Chapter 1 INTRODUCTION Goat is an important domestic animal in many parts of the world and has served mankind for ages. It provides substance in the form of food and clothing. This hardy ruminant can exist in harsh environment in which other livestock species would perish. Goat grows and reproduces under extreme conditions from rugged mountain areas where winters are bitter cold to desert regions where it is hot and dry, and water and forage are sparse. Goats are socio-economically important in developing countries, ensuring food and fiber supply and providing income to small households (Lebbie, 2004; Sahlu et al., 2004; Sahlu and Goetsch, 2005). Today, more than 90% of the goat population is in developing countries where goat meat and meat products are considered as one of the most important sources of income (Shrestha and Fahmy, 2007). The goat is being recognized as a significant food source, because goats can convert feed DM into milk as efficiently as other ruminants; 185 kg milk/100 kg of dry OM for does compared with 162 kg for cows in temperate environment (Spedding, 1970). Goat has been recently recognized as a tool for poverty alleviation. Owing to increased demand for goat products, more livestock producers are raising goats in developing countries (Sahlu and Goetsch, 2005). Goat production provides employment for poor rural families, especially for women and children. Especially during droughts when crops fail, goats due to their adaption capabilities, can survive on woody browses and infrequent watering; coupled with their high reproductive rate and short generation interval, goats their owners to recover quickly and economically (Lebbie, 2004; Peacock, 2005). The special characteristics of goats that make them particularly important in rural poor communities compared to other domestic ruminants include: ability to graze and utilize a wide range of poor quality forages and browse; ability to walk long distances; short generation intervals and high 1 reproductive rates; high turnover rates on investment and hence low risk on investment; efficient utilization of marginal lands; smaller carcasses. It is generally accepted that goats require low inputs and are easy to manage, contributing to a sustainable economic stock for more smallholders in the tropics and subtropics (Acharya and Battacharya, 1992). The goat is a very important animal genetic resource in the world. The world population of goats is 910 millions, of which 94% are found in the developing countries (FAOSTAT 2013). Africa and Asia account for about 90% of the total population in the developing countries, including a bewildering variety of breeds. India, China, Pakistan and Bangladesh possessed 31.2%, 29.3%, 10% and 7.5% of the total goat of Asia, respectively. These countries together possessed about 78% of the population of goats in Asia. Bangladesh possessed 50500 thousand goats that represented 6.7% of the total population in the world (FAOSTAT, 2011). More than 90% of the goat population in Bangladesh is comprised of Black Bengal having some variants in color and size; the majority of remainder is imported Indian breeds and their crosses (Husain, 1993). Goat Black Bengal goat is found almost in all villages of Bangladesh. There are wide variation in color, body size and weights of goats found in different location. Black Bengal goats are mostly black in color which comprises 80% of the total goat population and the rest are of white, brown, gray, mixed or spotted coat color and any combination of those colors at any proportion (Nozawa et al., 1984). In the livestock sector, Black Bengal goat is the only recognized breed amongst the domestic species available throughout Bangladesh. Black Bengal goat is a dwarf breed and famous for high fertility, prolificacy, superior chevon quality, best quality skin, early sexual maturity, resistance against common diseases, aseasonality, low kidding interval and very good adaptability (Hussain, 1993; Islam et al., 2001; Devendra and Burns, 1983). They are very much adaptive to the stressful and varied nutritional regimen. They graze a wide spectrum of plants, grasses, shrubs and leaves of perennial trees. They can grow optimally even without concentrate feeds. 2 Faruque (2009) classified Black Bengal goat into three sub groups according to the geographical distribution of the goats and DNA polymorphisms (Fig. 1). These are Bangladesh West (BBW), Bangladesh Central (BBC), and Bangladesh East (BBH). There is morphological and genotypic variation among these populations. A number of exotic breeds were introduced in the past for cross breeding purpose. As a result, many crossbred goat (cross between Black Bengal and exotic breeds) are visible in different part of the country. The exotic breeds and crossbreds are concentrated in the western part of the country. In the absence of any census, it is difficult to mention the exact population number of each population or breed. However, Black Bengal goats are clearly predominant. 100 CRW 99 JAM BBW BBC BBH Fig 1: Dendrogram for genetic relationship of five goat populations/breeds BBW: Bangladesh west, BBC: Bangladesh central, BBH: Bangladesh Hilly, JAM: Exotic breeds, CRW: Crossbred between Black Bengal and exotic breeds The Parasitism has been considered as one of the major constraints of livestock production. Parasitism is an important limiting factor that is responsible for deteriorating the health and productivity of livestock. Parasitic infestations exert adverse effects on the health and productivity of animals (Rehman et al., 2009). These effects are varied and more pronounced in goats (Iqbal et al., 1993). Many species of parasites are found in goats and usually include Haemonchus, Oesophagostomum, Ostertagia, Cchabertia, Nematodirus, Trichuris, Moniezia and Fasciola. One of the most important species is Haemonchus contortus (Husnain and Usmani, 2006). 3 Haemonchus contortus, also known as red stomach worm, wire worm or barber's pole worm, is very common parasite and one of the most pathogenic nematodes of ruminants. Adult worms are attached to abomasal mucosa and feed on the blood. This parasite is responsible for anemia, bottle jaw, and death of infected sheep and goats, mainly during summer months in warm, humid climates. Haemonchus contortus causes helminthiasis especially parasitic gastroenteritis (PGE) which constitutes a serious health problem and limitation to the productivity of goats and sheep throughout the world due to the associated morbidity, mortality and cost of treatment and control measures (Silvestre et al., 2000). It causes the animals to be unthrifty which may include the loss of weight, low birth weight, and difficulty in kidding. It exerts the greatest economic losses in temperate and tropical regions (Blood et al., 1979; Raza et al., 2009; Ijaz et al., 2009). Haemonchus contortus parasites pretenses the greatest challenge to goat health and production in humid areas. The standard treatment to control the challenge has been the use of anti helminthics. However, parasite resistance to anti helminthes drug is an increasing problem. It is increasing the cost of treatment and production. Livestock Producers and breeders are now trying to develop breeds that have resistant to infectious diseases. In this regards, they are trying to exploit the within and between breed genetic variation in resistance to infectious diseases. There is well-documented evidence for within and between breed genetic variations in resistance to infectious diseases, such as gastrointestinal nematode infections, diseases due to mycotoxins, bacterial diseases including foot root and mastitis, ectoparasites such as flies and lice, and scrapie, the small ruminant transmissible spongiform encephalopathy. Due to this document, within-breed variation of disease resistance in many cases is a heritable trait. This offers the opportunity to select animals for enhanced resistance to the disease. The feasibility of this approach has been experimentally demonstrated and in other cases, breeding programs selecting 4 commercial animals for enhanced resistance are being successfully established, especially for sheep as compared to goats. There are concerted efforts to find genetic markers associated with resistance to infections, potentially allowing selection for increased resistance in the absence of infection, especially for scrapie and nematode parasitism (Bishop and Morris, 2004). Black Bengal goat is the only breed of livestock in Bangladesh. Like other ruminants, it is also infected by stomach worm (Qadir, 1967; Haq and Shaikh, 1968, Howlader et al., 1996; Karim, 2003; Shahiduzzam et al., 2003; Akanda et al, 2012; Hossen, 2012; Hassan et al., 2014) resulting in deteriorate of the health of animal and reduction of production. It will, therefore, be worthy to develop Black Bengal goat resistant to stomach worm. However, information or report on within breed genetic variation for stomach worm of different populations of Black Bengal goat is not available. This work was therefore undertaken i. To investigate the prevalence of Haemonchus contortus in different populations of Black Bengal goat kept under naturally grazing condition. ii. To investigate the effect of artificial infestation of Haemonchus contortus in different populations of Black Bengal goat kept under confined condition. iii. To identify the population of Black Bengal goat related to resistant to Haemonchus contortus. 5 Chapter 2 REVIEW OF LITERATURE There are a lot of work have been done on the life cycle of Haemonchus contortus, its effect on the ruminant health and production and within and between breed genetic resistant specially of sheep and goat in abroad and few in the country. In the following sections, some of these reports have been presented. 2.1 Importance of Black Bengal goat in Bangladesh Goat is numerically and economically important and promising animal resources in the developing countries especially in Asia and Africa (Husain, 1993). It is estimated that more than 90% of goat population consists of Black Bengal goat (BBG). The Black Bengal goat is only breed of livestock in Bangladesh. It is well known for high fertility, fecundity and excellent skin quality. The Black Bengal goat is the most common and popular livestock of Bangladesh. Among the Asian countries, Bangladesh had the 4th highest population of goats (Amin et al., 2000). Small land requirement and adaptability to harsh climate have made goats more suitable for rearing in our country (Singh and Rai, 2006). Goats have been reared in Bangladesh from the time of human settlement in this part of the earth. They are also considered a potential genetic resource for poverty alleviation as they are the source of income for many small and landless farmers. All the goats in Bangladesh are reared under semi intensive system. The average number of goats per household is 2.31 and they are mostly reared by landless, small and medium farmers (Faruque et al., 2010). They are owned by almost all the categories of the people including ethnic groups and poor and subsistence farmers. Reproductive efficiency is always considered to be the most vital factor ensuring increase in productivity to a certain environmental condition (Hossain et al., 2004). Increased production efficiency can be obtained from goats since 6 they have a high reproductive efficiency with the potential for increased litter size and shorter generation interval and they have a relatively higher fertility rate in comparison to other farm animals (Williamson and Payne, 1978). Reproductive performance of goats is a major determinant of productivity and economic viability of commercial goat farms. The goats’ reproductive performance is an indicator of their adaptation to the adverse conditions. Black Bengal goat is that unique creature which has high reproductive and productive efficiency than any other crossbred. This breed has an excellent ability to accommodate and adapt to fluctuation in environment. The Black Bengal goat is the most prolific of all domestic ruminants under tropical and sub-tropical conditions and certain breeds are able to breed throughout the year. (Devendra, 1970; Riera, 1982; Song et al., 2006). 2.2 Prevalence of nematode and stomach worm in ruminant including Black Bengal goat in Bangladesh In Bangladesh, parasitic infection is the major cause of hindering the development of livestock population. The climate of Bangladesh is suitable for the parasites, which are to great extent responsible for kid mortality in this country. The hot and humid climatic conditions in Bangladesh are highly conductive for the development and multiplication of parasites (Jabber and Green, 1983). Bangladesh is a tropical country with moderate winter and summer. This climatic condition is suitable for the development and survival of many parasites. Besides, in this country most of the goats are reared in rural areas in scavenging or semi scavenging system (Devendra, 1970). In this type of rearing, goats graze on the fields. This type of management practice plays a vital role in the high rate of parasitic infection (Domke et al., 2011). Gastro intestinal Nematodes are spread by orally ingesting the infective stage of the parasite. This most commonly occurs during grazing. A warm-wet environment of Bangladesh is most conductive to build-up of worm population in ruminants. Amongst them, stomach worms of goat are 7 great problem (Mondal and Islam, 1994). Black Bengal goats of Bangladesh are affected by various intestinal helminths (Qadir, 1967; Haq and Shaikh, 1968). A number of studies carried out in different parts of the country revealed that Haemonchus contortus parasitic infection is common in Black Bengal goat (Haq and Shaikh, 1968; Howlader et al., 1996; Karim, 2003; Shahiduzzam et al., 2003; Akanda et al, 2012; Hossen, 2012; Hassan et al., 2014). These studied were conducted mainly on the naturally grazing Black Bengal goats in Chittagong, Sylhet and Mymensingh district. These studied revealed that there was infection of Haemonchus contortus in goats as determined by faecal egg count as well as by the presence of worm in the abomasums; however the occurrence of Haemonchus contortus varied with seasons of the year, and sex and age of animals. (Hassan et al. 2014) conducted an experiment on prevalence and pathological effects of intestinal Helminths including Haemonchus contortus in Black Bengal goat in Chittagong district. The study clearly suggested that Black Bengal goats were susceptible to intestinal helminths in both winter and summer seasons, and most of the parasites recovered were associated with the production of variable degree of pathological lesions. Black Bengal goat is assumed to be a disease resistance breed. In many researches, it has been shown that the rate of occurrence of parasitic infection in Black Bengal goat is very low. (Ratnesh et al., 2013) worked on variability of resistance in Black Bengal with various genetic and non-genetic factors. The study found that the resistance of kids under sire was varied significantly and it was also noticed that maternal genetic effect has a very little impact on resistance of kids. Males (buck) were most resistant and the kids were least resistant and the resistance of dam was in between the male and kids population. 2.3 Haemonchus contortus Haemonchus contortus is one of the most prevalent and pathogenic parasite infesting the stomach of ruminants irrespective of age, gender, and breed of the host throughout the world leading to tremendous loss in variety of ways. So, several attempts have been made to study this parasite by a number of researchers (Franklin, 1935; Ksull, 1939; Almedia, 1945; Silverman and 8 Patterson, 1960; Sahai and Deo, 1964; Altaif and Issa, 1983; Masud and Jamil, 1887; Gelaye and Wossene, 2003, Muzaffar, 2010, Kuchai, 2012). Adult worms are attached to abomasal mucosa and feed on the blood. This parasite is responsible for anemia, bottle jaw, and death of infected sheep and goats, mainly during summer months in warm, humid climates. The adult female worm can release between 5,000 and 10,000 eggs, which will be passed out in the feces. Eggs then develop in moist conditions in the feces and continue to develop into the L1 (rhabditiform), and L2 juvenile stages by feeding on bacteria in the dung. The L1 stage usually occurs within four to six days under the optimal conditions of 24–29 °C. The L2 rhabditiform sheds its cuticle and then develops into the L3 filiariform infective larvae. The L3 form has a protective cuticle, but under dry, hot conditions will not survive long. The L3s then crawl up the blades of wet grass and wait to be ingested by a grazing animal. Sheep, goats and other ruminants become infected when they graze and eat grasses containing the L3 infecting larvae. The infecting larvae pass through the first three stomachs to reach the abomasums. There, the L3s shed their cuticles and burrow into the internal layer of the abomasums, where they develop into L4s, usually within 48 hours, or preadult larvae. The L4 larvae then molt and develop into the L5 adult form. The male and female adults mate and live in the abomasum, where they feed on blood. 9 Fig. 2: Life cycle of Haemonchus contortus There are significant observable genetic and phenotypic divergences among Haemonchus contortus species. Microsatellite markers have been used to investigate genetic divergence, whilst phenotypic divergence has been considered through individual worm morphology, isolate life history traits and the effect of isolates upon the host. In an experiment genetic and phenotypic divergence between isolates of Haemonchus contortus in Australia was observed (Lello et al., 2004). They conclude that there is significant observable genetic divergence between isolates of H. contortus in Australia. Phenotypic divergence is also observed, and potentially has significant implications for both economic losses due to haemonchosis on individual properties and for decisions regarding the regulation of stock movements in Australia. 10 2.4 Prevalence of Haemonchus parasite and economic loss in ruminant including goat In the tropics, the most important nematode species affecting ruminants are Haemonchus contortus, Trichostrongylus species, Nematodirus species Cooperia species, Bunostomum species Oesophagostomum species. Heamonchus contortus commonly known as the twisted stomach worm is a blood sucking nematode parasite, primarily occurring in the abomasum of small ruminants, notably sheep and goats. It has been ranked as the most important parasite of ruminants in all regions across the tropics and subtropics and causes an insidious drain on production, weight losses and even mortality in young animals as reported by (Bhat et al., 2010). Gastrointestinal parasites not only affect the health but also affect the productive and reproductive performance of the cattle and buffalo. Gastrointestinal worms are recognized as by for the most significant part of diseases in livestock sector (Waller 1997). It has been established that parasitic infestation results in considerable losses in milk production in cattle and buffalo (Hayat et al., 1984). Among the predisposing factors of internal parasites infection are climates, nutritional deficiency, grazing habits, immunological status, pasture management, presence of intermediate host and vector and the number of infective larvae and eggs in the environment. Damages inflicted to the health and productivity includes loss in body weight, poor reproductive performance, digestive disturbance, and emaciation for longer period (Radostits et al., 1994). Other economic losses are poor work performance, involuntary culling, lower milk production, treatment costs, and mortality in heavily parasitized animals (Lebbie et al., 1994). So it is important to control internal parasites through better management as in developed countries, and knowledge on prevalence of these parasites is mandatory. 11 In most sheep production areas, internal or gastro-intestinal parasites (i.e. worms) are usually the primary disease affecting sheep and lambs. Sheep are more susceptible to internal parasites than most other types of farm livestock for several reasons. Their small fecal pellets disintegrate very easily thus releasing the worm larvae onto pastures. Nematode parasites are the major animal health constraint in sheep production on pasture. Chemical control using anthelmintic drenches has been a reliable means of nematode control for the last 40 years but increasingly nematodes are becoming resistant to anthelmintics. Nematodes resistant to all major classes of anthelmintics have now been documented throughout the world for the three major sheep nematode species – Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis. Multiply drug-resistant H. contortus is now making small ruminant production, in some areas of the tropics, unsustainable. (Vanimisetti et al., 2004) describes the Inheritance of fecal egg count and packed cell volume and their relationship with production traits in sheep infected with Haemonchus contortus. They concluded that ewes did not lose weight and lambs continued to grow throughout the measurement period, indicating no major negative effects of infection on BW in this production environment. There was considerable seasonal variation in patterns of FEC over time in ewes. Generally, autumn-lambing ewes showed an early increase in FEC, whereas springlambing ewes showed a later increase in FEC. Goat rearing is hindered by various problems, among them parasitism is an important limiting factor. Haemonchus contortus is a highly pathogenic and economically important gastrointestinal parasite of goats. These parasites are common blood feeders that cause anemia, reduced productivity and can lead to death in heavily infected animals. The results of an experiment revealed that 43.10% (459) goats were infected with different species of nematodes including Haemonchus contortus (14.65%), Trichuris ovis (8.17%), Trichostrongylus axei (7.61%), Trichostrongylus colubriformis (6.76%), Oesphagostomum columbianum (5.35%), Ostertagia circumcincta (5.35%), Chabertia ovina (4.79%) and Strongyloides 12 papillosus (4.51%). This experiment was carried out by (Akhter et al., 2011) in Hyderabad and Adjoining Areas. But there are some variations of resistance in goats infected with Haemonchus contortus. (Costa et al., 2000) studied the variability between and within breeds with respect to nematode egg counts (EPG), packed cell volume (PCV) and hemoglobin (Hb) in yearling female goats of the Caninde(15), Bhuj (6) and Anglo-Nubian (15) breeds, exposed to Haemonchus contortus. There are many associated risk factors influencing the prevalence of gastrointestinal helminthes including age, sex, weather condition and husbandry or management practices (Miller et al., 1998; Khan et al., 2009). Parasitism and gastrointestinal nematode parasitism is arguably the most serious constraint affecting small ruminant production world-wide especially goat population. Economic losses are caused by decreased production, cost of prevention, cost of treatment, and the death of infected animals. Problems with nematode parasitism are often classified as production disease (i.e. chronic subclinical condition affecting productivity such as weight loss, reduced weight gain, reproductive inefficiency, etc.). It should be noted here that is more when goats are managed as grazers. When goats are managed as browsers, exposure to nematode parasites is reduced and subsequently the effects are not as severe (Miller et al., 2005). 2.5 Prevention for Haemonchus contortus Internal parasites are a significant threat facing today’s small ruminant producer. Problems associated with parasites, particularly those of the gastrointestinal tract of goats can cause irreversible damage or even death to the animal, reduced performance and economic loss for the producer. Animals that are overburdened with parasites can be hindered in their reproductive performance, experience reduced growth rates, and become less productive overall, whether their purpose be meat, fiber, or milk. Control of internal parasites, especially gastrointestinal nematodes including Haemonchus contortus 13 (barberpole worm, stomach worm), is a primary concern for many goat producers and is particularly challenging in humid regions. Anthelmintics are drugs that either kill egg laying adults, or kill larvae before they become adults and become capable of laying eggs. Current control practices rely heavily upon the frequent use of anthelmintics which leads to the development of resistance to the anthelmintics (Pandey and Sivaraj, 1994). There are various types of anthelmintics (albendazole, fenbendazole, mebendazole, oxfendazole, ivermectin, moxidecti etc.). While some anthelmintics are effective in killing Haemonchus, there are two major problems that arise when using anthelmintics. The first problem that affects mainly sheep and goat producers is that there are very few anthelmintics that are actually approved by the FDA for use in small ruminants. The second problem is the resistance that parasites have developed to many anthelmintics. Resistance occurs when a drug is overused and the parasites develop a tolerance to the drug, making it no longer effective in killing them. Resistance makes it very difficult to effectively control Haemonchus because it lowers the number of options available to treat the parasite, especially since resistance to one drug often means that a parasite will be resistant to all drugs in that compound class. Prevention and control of the parasites that infect sheep and goats are becoming increasingly difficult due to generations of overuse and improper use of the available anthelmintic dewormers, which results in increasing resistance by parasites to common anthelmintics. In the past, control of parasites relied almost exclusively on multiple and regular anthelmintic drenching, with the aim to maximize livestock productivity and profitability. However, as it has been established that the use of anthelmintics has several drawbacks such as: the increasing incidence of parasite resistance against the available anthelmintics; consumer concerns regarding drug residues in food products and in the environment; the negative effect of preventive treatments on the development of natural immunity against helminthes (Ketzis et al., 2006). 14 Pasture management is one of the best outcomes of parasite control program is the reduction of number of parasites that the goats are exposed. This can be accomplished by managing pastures in a way that will reduce the parasitic load. Use control grazing practices to optimize pasture production. This is a better practice than continuous grazing on the same pasture because goats will return to the same areas where their favorite plants are growing. Those areas will then become heavily infected by gastrointestinal parasite larvae. Put goats in a browse area, such as a woodlot, when hot, humid environmental conditions favor the rapid life cycle of gastrointestinal parasites. By browsing, goats will not consume forage close to the ground where the parasite larvae are located. In addition, many browse plants have the additional benefit of harboring high tannin concentrations. Tannins have been shown to reduce fecal egg counts and possible gastrointestinal parasite larvae numbers (Kate, 2010). The another way of parasite control is the pasture rotation or rotational grazing which have the ability to break the parasite cycle has been tossed around for years. The main reason to use pasture rotation is not for parasite control but to provide the most nutritious forage for growth and development of goat. But pasture management have the same limitations that it cannot fully prevent the parasitic infection of goat. But individual goats vary in their degree of susceptibility to Haemonchus and other parasites. Some animals, by means of their genetics, are much more resistant or resilient to parasitic infections, and can survive parasite levels without showing any symptoms while another animal may be killed by that level of infestation. This genetic resistance can be used when selecting breeding stock, since a herd that exhibits more innate resistance to parasites will cost less to maintain and will ultimately be more profitable to the producer. So it should be the main to develop parasite resistance goat breed. 15 The increasing prevalence of anthelmintics resistance during the recent years and also great concern about drug residues in the food chain have necessitated the search for an effective alternative strategy to control roundworm (especially H. contortus). This can be resolved by utilizing principle of breeding for genetic resistance which is a component of integrated parasite management (IPM) programmes (Woolaston and Windon, 2001; Bishop and Morris, 2004). (Albers et al., 1987) reported that resistance to H. contortus was moderately heritable; indicating that selection and breeding goat for increased resistance is possible. Therefore shifting to resistant variety or designing cross breeding programmes involving resistant goat breeds are thus most promising application in combating nematode infection. In view of the above facts, the present work has been undertaken on Black Bengal goat to study the variability of resistance in Black Bengal goat naturally infected with H. contortus (Ratnesh et al., 2013). 2.6 Research on Haemonchus resistance gene The farm animal genetic materials are a rich collection of genetic variations with either useful or harmful consequences on health and productivity. These variations are usually remain in the form of single nucleotide polymorphisms (SNPs), deletions of nucleotides or whole genes, gene or whole chromosomal rearrangements, gene duplications, copy number polymorphisms, copy number variations and presence/absence of transposable elements. Selection for increased resistance exploits the genetic variability in resistance observed in most commercial sheep breeds and in some goat breeds (Baker and Gray, 2004). One approach is to select resistant animals using phenotypic traits such as the faecal egg count (FEC), PCV, eosinophil count, body weight (BW) and immunoglobulin A and E (IgE and IgA) activity which are indirect measures of resistance. Selection for phenotypic traits has been 16 successfully used in Australia and New Zealand (Karlsson et al., 1991; Kemper et al., 2010); however, it is costly and time-consuming as it requires animals to be challenged with parasites. Considering the cost and time, for goat breeding and genetics, MAS is now considered the optimal choice (Weller and Ron, 2011). Unfortunately, little information about the candidate genes affecting diseases resistance traits is available. For this reason, excavating the suitable candidate DNA markers that correlate with growth and diseases resistance traits in goat breeds has become a major objective. Exploration of genetic variation either within specific regions of genome or more specifically in candidate genes involved in innate and adaptive immune pathways may help to identify a set of DNA markers significantly associated with parasite resistance characteristics. The former approach in terms of quantitative trait locus (QTL) analysis is a powerful method to understand genotype-phenotype relationship. Several QTL studies on parasite resistance characteristics have been reported in sheep. Very few works have been done on goat in the whole world. The major histocompatibility complex (MHC) plays a key role in the immune response. Clear evidence has been reported of genetic markers in the class I and class II regions of the MHC on sheep chromosome 20 (OAR20) being associated with resistance to nematodes. For example, the DRB gene on OAR20 (a part of class II of MHC) and the interferon gamma gene (IFNG) (Schwaiger et al., 1995; Buitkamp et al., 1996; Paterson et al., 1998) both play a role in regulation of immune responses to infections. (Schwaiger et al., 1995) found in Scottish Blackface sheep that one allele (DRB1) of the DRB locus within the ovine MHC II on OAR20 was associated with 98% reduction in worm egg count. From 23 polymorphic alleles identified at the DRB locus in Polish Heath sheep, two alleles (482 bp and 530 bp) demonstrated a significant association with resistance to GIN, whereas another allele (568 bp) conferred increased susceptibility to parasites (Charon et al., 2002). (Stear et al., 1996) studied in 17 Scottish Blackface lambs infected with Ostertagia circumcincta and showed that class I alleles were in close linkage disequilibrium with the DRB1 alleles and they were associated with a 10-fold reduction in FEC. In another study, the MHC class I microsatellite (DYA) had a significant and moderately strong (eightfold) association with FEC (Buitkamp et al., 1996). These authors stated that the disease susceptibility locus is closer to the class II region than to the class I region, and both of these host defence mechanisms (MHC I and II) are likely to involve a type 2 helper T (TH2)-cells. The identification of QTL for parasite resistance may vary depending on the nematode species, the challenging regime and the indicator trait measured (Dominik, 2005). 18 Chapter 3 MATERIALS AND METHODS This experiment was conducted in the Department of Animal Breeding and Genetics, Bangladesh Agricultural University, Mymensingh, Bangladesh, Gurudaspur and Baraigram Upazila of Natore district and Bandarban Hill district on the Black Bengal goats from 15th July, 2013 to 30th September, 2014. Animal Genetics Laboratory under the Department of Animal Breeding and Genetics and Parasitology Laboratory under the Department of Parasitology were used for analysis of faeces and blood. To achieve the goal, overall activities were divided into the following three studies: To study the prevalence of Gastro-intestinal nematode including Haemonchus contortus in different populations of Black Bengal goats kept under natural grazing condition. To investigate the effect of artificial infestation of Haemonchus contortus in different populations of Black Bengal goat kept under confined condition. To identify the population related to resistant to Haemonchus contortus. Study –I 3.1 Study on the prevalence of parasites 3.1.1 Experimental site The experiment was carried out from August, 2013 to November, 2013 covering the rainy in three areas of Bangladesh. These were Chapainawabganj and Rajshahi (western part of Bangladesh), Mymensingh (the central part of Bangladesh) and Bandarban Hill district (eastern part of Bangladesh). The three areas represent three topographical conditions and three different ecologies. Chapainababgonj and Rajshahi district was dry area, Mymensingh was flood fed area. Bandarban Hill district was hilly and forest area. 19 3.1.2 Experimental animal Geographically and genetically, Black Bengal goat can be divided into three populations: BBW (Black Bengal goat in the western part), BBC (Black Bengal goat in the central part), BBH (Black Bengal goat in the eastern part and hilly region) (Faruque, 2009). No work had been done on the naturally grazing Black Bengal goats in hilly region like Bandarban Hill district (BBH) and dry region like Chapainawabganj and Rajshahi (BBW). Present study represents three genetically representative populations of Black Bengal goats and also wider geographical areas of Bangladesh covering these populations. 200 goats of various ages (4-18 months) were randomly selected from the three areas. Among them, 106 were female and 94 were male goats. The Black Bengal goat population of Chapainawabganj and Rajshahi has been termed as BBW (Black Bengal goat in the western part), the Black Bengal goat population of Mymensingh has been termed as BBC (Black Bengal goat in the central part), and the Black Bengal goat population of Bandarban Hill district has been termed as BBH (Black Bengal goat in the eastern part) also represent goat of hilly region. 20 BBC BBW BBH Plate -1: Different populations of Black Bengal goat. BBW: Black Bengal goat in the western part, BBC: Black Bengal goat in the western part, BBH: Black Bengal goat in the western part 3.1.3 Management of the animals All the goats under this study were reared in semi intensive system. This system allowed the goats to graze freely in the natural pasture in the day time about 6 to 8 hours and kept in confinement during night time. The BBW goats obtained leaves of fruit tress (Mango and Jack fruit) in addition to grass as the region was rich in fruit trees. The BBC goats lived on only grass of fellow land as the region was flood fed area and lack of fruit trees. The BBH goats browsed mostly on leaves of herbs in the forest. In all the cases, goats did not receive any anti helmintic drugs as the owners did not practice any deworming program for their goats. 21 A B C Plate -2: Black Bengal goats are under natural grazing condition. A represents BBW goats, B represents BBC goats and C represents BBH goats 3.1.4 Sample collection Fresh fecal sample (near to 5 gm) was collected from each goat. Precaution was taken so that there was no dust during the faeces collection using clean canvass floor mat in most cases. The goat under study was kept confined on this floor mat until it discharged the faeces. The faeces was preserved in 5% formalin and carried to laboratory. Blood was also collected from the same goat when it was allowed by the owners for estimating Haemoglobin value (Hb) and Packed cell volume (PCV %). Blood was collected in EDTA coated venoject tube, carried in ice box and kept in refrigerator at 40C until analyzed. 22 Plate 3. Clean canvass floor mat used for faeces collection 3.1.5 Faecal egg count (FEC) Feacal egg was counted in the laboratory of Parasitology. A modified McMaster technique was used to determine faecal egg counts and to identify different ova and oocyst of nematode species following Cable (1957). In this method, 4gm of faeces was thoroughly suspended in 56ml saturated salt solution. The suspension was stirred through a 150 mm mesh sieve to remove the course particles. A portion of the suspension was withdrawn with the help of Pasteur pipette and allowed to run into the chambers of the McMaster slide. The slide was allowed to stand for 5 minutes to float the eggs. The eggs in the two chambers were counted using low power objectives (10X magnification). The number of eggs per gram of feces was calculated by using the following formula: Number of egg in two chambers Number of egg in one gm = x dilution factor 0.3 23 Total volume of suspension in ml Dilution factor = Total volume of feces In this study, a sensitivity saws 50 i.e. each egg represented 50 epg 3.1.6 Estimation of Packed cell volume (PCV) Packed cell volume was measured from blood in the laboratory of Animal Genetics. Packed cell volume is the fraction of whole blood volume that consists of red blood cells (RBC). The procedure of PCV estimation has been given below: 1. Well mixed blood sample was drawn by the special loading pipette. 2. The loading pipette was placed at the bottom of the hematocrit tube. 3. The hematocrit was filled with blood through the little pressure on the rubber bulb and simultaneously removing the loading pipette up to 0 or 10 marks. 4. Blood above 0 or 10 mark should be removed with the help of cotton. 5. Then all of the hematocrit tubes were placed in the centrifuge machine and centrifuged for 30 min at 3000 rpm. 6. After centrifugation the tube was removed from the machine and packed cell volume or hematocrit was recorded from the bottom of the graduated scale. 7. The result was expressed in percentage (%). 24 3.1.7 Estimation of Haemoglobin value (Hb) Haemoglobin value was measured from blood in the laboratory of Animal Genetics. Haemoglobin value was measured by acid hematin method with the help of Haemometer. The procedure for measuring Hb has been described below: 1. 2% HCl solution was taken in the diluting tube up to 2 marks. 2. Well mixed blood sample was drawn by the shale pipette up to 20 mm mark. 3. The blood from the pipette was rinsed for 2-3 times. 4. The content was mixed thoroughly and left for five minutes in the comparator. 5. After five minutes distilled water was added drop wise and mixed with the help of stirrer. 6. The mixing was continued until and unless the color in the diluting tube matched with the color of the comparator. 7. After matching the tube was removed and result was recorded from the graduated scale. 8. The result was expressed in g/dl Study –II 3.2 Artificial challenge trial In order to determine the relative resistant of different populations of Black Bengal goats to Haemonchus contortus, an artificial challenge trial was conducted based on the result of prevalence of Haemonchus contortus in different regions and populations of goat. The prevalence of Haemonchus contortus was maximum in BBW (section 4.1) and minimum in BBH. Faruque (2013) conducted artificial challenge trial on BBW and BBH. So, BBH and BBC populations were selected in the present for artificial challenge trial. The artificial challenge trial was done as per the schedule shown below: 25 Table 1: Schedule of artificial challenge trial Date Activitity Day Transfer of BBC and BBH to individual goat pan of AI shed 01.05.14 Quarantine & acclimination 1 week Parasite culture, H.contortus 22.04.14 Faeces examination and Deworming 08.05.14 Faeces examination 16.05.14 Artificial challenge, infestation of L3 18.05.14 Day 0 FEC, PVC, Hb, BW 08.06.14 Day21 FEC, PVC, Hb, BW , Slaughter of animals for 15.06.14 Day 28 5000 L3 per kid FEC, PVC, Hb, BW tissue collection (liver) FEC= Faecal egg count, PCV = Packed cell volume, Hb = Haemoglobin, BW = Body weight 3.2.1 Experimental site This work was carried out in AI Centre at Bangladesh Agricultural University, Mymensingh from 1st May to 15th June, 2014. 3.2.2 Experimental animal Ten Black Bengal female kids of 5 months age were used for the study. Among them, 5 kids were procured from Mymensingh and 5 kids were procured from Bandarban Hill district. 26 3.2.3 Management of animals After procurement of kids, the feaces were collected from all the kids and examined for Haemonchus contortus ova. Haemonchus contortus ova were found in some kids of BBC group. So, all the kids were treated with anti-helminthes (Ivermectin @ 1 ml per kid). Feaces were again examined after 7 days for the presence of Haemonchus contortus ova. No Haemonchus contortus ova were found. So the kids were ready for artificial challenge trial. During that seven days prepatory period and the artificial challenge trial, all the kids were kept in individual kid pen and stall fed with grass and concentrate mixture. 3.2.4 Production of L3 larvae of Haemonchus contortus To produce L3 larvae of Haemonchus contortus, guts of a number of goats were collected from slaughter house of Mymensingh, abomasun was dissected and mature female stomach worms were collected. All the female worms were transferred to a pastel motor and mashed. PBS (Phosphate Buffer Solution) was added to it. Then the solution was filtrated with a sieve. One microscope slide was examined at very low powers initially 10x of microscope. It was done to know the concentration of eggs in the sample. The standard concentration of eggs in a sample was 200-300/drop. The sample, if found positive, was transferred to Petridis and kept at 250C in the lab. The sample was checked every day to find out the growth of larvae until third stage larval were observed. The culture was then ready for infesting the kids artificially. The culture was prepared in the laboratory of Parasitology. 27 Plate 4. Collection of Haemonchus contortus worm from slaughtered goat’s abomasums 3.2.5 Artificial challenge trial (infestation of larvae artificially) Larvae, cultured in the laboratory, were infested artificially to all 10 kids of two populations. Care was taken so that kid swallowed the larvae. Body weight of kids was taken before infestation of larvae. Faeces and blood was collected to estimate FEC, Hb and PCV. Date on which larvae were infested to kids as counted day 0. Body of weight kids were again taken on day 21 and 28. Faeces and blood was also collected to estimate FEC, Hb and PCV on day 21 and day 28. The artificial trail ended on day 28 as animals were slaughtered. FEC, PVC and Hb were used as indicator for resistance to parasite. 28 3.3 Identification of population resistance to Haemonchus contortus The individuals, kept under naturally grazing condition and having no Haemonchus contortus ova in the faeces, and higher PCV and Hb values, were considered resistance to Haemonchus contortus. Similarly the individuals, kept under artificial challenge trial, and having no Haemonchus contortus ova in the faeces, and higher PCV and Hb values, were also considered resistance to Haemonchus contortus. If most of the individuals in population had no parasitic or few load in the faeces (less than 300 epg), that population was considered resistance to Haemonchus contortus. However, all the data obtained in study I and study II was analyzed statistically to find out the difference in parasitic load of within and between populations of Black Bengal goat. For between population difference, data were analyzed following Completely Randomize Design after Snedecor and Cochran (1980). For within population difference, data was analyzed following student t-test after Snedecor and Cochran (1980). 29 Chapter 4 RESULTS Study –I 4.1 Prevalence of Haemonchus contortus Haemonchus contortus was found in all the three populations of Black Bengal goat populations. However, parasitic load varied within and between populations. The prevalence of Haemonchus contortus was 47.52%, 46.54% and 42.85% for BBW, BBC and BBH population respectively (Table 2 and Fig. 3). So, more than 50% of Black Bengal goats under natural grazing condition remained non-infected by Haemonchus contortus. Table 2: Prevalence of Haemonchus contortus in BBW, BBC and BBH population Population Total number of goat studied (n) No. goat infected with Haemonchus contortus (n) *Prevalence of Haemonchus contortus (%) BBW 101 48 47.52c BBC 39 18 46.54b BBH 56 24 42.85a *Values with different superscript within column differed significantly, at p<0.05. 30 70 Prevalence of H. contortus % 60 50 40 30 20 10 0 BBW BBC BBH Different populations of Black Bengal goat Fig. 3: Prevalence of Haemonchus contortus in BBW, BBC and BBH population Table 3: ANOVA table for prevalence of Haemonchus contortus in three populations of Black Bengal goat Sources of Level of Variation d.f. S.S. M.S. F significance Treatment 2 5880128 2940064 16.9 0.01 Error 87 15135122 173966.9141 Total 89 The prevalence of Haemonchus contortus differ significantly at 1% (P < 0.01) among three populations of Black Bengal goat. 31 The prevalence of Haemonchus contortus also varied with age and sex of the Black Bengal goats (Table 4). From Table 4, it appeared that the prevalence of Haemonchus contortus was more in female goats than male goats. The prevalence increased with the increase in age of the goats. Table 4. Prevalence of Haemonchus contortus in different sex and age gropus in Black Bengal goats Parameters No. of animals examined (n) Prevalence No of animal with positive faecal egg count % +ve (n) Sex Age Male 91 34 37.36 Female 107 52 48.59 4m-8m 76 34 44.73 9m-18m 90 47 52.22 19m-3y 32 21 65.62 The maximum and minimum faecal egg count (epg) of Haemonchus contortus were 2200 and 0, 1500 and 0, 200 and 0 for BBW, BBC and BBH population respectively. The mean faecal egg counts were 663.54 + 69.77, 647.22 + 112.11 and 81.25 + 7. 86 epg for BBW, BBC and BBH population respectively. Goats, which were infected by Haemonchus contortus, had different level of parasitic load as revealed by faecal egg count. This has been presented in Table 5 and Fig. 4. 32 Table 5. Faecal egg count (epg) and percent of animal affected by Haemonchus contortus Population of goat Faecal egg count( egg per gram) % of animal affected BBW >200 8.33 200-450 39.59 500-950 27.08 1000-1450 16.67 1500-2000 6.25 <2000 2.08 100.00 BBC >200 5.55 200-450 44.45 500-950 16.67 1000-1450 27.78 1500-2000 5.55 <2000 0.00 100.00 BBH >200 95.84 200-450 4.16 500-950 0.00 1000-1450 0.00 1500-2000 0.00 <2000 0.00 100.00 33 100 90 % of animal having parasitic load 80 70 60 50 BBW 40 BBC 30 BBH 20 10 0 Faecal egg count (egg per gram) Fig. 4: Distribution of animals having different level of faecal egg count of Haemonchus contortus From the tables and figs, it appears that BBH had the least prevalence and load of Haemonchus contortus among three populations of Black Bengal goat. Other two populations had almost similar prevalence and load of Haemonchus contortus. 4.1.1 Haematological values The maximum and minimum PCV (%) and Hb (g/dl) value were 48 and 10.5, 36 and 8.5, 24 and 8.5 for BBW, BBC and BBH population respectively that were infected with Haemonchus contortus. The maximum and minimum PCV (%) and Hb (g/dl) value were 59 and 9.8, 44 and 8.4, 31 and 9.6 for BBW, BBC and BBH population respectively that were not infected with Haemonchus contortus. The 34 mean and standard error of PCV and Hb value of BBW, BBC and BBH populations are shown in Table 6. Table 6. Variation in PCV and Hb values among the Haemonchus contortus Infected and non-infected goat Population Goat infected with Haemonchus contortus PCV (%) BBW Hb (g/dl) SE(±) Mean SE(±) Mean SE(±) Mean SE(±) 35.7 1.86 7.46 0.30 43.19 3.02 8.9 0.23 29.67 (20) 2.40 6.53 (8) 0.40 (5) BBH PCV (%) Mean (20) BBC Hb (g/dl) Goat not infected with Haemonchus contortus 24.00 (1) 36.38 (8) 2.71 (4) 00 8.50 (1) 00 24.43 (7) 7.80 (4) 1.27 8.00 (7) *Number of animal studied has been indicated in the Parenthesis From the above table the infectious and non-infectious goats show different PCV and Hb value. So we measured the level of significance between infectious and non-infectious goats for PCV and Hb value by t-Test. The results are shown in the Table 7 and 8. 35 0.32 0.55 Table 7. Level of significance between infectious and non-infectious goats for PCV value by t-Test Population df t-calculated t-tabulated Level of value value significance BBW 13 2.11 1.77 ** BBC 7 1.84 1.82 NS BBH 0 0.34 - NS ** Significant at 5% (P < 0.05); NS = Non-significant Table 8. Level of significance between infectious and non-infectious goats for Hb value by t-Test Population Df t-calculated t-tabulated Level of value value significance BBW 25 3.81 1.71 ** BBC 8 2.44 1.86 ** BBH 0 0.90 - NS ** Significant at 5% (P < 0.05); NS = Non-significant The correlation between parasitic load and Heamatological values has been presented in Fig. 5 and Fig. 6. From the figures it appears that parasitic load had negative effects on the haematological values of goats. 36 60 y = -0.0157x + 42.387 r = 0.689** 50 PCV value (%) 40 30 20 10 0 0 200 400 600 800 1000 1200 1400 No. of Ova Fig. 5: Correlation between PCV value (%) and different level of faecal egg count of Haemonchus contortus 12 y = -0.0022x + 8.4903 r = 0.612** 10 Hb value (gm/dl) 8 6 4 2 0 0 200 400 600 800 1000 1200 1400 1600 No. of Ova Fig. 6: Correlation between Hb value (gm/dl) and different level of faecal egg count of Haemonchus contortus Study –II 37 1600 4.2 Artificial infestation of Haemonchus contortus From the information from literatures and experiment I, two populations of Black Bengal goat viz., BBC and BBH were selected for artificial trial. The result of FEC, Hb and PCV at day 0 (Day when larvae were infested artificially), day 21 (21 days after the larvae were infested artificially) and day 28 (day after the larvae were infested artificially) has been presented in Table 9. Table 9. FEC, HB and PCV at and after artificial infestation of larvae (L3 @5000/kid) Population BBC BBH Kid No Day 0 Day 21 Day 28 FEC Hb PCV FEC Hb PCV FEC Hb Epg g/dl % epg g/dl % epg g/dl % BBC1 0 12.6 38 0 12.6 39 0 12.6 39 BBC2 0 10 28 50 9.8 28 200 9.5 26 BBC3 0 13 30 50 13 29 150 12.6 28 BBC4 0 10.6 34 0 10.6 33 0 10.6 34 BBC5 0 10 28 0 10 28 0 10 28 BBH1 0 10.8 30 0 10.8 30 0 10.8 30 BBH2 0 10.8 27 0 10.8 28 0 10.8 28 BBH3 0 10 24 0 10 25 0 10 24 BBH4 0 10 26 0 10 26 0 10 26 BBH5 0 11 28 0 11 28 0 11 29 FEC – Faecal egg count, Hb – Haemoglobin, PCV- Packed cell volume, epg - egg per gram 38 PCV Table 9 reveals that there was no egg in the faeces of Kids in BBH population indicating there was no Haemonchus contortus development. On the other hand, only two kids of BBC population had eggs in the faeces indicating there was Haemonchus contortus development. However, the total FEC was low ranging from 50 to 200 only. The other three kids had no egg in the faeces. The corresponding Hb and PCV values decreased slightly in those two kids. The other kids that had no egg of Haemonchus contortus even after artificial infestation of larvae showed almost constant level of HB and PCV. This indicates that BBH population was resistant to Haemonchus contortus whereas BBC was susceptible to Haemonchus contortus. This also reflected in body weight change of the kids after the artificial infestation of larvae. The result of body weight of kids at day 0 (Day when larvae were infested artificially), day 21 (21 days after the larvae were infested artificially) and day 28 (day after the larvae were infested artificially) has been presented in Table 9. 39 Table 10. Body weight of kids at and after artificial infestation of larvae (L3 @5000/kid) Population BBC BBH Kid No Day 0 Day 21 Day 28 Body weight (Kg) Body weight (Kg) Body weight (Kg) BBC1 7.5 8.0 8.2 BBC2 7.0 7.6 7.75 BBC3 7.5 7.9 8.0 BBC4 7.0 7.5 7.6 BBC5 7.0 7.7 8.1 BBH1 8.0 8.7 8.9 BBH2 8.0 8.65 8.9 BBH3 7.5 8.0 8.2 BBH4 7.5 8.1 8.35 BBH5 9.0 9.6 9.8 When this data was placed in the graphs, there appeared that Kid2 and kid3 gained almost no body weight (Fig. 7). 40 12 10 8 BWT at D0 6 BWT at D21 BWT at D28 4 2 0 BBC1 BBC2 BBC3 BBC4 BBC5 BBH1 BBH2 BBH3 BBH4 BBH5 Fig. 7: Body weight of kids at different days during artificial challenge trial 4.3 Identification of Haemonchus contortus resistant population The results of artificial challenge trial reveled that BBH population was resistance to Haemonchus contortus while BBC population is susceptible to Haemonchus contortus. The results of prevalence of Haemonchus contortus revealed that most of individuals of BBH had no parasitic load. On the other hands, individuals having parasitic load in BBH population had very low level of parasitic load (Table 2 and Table 4). These results support the between population difference in resistance to Haemonchus contortus in Black Bengal goats. Table 4 also supports and provides evidence of within-population resistance to Haemonchus contortus in Black Bengal goats. 41 Chapter 5 DISCUSSION Black Bengal goat is the only recognized breed of Livestock in Bangladesh. It is also one of most important ruminant livestock found almost every household in rural area of the country. Its contribution is reflected in supplying nutritious meat, valuable leather, income generation and poverty alleviation. It has also cultural and religious role in the society. However, a number of factors are limiting the production of Black Bengal goat in the country now a day. The reducing grazing land for goat, diseases and parasite infection are also limiting factors for the production of Black Bengal goat. Among the gastrointestinal nematodes, Haemonchus contortus is the most frequent in Black Bengal goat of Bangladesh as reported by a number of investigators viz., Qadir (1967), Haq and Shaikh (1968), Howlader et al., (1996), Karim (2003), Shahiduzzam et al. (2003), Akanda et al. (2012), Hossen (2012) and Hassan et al. (2014). Most of those investigators worked on the Black Bengal goats in Mymensingh district using slaughter house samples while few investigators worked on the Black Bengal goats in Chittagong district. It may be mentioned here that Mymensingh is considered as flood fed area which is also suitable area for harboring the gastrointestinal nematodes like Haemonchus contortus. The Black Bengal goats of Mymensingh and adjacent districts have been term as BBC in the present study. So it can be said those studies represent the prevalence of Haemonchus contortus in BBC. None of them worked on the naturally grazing Black Bengal goats in hilly region like Bandarban Hill district and dry region like Chapainawabganj and Rajshahi. The Black Bengal goats of these two regions have been termed as BBW and BBH respectively in the present study. It may therefore be said that the present study represents wider geographical areas of Bangladesh and includes naturally grazing goats of three majors Black Bengal populations viz, BBW, BBC and BBH. 42 In the present study, the prevalence of Haemonchus contortus was more in BBC and BBW populations than BBH (Table 1). The prevalence of Haemonchus contortus were 47.52%, 46.54% and 42.85% in BBW, BBC and BBH population respectively. Faecal egg count of individual goat, if occurred, was also very high in BBW and BBC (up to 2200) than BBH (up to 450). This is evidence from the faecal egg count as presented in Table 5. One reason might be the soil structure and vegetation pattern of Bandarban Hill district as well as feeding behavior of BBH goats there. The soil of Bandarban Hill district is loose sandy soil covered mostly by forest. There are a lot of herbs and shrubs there. BBH goat browses the leaves of these herbs and shrubs. That might assist in reducing gastrointestinal parasitic burden. On the other hand, BBC and BBW goats live in flood fed area and eat grasses in most cases. The topography as well as feeding habits might assist in increasing the parasitic burdens in these two populations. Karim (2003), Shahiduzzam et al. (2003), Akanda et al. (2012), Hossen (2012) and Hassan et al. (2014) reported slight higher prevalence of Haemonchus contortus in BBC than the present study. This might be use of abomasums as a source of parasite in their study while the present study is based on faecal egg count. There is no other investigation yet now except this about the prevalence of Haemonchus contortus in BBW and BBH population. Faruque (2009) reported differences in the genotypes of BBW, BBC and BBH goats in Bangladesh. There may be genetic difference in resistance to Haemonchus contortus in BBH population. However, this should be confirmed by gene expression study. In addition to population variation in prevalence of Haemonchus contortus, there was also variation in age and sex within the population for prevalence of Haemonchus contortus (Table 2). The prevalence of parasite increased with the age and sex. The older and female goats had higher percent of prevalence of Haemonchus contortus. This finding of present study is in agreement with the findings of Howlader et al. (2002), Shahiduzzam et al. (2003), Akanda et al. (2012), Hossen (2012) and Hassan et al. (2014). 43 The haematological values presented in Table 6, Fig. 5 and Fig. 6 revealed that goats free of Haemonchus contortus had higher haematological values than goats infested with Haemonchus contortus. This is supported by investigation made on goat and sheep by other scientists in abroad (Buvanendran, et al., 1981; Karlsson, et l., 1991; Yadav et al., 2006). The BBH population had significantly higher PCV and Hb values as this population had less Haemonchus contortus load. The artificial challenge trial also corresponded with the above findings. There was no egg or ova in the faeces at day 28 and 21 after the infestation of larvae parasite in BBH. On the other hand, two kids BBC2 and BBC3 had some eggs in the faeces at day 21 and day 28 after the infestation of larvae parasite. This study indicates that BBH is more resistance to Haemonchus contortus than BBC. In an artificial challenge trial done on BBH and BBW by Faruque (2013), BBH was found more resistance to Haemonchus contortus than BBW. The discussion made so far indicates that BBH goats are more resistance to Haemonchus contortus than BBC and BBW goats. There is also variation in resistance to Haemonchus contortus within BBH goat population. Further studies on the gene expression should be conducted to confirm these findings. The between and within population variation of resistance to Haemonchus contortus in different populations of Black Bengal goats will assist in future to develop Haemonchus contortus resistant Black Bengal goat in the country. 44 CHAPTER 6 CONCLUSION Black Bengal goat is the only recognized breed of Livestock in Bangladesh. a number of factors viz., reduced grazing land for goat, diseases and parasite infection are limiting the production of Black Bengal goat in the country nowadays. This experiment was conducted to investigate the genetic variation in resistance to Haemonchus contortus (a GI Nematode) in different populations of Black Bengal goat in Bangladesh. To achieve this goal, two studies were done. Study I was carried out to find out the incidence of Haemonchus contortus in different populations of Black Bengal goat kept under naturally grazing condition. 196 goats from different populations of Black Bengal goat (BBW, BBC, BBH) were studied. The prevalence of Haemonchus contortus was 47.52%, 46.54% and 42.85% for BBW, BBC and BBH population respectively. So, more than 50% of Black Bengal goats under natural grazing condition remained non-infected by Haemonchus contortus. The mean faecal egg counts were 663.54 + 69.77, 647.22 + 112.11 and 81.25 + 7. 86 epg for BBW, BBC and BBH population respectively. The study revealed that BBH had the least prevalence and load of Haemonchus contortus among three populations of Black Bengal goat. The maximum and minimum PCV (%) and Hb (g/dl) value were 48 and 10.5, 36 and 8.5, 24 and 8.5 for BBW, BBC and BBH population respectively that were infected with Haemonchus contortus. The maximum and minimum PCV (%) and Hb (g/dl) value were 59 and 9.8, 44 and 8.4, 31 and 9.6 for BBW, BBC and BBH population respectively that were not infected with Haemonchus contortus. The correlation between parasitic load and Heamatological values were estimated and it seemed that parasitic load had negative effects on the haematological values of goats. In study II, two populations of Black Bengal goat (BBC and BBH) were studied for artificial challenge trial. 5 kids of 5 months old were dewormed and infested with L3 larvae @5000/ kid. The body weight, FEC, Hb and PCV were measured at day 0 (Day when larvae were infested artificially), day 21 (21 days after the larvae 45 were infested artificially) and day 28 (day after the larvae were infested artificially). Only two kids of BBC had FEC at day 21 and day 28 thought it was low ranging from 50 to 200 only. On the other hands, no kids of BBH had FEC even at day 28. The studies revealed that BBH had the least prevalence and load of Haemonchus contortus than other two populations of Black Bengal goat in naturally grazing condition and artificial challenge trial. This supports the between population difference for resistance to Haemonchus contortus in Black Bengal goats. It might be topography, feeding habit or genotypic differences of three populations of Black Bengal goats. Further work on gene expression is needed to clarify the actual cause behind this fact. The between and within population variation of resistance to Haemonchus contortus in different populations of Black Bengal goats will assist in future to develop Haemonchus contortus resistant Black Bengal goat in the country. 46 Chapter 7 REFERENCES Acharya RM, Bhattacharyya NK 1992: Status of small ruminant production. Paper presented at the Vth International Conference on Goats, New Delhi. Akanda MR, Hossain FMA, Uddin MN, Belal SA, Ashad FA, Howlader MMR 2012: Prevalence of gastro-intestinal nematodiasis in Black Bengal goats of Sylhet Govt. Goat Development Farm, Bangladesh. Journal of Research in Biology 2(3) 246-250. Akhter N, Arijo AG, Phulan MS, Iqbal Z, Mirbahar KB 2011: Prevalence of gastrointestinal nematodes in goats in Hyderabad and Adjoining areas. Pak Vet J 31(4) 287-290. Albers GAA, Gray GD, Piper LR, Barker JSF, Le Jambre LF, Barger IA 1987: The genetics of resistance and resilience to Haemonchus contortus in young Merino sheep. International Journal for Parasitology 17 1355-1363. Almedia JL 1945: Revisao de genera Haemonchus cob 1898: Nematoda: Trichostrongylidae Mem. Inst. Osw. Cruz. 30 57-114. Altaif M, Issa K 1983: Abomasal and intestinal nematodes of sheep. J. Anim. Hlth. Prod. 38 31-36. Amin MR, Husain SS, Islam AB 2000: Evaluation of Black Bengal goats and their cross with Jamnapari breed for carcass characterisitics. Small Ruminant Research 38 (3) 211-215. Anthony Rowe, Kate McMaster, David Emery, Nicholas Sangster 2008: Haemonchus contortus infection in sheep: parasite fecundity correlates with worm size and host lymphocyte counts. Veterinary Parasitology 153(3-4) 285-93. Asanji MF, Williams MO 1987: A qualitative and quantitative survey and seasonal dynamics of gastrointestinal helminth parasites of livestock in Sierra Leone, Bulletin of Animal Health and Production in Africa 35 191-199. 47 Asif M, Azeem S, Asif S, Nazir S 2008: Prevalence of Gastrointestinal Parasites of Sheep and Goats in and around Rawalpindi and Islamabad, American-Eurasian Journal of Scientific Research 2 05-12. Baker RL, Gray GD 2004: Appropriate breeds and breeding schemes for sheep and goats in the tropics. In: Sani R. A., Gray G. D., Baker R. L., editors, Worm Control for Small Ruminants in Tropical Asia. Monogr. No. 113, Aust. Cent. for Int. Agric. Res., Canberra, ACT. Baker RL, Mwamachi DM, Audho JO, Aduda EO, Thorpe W 1998: Resistance of Galla and Small East African goats in the sub-humid tropics to gastrointestinal nematode infections and the peri-parturient rise in faecal egg counts. Vet. Parasitol. 79 53–64. Bhat AS, Reshi AA, Mir RM, Husain I, Sheikh BA, Khan HM 2010: Assessment of Prevalence of Parasitic Infections in Sheep Reared in Kashmir Valley India. J Anim Prod Adv 4(5) 416-421. Bishop SC, Morris CA 2004: Genetics of disease resistance in sheep and goats. Small Rumin. Res. 70 48–59. Blood DC, Henderson JA, Radostits OM 1979: Veterinary Medicine. 5th Ed., Bailliere Tindall, London, UK. Buitkamp J, Filmether P, Stear MJ, Epplen JT 1996: Class I and class II major histocompatibility complex alleles are associated with faecal egg counts following natural, predominantly Ostertagia circumcincta infection. Parasitology Research 82 693-696. Buvanendran V, Sooriyamoorthy T, Ogunsusi RA, Adu IF 1981: Haemoglobin polymorphism and resistance to helminths in Red Sokoto goats. Trop. Anim. Health Prod. 13 217–221. Cable RM 1957: An Illustrated Laboratory Manual of Parasitology, 4th edn., Burges Publishing Co., Minneapolis 15, Minnesota, USA. Charon MK, Moskwa B, Rutkowski R, Gruszczynska J, Swiderek W 2002: Microsatellite polymorphism in DRB1 gene (MHC class II) and its 48 relation to nematode faecal egg count in Polish Heath Sheep. Journal of Animal and Feed Sciences 11 47-58. Chauhan KK, Rout PK, Singh PK, Mandal A, Singh SK, Roy R 2003: Genetic resistance of Barbari and Jamunapari kids to natural infection with gastrointestinal nematodes. Trop. Anim. Hlth. Prod. 35 397-408. Choudhury SA, Bhuiyan MSA, Faruk S 2002: Rearing Black Bengal goat under semi-intensive management, physiological and reproductive performances. Asian-Australian J. Anim. Sci. 15(4) 477-484. Chowdhury SA, Faruque S 2001: Improvement of Black Bengal goat through selective breeding. Research Report. Bangladesh Livestock Research Institute, Savar Dhaka, Bangladesh. Coltman DW, Wilson K, Pilkington JG, Stear MJ, Pemberton JM 2001: A microsatellite polymorphism in the gamma interferon gene is associated with resistance to gastrointestinal nematodes in a naturally-parasitized population of Soay sheep. Parasitology 122 571-582. Costa CA, Vieira LD, Berne ME, Silva MU, Guidoni AL, Figueiredo EA 2000: Variability of resistance in goats infected with Haemonchus contortus in Brazil. Vet Parasitolol 88 153-158. Davies G, Stear MJ, Benothman M, Abuagob O, Kerr A, Mitchell S, Bishop SC 2006: Quantitative trait loci associated with parasitic infection in Scottish blackface sheep. Heredity 96 252-258. De la Chevrotière C, Bambou JC, Arquet R, Jacquiet P, Mandonnet N 2012: Genetic analysis of the potential role of IgA and IgE responses against Haemonchus contortus in parasite resistance of Creole goats. Veterinary parasitology, doi:10.1016/j.vetpar.2011.1011.1071. Devendra C 1970: Goat Production in the Tropics, Commonwealth Agricultural Bureaux, Farnham Royal, Bucks, England. pp. 88. Devendra C, Burns M 1983: Goat Production in the Tropics. Tech. Comm. No. 19 Commonwealth Bureaux Animal Breeding Genetics. Dominik S 2005: Quantitative trait loci for internal nematode resistance in sheep: a review. Genetics Selection Evolution 37 1-14. 49 Domke A, Chartier C, Gjerde B 2011: Worm control practice against gastrointestinal parasites in Norwegian sheep and goat flocks. Acta Vet Scand. 53 29. FAOSTAT 2011: http://faostat.fao.org/default.aspx. FAOSTAT 2013: http://faostat.fao.org/default.aspx. Faruque M.O. 2009: Final research report on “Phylogenetic studies of Bangladeshi goat based on morphological variation, blood protein and mtDNA polymorphisms as of characterization of small ruminants in Asia”. International Atomic Energy Agency, Vienna. Faruque M.O. 2013: Progress report on “Genetic variation on the control of nematodes in the small ruminant in Bangladesh”. International Atomic Energy Agency, Vienna, Austria. pp. 17. Faruque S, Chowdhury SA, Siddiquee NU, Afroz MA 2010: Performance and genetic parameters of economically important traits of Black Bengal goat. Journal Bangladesh Agril. Univ. 8 67–78. Franklin K 1935: Prevalence of gastro intestinal nematode parasites of sheep in Gurtuk. USSR. J. Parasit. Dis. 23 241-245. Gelaye E, Wossene AS 2003: Small ruminant Haemonchosis: morphology and prolificacy study in Eastern Ethiopia. Bull. Anim. Hlth. Prod. Afr. 51 6773. George Snedecor W, William Cochran G 1980: Statistical methods. Seventh Edition. The lowa State University Press, Ames, Lowa, U. S. A. Haq S, Shaikh H 1968: A Survey of Helminth Parasiting the Gastro-intestinal Tracts of Goats and Sheep in East Pakistan. East Pakistan Journal of Veterinary Science 2 54-62. Hassan MM, Hoque MA, Islam SKMA, Khan SA, Roy K, Banu Q 2014: A prevalence of parasites in Black Bengal goats in Chittagong, Bangladesh. Global Science Research journals 2 (1) 111-115. Hassan MM, Niaz Mahmud SM, Azizul Islam SKM, Miazi OF 2007: A comparative study on reproductive performance and productivity of the Black Bengal and crossbred goat at Atrai, Bangladesh. Univ. J. Zool. 26 5557. 50 Hassan Z 1964: Investigation into the intestinal helminths load in local goats. Indian Veterinary Journal 41 543-546. Hayat CS, Din RU, Hayat B, Akhter M 1984: Prevalence of coccidiossis in cattle and buffaloes with emphasis on age, breed, sex, season and management. Pakistan Vet. J. 14 214-217. Hossain MA 2003: Pashu Sampad Unnayan niti Mala. Directorate of Livestock Services. January, pp. 35-39. Hossain MJ, Amin M, Mostofa M, Sharif M, Khalid SMA 2004: Efficacy of levanid against natural gastrointestinal nematodiasis and paramphistomiasis in sheep. The Bang Vet 21(2) 70-73. Hossain SMJ, Alam MR, Sultana N, Amin MR 2004: Milk Production from Indigenous Black Bengal Goat in Bangladesh. J. Biol. Sci 4(3) 262-265. Hossen MA 2012: Prevence of gastrointentinal parasitic infections in goat and effects of temperature on the hatchability of Haemonchus contortus. MS thesis, Chittagong Veterinary and Anima Sciences University, Chittagong. Howlader MMR, Captain SS, Edaardo SL, Sevolla CC, Roxas NP 1996: Effect of experimentally infection with stomach worm (Haemonchus contortus) on the production performances of does. ALAS 9(4) 421 – 426. Howlader MMR, Mahbub-e-ilahe ATM, Habib S, Bhuyan MJU, Siddique MAB, Haye MA, Hossain GM 2002: Gastro intestinal infestations of Black Bengal goats in Sirajgong district of Bangladesh. Online J Biol Sci. 2(8) 556 -557. Hunt PW, Knox MR, Le Jambre LF, McNally J, Anderson LJ 2008: Genetic and phenotypic differences between isolates of Haemonchus contortus in Australia. Int J Parasitol. 38(8-9) 885-900. Husain SS 1993: A study on the productive performance and genetic potentials of Black Bengal goats. Ph. D. Dissertation. Department of Animal Breeding and Genetics. Bangladesh Mymensingh. 51 Agricultural University, Husnain HU, Usmani RH 2006: Livestock of Pakistan. 1st Ed. Livestock Foundation, Islamabad. Ijaz M, Khan MS, Avais M, Ashraf K, Ali M, Saima M 2009: Infection rate and chemotherapy of various helminths in goats in and around Lahore. Pakistan Vet. J. 28(4) 167-170. Iqbal Z, Akhtar M, Khan MN, Riaz M 1993: Prevalence and economic significance of haemonchosis in sheep and goats slaughtered at Faisalabad abattoir. Pakistan J. Agric. Sci. 30 51-3. Islam 1994: Studies on the stomach worms of goats and their prevention and control. BAU Res. Prog. 8 364-367. Islam MR, Shamsuddin M, Rahman MA, Das PM, Dewan ML 2001: An outbreak of peste des petits ruminants in Black Bengal goats in Mymensingh, Bangladesh. The Bangladesh Veterinarian 18 14-19. Jabber M, Green DAG 1983: The status and potential of livestock within the context of agricultural development policy in Bangladesh. InauguralDissertation. The University of Wales. Aberystwyth, UK. pp. 113. Javid Ahmad Kuchai, Fayaz Ahmad, Mohammad Zahoor Chishti, Hidayatullah Tak, Javid Ahmad, Shabir Ahmad, Muzaffar Rasool 2012: A Study on Morphology and Morphometry of Haemonchus contortus. Pakistan J. Zool 44(6) 1737-1741. Kagira JM, Kanyari PWN 2001: The role of parasitic diseases as causes of mortality in small ruminants in a highpotential farming area in central Kenya. Journal of the South African Veterinary Association 72 147–149. Karim 2003: Role of hypobiosis in the epidemiology of Haemonchus contortus in goats and the study of anthelminthic resistance. BAU Res. Prog. 14 4. Karlsson LJE, McLeod IM, Leelawardana DH, Sissoev KJS 1991: Selection for nematode resistance in sheep in the Australian Mediterranean climate zone. In: Breeding for Disease Resistance in Sheep. Australian Wool Corporation, Melbourne, Australia. Kate Hepworth 2010: Managing Internal Parasitism in Sheep and Goats. Animal Sciences 573. 52 Kemper KE, Palmer DG, Liu SM, Greeff JC, Bishop SC, Karlsson LJE 2010: Reduction of faecal worm egg count, worm numbers and worm fecundity in sheep selected for worm resistance following artificial infection with Teladorsagia circumcincta and Trichostrongylus colubriformis. Veterinary parasitology 171 238-246. Ketzis JK, Vercruysse J, Stromberg BE, Larsen M, Athanasiadou S, Houdijk JG 2006: Evaluation of efficacy expectations for novel and non-chemical helminth control strategies in ruminants. Vet. Parasitol. 31 321–335. Khan MN, Sajid MS, Iqbal Z, Hussain A 2009: Gastrointestinal helminthiasis: prevalence and associated determinants in domestic ruminants of district Toba Tek Singh, Punjab, Pakistan. Parasitol. Res. 107 787–794. Kotpal RL 2001: Modern Textbook of Zoology, Invertebrates, 8th edn.; Rastogi Publication, New Delhi, India. pp. 158. Ksull NP 1939: Anoplocephalate infection in sheep. Veterinariya Moscow USSR. 3 40-41. Kuchai JA, Tak H, Chishti MZ, Lone BA 2012: Faecal examination of Pashmina goats of Ladakh for nematode infections. Global J. Sci. Front. Res. 12 37-40. Kumar S, Lal SS 1987: Oedema due to Trichuris ovis: a case report. Archiva Veterinaria 18 33-36. Lapage G 1962: Mönnig’s Veterinary Helmithology and Entomology. 5th edn., Bailliere, Tindall and Cox Ltd. London. pp. 213-214. Lebbie 2004: Goats under household conditions. Journal of veterinary and parasitology 51(2) 131–136. Lebbie SHB, Rey B, Irungu EK 1994: Small Ruminant Research and Development in Africa: Proceedings of the Second Biennial Conference of the African Small Ruminant Research Network: AICC, Arusha, Tanzania. International Livestock Centre for Africa. 53 Lello J, Boag B, Fenton A, Stevenson IR, Hudson PJ 2004: Competition and mutualism among the gut helminths of a mammalian host. Nature. 428 840–844. Liu SM, Adams NR, Briegel JB, Smith TL, Martin GB 2007: Effect of genetic resistance to gastrointestinal nematodes on plasma concentrations of insulin-like growth factor-1 and leptin in Merino sheep. Australian Journal of Experimental Agriculture 47 905-911. Maichomo MW, Kagira JM, Walker T 2004: The prevalence of gastro-intestinal parasites in calves, sheep and goats in Magadi division, south-western Kenya. Onderstepoort Journal of Veterinary Research 71 257–261. Masud SA, Jamil M 1887: Prevalence of gastrointestinal nematodes in small ruminants of Kingort district of Tanzania. Ir. J. Vet. Helminthol. 17 58-62. McLeod RS 2004: Economic impact of worm infections in small ruminants in South East Asia, India and Australia. In: Worm Control of Small Ruminants in Tropical Asia (Sani R.A., Gray G.D and Baker R.L. eds), ACIAR Monograph 113 23-33. Meeusen NT 1999: Immunology of helminth infections, with special reference to immunopathology. Veterinary Parasitology 84 259-273. Meingi N, Gichigi MN, Njoroge GK 2001: Gastrointestinal nematode infection in sheep grazing on communal land in Nyandarua district of Central Kenya in relation to deworming practice. Bull Anim Health Prod (Africa) 49 153-161. Miller JE, Bahirathan M, Lemarie SL, Hembry FG, Kearney MT, Barras SR 1998: Epidemiology of gastrointestinal nematode parasitism in suffolk and gulf coast native sheep with special emphasis on relative susceptibility to Haemonchus contortus infection. Vet. Parasitol. 74 55–74. Miller JE, Stuedemann JA, Terrill TH 2005: Nematode parasites and grazing research. Proc. Southern Pasture and Forage Crop Improvement Conference, 11-13 May 2005, Philadelphia, MS. 54 Min BR, Hart SP, Sahlu T, Satter LD 2004: The effect of diets on milk production and composition, and on lactation curves in pastured dairy goats. Pub Med 2604-15. Mondal MMH, Islam MK 1994: Prevalence and pathological effects of Trichuris infection in Black Bengal goats. Bangladesh Veterinary Journal 28 15-20. Muzaffar R 2010: Helminth parasites in ruminants of Jammu. M.Phil. dissertation, Department of Zoology,University of Kashmir, Srinagar. Nahar L, Sarder MJU, Mondal MMH, Faruque MO, Islam MH 2012: Factors related occurrence of Haemonchosis of Goats in Rajshahi, Bangladesh. International Journal of Natural Sciences 2(3) 83-87. Nozawa K, Katsumata M, Hasnath MA, Mostafa KG, Faruque MO 1984: Coat color polymorphism in the Black Bengal Goat. In Genetic Studies on Breed Differentiation of the Native Domestic Animals in Bangladesh. Research Report, Tokyo University of Agriculture, 87-99. Nwosu CO, PP Madu, Richards WS 2007: Prevalence and seasonal changes in the population of gastrointestinal nematodes of small ruminants in the semi arid zone of North – Eastern Nigeria. Vet. Parasitol 144 118-124. Ouattara L, Dorchies P 2001: Gastro-intestinal helminths of sheep and goats in subhumid and sahelian areas of Burkina Faso. Rev Med Vet. 152 165-170. Pandey VS, Sivaraj S 1994: Anthelmintic resistance: an emerging serious problem in small ruminants in Malaysia. In: Sustainable Animal Production and the Environment. Proc. of the 7th AAAP Anim. Sci. Congr., Bali, Indonesia. 2 409-410. Patel MD, Nauriyal DS, Hasnani JJ, Gupta RS 2001: Prevalence of gastrointestinal parasitism in goats maintained under semi-intensive and field management systems. Indian Journal of Veterinary Medicine 21 99-101. Paterson S, Wilson K, Pemberton JM 1998: Major histocompatibility complex variation associated with juvenile survival and parasite resistance in a large unmanaged ungulate population (Ovis aries L.). Proceedings of the National Academy of Sciences 95 3714. 55 Peacock SJ 2005: Staphylococcus. In: Borriello SP, Murray PR Funke G (Editors), Topley and Wilson’s Microbiology and Microbiological Infections. Hodder Arnold, London. pp. 771-832. Perry BD, Randolph TF 1999: Improving the assessment of the economic impact of parasitic diseases and of their control in production animals. Vet Parasitol 84 145-168. Pisseri F, de Benedictis C, Roberti di Sarsina P, Azzarello B 2013: Sustainable Animal Production, Systemic Prevention Strategies in Parasitic Diseases of Ruminants. Altern Integ Med 2 106. Qadir ANMA 1967: Investigation on the incidence of gastrointestinal parasites of goats in the East Pakistan Agricultural University Campus. Bangladesh Veterinary Journal 15 58-61. Radostits OM, Blood DC, Gay CC 1994: Veterinary Medicine: A textbook of Disease of sheep, Pigs, Goats and Horses, 8th ed. Bailliere Tindall. pp. 448 – 449. Ratnesh Kumar, Sanjeev Ranjan, Guru Vishnu P, Mamta Negi, Senapati PK, Gnani Charita V 2013: Variability of resistance in Black Bengal goats naturally infected with Haemonchus contortus. J Parasit Dis. Raza MA, Murtaza S, Bachaya HA, Dastager G, Hussain A 2009. Point prevalence of haemonchosis in sheep and goats slaughtered at multan abattoir. J. Ani. & Plant Sci., 19(3) 158-159. Rehman KU, Javed K, Tunio MT, Kuthu ZH 2009. Passive survalance of Gastro intestinal parasites in buffaloes of mandi Bahauddin and Gujrat districts of the Punjab. J. Animal & Plant Sci., 19(1) 17-19. Riera S 1982: Reproductive efficiency and management in goats. Proceeding 3 rd International Conference on Goat Production and Disease. Tuscon, Arizona, USA. pp. 162-174. Sahai BN, Deo PG 1964: Studies on the Haemonchus contortus(Rudalphi 1803) Cobb 1898 and Haemonchus (Molin, 1860) Railliet and Henry (1909):with a note on the synonym of Haemonchus placel (place, 1893) with Haemonchus bispinosus. Ind. J. Helminthol. 16 5-11. 56 Sahlu T, Goetsch AL, Luo J, Nsahlai IV, Moore JE, Galyean ML, Owens FN, Ferrell CL, Johnson ZB 2004: Nutrient requirements of goats: developed equations, other considerations, and future research to improve them. Small Ruminant Research 53 191-219. Sahlu T, Goetsch AL 2005: A foresight on goat research. Small Ruminant Research 60 7-12. Sayers, G, Good B, Hanrahan JP, Ryan M, Sweeney T 2005: Intron 1 of the interferon [gamma] gene: Its role in nematode resistance in Suffolk and Texel sheep breeds. Research in veterinary science 79 191-196. Schwaiger FW, Gostomski D, Stear MJ, Duncan JL, McKellar QA, Epplen JT, Buitkamp J 1995: An ovine major histocompatibility complex DRB1 allele is associated with low faecal egg counts following natural, predominantly Ostertagia circumcincta infection. International journal for parasitology 25 815-822. Shahiduzzam M, Alim MA, Rahman M, Mondal MMH 2003: Seasonal influence on the occurrence of Haemoncus contortus in slaughtered Black Bengal goats in Bangladesh. Bang J Vet Med 1(1) 45 -48. Shill BK, Chowdhury SA, Hossain SMJ 2003: Chagol Palon Manual: Bangladesh Livestock Research Institute. 150 (2) 5-7. Shrestha JNB, Fahmy MH 2007: Breeding goats for meat production: a review (3) Selection and breeding strategies. Small Ruminant Research 67 113–125. Silverman PH, Patterson JE 1960: Histotrophic (parasite) stages of Haemonchus contortus. Nature, London 185 54-55. Silvestre A, Chartier C, Sauve C, Cabaret J 2000: Relationship between helminth species diversity, intensity of infection and breeding management in dairy goats. Vet. Parasitol 94 91-105. Singh A, Kirmani MA, Choudhary RP 1991: Factors affecting gender ratio in crossbred cattle. Indian Vet. J. 68 282–285. Singh NP, Rai B 2006: Goat rearing for meat and milk production: The scenario of eastern India. OUAT, Bhubaneswar, India pp. 26-39. 57 Sissay MM, Uggla A, Waller PJ 2007: University, Ethiopia. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in Eastern Ethiopia. Global Veterinaria 2 46-91. Song HB, Jo IH, Sol HS 2006: Reproductive performance of Korean native goats under natural and intensive conditions. Small Rumin. Res. 65 284-287. Spedding CRW 1970: Sheep production and grazing management. Bailliere, Tindall and Cox, London. Stear MJ, Bairden K, Bishop SC, Buitkamp J, Epplen JT, Gostomski D, McKellar QA, Schwaiger FW, Wallace DS 1996: An ovine lymphocyte antigen is associated with reduced faecal egg counts in four-month-old lambs following natural, predominantly Ostertagia circumcincta infection. International journal for parasitology 26 423-428. Talukder S, Bhuiyan MJ, Hossain MM, Uddin MM, Paul S, Howlader MMR 2010: Pathological Investigation Of Liver Fluke Infection Of Slaughtered Black Bengal Goat In A Selected Area Of Bangladesh. Bangl. J. Vet. Tariq KA, Chishti MZ, Ahmad F 2010: Gastro-intestinal nematode infections in goats relative to season, host sex and age from the Kashmir valley. India J Helminthol 84(1) 93-7. Vanimisetti HB, Andrew SL, Zajac AM, Notter DR 2004: Inheritance of fecal egg count and packed cell volume and their relationship with production traits in sheep infected with Haemonchus contortus. J. Anim. Sci. 82 1602– 1611. Waller PJ 1997: Anthelmintic resistance.Veterinary Parasitology 72 391-412. Waller PJ, Rydzik A, Ljungström BL, Törnquist M 2005: Towards the eradication of Haemonchus contortus from sheep flocks in Sweden. Veterinary Parasitology. Weller JI, Ron M 2011: Invited review: Quantitative trait nucleotide determination in the era of genomic selection. Journal of dairy science 94 1082-1090. Williamson G, Payne WJA 1978: An introduction to animal husbandry in the tropics. The English Language Book Society and Longmans, London. 58 Woolaston RR, Windon RG 2001: Selection of sheep for response to Trichostrongylus colubriformis larvae: genetic parameters. Animal Science 73(1) 41–48. Yadav AK, Tandon V 1989: Gastrointestinal nematodes infections of goats in a subtropical and humid zone of India. Vet. Parasitol 33(2) 135-142. Yadav NK, Ajoy Mandal, Sharma DK, Rout PK, Roy R 2006: Genetic Studies on Faecal Egg Counts and Packed Cell Volume Following Natural Haemonchus contortus Infection and Their Relationships with Liveweight in Muzaffarnagari Sheep. Asian-Aust. J. Anim. Sci. 1524 – 1528. 59