Animal Breeding and Genetics
Permanent URI for this collectionhttps://etd.hu.edu.et/handle/123456789/64
Browse
2 results
Search Results
Item PHENOTYPIC CHARACTERIZATION AND OESTRUS SYNCHRONIZATION OF INDIGENOUS GOATS FOR IMPROVED REPRODUCTIVE EFFICIENCY IN MIRAB-ABAYA AND ARBAMINCH-ZURIA DISTRICTS OF GAMO-GOFA ZONE, SOUTHERN ETHIOPIA(Hawassa University College of Agriculture, 2018) DEREJE DEAThe present study was designed with the objectives of describing the goat production systems, morphological features and evaluate oestrus synchronization of indigenous goats in Arba-Minch-Zuria and Mirab-Abaya districts of Gamo-Gofa zone. A total of 120 HHs were interviewed for goat production survey while 615 goats (151 males and 464 females) were used for morphological measurements and 60 does for oestrus synchronization from the two districts. The results confirmed that goats ranked 2nd after cattle and were primarily produced for generating income and saving purposes in the study areas. The major mating system was uncontrolled (80.83%). Goat castration (65.83%) and culling (93.33%) were common goat breeding practices whereas kid weaning was not well practiced. Body size, pedigree and prolificacy were the magnificent selection criteria for breeding does whereas color incorporated for bucks. Communal browsing areas were the main goat feed sources in which January through March months were commonly known for the feed shortage. Male goats have higher off-take rate at early age (94.17%) to the market than females (82.50%). Feed shortage (30.37%) followed by labor limitation (23.33%) and land shortage (15.56%) were the major goat production challenges identified. In morphological measurements, the predominant coat color pattern was plain for male (63.82%) and (70.02%) for females. Brown coat color for males (32.24%) and (34.05%) for females was possessed predominantly. Horned goats were (86.84% for males and 94.55% for females), toggle (14.47% for males and 9.85% for females), bearded (53.29% for males and 22.06% for females. The prominent horn shape was straight (93.13% for males and 93.11% for females). About 61.83% of male and 78.95% of female goats were characterized by possessing obliquely upward horn orientation. Except Body length, males possessed higher values for Body weight, Rump lenght, Head width and Horn length than females (P<0.05). Goats in Arbaminch-Zuriya district possessed significantly (P<0.05) higher values on BW, BL, CG, RW, HeW and SC than in Mirab Abaya district. In males, positive and strong association were depicted between BW and BL (r=0.68), WH (r=0.62), CG (r=0.61) and HoL (r=0.63). In case of females, positive and moderate associations were observed between BW and CG (r=0.38), RW(r=0.37) and HeL (r=0.31). CG was a single importance variable in the prediction of body weight in females where as BL in males (P<0.05). Regarding to the oestrus synchronization, about 85% of the does expressed oestrus within 55.68±19.92 hours after hormone administration where as the overall conception rate was 81.67%. Doe body weight, body condition, parity and age have significantly affected (P<0.05) oestrous response and conception rate where as location has not significantly (P>0.05) affected. Morphological traits’ variations suggest that this goat ecotype has not yet been selected through structured selective breeding. While conducting oestrus synchronization on goat, considering body weight, BCS, parity and age factors was better to reflect higher conception rate.Item GENETIC AND NON-GENETIC FACTORS AFFECTING SURVIVABILITY, GROWTH AND REPRODUCTIVE PERFORMANCE OF BOER AND CENTRAL HIGHLAND GOATS AND THEIR CROSSES REARED AT ATAYE FARM, NORTH SHOA, ETHIOPIA(Hawassa University College of Agriculture, 2017) AMINE MUSTEFAThis study was conducted at Ataye site of Debre-Birhan Agricultural Research Center. Data pertained to512 kids/ yearlings of Boer (B), Central Highland Goats (CHG), and F1 (B X CHG), F2 (a) (F1 X F1), F2 (b) (B X F1), were collected from 381 kiddings, recorded between 2012 and 2017. The study was aimed to access the effects of genetic and non-genetic factors on growth, reproductive and survivability performances of the above genotypes. The data was analyzed using GLM of SAS (9.0) to investigate the effect of genetic and non-genetic factors (dam parity, sex, year, season and type of birth) affecting body weight and daily weight gain from birth to 1 year of age, litter size and weight at birth and at weaning. Non-parametric tests were used to investigate the genetic and non-genetic factors influencing the conception, kidding and abortion rates. Survival analysis study was carried out using Weibull proportional hazards models using Survival Kit version 6.0 and chi square sub-dividing analysis using SAS (9.0) was used to access the genetic and non-genetic factors influencing the survival of the kids from birth to yearling age. Similarly Animal model were used for the estimation of genetic parameters and sire ranking based on their breeding value estimates using WOMBAT®. The overall least-squares means for body weight (kg) at birth, at weaning, at six months and at yearling and body weight gain to weaning, weaning to six-months and six months to yearling (grams) were 2.68±0.04, 9.11±0.19, 11.69±0.26, 16.41±0.38, 69.73±1.89, 30.48±1.54 and 24.33±1.21 respectively. Genotype and all the studied non genetic factors affected the body weight and weight gain from birth to yearling age. However, parity of the doe only influenced body weight gain six month to yearling. Weaning weights were not affected by sex of the kids. Yearling weights were not affected by breed and season of birth. Similarly season of birth did not affect six-month weight. The overall conception, kidding and abortion (%) of the does were recorded to be 48.75, 77.05 and 20.49 respectively. Genetic and non-genetic factors influence the studied traits but kidding and abortion percentages were not affected significantly by mating season similarly conception (%) were not affected by mating weight. The overall least-squares means for litter size at birth was (1.40±0.03), at weaning was (0.67±0.03), litter weight (kg) at birth was (3.63±0.07) and at weaning was (10.68±0.28) respectively. The traits were not affected by parity. Similarly litter size at birth and at weaning were not affected by breed of the doe and season of kidding. Litter size at birth was not affected by year of kidding while litter weight at weaning was not affected by type of birth. The overall least squares means for body weight at mating and at kidding (kg) of the does were 26.52±0.40 and 28.04±0.39 respectively. These traits were affected by breed of the does and year of mating year but not by season of mating. The heritability estimates ranged were slightly over estimated due to small sample size. The h2 among the (B and F1) for body weight at birth, at weaning, at six-months and at yearling ages were (0.43±0.28 and 0.73±0.17), (0.78±0.50 and 0.67±0.27), (0.75±0.52 and 0.65±0.27) and (0.23±0.70 and 0.65±0.27). Similarly genetic and phenotypic correlations were also over estimated. Sires were also ranked based on their estimated breeding values for body weight from birth to yearling age among the B and F1. The overall survival (%) of the kids at day 4, 90, 180 and 365 were 73.99, 53.57, 47.98 and 40.27 respectively. The above survivability traits were not influenced by sex and parity. Similarly survival at day 90 and 180 were not affected by genotype. Season of birth also influenced the survivability of the kids at the 4th day (after birth). So from this study we can conclude that the overall growth, reproductive and survivability performances of all the studied genotypes were quit low which indicating their sub-optimal adaptability to the study area. Thus, evaluating the genotypes based on a large sample size reared across different locations under different management is desired to come to a definite conclusion. Similarly as the yearling weight were highly correlated with the weaning and six month weight then we can therefore consider them as indicator traits for yearling weight of the goats. The findings also showed variation across bucks (based on their EBV) for the growth traits.