Abstract:
On-Station and On-Farm Performance Evaluation and Genetic Parameters Estimation of Boer x Central Highland Crossbred Goat in North Wollo Zone, Ethiopia
Zeleke Tesema 1, 2*, Kefyalew Alemayehu1, Damtie Kebede1 and Tesfaye Getachew3 1Bahir Dar University, Colleges of Agriculture and Environmental Science, Bahir Dar, Ethiopia; 2Sirinka Agricultural Research Center, Woldia, Ethiopia; 3International Center for Agricultural Research in the Dry Areas (ICARDA), Addis Ababa, Ethiopia
Performance evaluation and accurate estimation of genetic parameters are the prerequisites for successful genetic improvement program. This study was conducted with the objectives of on-station and on-farm performance evaluation and genetic parameters estimation for Boer x Central Highland crossbred goat. On-station and on-farm data collected from 2009-2018 as well as survey data collected through semi-structured questioner and focus group discussion were utilized for this study. A general linear model procedure of the Statistical Analysis System (SAS, version 9.0) was used to analyse the growth and reproductive performance data. The analyses of fixed effects for survival data were performed using the GENMOD procedure of SAS by a linear logit model and survival analysis was conducted with a Weibull proportional hazard model using Survival Kit version 6.1 software. The genetic parameters for growth and survival traits were estimated using WOMBAT and ASREML (with logit function) software fitted animal model, respectively. Six analysis models for growth and four models for survival traits were fitted in order to optimize the model for each trait. Log likelihood ratio test was used for selecting best fitted model. The overall least squares mean litter size at birth, litter size at weaning, litter weight at birth, litter weight at weaning and gestation length were 1.6±0.02 kids, 1.4±0.02 kids, 3.9±0.05 kg, 13.6±0.35 kg and 148.0±0.33 days, respectively. Birth type, season, year, parity and genotype of dam were important sources of variation for most of the reproductive traits. Under on-station management, the overall least squares mean body weight at birth (BWT), weaning (WWT), six-month (SMWT), nine-month (NMWT) and at yearling age (YWT) were 2.52±0.01, 9.81±0.13, 13.8±0.15, 17.8±0.19 and 20.5±0.29 kg, respectively. The weight gain from birth to weaning (ADG1), weaning to six- month (ADG2), six to nine month (ADG3) and nine month to yearling age (ADG4) were 80.3, 37.5, 41.9 and 31.2 g/day, respectively. Except for NMWT and ADG4