Abstract

The study was conducted at Aybera main animal breeding and feeding experimental site in Wag-Himra administrative zone in Amhara regional state, in Ethiopia. The site was established to conserve the indigenous Abergelle goat breed and improve the performance growth and milk production traits through selective breeding. A total of 516 kids for body weight, and 304 does for milk yield performance were used for this study. Animals were managed semi-intensively where they were arranged into pasture lands during day time with concentrate supplementation. Selection was based on bucks which were done once in a year using indexed estimated breeding value of yearling weight and their respective dam milk yield performances. Top-ranked bucks selected from the flock were used as replacements at the nucleus while the surplus bucks disseminated to nearby villages. The general linear model procedure of SAS software (version 9.0) was employed to evaluate the body weight and milk yield of the breed during the last five years (2016-2020). The overall birth-, three month-, six month-, nine month- and yearling weights were 1.98, 6.5, 8.6, 11.4, and 13.8 kg, respectively. The overall lactation milk yield, average daily milk yield and lactation length were 17.64 kg, 0.30 kg and 8.45 weeks, respectively. Within the last five consecutive selection years birth weight has increased from 1.64±0.04 to 2.3±0.02 kg, weaning weight from 5.6±0.25 to 7.5±0.15kg, and yearling weight from 13±0.43 to 15.2±0.27kg. All the fixed effects of birth type, parity, season and year of birth had significantly affected the birth weight. The pre-weaning and post-weaning body weights of kids were affected by the selection year. Wet season birth was important for increasing milk production and lactation length. Nucleus flocks in station the growth traits and milk traits can be improved by selection and selection at the station at once a year. The Selection of breeding bucks should be at age of six month. The station should be stopping the inlet of does from the market.