Investigation was carried out to assess the effects of environmental factors and to estimate genetic parameters and trends for reproductive traits in Bonga sheep, Ethiopia. Animals used in this study were managed by two communities involved in a community-based breeding programs (CBBPs) from 2009 to 2018. The database consisted of 15,595 individual phenotypic information from about 1500 ewes with variable number of records for each trait. The traits analyzed were age at first lambing (AFL), lambing interval (LI), and litter size (LS). Fixed effect analysis was done using the general linear model procedures of SAS. The Average Information Restricted Maximum Likelihood method of WOMBAT, fitting univariate animalmodel, was used to estimate heritabilities, repeatabilities and breeding values. Results showed that Bonga sheep had overall mean AFL, LI, and LS of 453 ± 109 days, 254 ± 51 days, and 1.43 ± 0.008, respectively. All traits were influenced (p < 0.01) by lambing year, lambing season, breeder communities, and parity of ewes. Estimates of heritability for AFL, LI, and LS were 0.015 ± 0.143, 0.009 ± 0.070, and 0.085 ± 0.110, respectively. The low heritabilities for the traits are expected and indicate low possibility of achieving rapid genetic progress through phenotypic selection. The repeatability estimates for LI and LS were low (0.109 and 0.196, respectively) indicating that non-genetic factors had significant influence to the variation in these traits among parities; therefore, selection decision on ewes should consider repeated records. The genetic trend for AFL, LI, and LS over the years was significant (p < 0.01). Positive values for LS and negative for AFL and LI were recorded, implying that the well-structured CBBPs have resulted in measurable genetic gains for the reproductive traits.

进行了调查，以评估环境因素的影响，并估计埃塞俄比亚邦加绵羊的遗传参数和生殖性状趋势。该研究中使用的动物由2009年至2018年由参与社区育种计划（CBBP）的两个社区管理。该数据库包含来自1500头母羊的15,595个个体表型信息，每个特征的记录数不等。分析的特征是第一次产羔的年龄（AFL），产羔间隔（LI）和产仔数（LS）。使用SAS的一般线性模型程序进行固定效果分析。采用WOMBAT的平均信息限制最大似然法（拟合单变量动物模型）来估计遗传力，重复性和育种值。结果显示，邦加绵羊的平均AFL，LI，和LS分别为453±109天，254±51天和1.43±0.008。所有特质都受到影响（p  <0.01）按产羔年，产羔季节，繁殖者群体和母羊同等价格计算。AFL，LI和LS的遗传力估计分别为0.015±0.143、0.009±0.070和0.085±0.110。预计该性状的遗传力较低，表明通过表型选择获得快速遗传进展的可能性较低。LI和LS的可重复性估计值很低（分别为0.109和0.196），表明非遗传因素对胎次之间这些性状的变异有重大影响；因此，关于母羊的选择决定应考虑重复记录。这些年来AFL，LI和LS的遗传趋势很显着（p <0.01）。记录的LS的正值和AFL和LI的负值，表明结构良好的CBBP已导致可测量的生殖性状遗传增益。