Department of Animal Production and Technology, Bahir Dar University, Bahir Dar, Ethiopia.
Department of Animal Science, Debre Tabor University, Debre Tabor, Ethiopia.
PLoS One. 2020 May 12;15(5):e0233040. doi: 10.1371/journal.pone.0233040. eCollection 2020.
The aim of this study was to identify breeding practices and trait preferences for indigenous sheep in three districts (Estie, Farta and Lay Gayient) located in the northwest highlands of Ethiopia. Questionnaire survey and choice experiment methods were used to collect data from 370 smallholder farmers. Respondents were selected randomly among smallholder farmers who own sheep in the aforementioned districts. A generalized multinomial logit model was employed to examine preferences for sheep attributes, while descriptive statistics and index values were computed to describe sheep breeding practices. Having the highest index value of 0.36, income generation was ranked as the primary reason for keeping sheep, followed by meat and manure sources. The average flock size per smallholder farmer was 10.21 sheep. The majority of the smallholder farmers (91%) have the experience of selecting breeding rams and ewes within their own flock using diverse criteria. Given the highest index value of 0.34, body size was ranked as a primary ram and ewe selection criteria, followed by coat color. Furthermore, choice modeling results revealed that tail type, body size, coat color, growth rate, horn and ear size have shown significant influences on smallholder farmers' preference for breeding rams (P<0.01). The part-worth utility coefficients were positive for all ram attributes except ear size. For breeding ewes, mothering ability, coat color, body size, lambing interval, growth rate, tail type and litter size have shown significant effects on choice preferences of smallholder farmers (P<0.05). Moreover, significant scale heterogeneity was observed among respondents for ewe attributes (P<0.001). Overall, the results implied that sheep breeding objectives suitable for the northwest highlands of the country can be derived from traits such as linear body measurement, weight and survival at different ages, and lambing intervals. However, selection decisions at the smallholder level should not only be based on estimated breeding values of traits included in the breeding objective but instead, incorporate ways to address farmers' preference for qualitative traits.
本研究旨在确定埃塞俄比亚西北部高地三个地区（埃斯特、法塔和莱盖延特）的本土绵羊的养殖实践和性状偏好。采用问卷调查和选择实验方法，从上述三个地区的 370 户小农户中收集数据。受访者是在拥有上述地区绵羊的小农户中随机选择的。采用广义多项逻辑回归模型来检验对绵羊属性的偏好，同时计算描述性统计数据和指数值来描述绵羊养殖实践。产生收入以 0.36 的最高指数值位居养羊的首要原因，其次是肉和粪肥的来源。每个小农户的平均羊群规模为 10.21 只羊。大多数小农户（91%）有根据不同标准从自己的羊群中选择种公羊和母羊的经验。体型以 0.34 的最高指数值位居种公羊和母羊选择的首要标准，其次是毛色。此外，选择模型结果表明，尾巴类型、体型、毛色、生长速度、角和耳朵大小对小农户选择种公羊的偏好有显著影响（P<0.01）。除了耳朵大小外，所有公羊属性的部分加权效用系数均为正。对于繁殖母羊，繁殖母羊的母性能力、毛色、体型、产羔间隔、生长速度、尾巴类型和产仔数对小农户的选择偏好有显著影响（P<0.05）。此外，小农户对母羊属性的差异很大（P<0.001）。总体而言，研究结果表明，该国西北部高地的绵羊养殖目标可以从线性体尺、不同年龄的体重和成活率、产羔间隔等性状中得出。然而，在小农户层面的选择决策不应仅基于包括在养殖目标中的性状的估计育种值，而应结合解决农民对定性性状偏好的方法。
