Getachew Tesfa, Asmare Bimrew, Alkhtib Ashraf, Jane Wamatu
Debre Birhan Agricultural Research Center, Debre Birhan, P. O. Box 112, Ethiopia.
Department of Animal Sciences, Bahir Dar University, Bahir Dar, P.O. Box 79, Ethiopia.
Vet Anim Sci. 2024 Nov 27;27:100413. doi: 10.1016/j.vas.2024.100413. eCollection 2025 Mar.
This study assessed the supplemental effect of flushing Menz breeding rams with local agro-industrial by-products on their reproductive performance and semen quality. In a completely randomized design, rams ( 49) with an initial weight of 25.69+2.8 kg and average age of 18.79±3.9 months were allocated to seven treatments with seven replicates. Supplementation consisted of varying combinations of metabolizable energy (7.02, 8.14, 9.91 MJ ME/kg DM) and crude protein (CP) (8.17 and 12.5 %) levels above the basal diet (pasture grazing). The experimental treatments were control, T0 (8 h of free grazing in natural pasture and fallow lands providing 4.7 MJ/Kg metabolizable energy and 6.65 CP) supplemented with T1 (500 g oats grain), T2 (500 g maize bran), T3 (500 g wheat bran), T4 (300 g oat grain +150 g broken lentil grain), T5 (300 g maize bran + 150 g broken lentil grain), T6 (400 g wheat bran). Supplementation significantly ( < 0.05) improve body condition score, scrotal circumference, semen ejaculation volume, spermatozoa concentration, and predictive potential of rams to serve ewes. Notably, all variables within the supplemented groups showed no significant differences ( > 0.05), except for scrotal circumference, where T1 and T3 showed a greater increase ( < 0.05) compared to other treatments. High and positive correlations ( = 0.89) between scrotal circumference and volume of semen were observed. Semen volume and concentration correlated positively ( = 0.7 and = 0.9 respectively) with the rams' potential to serve ewes. It is concluded that the reproductive activity of Menz rams is influenced by their nutritional state. Agro-industrial by-products can supply adequate protein and energy levels to enhance reproductive potential of rams. The studied agro-industrial by-products are relatively inexpensive and easily accessible compared to commercial concentrates. Hence, based on the cost-effectiveness of supplementary feed used; it is recommended that T3 and T6 wheat bran-based supplementation strategies be employed to enhance the reproductive performance, semen quality, and the potential of Menz rams to serve ewes. Further research is needed to evaluate how different seasons affect the levels of protein and energy supplementation required for ram flushing.
本研究评估了用当地农工业副产品对门兹种公羊进行催情补饲对其繁殖性能和精液质量的补充作用。在完全随机设计中，将初始体重为25.69±2.8千克、平均年龄为18.79±3.9个月的49只公羊分配到7种处理组，每组7个重复。补饲由基础日粮（放牧）之上不同组合的代谢能（7.02、8.14、9.91兆焦代谢能/千克干物质）和粗蛋白（CP）（8.17%和12.5%）水平组成。实验处理包括对照组T0（在天然牧场和休耕地自由放牧8小时，提供4.7兆焦/千克代谢能和6.65%粗蛋白），补充T1（500克燕麦谷物）、T2（500克玉米麸）、T3（500克麦麸）、T4（300克燕麦谷物+150克碎扁豆谷物）、T5（300克玉米麸+150克碎扁豆谷物）、T6（400克麦麸）。补饲显著（P<0.05）改善了公羊的体况评分、阴囊周长、射精量、精子浓度以及公羊配种母羊的预测潜力。值得注意的是，除阴囊周长外，补饲组内的所有变量均无显著差异（P>0.05），其中T1和T3的阴囊周长相较于其他处理组增加幅度更大（P<0.05）。观察到阴囊周长与精液量之间存在高度正相关（r = 0.89）。精液量和浓度与公羊配种母羊的潜力呈正相关（分别为r = 0.7和r = 0.9）。得出结论，门兹种公羊的繁殖活动受其营养状况影响。农工业副产品可提供充足的蛋白质和能量水平以提高公羊的繁殖潜力。与商业浓缩饲料相比，所研究的农工业副产品相对便宜且易于获取。因此，基于所用补充饲料的成本效益，建议采用以T3和T6麦麸为基础的补饲策略来提高门兹种公羊的繁殖性能、精液质量以及配种母羊的潜力。需要进一步研究以评估不同季节如何影响公羊催情补饲所需的蛋白质和能量补充水平。
