Kebede M, Greyling J P C, Schwalbach L M J
Oromia Agricultural Research Institute, Bako Agric. Research Centre, P.O. Box 03, West Shoa, Bako, Ethiopia.
Trop Anim Health Prod. 2007 Feb;39(2):149-54. doi: 10.1007/s11250-007-4297-z.
A total of 32 Horro (Bos indicus) bulls, with an average initial body weight and age of approximately 211 kg and 6 years were evaluated. The bulls were divided into two treatment groups. One group was given a supplementary concentrate at a rate of 1.5 kg/day and the second group served as the control and received no supplementation. The observation period lasted for 50 weeks. Semen was collected every two weeks by mean of electrical stimulation with the aid of an electro-ejaculator. The percentage of abnormal sperm (total abnormalities, head, midpiece and tail) remained lower in the supplemented group than in the non-supplemented group. The percentage of live sperm tended to be higher in the supplemented group throughout the 50-week trial period. Until week 17 of the trial there were no significant differences; however, starting at week 18 there were significant differences between the two treatment groups except for week 26. Thereafter, significant differences were recorded until week 38; from week 40 no significant differences were observed between the two groups in respect of percentage of live sperm (except for week 48). Season (week) during which the semen samples were collected had no significant effect on the percentage of abnormal sperm in both treatment groups (supplemented and non-supplemented). At the start of the trial the nutritionally supplemented group had a higher occurrence of sperm abnormalities (11.4% +/- 1.1%) compared to 8.3% +/- 1.3% in the control group. Thereafter, sperm abnormalities declined rapidly in the supplemented group (except for week 50). The sperm abnormalities for the non-supplemented group showed a tendency to increase during the entire observation period.
共评估了32头霍罗牛（印度瘤牛）公牛，其初始平均体重约为211千克，平均年龄约为6岁。这些公牛被分为两个处理组。一组以每天1.5千克的量给予补充精饲料，第二组作为对照组，不给予补充。观察期持续50周。每隔两周借助电刺激采精器通过电刺激采集精液。补充组的异常精子百分比（总异常、头部、中段和尾部）始终低于未补充组。在整个50周的试验期内，补充组的活精子百分比往往更高。在试验的第17周之前，两组之间没有显著差异；然而，从第18周开始，除了第26周外，两个处理组之间存在显著差异。此后，直到第38周都记录到显著差异；从第40周开始，两组在活精子百分比方面没有观察到显著差异（第48周除外）。采集精液样本的季节（周）对两个处理组（补充组和未补充组）的异常精子百分比均无显著影响。在试验开始时，营养补充组的精子异常发生率较高（11.4%±1.1%），而对照组为8.3%±1.3%。此后，补充组的精子异常迅速下降（第50周除外）。未补充组的精子异常在整个观察期内呈上升趋势。
