Romano Juan E, Alkar Abdalhamid, Fuentes-Hernández Victor O, Amstalden Marcel
Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA.
Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA.
Theriogenology. 2016 Apr 15;85(7):1323-7. doi: 10.1016/j.theriogenology.2015.12.018. Epub 2015 Dec 29.
The objectives of the present study were to assess the effect of permanent contact of teasers without copulation on the interval from controlled internal drug release (CIDR) removal to estrus onset, estrus duration, ovulation time, number of ovulations, and interval from CIDR removal to ovulation time on estrus-synchronized Boer goats. During the fall season, a controlled randomized design experiment with two groups, control (CON; n = 18) and treatment (TRE; n = 18), was performed. The TRE group was maintained permanently in a pen with an aproned buck immediately after CIDR removal. The CON group was maintained in a different pen without permanent exposure to the male. All females were estrus synchronized with CIDR maintained in the vagina for 7 days and received 50 μg of GnRH im at device insertion and 5 mg of natural prostaglandin F-2α at device removal. Females were considered to be in estrus when they accepted mounting by the aproned bucks. Estrus was detected four times a day after CIDR removal (at 6 AM, 12 noon, 6 PM, and 12 midnight) using bucks with canvas apron as teasers. The ovulation time and number of ovulations were assessed by transrectal ultrasonography starting 24 hours after estrus onset and repeated every 6 hours until complete ovulation was detected. The estrus onset for the CON group was 44.0 ± 8.3 hours and for the TRE group, it was 37.0 ± 7.7 hours (P = 0.01). Estrus duration from the CON group was 43.7 ± 9.2 hours and for the TRE group, it was 38.3 ± 6.6 hours (P = 0.05). The first, last, and mean ovulation times for the CON group were 32.4 ± 5.3, 38.4 ± 3.4, and 35.4 ± 3.9 hours, and for the TRE group, the times were 31.8 ± 2.8, 36.7 ± 3.0, and 35.8 ± 3.6 hours, respectively (P = 0.85, P = 0.23, and P = 0.82, respectively). The number of ovulations for the CON and TRE groups was 2.6 ± 0.7 and 2.6 ± 0.6 ovulations, respectively (P = 0.96). The interval time for CIDR removal to ovulation for the CON group was 79.2 ± 8.2 hours and for the TRE group, the interval time was 73.2 ± 6.2 hours (P = 0.05). It was concluded that the permanent presence of male without copulation with estrus-synchronized does hastened estrus onset, reduced estrus duration, and decreased the interval time from CIDR removal to ovulation without modification of ovulation time and number of ovulations in Boer goats.
本研究的目的是评估未交配的试情公羊持续接触对同期发情的波尔山羊从取出控制内部药物释放（CIDR）装置到发情开始的间隔时间、发情持续时间、排卵时间、排卵数以及从取出CIDR装置到排卵时间的影响。在秋季，进行了一项有两组的对照随机设计实验，即对照组（CON；n = 18）和处理组（TRE；n = 18）。处理组在取出CIDR装置后立即与一只带围裙的公羊永久性地饲养在一个围栏中。对照组则饲养在另一个围栏中，不与公羊长期接触。所有母羊均通过在阴道内放置CIDR装置7天来实现同期发情，并在插入装置时肌肉注射50μg促性腺激素释放激素（GnRH），取出装置时肌肉注射5mg天然前列腺素F-2α。当母羊接受带围裙公羊的爬跨时，即被认为处于发情期。在取出CIDR装置后，每天用带帆布围裙的公羊作为试情公羊检测发情4次（上午6点、中午12点、下午6点和午夜12点）。从发情开始后24小时起，通过经直肠超声检查评估排卵时间和排卵数，每6小时重复一次，直至检测到完全排卵。对照组的发情开始时间为44.0±8.3小时，处理组为37.0±7.7小时（P = 0.01）。对照组的发情持续时间为43.7±9.2小时，处理组为38.3±6.6小时（P = 0.05）。对照组的首次、末次和平均排卵时间分别为32.4±5.3、38.4±3.4和35.4±3.9小时，处理组的相应时间分别为31.8±2.8、36.7±3.0和35.8±3.6小时（分别为P = 0.85、P = 0.23和P = 0.82）。对照组和处理组的排卵数分别为2.6±0.7个和2.6±0.6个（P = 0.96）。对照组从取出CIDR装置到排卵的间隔时间为79.2±8.2小时，处理组的间隔时间为73.2±6.2小时（P = 0.05）。得出的结论是，未交配的公羊持续存在于同期发情的母羊中，可加快发情开始，缩短发情持续时间，并减少从取出CIDR装置到排卵的间隔时间，而不改变波尔山羊的排卵时间和排卵数。
