Departamento de Ciencias Agroforestales, Universidad de Huelva, Carretera de Palos de la Frontera s/n, 21819 Palos de la Frontera, Huelva, Spain.
Anim Reprod Sci. 2011 May;125(1-4):81-7. doi: 10.1016/j.anireprosci.2011.02.029. Epub 2011 Mar 17.
The aim of the present study was to determine whether a treatment of 3 mo of artificial long days and daily contact with bucks can stimulate reproductive activity during the normal seasonal anoestrous in female goats, and whether such treatment modifies the onset of the normal breeding season. Thirty-nine adult, open does were assigned to two treatments of similar mean body weight (BW) and body condition score (BCS). One treatment (LD; n=18) was housed in a light-proof building and exposed to long days (16 h of light/d) from 17 November to 5 February, and then exposed to the natural photoperiod in an open shed. The remaining females were housed in an open shed under natural photoperiod conditions throughout the experiment (control [C]; n=21). Plasma samples for progesterone, BW and BCS were recorded every wk. Oestrous activity was checked daily using aproned bucks. Bucks were housed close to females in a separate barn from the onset of the experiment. Ovulation rate was determined by laparoscopy 7 d after positive identification of oestrus. The interaction of treatment by time for temporal concentrations patterns of progesterone concentrations indicated that luteal activity in LD does were greater (P<0.001) than those of C does during the natural seasonal anoestrous season. None of the C does exhibited oestrous or luteal activity during the non-breeding season; whereas, 72% of LD does exhibited luteal activity only 33% of them showed oestrous activity and during this season (P<0.01). Differences in resumption of the oestrous or luteal activity were not observed (P>0.05) in the subsequent breeding season between treatments. In conclusion, 3 mo of exposing does to long days and daily contact with bucks during the breeding season appears to stimulate reproductive processes that normal would not occur during the anoestrous season. However, this treatment does not induce oestrus is adequate numbers of does to be of practical value. Finally, this treatment does not modify the onset of the subsequent natural breeding season.
本研究旨在确定 3 个月的人工长日处理和与公山羊的日常接触是否可以刺激雌性山羊在正常季节性乏情期间的生殖活动，以及这种处理是否会改变正常繁殖季节的开始。39 只成年开放母羊被分配到两个处理组，处理组之间的平均体重（BW）和体况评分（BCS）相似。一组处理（LD；n=18）被安置在一个不透光的建筑物中，并从 11 月 17 日到 2 月 5 日接受 16 小时的光照/天，然后在开放棚中暴露于自然光周期下。其余的母羊在整个实验过程中被安置在开放棚中，处于自然光周期条件下（对照组 [C]；n=21）。每星期记录血浆样品中的孕激素、BW 和 BCS。使用带围裙的公山羊每天检查发情活动。从实验开始时，公山羊就被安置在靠近母羊的单独畜棚中。排卵率通过腹腔镜检查在发情后 7 天确定。处理与时间的相互作用表明，在自然季节性乏情季节，LD 母羊的黄体活性更高（P<0.001）。在非繁殖季节，C 组母羊均未表现出发情或黄体活性；而 72%的 LD 母羊仅表现出黄体活性，其中 33%表现出发情活性，并且在这个季节（P<0.01）。在随后的繁殖季节，处理之间没有观察到发情或黄体活性恢复的差异（P>0.05）。总之，在繁殖季节让母羊暴露于长日和与公山羊的日常接触 3 个月似乎可以刺激生殖过程，而在乏情季节通常不会发生这些过程。然而，这种处理并没有诱导足够数量的母羊发情，因此没有实际价值。最后，这种处理不会改变随后的自然繁殖季节的开始。
