Mondragón Violeta, Galina Carlos S, Rubio Ivette, Corro Manuel, Salmerón Frida
Departamento de Reproducción, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad Universitaria, México DF, 04510, Mexico.
Centro de Enseñanza Investigación y Extensión en Ganadería Tropical, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Tlapacoyan, Veracruz 93650, Mexico.
Anim Reprod Sci. 2016 Apr;167:89-95. doi: 10.1016/j.anireprosci.2016.02.011. Epub 2016 Feb 16.
With the aim of evaluating the effect of restricted suckling on the onset of follicular dynamics and body condition, multiparous Bos indicus cows were distributed in two groups. One group (RS=36) was subjected to a scheme of restricted suckling starting at 21 days postpartum. Calves were allowed to suckle once per day for a period of two h whilst the control group (C=18) remained with their dams at all times. At calving, body condition score, back fat thickness and body weight had similar values (p>0.05) for both groups. By day 85 postpartum both groups had recorded losses in body weight. The cows in the continuous group formed a greater (p<0.05) number of follicles of class size <6mm in both periods before and after synchronization. The proportion of cows showing estrus and ovulation before 45 days, was not different (p>0.05). The number of cows that exhibited estrus after 45 days, was greater (p<0.05) in RS than C group, 72.2% and 55.5%, respectively. Same situation (p<0.05) occurred in cows that ovulated, 88.8 and 66.7%, for groups RS and C, respectively. The subset in the intensive observations showed that the size of the bigger follicle was larger (p<0.05) for RS cows than C cows from 36 h after CIDR withdrawal. At 57 h, the size of the biggest follicle recorded was not different between groups (p>0.05). A regime of restricted suckling favors the earlier growth of follicles and the prompt restoration of ovarian activity.
为了评估限制哺乳对卵泡动态变化起始和体况的影响，将经产印度瘤牛分为两组。一组（RS = 36头）在产后21天开始采用限制哺乳方案。犊牛每天允许哺乳一次，每次两小时，而对照组（C = 18头）始终与母牛在一起。产犊时，两组的体况评分、背部脂肪厚度和体重具有相似的值（p>0.05）。到产后85天，两组母牛体重均有所下降。在同期发情前后两个时期，持续哺乳组的母牛形成的直径<6mm的卵泡数量更多（p<0.05）。45天前出现发情和排卵的母牛比例没有差异（p>0.05）。45天后出现发情的母牛数量，RS组比C组更多（p<0.05），分别为72.2%和55.5%。排卵母牛的情况相同（p<0.05），RS组和C组分别为88.8%和66.7%。密集观察的子集中显示，从取出阴道孕酮释放装置（CIDR）后36小时起，RS组母牛最大卵泡的尺寸比C组母牛更大（p<0.05）。在57小时时，两组记录的最大卵泡尺寸没有差异（p>0.05）。限制哺乳方案有利于卵泡的早期生长和卵巢活动的迅速恢复。
