School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia.
Theriogenology. 2011 Apr 15;75(7):1301-10. doi: 10.1016/j.theriogenology.2010.12.001. Epub 2011 Feb 4.
The objective was to investigate the effects of moderate restriction of pre- and peri-pubertal liveweight gain on ovarian development and oocyte meiotic competence. At 70 d of age, and 27.7 ± 0.4 kg liveweight (LW), 64 Large White/Landrace crossbred gilts were allocated to two treatment groups (n = 32 gilts/treatment); one group was fed to attain a LW of 70 kg at 161 d of age (LIGHT), while the other group was fed to reach 100 kg LW (HEAVY). At 161 d of age, half of the gilts in each group (n = 16) were fed to gain LW at 0.5 kg/d (LOW), while the remaining half (n = 16) were fed to gain LW at 1.0 kg/d (HIGH) between 161 and 175 d of age, at which point they were killed and ovaries collected. For each gilt, surface antral follicles were counted and aspirated according to three size categories: 1-2.9 mm (small); 3-6 mm (medium); and > 6 mm (large). Follicles were pooled for each size class and treatment. Cumulus-oocyte-complexes (COC) recovered from small and medium follicles were matured in vitro (IVM) for 44 to 46 h, and meiotic maturation assessed. There was an effect of treatment (LIGHT versus HEAVY) on the number of medium sized follicles: 25.1 ± 2.59 versus 34.3 ± 2.60 (P < 0.05). The ovaries of LOW gilts had more small follicles and fewer medium follicles compared to those of HIGH gilts: 92.8 ± 8.35 versus 59.8 ± 5.24, and 25.1 ± 2.59 versus 32.5 ± 2.86 (P < 0.05). Target LW at 161 d did not affect meiotic progression of oocytes. However, LOW compared to HIGH LW gain between 161 and 175 d resulted in fewer oocytes reaching MII (0.40 versus 0.54; P < 0.05). In conclusion, moderately restricting feed intake impaired follicle growth beyond 3 mm and reduced oocyte meiotic competence. Further, although a carry-over effect of long-term feed restriction on follicle growth was evident, acute changes in feed intake during the 14 d prior to ovary collection had the greatest effect on oocyte nuclear maturation in vitro.
本研究旨在探讨青春期前和青春期体重适度限制对卵巢发育和卵母细胞减数分裂能力的影响。70 日龄、体重 27.7±0.4kg 的 64 头大约克/长白杂交后备母猪被分配到两组（每组 32 头母猪）；一组母猪自由采食至 161 日龄时体重达到 70kg（ LIGHT 组），另一组母猪自由采食至 100kg（ HEAVY 组）。161 日龄时，每组一半母猪（每组 16 头）自由采食，每天增重 0.5kg（ LOW 组），另一半母猪（每组 16 头）自由采食，每天增重 1.0kg（ HIGH 组），161-175 日龄时屠宰并采集卵巢。每头母猪按三个大小类别（1-2.9mm 为小；3-6mm 为中；>6mm 为大）计数和抽吸窦前卵泡。根据大小类别和处理方式对卵泡进行分组。从小和中卵泡中回收的卵丘卵母细胞复合物（COC）在体外（IVM）成熟 44-46 小时，评估减数分裂成熟情况。 LIGHT 组和 HEAVY 组在中卵泡数量上存在差异：25.1±2.59 个与 34.3±2.60 个（P<0.05）。与 HIGH 组相比，LOW 组的小卵泡数量更多，中卵泡数量更少：92.8±8.35 个与 59.8±5.24 个，25.1±2.59 个与 32.5±2.86 个（P<0.05）。161 日龄时的目标体重并不影响卵母细胞的减数分裂进程。然而，与 HIGH 组相比，LOW 组在 161-175 日龄之间的低体重增长导致达到 MII 的卵母细胞数量减少（0.40 个与 0.54 个；P<0.05）。综上所述，适度限制采食量会损害 3mm 以上的卵泡生长，并降低卵母细胞的减数分裂能力。此外，尽管长期限饲对卵泡生长的后续影响明显，但在卵巢采集前 14 天内急性改变采食量对卵母细胞体外核成熟的影响最大。
