EFFECT OF NUTRITION ON RESPONSE TO EXOGENOUS FSH IN BEEF-CATTLE
EFFECT OF NUTRITION ON RESPONSE TO EXOGENOUS FSH IN BEEF-CATTLE
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DOI：
10.2527/jas1979.4851182x
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发表时间：
1979-01-01
影响因子：
3.3
通讯作者：
CARR, JB
中科院分区：
文献类型：
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作者：
STAIGMILLER, RB;SHORT, RE;CARR, JB
40 头奶牛被分配到 2 组中的一组，喂食高 (H) 或低 (L) 水平的日粮（分别为 NRC [国家研究委员会] TDN [总可消化营养素] 要求的 130% 和 70%）。 92 天里，H 奶牛每天增重 0.63 公斤，L 奶牛每天减重 0.15 公斤。喂养方案第98天，同步发情并注射卵泡刺激素（FSH），每天两次，持续5天，然后将2组再分为4组。最后一次注射 FSH 后 15 小时，每组有 10 头奶牛被切除卵巢，以提供排卵前卵泡发育 [Fol] 的数据（H-Fol 和 L-Fol）。每组另外10头奶牛进行两次人工授精，第一次检测发情，12小时后再次人工授精，提供排卵和卵子受精数据（H-Cl和L-Cl）。 3 头 H-Fol 奶牛和 5 头 L-Fol 奶牛在剖腹手术前排卵，3 头 L-Fol 奶牛有囊性卵巢。 L-Fol 奶牛比 H-Fol 奶牛具有更高的卵巢重量（P < 0.01）和卵泡液重量（P < 0.05）以及更多的大卵泡（P < 0.01）。大卵泡加黄体 (CL) 的数量与剖腹手术时估计的身体状况相关（相关系数 = 0.77；P < 0.01）。 H-Cl 组和 L-Cl 组奶牛的排卵率和受精率没有差异。在整个饲养期间或同步发情期间每周收集的血清中，H 组和 L 组之间的黄体生成素 (LH) 浓度没有差异，并且在超排卵后动情周期的黄体期期间，H-Cl 和 L-Cl 组之间也没有差异。在排卵前同步发情期间，高饲喂奶牛血清中的黄体酮浓度往往高于低饲喂奶牛血清中的孕酮浓度（分别为9.6±1.0和7.1±0.8ng/ml；P<0.07）。当根据 CL 数校正血清孕酮值时，饲料处理造成的差异并不显着。
Forty cows were assigned to 1 of 2 groups and fed either a high (H) or low (L) level of ration (130% and 70% of NRC [National Research Council] requirements for TDN [total digestible nutrients], respectively). Over 92 days, the H cows gained 0.63 kg/day and the L cows lost 0.15 kg/day. On day 98 of the feeding regimen, after a synchronized estrus and follicle stimulating hormone (FSH) injected twice daily for 5 days, the 2 groups were subdivided into 4 groups. Ten cows in each group were ovariectomized 15 h after the last FSH injection to provide data on follicular development [Fol] before ovulation (H-Fol and L-Fol). The other 10 cows in each group were bred twice by artificial insemination, at 1st detection of estrus and again 12 h later, to provide ovulation and ovum fertilization data (H-Cl and L-Cl). Three H-Fol and 5 L-Fol cows ovulated before laparotomy and 3 L-Fol cows had cystic ovaries. L-Fol cows had higher ovarian weights (P < 0.01) and follicular fluid weights (P < 0.05) and more large follicles (P < 0.01) than H-Fol cows. The number of large follicles plus corpora lutea (CL) was correlated with body condition estimated at the time of laparotomy (correlation coefficient = 0.77; P < 0.01). Neither ovulation rate nor fertilization rate differed between cows in the H-Cl and L-Cl groups. Concentrations of luteinizing hormone (LH) did not differ between the H and L groups in serum collected weekly throughout the feed period or during the synchronized estrus and did not differ between the H-Cl and L-Cl groups during the luteal phase of the estrus cycle after superovulation. Progesterone concentration tended to be higher in serum of cows on the high feed than in those on low feed (9.6 .+-. 1.0 and 7.1 .+-. 0.8 ng/ml, respectively; P < 0.07) during the synchronized estrus before ovulation. When serum progesterone values were corrected for CL number, differences due to feed treatments were not significant.