营养对奶牛繁殖性能的影响

A Study Progress in the Effects of Nutrition on Reproductive Performance of Dairy Cattle

动物摄取营养是为了生存和生产。繁殖是动物的一种特殊生产 ,营养状况与其密切相关。近些年奶牛在泌乳量得以提高的同时 ,繁殖能力下降。营养主要通过影响奶牛的排卵率、胚胎存活率等直接影响受精率。适量的限饲可以提高奶牛优质胚胎的数量 ,但若出现能量负平衡 ,则会通过抑制促黄体素 (L H)的分泌和降低卵巢对 L H的敏感性 ,使卵巢上的优势卵泡不能及时排出 ,容易形成卵巢囊肿 ,从而影响下一轮卵泡发育。营养状况可以改变血液中孕酮的浓度而改变受胎率。营养状况也会通过改变血液中的尿素和氨的浓度来改变子宫内 PH值的变化 ,从而影响胚胎的着床和早期发育。另外 ,营养还可以改变动物机体内的胰岛素和胰岛素样生长因子的水平来影响胚胎的发育。因此 ,在生产中通过改善营养状况 ,可以充分发挥奶牛的生产性能。

Nutrition intake of animal is just for surviving and production. Reproduction is a special production and has a close relationship with nutrition. Increased capability for milk production has been associated with a decline in reproduction capacity of dairy cattle in recent years. Nutrition affects fertility from the aspects of ovulation and embryo survive of dairy cattle. Proper nutritional stress can increase the number of high quality embryo. On the contrary, negative energy balance (NEBAL) delays the time of ovulation through inhibition of LH secretion and reduces ovarian responsiveness to LH stimulation. The dominant follicle fails to ovulate and likely becomes cystic. The development of non-ovulatory dominant or cystic follicles prolongs the next ovulation. Nutrition condition affects gestation through change the progesterone concentration and it also can affect the embryo embedding and early embryo development. In addition, nutrition change the concentration of insulin and insulin like factor in blood eventually it affects the development of embryo. So, if we improve the nutrition condition of diary cattle, we can sufficiently exert their reproduction potential.