日粮不同NFC/RDP水平对围产期奶牛血清中生殖泌乳相关激素的影响

Effect of Different NFC/RDP Levels in Diet on Blood Concentrations of Selected Reproduction and Lactation Related Hormone of Dairy Cow

旨在研究日粮不同非纤维性碳水化合物/瘤胃降解蛋白(NFC/RDP)水平对与围产期奶牛生殖和泌乳相关的血清雌二醇(E2)、孕酮(P)、催乳素(PRL)、促黄体生成素(LH)及促卵泡激素(FSH)的影响。随机选取体况良好的围产期荷斯坦奶牛48头,随机分为6组(试验Ⅰ~Ⅵ组),每组8头,于产前28 d起各组饲喂能氮水平一定,NFC/RDP水平分别为2.87(试验Ⅰ组)、3.31(试验Ⅱ组)、3.47(试验Ⅲ组)、4.04(试验Ⅳ组)、5.06(试验Ⅴ组)、5.17(试验Ⅵ组)的日粮,产后各组奶牛均饲喂相同日粮,试验至产后7 d结束。结果显示,饲喂不同NFC/RDP水平日粮后,不同观测时间的奶牛血清E2、P、PRL、LH以及FSH浓度存在不同程度的差异。其中,日粮NFC/RDP水平为4.04的试验组(试验Ⅳ组)奶牛产后第1天、第7天血清P含量极显著高于其他各试验组(P<0.01);产后第1天、第7天血清PRL浓度分别极显著、显著高于其他各试验组(P<0.01、P<0.05);产后第1天、第7天血清LH含量极显著高于其他各试验组(P<0.01);分娩前28 d、14 d,产后第1天、第7天血清FSH含量分别显著、极显著高于其他各试验组(P<0.05、P<0.01)。结果提示,日粮NFC/RDP水平与围产期奶牛血清E2、P、PRL、LH以及FSH浓度存在着较密切的关系,且当日粮NFC/RDP水平为4.04时,有助于维持奶牛能氮平衡状况、降低奶牛围产期代谢障碍性疾病发生风险。

The purpose of this study was to investigate the effect of different NFC/RDP levels in diet on serum concentrations of estradiol(E2), progesterone(P), prolactin(PRL), luteinizing hormone(LH) and follicle stimulating hormone(FSH) which associated with reproduction and lactation of transition dairy cows. A total of forty-eight healthy transition dairy cows were allocated and randomly divided into 6 groups with 8 cows for each group. The cows fed the diets with the same energy and nitrogen levels but with different NFC/RDP levels as followed: 2.87(groupⅠ), 3.31(groupⅡ), 3.47(groupⅢ), 4.04(groupⅣ), 5.06(groupⅤ)and 5.17(groupⅥ)during the last 28 days before calving. After calving, all of the cows were offered the same diet until7 days postpartum. The results showed that the serum concentrations of E2, P, PRL, LH and FSH of the dairy cows fed diet with different levels of NFC/RDP varied in different observing times. The serum concentrations of P of cows fed diet with NFC/RDP of4.04(group Ⅳ) in the 1st and 7th day postpartum were significantly higher than that of those groups(P <0.01); The serum concentrations of PRL of group Ⅳin the 1st and 7th day postpartum were very significant and significant higher than that of those groups(P<0.01 and P<0.05), respectively; The serum concentrations of LH of group Ⅳ in the 1st and 7th day postpartum were very significant higher than that of those groups(P<0.01);The serum concentrations of FSH of group Ⅳin the 1st and 7th day postpartum and 28 thand 14thd before calving were very significant and significant higher than that of those groups(P <0.01 and P <0.05),respectively. The results indicated that NFC/RDP level in diet closely associate with the serum concentrations of E2, P, PRL, LH and FSH of transition cows, and the NFC/RDP level of 4.04 have the best effect on maintaining energy and nitrogen balance and reducing the incidence of metabolic disorder of cows in perinatal period.