日粮蛋白质水平对奶牛产后卵巢机能恢复及生殖激素的影响

Effect of Dietary Protein Level on Restoration of Ovarian Function and Reproductive Hormones after Delivery of Dairy Cow

[目的]本试验旨在探讨不同蛋白质水平日粮对奶牛产后卵巢机能恢复及生殖激素的影响,以确定奶牛日粮适宜蛋白质水平。[方法]采用单因素对比实验设计,根据生理状况和泌乳性能相近原则将72头中国荷斯坦牛,随机分成3组,每组24头,分别在围产期和泌乳盛期饲喂9.8%(A1)和13.8%(A2)、12.6%(B1)和16.2%(B2)、14.1%(C1)和17.8%(C2)不同蛋白质水平日粮,即A组(A1,A2)、B组(B1,B2)和C组(C1,C2)。[结果]B组和C组产后5 d1、0 d1、5 d外周血浆中P4均显著低于A组(P<0.05),10 d和15 d外周血浆中LH和E2均显著高于A组(P<0.05);在发情周期第15 d和20 d,A组和B组血浆中P4浓度均显著高于C组(P<0.05),第20 d,B组外周血浆中E2浓度显著高于C组(P<0.05)。[结论]奶牛围产期和泌乳盛期日粮蛋白质水平分别为12.6%和16.2%,能促进奶牛产后卵巢机能尽早恢复,有利于体内生殖激素代谢协调,能更好的发挥其繁殖性能。

【Objective】The experiment was conducted to study the effects of different protein levels of ration compound on the restoration of ovarian function and reproductive hormones to determine the appropriate protein levels of dairy cows＇ diet.【Method】According the similar principle of the physiological status and lactation performance,comparison of single factor experiment was designed.72 Chinese Holstein were randomly divided into 3 groups,and there were 24 in each group.Different protein levels diet was fed 9.8%（A1） and 13.8%（A2）,12.6%（B1）and 16.2%（B2）,14.1%（C1） and 17.8%（C2）,that is A group（A1,A2）,B group（B1,B2）and C group（C1,C2）in perinatal and peak lactation,respectively.【Result】The concentration of P4 in plasma of B and C group was significantly lower than A group（P〈0.05）on the 5th day,10th day and 15th day after delivery,and the concentration of LH and E2 in plasma of B and C group was significantly higher than that of A group（P〈0.05）on 10th day and 15th day after delivery;the concentration of P4 in plasma of A and B group was higher than that of C group（P〈0.05）on the 15th and 20th day of estrous cycle,and the concentration of E2 in plasma of B group was higher than C group（P〈0.05）on the 20th day of estrous cycle.【Conclusion】Respectively being fed protein levels diet 12.6% and 16.2% in perinatal and peak lactation,so that dairy cow could resume ovarian function as early as possible and the reproductive hormone of organism was good to the metabolic coordination after delivery,and dairy cow could play its reproductive performance better.