【作者】 李红宇；

【导师】 苗树君；

【作者基本信息】 黑龙江八一农垦大学 ， 动物营养与饲料科学， 2010， 硕士

【摘要】 本试验针对东北寒区高产奶牛日粮配制中存在的营养不平衡,特别是在围产期和泌乳盛期日粮蛋白质水平过低或过高给奶牛健康和生产性能造成不利影响的关键问题,采用对比实验设计,将年龄、体重、胎次、预产期及上一个泌乳期校正泌乳量相近的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)。进行研究日粮蛋白质水平与奶牛体内尿素氮的关系及其对相关繁殖性能指标的影响。通过试验结果分析,确定日粮适宜蛋白质水平,为奶牛高效日粮配制及健康高产提供依据。试验结果表明:1.日粮蛋白质水平与奶牛体内尿素氮的关系及对泌乳性能的影响乳中尿素氮(MUN)和血浆尿素氮(PUN[0])浓度随着日粮蛋白质水平的升高极显著上升(P﹤0.01);MUN与PUN显著线性正相关(P﹤0.001),MUN=0.79×PUN+1.02(R2=0.91);围产期和泌乳盛期不同蛋白质水平日粮对乳成分未产生显著的影响(P﹥0.05);泌乳盛B组产奶量显著高于A组(P﹤0.05),与C组差异不显著(P﹥0.05)。2.日粮蛋白质水平对奶牛生殖激素的影响B组和C组产后10d和15d外周血浆中LH和E2浓度差异不显著,均显著高于A组(P﹤0.05);B组和C组奶牛产后5d、10d、15d外周血浆中P4浓度差异不显著,均显著低于A组(P﹤0.05);在奶牛产后5d、10d、15d,B组和C组外周血浆中E2浓度差异不显著,均显著高于A组(P﹤0.05);在发情周期第20d,B组外周血浆中E2浓度显著高于C组(P﹤0.05);在发情周期第15d和20d,A组和B组血浆中P4浓度差异不显著,均显著高于C组(P﹤0.05)。3.日粮质水平对奶牛产后繁殖性能指标的影响产后A组奶牛胎衣排出时间和恶露排放历期均比B组和C组延迟并差异显著(P﹤0.05);C组奶牛产后卵巢恢复活动时间、首次发情时间和第一次配种时间显著早于A组(P﹤0.05),与B组比较差异不显著;B组奶牛产后情期受胎率最高,为57.14%,比A组高11.31%,比C组高10.08%;B组奶牛的配种指数最低,为1.75,比A组低0.43,比C组低0.38;B组奶牛产后空怀期显著短于C组(P﹤0.05),与A组差异不显著。更多还原

【Abstract】 According to the problem of the preparation of the nutritional imbalances of ration compound, particularly in the perinatal and peak lactateion too low or too high dietary protein levels had a adverse effect on dairy cow healthy and performance,the test used the contract test design, milk urea nitrogen, milk yield and milk composition by using contrast test of 72 Chinese-Holstein with similar age, weight, birth order, parturition date and correction lactation yield randomly divided into 3 groups, 24 in each group in north frigid area. respectively fed different protein levels diet 9.8%(A1)和13.8%(A2 )、12.6%(B1)和16.2%(B2)、14.1%(C1)和17.8%(C2),that was A group(A1,A2)、B group(B1,B2)和C group(C1,C2)in perinatal and peak lactation,studied the relation of dietary protein levels and BUN and the effect on related reproductive traits. Analysising for the testing results ,the test determined the appropriate dietary protein levels, and provided the basis for efficient ration compound and healthy highyield.1. The relation of dietary protein levels and BUN and the effect on milk performanceThe concentration of MUN and PUN rose significantly((P﹤0.01) with dietary protein levels rosed, A significant linear positive correlation between MUN与PUN(P﹤0.001), MUN=0.79×PUN+1.02(R2=0.91);dietary protein levels had no significant effecton milk composition(P﹥0.05)in perinatal and peak lactation;B group milk yield was significantly higher than A group (P﹤0.05), had no obvious difference with C group (P﹥0.05)in peak lactation.2. Effect of dietary protein levels on reproductive hormones of dairy cowThe concentration of LH和E2 in plasma of B and C group was significantly higher thanA group(P﹤0.05),but had no obvious difference between B and C group on 10day and 15day after delivery;the concentration of P4 in plasma of B and C group had no significant difference,but was lower than A group(P﹤0.05)5day, 10day and 15day after delivery; the concentration of E2 in plasma of B group was higher than C group(P﹤0.05)on the 20th day of estrous cycle; the concentration of P4 in plasma of A and B group had no significant difference,but was higher than C group(P﹤0.05)on the 15th and 20th day of estrous cycle.3. Effect of dietary protein levels on reproductive performance index after delivery of dairy cowThe expulsion period of afterbirth and lochia of A group was later than B and C group and difference was significant(P﹤0.05);The period of ovarian reactivation、the first estrusand the first service of C group was earlier than A group(P﹤0.05) and; the sexual period pregnancy rate of B group was highest,57.14%,respectively higher than those of A and C group 11.31% and 10.08%;the mating index of B group was lowest, 1.75%, respectively lower than those of A and C group 0.43% and 0.38%;the open period of afterbirth was significantly shorter compared with C group(P﹤0.05)and had no significant difference compared with A group.更多还原