体况对奶牛分娩行为、血浆激素含量及其犊牛初生重、初乳采食量的影响

Effects of Body Condition on Cows’Calving Behavior,Plasma Hormone Contents and Their Calves’Birth Weight,Colostrum Intake

本试验旨在研究不同体况奶牛分娩行为和血浆激素含量的差异并探究奶牛体况对新生犊牛初生重及初乳采食量的影响。试验选取36头健康的产母犊的头胎荷斯坦奶牛,依据分娩时的体况评分(BCS)分为体况肥胖组(3.75≤BCS≤4.25) 20头、体况正常组(3.25≤BCS≤3.50)16头。录像记录奶牛分娩时的行为,检测奶牛血浆激素含量,记录犊牛的初生重和初乳采食量。结果表明:1)体况肥胖组奶牛分娩过程中出现腹部收缩到犊牛产出的时间间隔较体况正常组奶牛显著增长(P<0.05),羊膜囊可见到犊牛产出时间间隔有高于体况正常组奶牛的趋势(P=0.092),露蹄后至犊牛产出这段时间里的起卧次数也有高于体况正常组奶牛的趋势(P=0.076)。2)体况肥胖组奶牛血浆中催乳素含量显著低于体况正常组奶牛(P<0.05),血浆中催产素含量较体况正常组奶牛有降低的趋势(P=0.060),血浆中皮质醇含量显著高于体况正常组奶牛(P<0.05)。3)体况肥胖组总采食6 L初乳的犊牛比例较体况正常组有减少的趋势(P=0.091)。综上所述,相比体况正常奶牛,分娩时体况肥胖奶牛应激反应较大,产程较长,所产犊牛初乳采食量较低,影响其健康,因此应加强围产期奶牛的体况管理,避免过肥。

This experiment was conducted to study the differences of calving behavior and plasma hormone contents in different body condition cows,and to explore the influence of body condition on the birth weight and colostrum intake of newborn calves.Thirty-six healthy Holstein cows were selected and divided into high body condition score(BCS)group(3.75≤BCS≤4.25)20 cows and moderate BCS group(3.25≤BCS≤3.50)16 cows.The calving behavior was recorded by video recording.The plasma hormone content of cows after delivery was detected.The birth weight and the colostrum intake of calves were recorded.The results showed as follows:1)the time from the onset of rhythmical abdominal contractions to the birth of the calf in the high BCS group was significantly longer than that in the moderate BCS group(P<0.05),the time from a visible amniotic sac to the birth of the calf tended to be longer than that in the moderate BCS group(P=0.092),and the times of posture change from standing to lying tended to be more than that in the moderate BCS group(P=0.076).2)The plasma prolactin content in high BCS group was significantly lower than that in moderate BCS group(P<0.05),the plasma oxytocin content tended to be lower than that in the moderate BCS group(P=0.060),and the plasma cortisol content was significantly higher than that in the moderate BCS group(P<0.05).3)The percentage of calves with 6 L total colostrum intake in the high BCS group tended to be lower than that in the moderate BCS group(P=0.091).It is concluded that high BCS cows have greater stress response and longer calving labor process compared with moderate BCS cows,and their calves’colostrum intake is lower,which affects calves’health.Therefore,we should pay attention to the body condition management of perinatal cows to avoid obese body condition.