奶牛分娩前体况对泌乳量、脂代谢及氧化状态的影响

The effects of body condition before prepartum on milk production,lipid metabolism and oxidation state of dairy cows

本研究旨在探讨分娩前奶牛体况评分对荷斯坦奶牛产奶量、脂质代谢和氧化状态的影响。试验选择128头多胎次荷斯坦奶牛,根据体况评分随机分为4组,每组8个重复,每个重复4头。4组奶牛的平均体况评分为3.0~3.2、3.4~3.6、3.8~4.0和4.2~4.4。分别在产犊前7、14和21d及产犊后7、14和21d采集血液用于脂代谢和氧化状态分析。结果 :4.2~4.2体况评分组较其他组初乳密度分别提高50.77%、44.83%和46.19%(P <0.05),乳蛋白分别提高45.63%、49.45%和39.54%(P <0.05)。4.2~4.4体况评分组初乳乳糖含量较3.0~3.2和3.4~3.6体况评分组分别提高25.45%和32%(P <0.05)。奶牛血清非酯化脂肪酸浓度受奶牛体况评分、时间的显著影响(P <0.05),而β-羟丁酸浓度仅受奶牛体况评分的显著影响(P <0.05)。体况评分为4.2~4.4组奶牛在产犊时及产犊后血清丙二醛、维生素A、维生素E含量以及超氧化物歧化酶和过氧化氢酶(CAT)活性均显著高于其他各组(P <0.05)。结论 :在本试验条件下,低体况评分(3.0~3.2)的奶牛在产犊后具有更好的泌乳性能,而高体况评分(4.2~4.4)的奶牛在产犊后表现出更大的体况损失及更高的氧化应激。

The purpose of this study was to investigate the effects of cow body condition score before delivery on milk yield,lipid metabolism and oxidative status in Holstein cows.One hundred and twenty eight multiple-parity Holstein cows were selected and randomly divided into four groups according to the body condition score,8 replicates for each group and 4 replicates for each group.The average body condition scores of the four groups were 3.0~3.2,3.4~3.6,3.8~4.0,and 4.2~4.4.Blood was collected on days 7,14 and 21 before and 7,14 and 21 after calving for lipid metabolism and oxidation status analysis.Results:compared with other groups,colostrum density in 4.2~4.2 group increased by 50.77%,44.83%and 46.19%respectively(P<0.05),and milk protein increased by 45.63%,49.45%and 39.54%respectively(P<0.05).Compared with 3.0~3.2 and 3.4~3.6,lactose content in colostrum was 25.45%and 32%higher(P<0.05).The serum concentration of non^esterified fatty acids in dairy cows was significantly affected by the body condition score and time of dairy cows(P<0.05),while the serum level ofβ-hydroxybutyric acid was only significantly affected by the body condition score of dairy cows(P<0.05).The contents of malondialdehyde(MDA),vitamin A(VA)and vitamin E(VE),superoxide diamutase and catalase(CAT)in serum of the group with body condition score of 4.2~4.4 at calving and after calving were significantly higher than those of the other groups(P<0.05).Conclusion:in this study,cows with a low body condition score(3.0~3.2)had better lactation performance after calving,while cows with a high body condition score(4.2~4.4)showed greater body condition loss and higher oxidative stress after calving.