亚临床酮病对围产期奶牛生产性能和血液糖脂代谢指标的影响

Effects of Subclinical Ketosis on Production Performance and Blood Glucose and Lipid Metabolism Indexes of Perinatal Dairy Cows

为研究奶牛亚临床酮病与生产性能的关系,研究选择2~4胎次中国荷斯坦奶牛,根据产后血液中β-羟丁酸(BHBA)水平将奶牛分为亚临床酮病组(SCK组,16头)和健康对照组(C组,20头),记录围产期奶牛体况(BCS)和产后1~8周的泌乳量,分析产后第60 d乳成分变化;并于产前21、14、7 d和产后1、3、5、7、14、21 d分别进行血液样本检测,分析围产期奶牛血液中游离脂肪酸(NEFA)、血糖(GLU)、三酰甘油(TG)、总胆固醇(CHO)、高密度脂蛋白(HDL-C)、低密度脂蛋白(LDLC)、胰高血糖素(GC)、胰岛素(INS)水平的变化。结果表明:与健康对照组奶牛相比,SCK组奶牛血液中BHBA浓度在产后3~21 d显著高于C组(P<0.05),1~8周泌乳量低于C组,但差异不显著(P>0.05),乳样中乳脂率和脂蛋比显著高于C组(P<0.05)。血液样本分析表明SCK组奶牛血液NEFA在产后7、14 d显著高于C组(P<0.05),GLU水平在产后3、5、7、21 d显著低于C组(P<0.05);SCK组奶牛血液中TG、CHO、HDL-C有所下降,但LDL-C、GC、INS的水平整体水平有所升高(P>0.05)。综合以上结果表明,奶牛亚临床酮病的高发期主要集中在产后5~21 d,奶牛患亚临床酮病会导致血液中糖脂代谢指标异常,虽然对奶牛产奶量的影响并不显著,但会导致乳蛋白含量下降。

The aim is to study the relationship between subclinical ketosis and production performance in dairy cows in this study.Chinese Holstein cows with 2~4 parity were selected.They were divided into subclinical ketosis group(SCK,n=16)and healthy control group(C,n=20)according to the level of BHBA in blood.The body condition of perinatal cows and lactation amount from 1 to 8 weeks after delivery were recorded,and the change of milk composition in milk samples was analyzed on day 60 after delivery.Blood samples were collected for analysis of nonestesterified fatty acids(NEFA),blood glucose(GLU),triglyceride(TG),total cholesterol(CHO),high density lipoprotein(HDL-C),low density lipoprotein(LDL-C)and glucagon(GC),insulin(INS)levels at day 21,14 and 7 before delivery and day 1,3,5,7,14 and 21 after delivery.The results showed that,compared with C,the blood BHBA concentration of SCK was significantly higher(P<0.05).It failed to observe the difference in milk yield between 1 and 8 weeks,although SCK was lower.A significant increase in milk fat percentage and fat-egg ratio was observed in SCK compared to C.The analysis of blood samples showed that blood NEFA in SCK was significantly higher than that in C at day 7 and 14 after delivery(P<0.05),while GLU level was significantly lower at day 3,5,7 and 21 postpartum(P<0.05).Although TG,CHO,HDL-C decreased and LDL-C,GC,INS increased in blood of SCK group,it failed to observe a significant difference compared with C.In conclusion,the high incidence of subclinical ketosis in dairy cows is mainly concentrated in 5~21 days after delivery.The subclinical ketosis in dairy cows will lead to abnormal glucose and lipid metabolism indexes in blood.Although the impact on milk yield is not significant,it will lead to the decline of milk quality.