Relationship between the degree of insulin resistance during late gestationand postpartum performance in dairy cows and factors that affect growth and metabolicstatus of their calves

[摘要] References(39)This study aimed to investigate the effects of insulin resistance (IR) during theclose-up dry period on the metabolic status and performance of dairy cows as well as todetermine the effects on body weight (BW) and metabolic status of their calves. An insulintolerance test (ITT) was conducted by administering 0.05 IU/kg BW of insulin to 34multiparous Holstein cows at 3 weeks prepartum. Blood samples were collected at 0, 30, 45and 60 min after insulin injection, and cows were divided into two groups based on thetime required for glucose to reach the minimum levels [non-IR (NIR), 45 min (n=28); andIR, 60 min (n=6)]. Blood or milk sampling and body condition score (BCS) estimation wereperformed twice weekly during the experimental period. Blood samples from calves werecollected immediately after birth. Cows with IR showed lower BCS(P<0.05) and serum urea nitrogen (P<0.05) andglucose concentration (P=0.05) before calving, and lower serumnon-esterified fatty acid concentration (P<0.05) and milk yield(P<0.05) and earlier resumption of luteal activity(P<0.05) after calving; their calves showed lower BW(P<0.05) and plasma insulin-like growth factor-I concentration(P<0.001) and higher plasma insulin concentration(P<0.05). In conclusion, IR at 3 weeks prepartum in dairy cows isrelated to postpartum metabolic status and performance along with growth and metabolicstatus of their calves.

[学科分类] 兽医学

[关键词] dairy cow;dry period;insulin tolerance test;metabolic status;postpartum performance