Adaptive Responses of Thyroid Hormones, Insulin, and Glucose during Pregnancy and Lactation in Dairy Cows

Animals

Paola Crepaldi¹  Vincenzo Lopreiato²  Arianna Bionda²  Pietro Medica²  Luigi Liotta²  Vincenzo Chiofalo²  Esterina Fazio² 

[1] Department of Agricultural and Environmental Sciences, Università di Milano, Via Celoria, 2, 20133 Milan, Italy;Department of Veterinary Sciences, Università di Messina, Viale Palatucci, 13, 98168 Messina, Italy;

关键词: thyroid hormones;    insulin;    glucose;    dairy cows;   

DOI  :  10.3390/ani12111395

来源: DOAJ

【 摘 要 】

The study examined the effects of different stages of pregnancy and lactation on thyroid, insulin, and glucose responses in dairy cows. In the present study, 30 dairy cows (10 Holstein, 10 Simmental, and 10 Brown) at 30 ± 20 d of lactation were randomly selected and blood samples were collected once every 60 d for one year to measure circulating thyroid stimulating hormone (TSH), total and free triiodothyronines (T₃, fT₃) and thyroxines (T₄, fT₄), insulin, and glucose. Pregnant cows showed higher T₄ (p = 0.010) and insulin (p = 0.046) concentrations at >180 d than at >60–120 d of pregnancy and in nonpregnant cows. Along the lactation phase, circulating T₄ concentrations showed a biphasic trend, decreasing from 0–60 d to >60–120 d phase, which showed the lowest values, and then increasing until the end of lactation (>300 d) (p = 0.016). Glucose showed the highest concentrations at the start of lactation (0–120 days) and the lowest values at the end (p = 0.008). The monitoring of thyroid hormones, insulin, and glucose changes represents an important tool to evaluate the anabolic and/or catabolic adaptation in response to functional periods in dairy cows, which can potentially predispose the cows to an excessive negative energy balance and related metabolic issues.

【 授权许可】

Unknown