Plasma profile of hormones and energy metabolites in low and high producing periparturient Sahiwal cows during summer and winter season

In order to study the plasma hormonal and metabolic changes in Zebu (Sahiwal) cattle during summer and winter season, five each of periparturient high and low yielding cows were selected from Livestock Research Centre, ICAR-NDRI, Karnal. Blood samples were collected on days -45, -30, -15 (prior to parturition), 0 (day of parturition) and 15, 30, 45 (postpartum) during both the seasons and plasma was separated. Plasma cortisol levels were significantly higher on day of parturition and during postpartum period in both the groups during both the seasons. Plasma insulin levels were significantly (P<0.05) lower during summer in high yielder group. On the day of calving, plasma T3 andT4 levels were significantly (P<0.05) lower in high yielders during both seasons. Plasma leptin levels were lower (P<0.05) on day of parturition in high yielders than low yielders during both seasons. Plasma glucose levels were significantly lower (P