author(s)
S Usha and TK Mohanty

abstract
The present study reports the seasonal variation of certain plasma metabolites in normal and delayed sexual maturity Karen Fries crossbred heifers at Livestock Research Center, ICAR-National Dairy Research Institute, Karnal, Haryana over a period of one year. Total 160 heifers; eight healthy heifers in each month [24, 16, 32, 24 healthy heifers in rainy, autumn, winter and summer, respectively and 8 heifers from each group (delayed sexual maturity and low growth rate) per season were selected for the study. Plasma metabolite like glucose, urea nitrogen, cholesterol and non-esterified fatty acid (NEFA) was estimated. There was significant (P< 0.05) seasonal variation of plasma metabolites like glucose, urea nitrogen, cholesterol and NEFA was observed. In delayed sexual maturity and low growth rate heifers mean plasma glucose, cholesterol and NEFA concentration differed significantly (P< 0.05) from healthy heifers and and also did not follow a similar pattern. It might be due to change or variation in the fodder other management effects. Herd status regarding metabolic parameters need to be evaluated regularly in different seasons to achieve set targets in terms of growth performance of heifers by adjusting feeding management.