Impact of passive immunity failure on early age growth performance of Jersey crossbred calves

Birth weight and growth indicate health and future performance of dairy calves. Colostrum antibodies act as barrier against several pathogens at initial phase to prevent various infection and illness. In this study, we report growth performance and body dimensions of calves up to three months of age in relation to adequate and inadequate levels of passive immunity. Jersey crossbred calves were divided into two groups based on serum IgG level i.e. failure of transfer of passive immunity (FTPI <10 mg/ml IgG) group and adequate transfer of passive immunity (ATPI>10 mg/ml) group. Standard colostrum feeding practice @10 % calf body weight was followed. Total of 29 Jersey crossbred calves were taken where ATPI group had 20 and FTPI group had 9 calves. The birth weight of calves was 23.15±0.76 and 23.78^a±1.04 kg in ATPI and FTPI groups, respectively. Significant (p<0.05) increase in body weight gain was found in APTI as compared to FTPI calves (36.14 kgvs30.28 kg) at 3 months age. Average daily gain (ADG) from 0 to 90 days of life was significantly higher in ATPI calves (0.44 kg/day) as compared to FPTI calves (0.34 kg/day). Height (at withers) of calves did not differ between the groups (p<0.05), however heart girth and body length increased significantly in ATPI calves from 8^th week to 12^th week of age as compared to calves of inadequate passive immunity levels. The study revealed that passive immunity failure in neonatal Jersey crossbred calves had negative impact on their future growth performance.