PASSIVE TRANSFER OF IMMUNITY OF DAIRY CALVES IN THE CENTRAL NORTHERN REGION OF COSTA RICA
The objective of this study was to characterize the immune status of dairy calves in the Central Northern region of Costa Rica. The data correspond to total serum protein (TSP) measurements obtained during the period of August and November of 2012 in 47 dairy farms. 337 female and 127 male calves were sampled. Dam breeds were classified into Holstein, Jersey, HolsteinxJersey crosses and other. For the purpose of this study, failure of passive immunity was considered when TSP concentration was less than 5.5 g/dL. TSP concentration ranged from 3.0 to 10.0, with an overall mean of 5.7 g/dL. Of all the animals evaluated, 40.5% had failure of passive transfer. When sex of the calves was considered, 39.2% of females and 44.1% of males failed to obtain adequate concentration of TSP and there were no significant differences (5.8 vs. 5.7 g/dL, respectively) (P>0.05). Calves born to Holstein cows had significantly lower TSP concentrations than calves born to other breeds (P>0.05). When considering calving of the dam, there were no significant differences on TSP concentration of calves, however offsprings born to fourth lactation cows showed the highest percentage of animals with inadequate transfer of immunity. Calves that were allowed to suckle their dams showed a 48.8% failure of passive immunity against 34.1% of calves that were given colostrum by bottle. The findings of this study suggest that colostrum management practices should be placed in order to minimize the risk of failure of passive transfer in dairy herds in the Central Northern region of Costa Rica.
Total serum protein, Immunity, Passive immunity