Identification and quantification of factors affecting neonatal immunological transfer in dairy calves in the UK

The object of the study was to quantify the prevalence of failure of passive transfer in UK dairy farms and to identify variables that had a significant impact on the rate of immunological transfer. In a six-month study of 444 calvings from seven UK dairy farms, 26 per cent of calves failed to receive adequate immunoglobulin transfer as judged by a plasma total protein (pTP) concentration less than 5.6 g/dl. Colostrum immunoglobulin concentration, indirectly measured using Brix refractometry, showed wide variations with samples ranging from 10.3 to 34.7 Brix units. Thirty-seven per cent of samples were below the suggested cut-off Brix score for colostrum quality of 22 per cent. Potential associations between covariates and plasma protein concentration were investigated using multiple linear regression models. The covariate with the greatest impact on the pTP concentration was the farm on which the calf was born (P<0.05). A significant but small association was demonstrated between colostrum immunoglobulin concentration and calf pTP concentration (P<0.01). Multiple linear regression models suggested that the time of colostrum collection after calving, parity of the dam, and the individual farm were associated with the Brix measurements (P<0.05). This study suggested that veterinary review of colostrum protocols on farm with emphasis on prompt collection and dosing after calving remains a simple and effective measure to improve passive transfer and thus calf health on UK dairy farms.