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Colostrum: Its effect on cattle health and performance
Colostrum is necessary for the development of immunity in the neonatal calf. However, 60 % of the colostrum produced on US dairy farms does not meet minimum quality standards (< 50 g/L immunoglobulin G (IgG)) resulting in over 40 % of calves not achieving passive transfer (serum IgG < 10 g/L). This poor quality colostrum is a major contributing factor toward the US calf mortality rate of 10.5 %. Therefore, improving colostrum quality and uptake of IgG by calves is imperative in enhancing health, performance and profitability. This review will focus on means of improving IgG uptake in the newborn including: colostrum quality, time of feeding related to harvest, parity, bacterial contamination, and pasteurization. Feeding colostrum via esophageal intubation as compared to conventional feeding methods will be reviewed as intubation appears to be as efficacious as conventional (nipple bottle) feeding methods. Colostrum additives such as sodium bicarbonate, and selenium have sometimes enhanced IgG uptake. Feeding colostrum for more than one day improved local immunity in calves. Prepartum cow diets that predispose cows to hypocalcemia may reduce IgG uptake in the neonate whereas; prepartum supplementation of nicotinic acid to cows appeared to increase IgG uptake in the newborn. Behavioral changes such as artificial mothering may enhance IgG uptake. Reducing heat stress of cows during colostrogenesis increased calf weight and uptake of IgG compared to cows that were heat stressed. Feeding at least four L of good quality colostrum (≥ 50 g/L IgG) has been shown to improve growth, reduce veterinary costs and increase milk yield compared to calves fed two L of the same quality colostrum. Lacteal-based colostrum replacers can provide adequate passive transfer of IgG. Utilization of colostrum supplements resulted in mixed outcomes in regards to passive IgG transfer. New research ideas will be presented describing ways to improve colostrum quality and immunity in the calf resulting in enhanced health and performance.
Keywords: calf colostrum immunoglobulin G