Dairy Science Department
BS in Dairy Science
The objective of this study was to determine if fresh frozen, pasteurized frozen, or fresh refrigerated colostrum impacted morbidity, growth rates, and the overall serum immunoglobulins (IgGs) in newborn calves. The second objective was to compare the effects that pasteurization and freezing had on colostrum IgG concentration and total bacteria counts compared to raw refrigerated colostrum. A controlled trial was completed on a 6,000-cow dairy in California where colostrum was harvested twice daily, pooled, and then divided into three different treatment groups and processed accordingly. One treatment was pasteurized at 60oC for 60 min and then frozen, the other two were both fresh, one going into the freezer and the other into the refrigerator. Samples of all treatment groups were taken to determine total plate count, total E. Coli count, and total IgG immediately before the colostrum was fed. Newborn calves were randomly assigned to be fed 4 quarts of either pasteurized frozen (Past, n=60), fresh-frozen (FF, n=60), or fresh-refrigerated (FR, n=60) colostrum within 2 hours of birth. Calves were weighed daily and picked up after receiving 2 or 3 feedings of treatment colostrum (dependent on time of birth) and taken to a custom heifer raising facility where they were weighed and monitored for morbidity (number of treatments) until weaning (60d). Pasteurization improved the serum IgG count in the calves compared to fresh and fresh frozen treatments. Pasteurization decreased bacteria counts and appeared to decrease IgG concentration in the colostrum but had no effects on morbidity or weaning weight.