Effect of quality of colostrum on health, growth and immunoglobulin G concentration in Holstein calves in a hot environment

摘要

The aim of this study was to determine the effect of ingestion of pasteurized and subsequently frozen-thawed pooled colostrum (50mg Ig/mL) with different bacterial counts and immunoglobulin concentration (IgC) on the occurrence of diarrhea and pneumonia in 306 neonatal Holstein calves in a hot environment. Calves were assigned to be fed colostrum with total bacterial counts (TBC) lower or greater than 100000 colony-forming units (cfu)/mL, total coliform counts (TCC) greater or lower than 10000cfu/mL, and IgC lower or higher than 85mg Ig/mL. Calves fed colostrum with TBC 100000cfu/mL were more likely (risk ratio 1.34, confidence interval 1.05-1.71; P0.05) to present pneumonia than calves receiving colostrum with lower TBC (incidence 53.2 vs. 39.8%). Calves fed colostrum with high TCC had increased chances of suffering pneumonia (51.4 vs. 42.1%; P0.05) than calves fed colostrum with lower TCC. Calves fed colostrum with 85mg Ig/mL tended to present higher daily weight gain (505 +/- 113 vs. 484 +/- 126g; P=0.09). TBC and TCC in colostrum did not influence the incidence rate of diarrhea. It was concluded that under the conditions of the present study, heavy contamination of on-farm pasteurized frozen-thawed colostrum is seemingly unavoidable and this contamination poses a threat for pneumonia, but not for diarrhea.