Transfer of Colostral Immunoglobulin to Newborn Dairy Calves. Effects of Housingon Suckling Patterns and Consequences for the Intestinal Transmission of Macromolecules

摘要

The purpose of this thesis was to study the influence of housing on the transferof passive immunity from cow to calf. Behavioral observations were performed on three farms having different housing systems. The behavior of cows and calves was analyzed in detail. Consequences of irregular suckling patterns for the transmission of antibodies were studied in feeding experiments, where new-born calves were fed pooled colostrum with known levels of IgG and the transmission of colostral antibodies to the blood circulation was measured for each feed separately, using marker macromolecules. In the feeding experiments it was observed that calves can transmit considerable amounts of IgG from the first feed at least up to 24 hours after birth, but the ability to transmit macromolecules declines slowly with age. Calves that fail to suckle soon after birth reach lower levels of serum IgG, but they can reach acceptable levels if they ingest a large amount of good colostrum in the first feed. Calves that suckle cows other than the mother on average obtain lower levels of serum IgG. The reason for this appears to be a lower total ingestion of IgG.