Improving passive transfer of immunoglobulins in calves. II: Interaction between feeding method and volume of colostrum fed

The objective of this study was to investigate the effect of method of feeding (nipple bottle vs. esophageal tube feeder) on passive transfer of immunoglobulin (Ig) G when either a large or small volume of colostrum was fed. Newborn bull calves were removed from the dam before suckling and randomly assigned to 1 of 4 colostrum replacer (CR) treatment groups: 1.5 L (100 g of IgG) of CR fed using a nipple bottle (group 1; n = 24); 1.5 L (100 g of IgG) of CR fed using an esophageal tube feeder (group 2; n = 24); 3.0 L (200 g of IgG) of CR fed using a nipple bottle (group 3; n = 24), or 3.0 L (200 g of IgG) of CR fed using an esophageal tube feeder (group 4; n = 25). Blood samples collected at 24 h of age showed that serum IgG levels were significantly greater in calves fed large (3 L) volumes of CR compared with calves fed small (1.5 L) volumes of CR, regardless of feeding method. These differences were attributed to the larger mass of IgG ingested by calves fed 3 L of CR (200 g of IgG) compared with calves fed 1.5 L of CR (100 g of IgG). For calves fed small (1.5 L) volumes of colostrum, serum total protein (TP, g/dL), serum IgG (IgG, mg/mL), acceptable passive transfer rates (APT, %), and apparent efficiency of absorption of IgG (AEA, %) were significantly greater for calves fed with a bottle (TP = 5.3 g/dL; IgG = 12.5 mg/mL; APT = 100%; AEA = 51.1%) compared with calves fed with an esophageal tube feeder (TP = 5.0 g/dL; IgG = 9.8 mg/mL; APT = 41.7%; AEA = 40.5%). However, for calves fed large (3 L) volumes of colostrum, there was no difference in passive transfer indices for calves fed with a bottle (TP = 5.8 g/dL; IgG = 19.7 mg/mL; APT = 100%; AEA = 41.1%) compared with calves fed with an esophageal tube feeder (TP = 5.9 g/dL; IgG = 18.7 mg/mL; APT = 100%; AEA = 39.0%).