Addition of sodium bicarbonate to either 1 or 2 feedings of colostrum replacer: Effect on uptake and rate of absorption of immunoglobulin G in neonatal calves1

Abstract

Forty Holstein dairy calves were blocked by birth date and sex, and randomly assigned to 1 of 4 treatments within each block to elucidate the effect of feeding regimen and sodium bicarbonate (NaHCO3) supplementation on absorption of IgG from colostrum replacer (CR). Calves received CR containing 191.4g of IgG fed either in 1 feeding at 0h (within 45min of birth), with or without 30g of NaHCO3, or in 2 feedings (127.6g of IgG at 0h, with or without 20g of NaHCO3, and 63.8g of IgG at 6h, with or without 10g of NaHCO3). The treatments were (1) 1 feeding of CR+0g of NaHCO3; (2) 1 feeding of CR+30g of NaHCO3; (3) 2 feedings of CR+0g of NaHCO3; and (4) 2 feedings of CR+30g total of NaHCO3. Only calves born with no dystocia were used on this study. Blood samples were taken at 0, 6, 12, 18, and 24h postpartum and were analyzed for IgG using a radial immunoassay. Results indicated that, individually, feeding regimen and NaHCO3 treatments had no effect. However, the interaction was significant for 24-h IgG and area under the curve, and showed a trend for apparent efficiency of absorption. Absorption rate data indicated that, for calves fed within 45min of birth, most IgG absorption occurred in the first 6h after birth. From 6 to 12h postpartum, IgG absorption started to decrease; however, IgG absorption remained higher for calves fed in a single feeding than in 2 feedings. These data indicated that NaHCO3 may increase IgG absorption when calves are fed colostrum in a single feeding but is not beneficial when colostrum is fed in 2 feedings. © 2012 American Dairy Science Association.