University of New Hampshire Scholars\u27 Repository
Abstract
The objective of this experiment was to determine the effect of various levels of lactoferrin supplementation in colostrum replacer fed as 1 or 2 doses on apparent efficiency of IgG absorption, serum IgG concentrations, and intestinal development in neonatal Holstein bull calves. Eighty-Holstein bull calves were assigned to a 2 x 4 factorial arrangement of treatments in a completely randomized block design. Bull calves were collected at two locations, Fairchild Teaching and Research Center at the University of New Hampshire (n = 48) and a commercial dairy (n = 32). All calves were fed colostrum replacer (CR) according to manufacturer\u27s recommendations within 90 min of birth with or without lactoferrin treatment. Lactoferrin treatments were 0 (control), 0.5, 1, and 2 g/d. At 12 h of age calves were fed either a second feeding of CR with or without Lf or 2 L of milk replacer (MR) with or without Lf Calves continued to be fed MR with or without Lf in 12 h increments throughout the duration of study. Calves from the commercial dairy were removed from study at 48 h, while calves born at the university were removed from the study at 72 h. Blood samples were collected for IgG at 0, 6, 12, 18, 24, and 48 h. On average, all calves attained blood serum IgG concentration ≥ 10 mg/mL resulting in successful passive transfer, except for calves fed 1 dose of CR 1 or 2 g/d of supplemental Lf. However, there was an effect on CR feeding with calves fed 2 doses of CR having significantly higher blood serum IgG concentrations. There was no effect of Lf supplementation on plasma IgG and serum protein. There was a decrease in apparent efficiency of absorption (AEA) of IgG when 2 doses of CR were fed versus 1 dose of CR. Lactoferrin supplementation resulted in a suppressing quadratic effect on AEA of IgG. At the sixth feeding in which calves were 60 +/- 2 h of age, D-xylose (0.5g/kg BW) was mixed with the MR with or without supplemental Lf (UNH calves) to determine xylose absorption by the small intestine. Blood samples were collected before xylose was fed at 0, and 2, 4, 6, 8, and 12 h after feeding xylose, for measurement of plasma glucose and xylose concentrations. Xylose means and area under the curved showed Lf to have a quadratic effect on xylose absorption with 0.5 and 1 g/d of supplemental Lf having lower plasma xylose concentrations then calves fed 0 and 2 g/d of supplemental Lf There was no effect of CR feeding or supplemental Lf on plasma glucose concentrations. This study indicates supplementing Lf to a CR has a negative effect on both serum IgG and xylose absorption, demonstrating supplemental Lf is not beneficial to the neonatal calf