Effect of butyrate on passive transfer of immunity in dairy calves

The objectives of this study were to determine the effects of supplemental butyrate on (1) Ig production in dams and (2) Ig absorption in their calves. Twenty dry dams fed a close-up total mixed ration were assigned to either a control treatment (CTRL-D) or a butyrate treatment where the close-up total mixed ration was supplemented with butyrate at 1% of dry matter intake (wt/wt; BUT-D). At calving, calves were assigned to 1 of 2 treatments: a control group fed colostrum replacer only (CTRL-C) and a butyrate group fed colostrum replacer with supplemental butyrate at 2.5% (wt/vol; BUT-C). Serum IgG, glucose, and beta-hydroxybutyrate were measured weekly in both dams and calves. Additionally, calves were weighed weekly to determine average daily gain. In dams, serum IgG concentration was not different between CTRL-D and BUT-D (1,785 +/- 117 vs. 1,736 +/- 137 mg/dL, respectively), nor was there a change in Ig levels in the colostrum between control and butyrate groups. Serum total protein did not differ between CTRL-D and BUT-D dams. Dam dry matter intake did not differ between CTRL-D and BUT-D but did decrease 1 wk before parturition. Compared with CTRL-C calves, BUT-C calves had significantly decreased serum IgG concentration at 24 h (2,110 +/- 124 vs. 1,400 +/- 115 mg/dL), wk 1 (1,397 +/- 121 vs. 866 +/- 115 mg/dL), and wk 2 (1,310 +/- 121 vs. 797 +/- 115 mg/dL). Additionally, apparent efficiency of absorption was lower for the BUT-C group compared with the CTRL-C group (35.3 +/- 2.1 vs. 25.9 +/- 2.0). Differences in serum Ig concentrations between the CTRL-C and BUT-C groups did not affect average daily gain (0.59 +/- 0.05 vs. 0.48 +/- 0.05 kg/d, respectively), serum glucose concentrations, or serum beta-hydroxybutyrate concentrations. These data demonstrate that butyrate inclusion in colostrum negatively affects IgG absorption in newborn calves, whereas calf body weight gains were unaffected.