EFFECT OF FEEDING RATE AND GLUCOSE PROVISION ON PLASMA GLUCAGON-LIKE PEPTIDE 2 CONCENTRATION IN DAIRY CALVES

Glucagon-like peptide 2 (GLP-2) may have therapeutic potential in young calves encountering stressors, such as weaning and diarrheal disease, because of its pleiotropic actions on intestinal mucosal and barrier function. During diarrhea, feed intake decreases, which is a major negative effector of GLP-2 secretion and increases intestinal atrophy. We determined the effects of feeding rate and supplementation with potential GLP-2 secretagogues in milk replacer (MR) on GLP-2 concentration [GLP-2] in calf plasma. Three days after birth, male Holstein calves (n = 45) were randomly assigned to 1 of 12 treatments arising from factorial combination of feeding rate (FR) and supplement type. Feeding rates were 25, 50, 75, and 100% of standard feeding level on d 5 (1.5% of BW as DM). Supplement treatments were Control: MR, no supplement; GLC: MR plus glucose (220 mg/kg BW per day); and 3OMeGLC, MR plus 3-O-Methyl glucose (6 mg/kg of BW per day). A commercial MR (12.5% solids) was fed twice daily at 10% of BW for d 1–2 and 12% of BW for d 3–5. On d 6–7 calves were fed the FR plus supplement treatments. On d 8, calves were fed 0, 25, 50, and 75% of respective MR allowance on d 5 plus supplement treatments, and plasma was obtained at −15, 15, 30, 60, 90, and 240 min relative to feeding for determination of [GLP-2]. No starter was fed but water was offered ad libitum. Generalized linear models with normal and Poisson distributions were used to analyze [GLP-2] and fecal score data, respectively. As designed, MR intake differed (P < 0.0001) among treatments. Occurrence of diarrhea did not differ among treatments. For log [GLP-2], there was a quadratic effect of FR (P = 0.0003) and effect of supplement, with 3OMeGLC greater than GLC but not control (P = 0.002). Increasing FR increased (P < 0.0001) area under the curve for [GLP-2] after feeding; calves fed the 25% rate had the lowest area under the curve and calves fed 100% had the greatest (10,188 vs. 22,023 pg·h/ mL). Feeding rate had a significant effect on GLP-2 with calves allotted greater MR intakes having greater plasma [GLP-2].