Feeding colostrum or a 1:1 colostrum: milk mixture for 3 days postnatal increases small intestinal development and minimally influences plasma glucagon-like peptide-2 and serum insulin-like growth factor-1 concentrations in Holstein bull calves

摘要

This study evaluated how feeding colostrum- or acolostrum-milk mixture for 3 d postnatal affects plasmaglucagon-like peptide-2 (GLP-2), serum insulin-likegrowth factor-1 (IGF-1), and small intestinal histomorphologyin calves. Holstein bulls (n = 24) were fedcolostrum at 2 h postnatal and randomly assigned toreceive either colostrum (COL), whole milk (WM),or a 1:1 COL:WM mixture (MIX) every 12 h from 12to 72 h. A jugular venous catheter was placed at 1h postnatal to sample blood frequently for the durationof the experiment. Samples were collected at 1, 2,3, 6, 9, 11, and 12 h. Following the 12-h meal, bloodwas collected at half-hour intervals until 16 h and thenat 1-h intervals from 16 to 24 h. A 27-h sample wastaken, then blood was sampled every 6 h from 30 to60 h. Again, blood was taken at half-intervals from 60to 64 h, then at 65 and 66 h, following which, a 2-hsampling interval was used until 72 h. Plasma GLP-2(all time points) and serum IGF-1 (at time points: 1,6, 12, 18, 24, 36, 48, and 72 h) were both analyzed.Duodenal, jejunal, and ileal tissues were collected at75 h of age to assess histomorphology and cellular proliferation.Feeding COL, rather than WM, increasedplasma GLP-2 by 60% for 2 h and tended to increaseGLP-2 by 49.4% for 4 h after the 60-h meal. Insulinlikegrowth factor-1 area under the curve (from 12 to72 h) tended to be 27% greater for COL than WMcalves but was otherwise unaffected by treatment. Ilealcrypts tended to proliferate more with MIX thanWM, whereas ileal crypt proliferation did not differ forCOL compared with MIX or WM and was not differentbetween treatments in the proximal jejunum. Villiheight was increased 1.8 and 1.5× (COL and MIX vs.WM) in the proximal and distal jejunum, respectively,whereas MIX duodenal and ileal villi height tended tobe 1.5 and 1.4× that of WM. Crypt depth did notdiffer in any region. Surface area of the gastrointestinaltract was reduced for WM by 60 and 58% (proximaljejunum) and 38 and 52% (ileum) relative to COL andMIX and was 54% less than MIX in the distal jejunum.Overall, extended COL feeding minimally increasedplasma GLP-2 and serum IGF-1 compared with WMfeeding. As COL and MIX similarly promoted smallintestinal maturation, feeding calves transition milk topromote intestinal development could be a strategy forproducers.