Abstract #M235

# M235
Impact of ad libitum milk feeding and butyrate supplementation on organ and epithelial growth in the gastrointestinal tract of dairy calves.
C. Gerbert1, D. Frieten*2, C. Koch1, G. Dusel2, K. Eder3, R. Zitnan4, H. M. Hammon5, 1Educational and Research Centre for Animal Husbandry, Hofgut Neumuehle, Muenchweiler an der Alsenz, Germany, 2Department of Life Sciences and Engineering, University of Applied Sciences Bingen, Bingen, Germany, 3Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University Giessen, Giessen, Germany, 4National Agricultural and Food Centre, Research Institute for Animal Production, Nitra, Slovakia, 5Institue of Nutritional Physiology, Leibniz Institute for Farm Animal Biology (FBN), Dummerstorf, Germany.

Ad libitum milk replacer (MR) feeding as well as butyrate (B) have independently shown that both stimulate postnatal growth and development in calves. We hypothesized that the combination of intensive MR feeding and B supplementation expedites the development of the gastrointestinal tract in preweaning calves in a synergistic manner. Holstein male calves were studied from birth until d 80 of age. All calves received colostrum and transition milk until d 3 of age and from d 4 onwards were fed MR (12.5% dry matter) in amounts of either 6 L/d (Res; n = 16) or ad libitum (Adl; n = 16) for 8 wk. In both feeding groups half of the calves were fed MR with 0.24% B (ResB+; AdlB+) or same MR with no B supplement (ResB-; AdlB-). From wk 9 to wk 10 MR was linearly reduced in all calves to 2 L/d. Hay, water, and concentrate were offered ad libitum. At d 80 calves were harvested and mucosa samples of the rumen and small intestine were taken for measurement of rumen papilla and intestinal villus and crypt size. Data (LSM) were analyzed by the Mixed Model of SAS with feeding regimen, B supplementation, and rumen/intestinal segment as fixed effects. Body weight (124 vs. 110 kg) and kidney fat weight (514 vs. 363 g) were greater (P < 0.05) but pancreas weight (92 vs. 106 g) was lower (P < 0.05) in Adl than in Res. The small intestine was longer (P < 0.05) in AdlB- than in ResB- (27.3 vs. 23.6 m). Villus height in duodenum, proximal jejunum and ileum were greater (P < 0.05) in Adl than in Res (567, 637, 555 vs. 546, 611, 529 µm, resp.). Villus height was greater (P < 0.05) in B+ than in B- (585 vs. 554 µm). Crypt depth was reduced (P < 0.01) by B in ileum (262 vs. 253 µm). The villus height/crypt depth ratio increased by ad libitum feeding and by B and was greatest (P < 0.05) in AdlB+ throughout the small intestine (2.27, 2.44, 2.24, 2.35 for AdlB-, AdlB+, ResB-, ResB+, respectively). Intensive MR feeding and B increased small intestinal mucosa growth. These findings indicated a synergistic effect on small intestinal mucosa growth by intensive MR feeding and B supplementation.

Key Words: ad libitum milk replacer feeding, butyrate, intestine