Interaction of Dietary Selenium and Magnesium Level on Digestive Function in Lambs Fed High-concentrate Diets

Hernández-Calva, L.M., Guerrero-Legarreta, M.I., Pérez-Chabela, M.L., López-Arellano, R. and Ramírez- Bribiesca, J.E. 2007. Interaction of dietary selenium and magnesium level on digestive function in lambs fed high concentrate diets. J. Appl. Anim. Res., 31: 41–46. A metabolism trial involving 4 Suffolk lambs (30.8 kg) cannulated in the rumen and proximal duodenum were conducted to evaluate the interaction of dietary Sel 0.10 vs 0.30 μ-g) and Mg level (0.18 vs 0.32%) on digestive function. Passage of feed N to the small intestine was greater (P<0.1) with 0.32% dietary Mg, and there was an interaction (P<0.05) between Mg and Se supplementation on feed N flow to duodenum and rumen digestion. There was an interaction between dietary Mg and Se level on passage of Mg and Se to the small intestine (P<0.05), ruminal solubility Mg concentration, molar proportion of acetate and acetate: propionate molar ratios. 0.3 μg Se increased (P<0.05) molar concentrations of butyrate. It is concluded that requirement levels of Se and Mg for feedlot lambs is substantially higher than that recommended by NRC.