1División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, México.
2División de Farmacéutica, FES-C, Campo I, Universidad Nacional Autónoma de México, México.
3Colegio de Postgraduados, Enlace de Ganadería, Campus Montecillo, Km 36.5 Carr. México-Texcoco, Montecillo Edo. de México CP50230, México.
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 μg) 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.
Selenium, magnesium, lambs, digestive function
