Digestibility and ruminal fermentation of diets differing in forage type and forage to concentrate ratio in sheep and goats

Abstract

7 páginas, 3 tablas.Ramos S., Molina Alcaide E., Cantalapiedra-Híjar G., Yáñez Ruiz D.R., Tejido M.L., Carro M.D. Digestibility and ruminal fermentation of diets differing in forage type and forage to concentrate ratio in sheep and goats. In : Ranilla M.J. (ed.), Carro M.D. (ed.), Ben Salem H. (ed.), Morand-Fehr P. (ed.). Challenging strategies to promote the sheep and goat sector in the current global context. Zaragoza : CIHEAM / CSIC / Universidad de León / FAO, 2011. p. 41-46. (Options Méditerranéennes : Série A. Séminaires Méditerranéens; n. 99). 13. International Seminar of the Sub-Network on Nutrition of the FAO-CIHEAM Inter-Regional Cooperative Research and Development Network on Sheep and Goats, 2009/10/14-16, León (Spain). http://om.ciheam.org/om/pdf/a99/00801534.pdfThe aim of this work was to compare digestibility and ruminal fermentation variables in sheep and goats fed good-quality diets at similar levels of intake. The four experimental diets had forage:concentrate ratios of 70:30 (H) or 30:70 (L) and either alfalfa hay (A) or grass hay (G) as forage. Four Granadina goats and 4 Merino sheep fitted with ruminal cannulae were used in a 4 x 4 Latin square design. Animals were fed the diets at a daily rate of 56 g dry matter (DM)/kg body weight0.75 to minimise feed selection. Intake of neutral- detergent fibre (NDF; g/kg body weight0.75) was lower in goats compared to sheep for HA, LA and HG diets (P=0.02, 0.03 and 0.02, respectively). No differences between AS were found in either DM (P =0.28) or NDF digestibility (P=0.23), but crude protein digestibility of HA and LG diets was 4.9 and 12.1 percent greater in goats than in sheep. Ruminal pH and proportions of propionate and isoacids were similar (P>0.05) in both animal species, but VFA concentrations in ruminal fluid were greater (P0.05) were found with L diets. Total protozoa numbers were 5.8 and 3.7 percent greater in goats than in sheep for LA and LG diets, respectively, but no differences (P=0.10) were found in the proportion of Holotricha. The results indicate that both AS can show similar digestive capacities when they are fed good-quality diets at a restricted level of intake, in spite of subtle differences in ruminal fermentation.Peer Reviewe