Effect of sward attributes on legume selection by oesophageal-fistulated and non-fistulated steers grazing a tropical grass-legume pasture
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Permanent link to this item: http://hdl.handle.net/10568/43391
A grazing trial was carried out in the Eastern Plains of Colombia to compare legume selection by transiently grazed oesophageal-fistulated steers and non-fistulated steers permanently grazing pastures. The 6 pasture types investigated were Arachis pintoi-Brachiaria humidicola mixtures which differed in legume and grass mass per hectare and grass:legume ratios. The sward attributes explaining the greatest variation in legume selection by fistulated and non-fistulated steers were legume percentage in the forage on offer (r2 = 0.67) and available legume mass (r2 = 0.56), respectively. Legume selection by both groups of steers was correlated with legume bulk density (kg DM/ha/cm). However, the relationship was linear (r2 = 0.53) for fistulated steers with maximum dietary legume proportion reaching 92% and exponential (r2 = 0.52) for non-fistulated steers with a plateau at 25% dietary legume with individual values never exceeding 35%. This study confirms that legume selection under grazing differs between oesophageal-fistulated steers transiently grazing the pastures and resident intact steers, and indicates that this difference is associated with their contrasting response to changes in sward attributes.
ARACHIS PINTOI; BRACHIARIA HUMIDICOLA; GRAZING; PASTURES; FEED LEGUMES; FEED GRASSES; SELECTION; NUTRITIVE VALUE; DIET; BOTANICAL COMPOSITION; COLOMBIA; ARACHIS PINTOI; BRACHIARIA HUMIDICOLA; PASTOREO; PASTIZALES; LEGUMINOSAS FORRAJERAS; GRAMÍNEAS FORRAJERAS; SELECCIÓN; VALOR NUTRITIVO; DIETA; COMPOSICIÓN BOTÁNICA; COLOMBIA