Change in metabolite levels and liveweight of grazing cattle when supplemented with Leucaena leucocephala or urea-molasses

Abstract

Liveweight change and the concentration of a number of metabolites in rumen fluid, blood and faeces weremonitored in cattle from weaning until they were 33 months old, grazing spear grass alone and when supplemented with either Leucaena /eucocephala, urea-molasses, or both. Levels of metabolites in unsupplemented cattle in winter reflected the poor protein content of spear grass. A low molar percentage of higher volatile fatty acids in rumen fluid (1.09 and 1. 72% for weaners and two year- old cattle, respectively) indicated a shortage of amino acids in the feed; and the low ammonia nitrogen concentrations (7 and 18 mgfL, respectively) would have limited bacterial protein production.