DIGESTA FLOW STUDIES IN SHEEP FED 2 MATURE ANNUAL LEGUMES

Mature subterranean clover (Trifolium subterraneum cv. Junee) and Pers ian clover (Trifolium resupinatum cv. Kyambro) were fed to cannulated sheep. Flow rates of dry matter and nitrogen in the abomasum and ileum were estimated using a double marker method. Contents of hemicellulos ic polysaccharides (xylose and mannose monomers) were higher in Kyambr o than in Junee. Although Junee contained higher levels of total N and amino acids, the relative concentrations of cystine and methionine we re markedly higher in Kyambro. Dry matter intakes and flow rates in th e abomasum, ileum and faeces were similar on Kyambro and Junee. Dietar y nitrogen intake was lower and endogenous re-cycled nitrogen higher o n Kyambro than on Junee. Ileal flow of nitrogen was similar to nitroge n intake on Kyambro. Apparent nitrogen digestibility was lower in the whole tract and higher in the intestines on Kyambro. The higher appare nt digestibility of nitrogen in the intestines of sheep eating Kyambro was associated with a greater proportion of nitrogen leaving the stom ach coming from endogenous sources. The lower nitrogen digestibility o f Kyambro in the whole tract indicated lower digestibility of dietary nitrogen, which was associated with higher contents of xylose and mann ose.