Nutritive values and chemical composition of seven tropical legumes and lucerne grown in subtropical south-eastern Queensland

Abstract

The chemical composition and feeding value of seven tropical legumes and lucerne were determined by pen feeding experiments with sheep. Most of the legumes were harvested during autumn and winter. Lucerne had the highest feeding value and the highest values for the tropical legumes were obtained for Vigna vexillata, Lotononis bainesii, and Desmodium uncinatum. After frosting, the feeding values of Phaseolus lathyroides and Vigna vexillata were reduced but that of Desmodium uncinatum was not changed. This may have been due to a greater loss of leaf by both P. lathyoides and V. vexillata than by D. uncinatum. Frost did not affect Lotononis bainesii and Medicago sativa, and both had a higher feeding value than the legumes affected by frost. The usefulness of crude protein and crude fibre for estimating dry matter digestibility and dry matter intake and the relation between dry matter digestibility and dry matter intake is discussed. The use of dry matter digestibility to express the nutritive value of feed energy in preference to organic matter digestibility, starch equivalents, and total digestible nutrients is also discussed.