Screening white clover cultivars- for improved nutritive value - development of a method

Abstract

A method has been developed which enabled 100 white clover cultivars to be screened and ranked for improved nutritive value. Our objective was to identify cultivars having protein which was relatively insoluble and resistant to rumen degradation. The methods were developed for fresh forages, so that the results were applicable to the grazing animal. The clover was harvested and minced to give a particle size distribution similar to material chewed by ruminants during eating. Crude protein solubility was estimated by measuring nitrogen (N) loss from minced clover incubated in nylon bags in the rumen of a cow. This required the optimal amount of dry matter (DM) and incubation times to be determined, variation between animals to be defined and repeatability of measurements established. Crude protein degradation was measured by incubating minced clover with buffered rumen bacteria in vitro and determining net conversion of plant N to ammonia N. Nitrogen loss to degradation and cultivars w&e identified as having low solubility _ ability-for-the-1.OO-cultivar-were-positively and slow degradation and five cultivars having high solubility and rapid degradation. Mean values correlated (r=+O.29; P