NAPIER OR GROUNDNUT HAY AS SUPPLEMENTS IN DIETS OF SHEEP CONSUMING POOR QUALITY NATURAL PASTURE-HAY .2. EFFECT ON INTAKE AND RUMEN DIGESTA KINETICS

Three experiments, each of a 5 x 5 Latin square design, were carried o ut using sheep to assess the effect of supplementing poor quality natu ral pasture (veld) hay with graded levels of napier or groundnut hay o n feed intake, rumen fermentation, digesta pool size and passage rate. In experiment 1, napier hay was fed at 0 g day(-1), 100 g day(-1), 20 0 g day(-1), 300 g day(-1) or ad libitum. In experiment 2 the same lev els of feeding were used with groundnut hay, while in experiment 3, na pier and groundnut hay were each fed at 0 g day(-1), 150 g day(-1) or 300 g day(-1) to enable a direct comparison of the two supplemental fo rages. All the forages used were chopped to a particle size of about 1 cm prior to feeding. The veld hay was supplemented with 1% urea and w as always offered ad libitum. The forage supplements were fed separate ly. In all the experiments, the forage supplements increased total fee d intake, digestibility and concentration of ammonia and volatile fatt y acids in the rumen. Incubation of veld hay in the rumen of sheep giv en napier and groundnut hay as supplements or as sore feeds, showed no effect on degradation pattern including rate of degradation. Rumen di gesta pool size was not altered, but fractional outflow rate was incre ased by supplementation. The increase in feed intake was therefore lar gely facilitated by an increase in digesta passage rate. (C) 1997 Else vier Science B.V.