Effect of yeast supplementatin on the whole tract digestibiiity of nutrients and ruminal degradability of fibre and protein

Abstract

The influence of yeast culture (Yea- sacc1026) supplementation in the ration of lactating cows was investigated on the whole tract digestibility of nutrients and on in situ rate and extent of degradation of fibre fractions and protein in the rumen. Crossbred cows (12) were divided into 2 groups and digestion trials were carried out in a switch over design with 2 periods and 2 treatments. The diet comprised ragi (finger millet) straw and a concentrate mixture in the ratio of 35:65. The cow in the treatment group received 10 g/day of yeast as a top dress to concentrate mixture. The digestion trial was conducted using lignin as an internal marker in a 'grab collection' method. The Yea-sacc1026 supplementation had no influence on the whole tract digestibility of dry matter, organic matter, crude protein, neutral detergent fibre (NDF) and acid detergent fibre (ADF). It also had no effect on the degradability of fibre fractions NDF and ADF or protein in the rumen of lactating cow. The reasons for yeast not exerting any effect might be the less soluble carbohydrates and low energy density of the diet. Future investigation may be focussed to identify other dietary situations. which might benefit from yeast culture supplementation and on the use of mixed cultures.