Evaluation of exogenous laccase enzyme treated finger millet straw on body weight gain, DM Intake and nutrient digestibility in heifers

Abstract

Background: Fungal laccases have widespread application in a number of biotechnological processes including the biodegradation of lignin. Their low yield in the native state limits their practical use in the deconstruction of lignocellulosic biomass for feeding ruminants. Enzymes in bulk quantities are required to treat biomass which has got greater product consistency and less lot to lot variations. The present study was an attempt to evaluate the effect of feeding finger millet straw treated with exogenous laccases in heifers. Methods: The effect of feeding exogenous laccases obtained from immobilized Schizophyllum commune (MTCC 11893) on body weight gain, dry matter intake and nutrient digestibility in heifers was evaluated in three groups of heifers (4-each) with body weights ranging between 275 ± 47.12 to 276.75 ± 64.48kg. The control group received ad lib. finger millet straw treated with only production media (GI). Test group 1 (GII) received ad lib. straw treated with laccase rich media in a 3:5 (w/v) ratio, while test group 2 (GIII) received ad lib. straw treated in a 4:5 (w/v) ratio. Result: After 14- days of feeding, gain in body weights for GI, GII and GIII were 277.9 ± 68.47; 277.50 ± 46.43 and 278.85 ± 37.22 respectively with an overall increase of 1.15, 4.25 and 3.60 kgs. No significant variation (P>0.05) was observed with regard to DMD (%) between the groups which was 46 ± 5.8 for the control animals and 41±13.0 and 41± 3.4 in G2 and G3 groups. Though significant variations were observed digestibility studies proved inconclusive. Though preliminary results indicate that applying lignin degrading enzymes as feed supplements could enhance digestibility of crop residues in ruminants.