Abstract

Fibrolytic bacterial strains were isolated from the rumen liquor of permanently fistulated buffaloes kept on high fibre diet (roughage: concentrate: 60:40; w/w) on the basis of in vitro true dry matter digestibility study on pure neutral detergent fibre isolated from wheat straw and on high fibre based diet (wheat straw: concentrate: 80:20; w/w). Based on enzyme activity, the most potent fibre degrading bacterial isolate was selected which was further characterized on the basis of its morphology, biochemical properties and molecular properties and was found to be Ruminococcus flavefaciens strain FD-1 which was finally used as feed supplement for in vivo trial on lactating Murrah buffaloes. 12 lactating buffaloes divided into treatment and control groups of six animals each were fed with experimental diets and live and autoclaved culture of best selected fibrolytic bacterial isolate (NB-1) that is, R. flavefaciens strain FD-1; 300 ml orally alternate day continuously for one month period. No significant difference was observed in the mean body weight changes and daily milk yield between the treated and control groups although the live body weight and daily milk yield was increased in live culture supplemented treated group. There was no effect on milk composition of the animal. The difference in mean dry matter intake was significant (P <0.05) between control (11.11 kg/day) and treated groups (11.77 kg/day) during the experimental period. The digestibility of NDF and ADF was found to be higher in treated group by 9.66 and 19.20% over that of the control group although the effect was not significant. Thus, the bacterial culture of R. flavefaciens strain FD-1 showed the potential to be used as feed additive in the diet of ruminants for improving live body weight gain, daily milk yield as well as utilization of nutrients from lignocellulosic feeds.

Key words: Fibrolytic bacterial culture, lactating buffaloes, milk yield, nutrient utilization.

Abbreviation

ADF, Acid detergent fibre; AOAC, Association of Official Analytical Chemists; CIRB, Central Institute for Research on Buffaloes; CMC, carboxy methyl cellulose; CP, crude protein; CPI, crude protein intake; DCP, digestible crude protein;DFM, direct fed microbials; DM, dry matter; DMI, dry matter intake; DMI/day, dry matter intake per day; EE, ether extract; FCM, fat corrected milk; GF, green fodder;HC, hemicellulose; NDF, neutral detergent fibre; NB, NDRI buffaloes; NFE, nitrogen free extract;  OM,  organic matter; TA, total  ash; TDN, total digestible nutrient;TDNI/day, total digestible nutrient intake per day; TMR, total mixed ration; WS, wheat straw.