Improvement of Rumen Fermentation and Performance of Growing Lambs by Adding Natural Microbial Resources

Abstract

The objective was to study effect of three natural microbial sources as additives on lamb performance, digestibility, feeding value some rumen and blood parameters, rumen cellulolytic bacteria counts as well as economical return. Methodology: Twenty four weaning Rahmany lambs averaged live 20.0±0.30 kg b.wt. were assigned to 4 similar groups (6 animals each), fed concentrate feed mixture and berseem (60:40%), (as a basal ration); (G1) Fed a basal ration without feed additives as control group, (G2) Fed the basal ration supplemented with 10 g per lamb per day of isolated bacteria (cellulolytic bacteria), (G3) Fed a basal ration plus 10 g per lamb per day of fibrozyme, (G4) Fed a basal ration with 10 g per lamb per day of yeast culture (Saccharomyces cerevisiae) during 24 weeks of growing period. Results: Indicated that there were significant differences in all nutrient digestibility, showing the lowest values with G1, while the highest values were obtained with G4. Furthermore, the rations with biological additives were (p<0.05) higher crude fiber digestibility. Animals fed isolated bacteria recorded the highest significantly values of cellulose, hemicelluloses and all cell wall constituents digestibility (%). Supplementing rations G2, G3 and G4 showed significantly high values of TDN and DCP% as well as digestible energy (Mcal kgG1 DMI) but no significant. Feed intake (kg per lamb per day) as DM was no significant difference while feed intake as TDN and DCP appeared to increase with supplemented rations compared with control ration. Data observed that body weight gain, average daily gain, feed efficiency were higher with biological additives rations. Total counts of cellulolytic bacteria in rumen were the highest (p<0.05) values in G2. Blood total protein and globulin for animals fed biological additives had higher values than those fed control ration (G1). The net revenue were 320, 228 and 226% (G4, G2 and G3, respectively). Conclusion: The biological additives can enhance lamb performance, digestibility and economic income with the superiority effect for adding yeast culture. Moreover, it can be enhance ruminal culture and fiber fraction digestibility with adding isolated bacteria with no side effects on physiological status.