EVALUATION OF DIRECT-FED MICROBIAL SUPPLEMENTATION TO IMPROVE UTILIZATION OF THE LOW QUALITY ROUGHAGES IN RUMINANTS

Direct-fed microbials (DFM) feed additives have been shown to improve average daily gain (ADG) and feed efficiency in ruminant animals in many studies. So, this study aimed to evaluate effect of using fungal and bacterial DFM and their mixture on productive performance of growing lambs. Thirty-two Barkey lambs (3 months old, 22.31± 1.57 kg) were randomly assigned into four groups, 8 lambs of each according to live body weight. The first group (control) was fed control rations without DFM supplementation, while treated groups (Fungal DFM, Bacterial DFM and Mixed DFM) were fed the control ration plus 2.5 g fungal, bacterial or mixed (1:1) DFM; respectively. Results showed that groups fed ration supplemented with DFM (fungal, bacterial and mixed) recorded higher DM, TDN and digestible CP intake. Supplementation of lambs ration with DFM (fungal, bacterial and mixed) showed not significant (P>0.05) effects on rumen liquor TVFA's and ammonia concentration at 0, 3 and 6 hrs post feeding. While DFM supplemented rations showed significant higher rumen liquor pH at 0, 3 and 6 hrs after feeding compared to the control group. Numerically increase was recorded in cellulose activity as unit per ml rumen liquor for groups fed ration supplemented with bacterial and mixed DFM. Direct fed microbial supplementation significantly (P<0.05) improved nutrients digestibility as dry matter, organic matter, crude protein, crude fiber, nitrogen free extract, neutral  detergent fiber (NDF) and acid detergent fiber (ADF) as well as feeding values as TDN and digestible crude protein. Bacterial or mixed DFM supplementation showed numerically increased (P>0.05) in plasma total protein concentration compared to lambs fed ration not supplemented. While albumin, globulin, urea, triglycerides, creatinine ALT and AST, alkaline phosphates activity were not significantly (P>0.05) affected by DFM supplementation. Total gain and ADG were significantly increased (P≤0.05) for groups received rations supplemented with DFM compared to control group. Also DFM supplementation significantly (P≤0.05) improved feed conversion as DM, TDN, CP and DCP compared to the control group. It could be concluded that supplementing lambs ration with fungal, bacterial or mixed DFM improved feed intake, digestibility, average daily gain and feed conversion without any adverse effects on animal health and performance.