Effect of Ration Fermentability on Ruminal Protozoa Population of Finishing Lambs

This study was conducted to evaluate the effect of ration fermentability on ruminal protozoa population during different hours after feeding. Fifteen hybrid Ghezel*Arkhar-merino male lambs were fed experimental rations. Experimental rations were contain different levels of barley grain and restaurant waste. Restaurant waste was substituted barley grain at the levels of 50 and 100 percent. Ruminal fluid was gotten from the lambs before and 2 and 4 hours after feeding. Rations fermentability was determined using gas production technique. The results showed that barley grain had higher fermentability (about 16%) than restaurant waste during 48 hours of incubation (341 vs 294 ml/g DM for barley grain and restaurant waste respectively). It also had higher constant of degradability (0.107 vs 0.099 for barley grain and restaurant waste, respectively). The rations containing restaurant waste resulted to higher pH and molar proportions of total VFA (P<0.05). Total protozoa counts were highest and lowest for restaurant waste and barley grain before feeding (79.5 vs 69.4 ×104 for restaurant waste and barley grain, respectively). No differences in the protozoa count was found among the treatments during two hours after feeding, but restaurant waste containing ration resulted to the lowest and conversely barley ration resulted to the highest protozoa count four hours after feeding (56 vs 78.5 × 104 for restaurant waste and barley grain rations, respectively). It seems that higher fat content and lower pH of ration containing restaurant waste are the main causes of lower protozoa count, so more attention should be take place when high levels of restaurant waste is used in the ruminants ration.