The investigation of rumen defaunation in growing lambs and its effects on utilization of different rations

This study was conducted to investigate the effect of rumen defaunation on performance, blood parameters, and nutrient digestability in growing lambs using different rations. Twenty-four native lambs were randomly divided into two groups with equal number of lambs. One group was defaunated usine Dioctyl Sodium Sulphosuccinate (DSS) and another group were left intact (control). After 14 days adadptation, each group was divided into three subgroups; first subgroup was fed with a high protein, second subgroup was fed with a fibrouse ration, and third subgroup was fed with a fat supplemented ration. All lambs were kept in individual metabolic cages and were fed in 2×3 factorial for 56 days. The weights of lambs were recorded at the beginning and repetead by two weeks till end of the fattening period. In the last four days of the fattening period, total collection of urine and feces was conducted to determine nutrient digestibility and urine parameters. Blood samples were taken 3-4 h after feeding at the end of fattening period. Results showed that daily weight gain, feed intake and feed conversion rate in all treatments were not significantly different (P>0.05). However, the interaction of defaunation procedure and rations for daily gain was significant (P<0.05). Lambs with defauneted rumen showed significant lower cholestrole and blood urea nitrogen concentration compared to the intact group (P<0.05). Ether extract and crude protein digestibility showed significant difference between two groups (P<0.05). High protein ration also showed superiority among all rations for nutrient digestibility (P<0.05). Based on the present data it can be concluded that the effectivness of rumen defaunation is related to ration composition, because fermentation pattern in defauneted lambs will be varied in relation to nutrient availibilty within the rumen.