Evaluation of Fermentability Process of a Ration Consist of Different Levels of Saponin and Tannic Acid According to in vitro Condition

Two experiments were conducted for evaluation the effect of different levels of saponin (0، 30 and 60 g per kg DM) and tannic acid (0، 25، 50، 100 and 150 g per kg DM) on rumen fermentability parameters. In the first stage، gas production at 2، 4، 6، 8، 16، 24، 48، 72 and 96 hours after incubation was measured. Constant rate of gas production decreased with increasing of saponin and tannic acid to the batch culture Compared the to control treatment، although this value increased in the saponin treatment alone. Cumulative gas production with tannic acid with or without saponin at 24، 48 and 96 hours after incubation increased in comparison with the to control treatment additon low levels of saponin (30 g per kg DM) with tannic acid had the most cumulative gas production at this times. In the second stage، according to batch culture pH، Nitrogen-ammonia and degradability potential of dry matter was determined. The pH was the less for all of the treatments than control treatment but there wasn’t a significant difference between treatments. Nitrogen-ammonia concentration with increasing of saponin and tannic acid levels was decreased compare to control group and saponin with tannic acid treatments had the most concentration. Degradability potential of DM in all of the treatments was higher than control group، but this higher value was specific for saponin with tannic acid treatments. Short chain fatty acids، metabolism energy and organic matter digestibility concentrations for all of the treatments was higher than control group، but this values at the different levels of saponin with tannic acid together was higher than tannic acid or saponin alone. The obtained results indicated that combination of saponin and tannic acid at low level could affect rumen fermentation pattern and nutrient digestibility positively.