Effects Of Active Yeast And Its Fermented Feeds On The Rumen Fermentation And Nutrient Digestibility

Yeast,its fermentation product,has been widely applied to ruminant production,there was controversy over the active yeast or metabolic product which is more important in this process,similarly,there were few reported studies on the comparison research of active yeast and metabolic producs.Given this,the comparison and analysis of the effects of 13 strains of active yeast and its fermentation feeds on rumen fermentation parameters and digestibility of nutrient substances were used in vitro.The 3 strains of screened highly active yeast and 3 types of yeast fermented feeds were respectively put into fermental cultivation in vitro,then the optimum additions were defined.Results of the test indicate that:1.Active yeast Strain BY?XR4?BC can remarkably increase the fermentation broth and volatile fatty acids content as well as the nutrient digestion rate(P<0.05).2.Fermented feed Strain SC18?BY?BC can significantly improve the gas production of fermentation broth,protein and volatile fatty acids meanwhile the nutrient digestion rate is on the rise(P<0.05).Yeast fermentation feed is superior to its active yeast(P<0.05)in terms of scaling up gas output and total volatile fatty acids content.3.It is optimum for fermentation in vitro that active yeast is added as 6x107 cfu/g the number of live bacteria.4.The yeast fermentation feed Strain BC and BY added in a ratio of 5.47%present best.Yeast feed of Strain SC 18 enjoys optimal effect when added in a ratio of 4.42%.