Effects of Calcium Propionate on in Vitro Ruminal Gas Production, Fermentation Parameters and Dry Matter Degradation Rate of Substrate with High Concentrate

This experiment aimed to study the effects of calcium propionate on in vitro ruminal gas production, fermentation parameters and dry matter degradation rate of substrate with high concentrate. Donor animals of rumen fluid were three 350 kg Simmental steers with permanent rumen fistulas. The basal fermentation substrate was supplemented with 0( control group),2. 5%,5. 0%,7. 5% and 10. 0% calcium propionate( dry matter basis),respectively. Gas production,fermentation parameters and dry matter degradation rate were determined after in vitro rumen fermentation by the method of in vitro gas production. The results showed as follows: calcium propionate had no significant influences on theoretical maximum gas production and gas production rate( P 0. 05). With the increase of calcium propionate supplemental level,ammonia nitrogen and isobutyric acid concentrations were not significantly changed( P 0. 05); the concentrations of acetic acid, propionic acid,butyric acid,valeric acid,isovaleric acid and total volatile fatty acid,as well as dry matter degradation rate showed the same quadric curve response,which were decreased at first and then increased( P Q 0. 05); fermentation fluid pH showed an opposite quadric curve response,which was increased at first and then increased( P Q 0. 05),and the values in 10. 0% group and control group were close. Under conditions in the experiment,the supplementation of calcium propionate in substrate with high concentrate can't improve rumen fermentation,increase dry matter degradation rate and increase nutrients utilization,but can increase fermentation fluid pH and be used as feed additive to prevent rumen acidosis.