Effects Of Different Release Rate Of Rumen Modulators On In Vitro Fermentation Characteristics Of Subacute Rumen Acidosis

The aim of this study was to evaluate the effects of different releasing rates of rumen modulators on in vitro fermentation characteristics and S. bovis number by the means of induced SARA model. The paper had three parts:Part1. The development of SARA modelWe used three Xuanhan steers fitted with permanent ruminal cannulas and SARA was induced by adding corn and fresh distilled grain(1:1). And this experiment was divided into 2 groups:group A (Corn/Fresh distilled grain=80:20) and group B(Corn/Fresh distilled grain=50:50). It was found that rumen pH decreased significantly with the proportion of corn/fresh distilled grain increased as well as the time below 5.5. The results also showed that rumen pH needed much longer time to reach 5.5 in group A, while rumen pH of group B reached 5.5 in 7h and duration below 5.5 was more than 8h. Therefore, when added corn and fresh distilled grain(1:1), SARA was induced successfully.Part2 Preparation of different release rate of rumen modulators and the evaluation of accumulative releasing rates.Sodium bicarbonate, magnesium oxide, nicotinic acid(NA), cobalt sulphate, zinc sulfate and starch, hydroxypropyl methyl cellulose(HPMC) and absolute ethyl alcohol were mixed to prepared for the modulators and evaluated their accumulative releasing rates. Finally,6h release group,8h release group and 10h release group were successfully prepared. The results showed that HPMC could regulate the releasing rates of kalinous materials and the accumulative releasing rates met the requirements of this design.Part3 The effects of different releasing rates of rumen modulators on in vitro fermentation characteristics and S. bovis number...