Abstract
The influence of Avotan (Firm Cyanamid) was studied on VFA concentration, pH, dynamics of NH3 and on numbers of chosen species of rumen microorganisms in physiological experiments with four young bulls and two wethers with rumen cannulas.
It was found no marked physiological change in pH of rumen fluid under the influence of Avotan. Difference between groups were statistical significant. Avotan caused significant (P s 0.01) decrease of molar % of acetic acid (from 67.0 to 62.1) and an increase of propionic acid (from 16.41 to 28.21 mol %) in wethers. These changes were nonsignificant with bulls. The acetate : propionate ratio decreased significantly from 4.1 to 2.2 in wethers. Avotan decreased highly significantly (P ≤ 0.01) the level of NH3 in the rumen fluid during the observed period (0, 1.5, 3, 4.5 and 6 hours after feeding) in bulls. It was observed the similar effect in wethers 3 hours after feeding (from 170 mmol to 81 mmol/1). Decrease of the total number of microorganisms in the rumen fluid was observed in animals which received Avotan (on the average 3.5 times in young bulls, and 4.5 times in wethers). The number of enterococci decreased singificantly (2.8–4.5 times), number of amylolytic bacteria decreased less significantly.
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