Investigating the Effects of Cadmium on Rumen Microbial Fermentation and Nutrient Digestibility Using Gas Production

Abstract

Effects of different levels of cadmium (0.1, 1, 2, 4, 8, 16, 32, 64, 128, 256 mg/l of culture medium) were evaluated using gas production technique. In the glass vials used to measure gas production 30 mg of buffered rumen fluid (2:1 ratio of rumen fluid: buffer) poured in glass and cultured at 38.6 temperature. Volume and pressure of produced gas were measured with syringes and digital pressure meter at different times and exponential model were used to determine the gas production parameters. The results of the experiment indicated that using different levels of cadmium sulfate caused a significant reduction in b parameter, partitioning factor, metabolizable energy and digestion of organic matter. Addition of 0.1, 1, 2, 4 and 16 mg cadmium/l did not affect c parameter in comparison with the control treatment. The results of this study suggest that cadmium in higher levels of 8 mg per liter had strong inhibitory effect on rumen anaerobic microorganisms' activity