The effects of a non-ionic surfactant on the fermentation characteristics, microbial growth, enzyme activity and digestibility in the rumen of cows

Abstract

The non-ionic surfactant (NIS) was evaluated for its ability to influence rumen fermentation characteristics, microbial growth, enzyme activity and digestibility in the rumen of Korean native cows. The administration of NIS solution to the rumen significantly ( P<0.01) increased the enzyme activities of protease, amylase, carbxymethylcellulase (CMCase) and xylanase in the rumen contents, the digestion rates of rice straw in in situ, the concentrations of volatile fatty acid (VFA) and NH 3-N in rumen fluids, and the growth rate of rumen anaerobic microorganisms. In situ dry matter degradation rate of rice straw was significantly ( P<0.01) improved by 31.4, 30.0 and 14.8% compared with control, when nylon bags were incubated for 36, 48 and 72 h, respectively to the rumen of the cows receiving daily intraruminal doses of 200 ml of NIS solution. Total viable bacterial counts increased more than four-fold (from 7.50±1.3 to 31.0±4.6×10 9 cfu per ml of rumen fluids) by NIS administration, compared to control ( P<0.01). These results indicated that the addition of NIS could greatly stimulate the release of certain enzymes without decreasing cell growth rate in contrast to trends reported with aerobic microorganism. Our results showed that NIS might be of use as an alternative feed additive to stimulate multiple enzyme activity and microbial growth in the rumen.