Rates of rumen fermentation in relation to ammonia concentration

TLDR

Four sheep were fed whole barley fortified with graded urea levels via automatic feeders, and barley fermentation rates at different rumen NH3 concentrations were measured by tracking dry matter disappearance from polyester bags in the rumen. The approach largely maintained steady rumen ammonia levels, and the minimal NH3 concentration for maximal fermentation rate was estimated at 235 mg l⁻¹. The other section lists items 1, 2, and 3.

Abstract

1. Four sheep were fed from automatic continuous feeders on whole barley fortified with graded levels of a urea solution. This approach was to a large extent successful in maintaining relatively steady states of rumen ammonia concentration. 2. Rates of barley fermentation in the rumen at various rumen NH3 concentrations were assessed by measuring the disappearance of barley dry matter from polyester bags suspended in the rumen of these sheep. 3. The minimal NH3 concentration for maximal rate of fermentation was estimated as 235 mg/l rumen fluid.