ADDITION OF DIFFERENT SOURCES AND LEVELS OF AMINO-ACIDS AND SUGARS TOBROILER LITTER BEFORE DEEP-STACKING

Different sources and levels of amino acids (soybean meal at 0, 10, 20 or 40% of dry matter; similar quantities of lysine and methionine in synthetic forms) and sugars were mixed with broiler litter and placed in dacron bags embedded in a deep-stack for 3 or 9 weeks to determine changes in concentrations of nitrogen fractions and digestibility in r uminants. Pepsin-insoluble nitrogen concentration after 48 h of rumina l incubation was not changed by deep-stacking for 3 wk and only slight ly elevated at 9 wk; Deep-stacking did not markedly alter in situ rumi nal disappearance of broiler litter nitrogen. Conversely, in situ rumi nal nitrogen disappearance of soybean meal substrates was decreased by deep-stacking; the change was greater for 16 than for 48 h of ruminal incubation. Sugar addition to soybean meal substrates did not appear to enhance rumen undegradable protein concentration. In conclusion, th ese results suggest that potential exists to markedly increase rumen u ndegradable protein in soybean meal and possibly other feedstuffs high in rumen digestible protein by addition to broiler lifter before deep -stacking.