The effect of bulk fodder ensiling on nutrient digestibility and nitrogen utilization
1991
Vencl, B. (Vyzkumny Ustav Zivocisne Vyroby, Prague-Uhrineves (CSFR))
The coefficients of digestibility, dry matter, organic matter, crude protein, fat, fibre, nitrogen free extract (BNLV) and urinary output of nitrogen when feeding a set of ensiled forage crops with an increased dry matter content due to wilting, were determined in metabolism experiments with wethers. The contents of soluble fractions of crude protein and N-ADF (N in acid-detergent fibre) were determined in silages. To evaluate this set of silages, it was divided into a group with the lower (26 to 34.9 per cent) and a group with the higher (more than 35 per cent) content of dry matter. In the set of silages with the lower content of dry matter, the percentage of the soluble fraction of crude protein and the urinary output of nitrogen, expressed as the percentage of ingested nitrogen, were found to be higher in comparison with the set of silages with the higher content of dry matter. The organic matter digestibility coefficients depended on the digestibility of crude protein, fibre and nitrogen-free extract in both sets. In silages with the higher content of dry matter, the organic matter digestibility was related to the N-ADF content (r=-0.696). The amount of the soluble fraction of crude protein was found to be related to the coefficient of crude protein digestibility or to the content of digestible crude protein. The urinary output of nitrogen, expressed as the percentage of ingested nitrogen, was decreasing with the higher contents of silage dry matter (r=-0.755). Proteolysis in silages with the lower content of dry matter and a decrease in the organic matter and nitrogen digestibility in silages with the higher content of dry matter are the main factors influencing the nutritive value of ensiled forage crops.
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