Written Paper

Evaluation of protein characteristics of underutilized by-products as feedstuff for ruminant  [2005]

Enishi, O.(National Inst. of Livestock and Grassland Science, Tsukuba, Ibaraki (Japan)) Kuroiwa, R. Saeki, M. Kawashima, T.

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This experiment was carried out to clarify the contents of protein fractions, disappearances of dry matter (DM) and crude protein (CP) in the rumen, and in vitro intestinal CP digestibility (IICPD) of 11 by-products and 4 heat- treated by-products. The temperatures of heat-treatment were 60, 80, 100 and 130 deg C for 6 h, respectively. Ruminal DM and CP disappearances were determined by the nylon bag technique. Percentage of IICPD was determined by amounts of residue after 16 h incubation in the rumen. The protein fractions, ruminal DM and CP disappearances and IICPD widely varied among the by-products. CP content ranged from 4.8 (sweet potato peel) to 32.0% DM (green tea ground). Soluble CP fraction (A+B1 fraction) ranged from 2.3 (oolong tea ground) to 56.1% CP (sweet potato peel). Acid detergent insoluble CP fraction (C fraction) ranged from 1.2 (bread crumbs and stale bread) to 37.0% CP (cacao husk). Effective CP degradability ranged from 44.4 (brewer's grain) to 73.3% (sweet potato peel). IICPD ranged from 53.4% (oolong tea ground) to 91.2% (brewer's grain). Total CP content was not affected by heat treatment, but the treatment decreased soluble CP fraction for brewer's grain and winary waste, and increased acid detergent insoluble CP fraction for brewer's grain, oolong tea ground and winary waste. IICPD was significantly reduced by heating at 130 deg C for brewer's grain, green tea ground, oolong tea ground and winary waste.

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Japanese Journal of Grassland Science (Japan)

ISSN : 0447-5933