Effect of heat treatment and subsequent urea supplementation of sunflower meal on the in vitro ruminal degradability of crude protein content and its postruminal digestibility
1989
Veresegyhazy, T. | Kutas, F. | Fekete, S. (University of Veterinary Science, Budapest (Hungary)) | Csapo, J. (Agricultural Univ., Kaposvar (Hungary). Faculty of Animal Science)
A three phase laboratory procedure was used for predicting the degradability of the protein of extracted sunflower meal before (SFM) and after treatment (HSFM). The rumen fluid degraded 69.1 per cent and 67.1 per cent of the SFM and HSFM protein, respectively. The digestibility values of rumen undegraded protein (UDP) were 57.3 per cent (SFM) and 57.0 per cent (HSFM) with pepsin and 17.6 per cent (SFM) and 15.9 per cent (HSFM) with pancreatin. Urea supplementation practically did not alter the rumen degradability of HSFM protein, while the pepsin digestibility of UDP decreased to 47.2 per cent. Four fractions (NH3, dissolved amino acids, oligopeptides and proteins) of rumen degradable crude protein (RDP) were also determined in vitro: 81 to 92 per cent of the degraded crude protein was found in the fractions tested. Heat treatment reduced free NH3 content but did not alter the other three fractions. Urea supplementation decreased the quantity of NH3, peptides and proteins as well.
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