In Situ Ruminal Disappearance of Crude Protein and Phytate from Differently Processed Rapeseed Meals in Dairy Cows.

BACKGROUND The influence of different processing conditions of rapeseed meal on ruminal degradation of crude protein and phytate in dairy cows was investigated. Following oil extraction, five residence times in the desolventiser/toaster were chosen to remove the solvent from the mark. The rapeseed cake and the respective rapeseed meals were incubated in situ in the rumen of three fistulated dairy cows to determine ruminal degradation parameters. RESULTS With increasing residence time in the desolventiser/toaster the ruminal degradation of crude protein decreased significantly for every treatment step. Ruminal phytate degradation was affected almost identically to crude protein degradation. CONCLUSION The processing conditions of rapeseed meal have a major impact on the ruminal degradation of crude protein and phytate indicating a potential conflict of interest regarding the production process. High amounts of rumen undegradable protein are often intended for high yielding dairy cows while for phytate a high ruminal degradation is preferred to increase absorption of phosphorus in the small intestine. This article is protected by copyright. All rights reserved.