Rumen degradable and undergradable protein fractions of some local feed ingredients in dairy cattle
2024
Bacorro, T.J.
Protein stands as an important yet expensive nutrient in animal nutrition. Precision feeding to mitigate N loss considers balanced rumen degradable protein (RDP) and rumen undegradable protein (RUP) in ruminant rations. To determine the RDP and RUP of 12 cattle feed ingredients, two sets of in sacco protein degradability were conducted using rumen-cannulated Holstein-Friesian x Sahiwal cows. The additivity of RDP and RUP values derived from protein degradability were also investigated. Results indicated variations in nutrient degradation over a 72-h incubation period. Porcine meal and yeast protein exhibited rapid degradation, while yellow corn extended beyond 72 h. Wheat showed the highest effective degradability for dry matter (DM) and organic matter (OM), while yellow corn and spent grain displayed the lowest. Crude protein (CP) degradation varied. Considering medium feed intake (0.05/h), RDP (100% of CP) ranged from 57.01+-1.69 to 99.20+-0.78%, while RUP ranged from 0.80+-0.78 to 42.99+-1.69%. The additivity models derived from this study suggest that RDP and RUP in common cattle feed ingredients in the Philippines were a good fit (R sq=0.5997) at predicting actual values in mixed feeds, albeit being underestimated in RDP and overestimated in RUP.
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