Prediction of degradability and digestibility parameters of protein supplements used in sheep nutrition from nutrient composition

The objective of this study was the formation of prediction equations of the degradability and digestibility parameters of protein supplements used in sheep nutrition by the use of their chemical composition. Four trials were conducted (one in situ degradability trial, using 3 × 9 incomplete Latin square experimental design and three in vivo digestibility trials using 3 × 3, 4 × 4, 4 × 4 Latin square experimental design, respectively). The nine tested feeds were soybean meal (SBM), rapeseed meal (RSM), sunflower meal (SFM), lupin seeds (LS), faba bean seeds (FBS), Vetch seeds (VS), pea seeds (PS), chickpea seeds (CS) and flax seeds (FS). Incubation in the rumen of the three ruminally cannulated indigenous Chios breed rams lasted 0, 3, 6, 12, 24 and 48 h in order to measure dry matter and crude protein degradability parameters (“a”, “b”, “degradability-D”, “effective degradability-ED” and “c” for 0–48 h). Additionally, three in vivo digestibility trials were conducted in order to measure digestibility coefficients of nutrients of these nine protein supplements. The best fit equation for CP effective degradability was ED (g/100 gDM) = 100.757 + 0.182 × ADF + 0.042 × ADF2 − 4.351 × ADL + 0.036 × ADL2 (adjusted R2 = 0.90). In conclusion, it can be said that prediction equations can be constructed to estimate nutritional parameters for different feeds.