EUROPEAN GROUP ON RABBIT NUTRITION

ABSTRACT: In order to validate in two laboratories an enzymatic method of in vitro digestibility of rabbit diets and evaluate the efficacy of different enzymes, 19 rabbit diets were analysed to determine the in vitro digestibility of organic matter (vMO). The analyses were performed by using Viscozyme enzyme on the same set of diets, both in Padua (V.PAD) and in Madrid (V.MAD). In addition, in Padua the efficacy of Viscozyme was compared to that of other enzymatic treatments performed during the 3rd phase of the reference method: Bio-Feed Plus, Energex or No-Enyme (absence of enzyme). Multiple regression equations based on vMO and/or chemical composition of the diets were calculated by step-wise analysis, to estimate the in vivo nutritive value (digestibility of organic matter, dMO, and digestible energy content, ED). The reference method resulted to be suitable in th estimation both of dMO and DE (R²=0.71-0.80; coefficient of residual variability -CVR= 2.6-3.2%), enabling to improve significantly the nutritive value estimation based on chemical composition of diets (R²=0.54-0.58; CVR= 3.8-4.2%, using crude fibre or NDF as predictors). The two laboratories, although utilising the same method and enzyme (Viscozyme), obtained significantly different results, especially with the diets rich in fibre and poor in DE, and gave different regression equations (P<0.05). Comparing the different enzymes, Viscozyme (both in Padua and Madrid) and Energex resulted to be the best predictors of nutritive value; on the contrary, Bio-Feed Plus and Non-Enzyme were comparable in efficacy to the chemical data. The multiple regression equations based on in vitro and chemical analysis further increased (p<0.05) the precision of the estimate of the nutritive value (R²=0.77-0.85; CVR= 2.4-3.0%)

More information about this work: Journees de la Recherche Cunicole