Effects of Dietary Incorporation of Grape Stalks Untreated and Fungi-Treated in Growing Rabbits: A Preliminary Study.

This study aimed to evaluate the effect of the incorporation of untreated grape stalks (U GS ) and fungi-treated grape stalks ( Lentinula edodes , T GS ) in rabbits' diets. The control group was fed with a control diet without grape stalks (C), two experimental groups were fed on diets with 5% and 10% incorporation of U GS (5U GS and 10U GS ), and two with 5% and 10% incorporation of T GS (5T GS and 10T GS ). Rabbits fed with T GS diets showed higher daily weight gain ( p = 0.034), feed conversion rate ( p = 0.002), carcass weight ( p = 0.038), and reference carcass weight ( p = 0.03) when compared to the control diet. Moreover, animals fed with T GS diets showed an increase in the caecum ( p = 0.015) and small intestine ( p = 0.021) lengths and in the total volatile fatty acid content ( p = 0.005) compared to animals fed U GS diets. Blood triglyceride levels were lower in animals fed with T GS diets compared to U GS ( p = 0.005) and C ( p ≤ 0.001) diets (12% and 19% lower, respectively), and a trend to lower cholesterol levels was observed ( p = 0.071). Meat from rabbits fed with T GS diets had higher levels of linoleic acid, γ-linolenic, ∑ω-6, ∑PUFA, and ∑PUFA/∑SFA ratio compared to rabbits fed with the C diet. Results indicated that grape stalks (U GS and T GS ) could be effectively used as an alternative raw material in rabbits' diets without compromising animal performance.