Carob (Ceratonia siliqua) pulp as an energy source in diet for growing rabbits

Abstract

An important objective in livestock feeding is to promote the use of local feeds and by-products in order to reduce feeding costs. Carob pulp had been frequently used for feeding ruminants in the Mediterranean areas. This study aimed to evaluate carob pulp as an alternative dietary energy source to barley in a diet for growing rabbits. Three dietary treatments designated as D0 (commercial feed without carob pulp), D8 (commercial feed incorporating 8% carob pulp) and D15 (commercial feed incorporating 15% carob pulp) were fed to 60 rabbits (20 rabbits per group) weaned at 28 d of age to evaluate growth performance (from 29 to 70 days of age). At the end of the growth trial, 10 rabbits were slaughtered in each group, and used for the evaluation of carcass traits. Another 15 rabbits (5 rabbits per group; 2,100±200 g) were used in a digestibility trial to determine digestibility coefficient of diets. No significant effect was detected on the final weight and the daily gain. The feed intake was higher in rabbits fed the commercial diet (D0) than in other rabbits (123.3, 109.5 and 119.1 g/d in rabbits fed the D0, D8 and D15, respectively; P<0.05). Similarly, feed conversion tended to be higher (3.33, 3.05 and 3.03 kg/kg in rabbits fed D0, D8 and D15, respectively; P<0.05), while dressing out percentage was significantly lower (57.67, 59.08 and 59.89% in rabbits fed D0, D8 and D15, respectively; P<0.05) in rabbits fed the commercial diet. There were small significant differences in digestibility of energy and organic matter between the 3 experimental diets. It can be concluded from the finding that incorporation of carob pulp at 15% inclusion level can replace barley grain as an energy source for growing rabbits