Replacement of cereal grains by orange pulp and carob pulp in faba bean-based diets fed to lambs: effects on growth performance and meat quality

Fourteen weaned lambs (43 days of age) were divided into two equal groups of seven animals and received two different diets. The experimental diet contained 10% of carob pulp and 10% of orange pulp associated to 54% of faba bean. The control diet contained 12% of maize meal and 12% of barley meal associated to 49.2% of faba bean. Both diets were pelletted and given ad libitum. The two diets had comparable contents of dry matter, ash, crude fat, fibre and crude protein. Control diet was relatively higher in soluble nitrogen than the experimental one. However, experimental diet was higher in fibre-bound nitrogen and in total and condensed tannins than control one. At the end of the feeding trial (120 d of age) growth and slaughter performance were comparable between treatments. Chemical analysis of meat samples did not show any significant difference between groups. Physical analysis of meat showed a higher (P < 0.05) lightness (L*) value in experimental group than in the control one. Sensory analysis allowed the panellists to discriminate lamb meat from the two groups. Flavour, tenderness and juiciness were judged to be more intense (P < 0.01) in the meat of control group; also overall acceptability was higher (P < 0.05) in this group. It was concluded that the replacement of cereal grains with carob and orange pulp in lamb fattening diet is useful to reduce feeding costs. Nevertheless, we need further investigations on the level of inclusion in the diet, in order to avoid the negative effects on sensory attributes without detrimental effect on growth performance.