Cocoa husks in diets of Italian heavy pigs

According to their nutritional composition, some wastes from the agroindustry may have a potential for use in livestock production. In particular, by-products derived from chocolate production can be considered worth of interest for animal nutrition. Cocoa husks have a high concentration of lignin, but also a high content of proteins, lipids NDF and it is also rich in antioxidants. To verify the possibility of using cocoa by-products in pig nutrition, the effect of cocoa husks feeding on liver composition of Italian heavy pigs was studied. For this purpose, 8 finishing pigs were divided into 2 homogeneous groups: a control group fed a traditional diet, based on cereals, and a treatment group fed a diet obtained by substitution of 10% of the control diet with coarsely-ground cocoa husks. The trial was conducted during the hot season and lasted 6 weeks, at the end of which, all the pigs were slaughtered. Cocoa husks diet reduced individual dry matter intake (P < 0.01) and energy intake (P < 0.01). Despite this, neither body weight (P = 0.90) nor backfat thickness (P = 0.63) was affected by cocoa husks diet. Treatment did not influence carcass weight (P = 0.83) and hot dressing percentage (P = 0.72), but reduced liver weight (P = 0.03), liver dry matter percentage (P < 0.01), DNA (P = 0.01) and glycogen content (P = 0.01). By contrast, cocoa husks increased liver ether extract (P = 0.05), without affecting cholesterol content (P = 0.73). Liver weight loss, reduction of protein synthesis and a shift toward glycogen utilization, instead of fat oxidation, are considered metabolic strategies to reduce heat production under hot conditions. It is possible, therefore, that cocoa husks feeding promoted the process of acclimation, as suggested by the fact that treated pigs needed less feeding to reach similar body and carcass weight of the control ones.