Effect of breed and diet on carcass parameters and meat quality of spent hens

Two spent hen breeds (Mos and Isa Brown) fed with three different diets [commercial feeding (CF); corn, pea, and triticale (CPT); and corn and wheat (CW)] were studied to assess their laying performance, carcass characteristics, and meat quality parameters (breast and drumstick). A total of 48 hens reared in a traditional free-range system were used. Birds were slaughtered at 72 weeks of age after the moulting in an accredited abattoir, and measurements (for each bird) of carcass and meat started at 24h post-mortem. The results demonstrated a breed and diet effect (P < 0.05) on laying performance, carcass, and meat quality. The Mos breed showed lower laying performance, higher live weight (P < 0.001), carcass weight (P < 0.001), dressing percentage (P < 0.001), and carcass fat (P < 0.001) than Isa Brown. The breed also affected physicochemical parameters of drumstick and breast (P < 0.05). Concerning the diet effect, spent hens fed with commercial feeding shown heavier live weight (P <0.01) and carcass weight (P <0.01). Diet significantly affected most of meat quality parameters, being CPT the formulation that most affected (P < 0.05) drumstick composition, while in the breast was CF (P <0.001). Significant (P <= 0.005) effect in breast colour, cooking loss and hardness were observed in animals fed with alternative diets to CF. Regarding nutritional quality, no breed or diet effect (P < 0.05) was observed in MUFAs, PUFAs and n-6 contents of meat. Overall, both breeds showed a high protein and low-fat content in the breast, showing these hens as an opportunity for the development of meat products as well as an economic purpose for spent hens that reach the end of their productive lives.