Carcass yield and meat quality parameters of two Italian autochthonous chicken breeds reared outdoor: Modenese and Romagnolo

The safeguard of biodiversity is a primary interest in outdoor poultry production in Italy. In the Emilia-Romagna region, two autochthonous chicken breeds are still present: the Modenese (MOD) and the Romagnolo (ROM). They are white ear-lobed light breeds of Mediterranean class. Aim of this study is to improve the knowledge about carcass and meat characteristics in these two breeds. Twenty-five MOD and 26 ROM (from the nucleus flock raised at the Faculty of Veterinary Medicine of Parma, Italy) and 13 commercial Hy-Line W36 male chicks were reared outdoor in three contiguous paddocks (about 4 m 2/chicken) and fed with pasture and commercial pellets (19.3% crude protein) ad libitum until slaughter at the age of approximately 210 d. Chickens were individually weighted and slaughtered after a 18 hours fasting; carcasses and cuts were weighed and yields calculated. Determination of meat colour was made on breasts by Minolta Chromameter Reflectance II CR100/08 and expressed as L* a* b*. Hue and chrome were calculated as arctg(b*/a*) and �(a* 2 + b* 2), respectively. The chemical composition of breast meat was determined, according to AOAC, for 10 chickens per breed. The data were submitted to ANOVA (fixed factor: breed; age at slaughter as a covariate). Chickens were slaughtered at a mean weight between 2142 g (MOD) and 2212 g (Hy-Line W36) (P>0.05). Carcass yield (calculated as the weight of ready-to-cook carcass/live weight at slaughter) was higher in MOD than in Hy-Line W36 (P<0.10), as ROM were intermediate. Breast yield was not significantly different among breeds (P>0.05), as thigh + drumstick yield was higher in MOD than in ROM and Hy-Line W36 (P<0.05). Breast meat colour showed lower b* and hue values in ROM than in MOD and Hy-Line W36 (resp.: 6.53 vs 9.50 and 8.39; 0.87 vs 1.08 and 1.11; P<0.05), as chrome was lower in ROM than in MOD (8.43 vs 10.90; P<0.05) and Hy-Line W36 was intermediate, according to the previously reported strong reduction of yellow pigment in the skin and egg shell surface of ROM breed. The chemical composition of breast meat showed higher moisture and ash content in Hy-Line W36 than in MOD and ROM (resp.: 73.73% vs 72.66% and 72.70%; 1.17% vs 1.12% and 1.11%; P<0.05); fat content was higher in the two local breeds (0.90% and 0.89% in MOD and ROM, resp.) than in Hy-Line W36 (0.13%)