Comparison of growth and meat yield of naked-neck, full-feathered F1 chickens reared under backyard conditions in a dry tropical environment

Meat yield and growth was evaluated in crossbred F1 chickens (Gallus gallus domesticus) (Full Plumage and Naked Neck x Rhode Island Red) in backyard production systems under dry tropic conditions. Seventeen naked neck (MCD) and seventeen full plumage males (MPN) were used at the locality of San Nicolas Arroyo Hondo, Municipality of Huetamo, Michoacan, Mexico, fed with a traditional scheme (commercial concentrate plus corn). The variables analyzed were body weight (PC); food consumption (CA); feed conversion (CaI); weight gain (GP) phenotype-1; as well as: total feed intake (CAt); slaughter and carcass weight and weight of higher commercial value pieces (PPMVC). The experimental design used for PC using a split plot over time with repeated measurements and the data was analyzed with a mixed model. The other variables were analyzed using a one-way ANOVA with phenotypes as the source of variation. In both cases, the differences between phenotypes were obtained by "t" tests between the least square means. The results showed that a significant genetic interaction group*time interaction (P<0.001); The Gompertz equation was used for modelling PC, the estimated parameters of the model were: at start (88.2 and 78.5 g); increase growth rate (0.061 and 0.068 g) and decrease growth rate (0.0193 and 0.0235 g), for the MCD and MPN groups, respectively. Likewise, a phenotypic effect (P<0.01) was found on: CA, CAt, GP, and Cal, in favor of MCD (P<0.05). The most relevant results were slaughter weight (1806.1 +/- 28.3 vs. 1306.1 +/- 28.3 g) and carcass weight (1040.0 +/- 35.5 vs. 804.1 +/- 35.5 g) for MCD and MPN, respectively. PPMVC were legs 174.2 +/- 5.4 g vs. 130.8 +/- 5.4 g, thigh 151.8 +/- 4.7 g vs. 114.2 +/- 4.7 g and breast 228.2 +/- 11.2 g vs. 176.6 +/- 11.2 g for MCD and MPN, respectively. These results suggest that bare neck F1 birds are a suitable alternative for backyard poultry farms in the dry tropics.