CARCASS AND PARTS YIELD OF MEXICAN CRIOLLO AND SASSO CHICKENS RAISED IN CONFINEMENT OR GRAZING

Abstract

The consumption of chicken meat (Gallus gallus domesticus L.) has gradually increased. Changes in economic and social development have changed consumer perceptions of the quality and safety of food in terms of animal welfare, resulting in the implementation of new alternative farming systems. This research was conducted at the poultry farm “El Horno” within the Valley of Mexico Experimental Field of the National Institute of Forestry, Agriculture, and Livestock Research (CEVAMEX-INIFAP) in 2022. The objective was to determine the carcass and parts yield of Mexican Criollo (CM) and Sasso (S) chickens raised in confinement or grazing conditions. Ninety-two birds (44 CM and 48 S), randomly distributed in both production systems, were used to obtain four replicates of the following combinations of bird genotype and production system: CM grazing, CM confinement, S grazing, and S confinement, with feed and water ad libitum. At 84 days of age, the birds were weighed individually per treatment and sacrificed by desensitizing them by cervical dislocation. The weight of the legs, thigh, breast, skin, muscle, and bone was evaluated separately for each piece. A completely randomized experimental design with a 2 × 2 factorial arrangement was used, with genotype and production system as main factors. Data were analyzed using PROC MIXED of SAS. Cold and hot carcass yield was higher in S birds compared to CM birds. The live weight recorded in S birds was 946 g higher compared to CM birds. It is concluded that S birds perform better in the main pieces (breast, leg, and thigh), as well as in their variables (skin, muscle, and bone), regardless of the production system to which they are subjected (grazing or confinement).