Effects of feed withdrawal periods on carcass yield and breast meat quality of chickens reared using an alternative system

The purpose of this work was to evaluate the effects of different feed withdrawal (FW) periods ( 3, 6, 9, 12, 15, and 18 h) on live broiler weight loss, dressed and chilled carcass yields, and chilled breast meat quality attributes of chickens reared in an alternative system, without the use of any antibiotics, growth promoters, coccidiostats, or ingredients from animal sources. Live weight loss and dressed and chilled carcass yields after FW were determined, and also fillet color, water-holding capacity (WHC), pH, shear value, cooking loss, and proximate composition, and a sensory analysis was conducted. Longer FW periods resulted in significant ( P = 0.05) increases in live broiler weight losses, from 1.3 to 5.3% in the 18-h period. The drops in dressed and chilled carcass yields became statistically significant at 12 h of FW, with dressed carcass yields of 65.2% after 3 h of FW and 63.8% after 12 h. Chilled carcass yields dropped from 68.8% after 3 h of FW to 67.0% after 12 h. Fillet color, as indicated by the L* values, became darker with longer FW periods, as shown by regression analysis. No statistical differences were observed for the a* values, b* values, WHC, cooking losses, and proximate composition of the fillets for the different FW periods. The Pearson correlation values showed a significant but low negative correlation between fillet pH and shear force, which varied with FW period. The highest carcass yields were obtained for broilers submitted to FW periods of between 3 and 9 h.