Effect of slaughter age on performance and meat quality of slow-growing broiler chickens

The aim of the study was to determine the effect of age of slow-growing broiler chickens on growth performance and meat quality. Subjects were hybrids between Hubbard meat-type cockerels and Yellowleg Partridge Polish native hens. Chickens were raised indoors to 56, 70 or 84 days of age on deep litter under the same environmental conditions and fed ad litibum complete starter, grower and finisher diets containing 20, 18, 15 CP and 2825, 2825 and 2740 ME/kg feed, respectively. At the end of the experiment, 5 cockerels and 5 pullets were selected for slaughter from each age group and subjected to a simplified carcass analysis. Breast muscles and leg muscles were evaluated for technological properties such as pH, colour, water holding capacity, drip loss, cooking loss and shear force. The results were analysed statistically using analysis of variance and Duncan’s multiple range test. The duration of rearing had an effect on carcass and meat quality. The highest, statistically significant differences in the analysed traits were found between chickens slaughtered at 56 and 84 days of age. The highest dressing percentage was obtained in birds raised until 84 days of age. Youngest birds were characterized by the poorest muscle content of the carcass and the least favourable technological properties of meat. The highest growth efficiency was obtained when the hybrids were raised to 70 days of age.