Physical quality characteristics of breast and leg meat of slow- and fast-growing broilers raised in different housing systems

Abstract

This study was made to determine the effects of genotype and housing system on physical quality characteristics of breast and leg meat of broilers under experimental conditions. The 150 slow-growing and 150 fast-growing 1 d old chicks were divided into three sub-groups with indoor raised slatted plastic floor, indoor concrete floor with rice hull litter, and free-range housing systems (2 genotype groups $\times$ 3 housing systems). All birds were offered the same diet and were housed in similar conditions until they were 56 d old. At slaughter, 10 birds from each main group were selected randomly to determine the quality characteristics of the meat. In total, 60 breast meat pieces (pectoralis major muscle) and 60 legs of the chickens were used for meat quality analysis including pH, shear force, and colour characteristics such as lightness ( $L^{\ast }$ ), redness ( $a^{\ast }$ ), yellowness ( $b^{\ast }$ ), saturation ( $C^{\ast }$ ), and hue angle ( $h^{\ast }$ ). The pH of breast meat was significantly affected by genotype and housing system ( $P<0.001$ and $P<0.001$ ). There were significant genotype $\times$ housing system interactions for pH ( $P<0.015$ and $P<0.001$ ) and shear force values ( $P<0.007$ and $P<0.012$ ) of leg and breast meat. There were no significant effects of genotype and housing system on leg and breast meat colour properties except for effects of genotype on redness ( $a^{\ast }$ ) of breast meat ( $p<0.005$ ) and effects of housing on redness of leg meat colour ( $p<0.031$ ). Slow-growing chickens and chickens housed in deep litter had a higher redness (darker) value of breast and leg meat colour compared to fast-growing birds and free range and slatted floor. In conclusion, it can be said that fast-growing broilers may be more appropriate for slatted plastic floor housing and slow-growing broilers may be more suitable for a free-range housing system, but further research on factors affecting meat quality would be very beneficial, especially in slow-growing broilers.