Effect of different pasture species on growth performance, carcass traits, internal organ weights, and meat quality of slower growing broilers in free-range production system

Abstract

This study examined the effect of Medicago sativa (A), Trifolium repens (WC), Lolium perenne (PR), and their mixture (Mix) on growth performance, carcass characteristics, internal organ weights, and meat quality of slower-growing broiler chickens in a free-range production system. The animal materials comprised of mixed-sex Hubbard ISA Red JA, which were reared in the deep litter system for the first 3 weeks, and thereafter, the pop hole in each of the indoor pens was opened to allow birds access to the range containing one of the above pasture treatments. The range availability was ensured from 08:30 a.m. to 4:30 p.m. The results indicated no significant difference in broiler live body weight, feed conversion ratio, and livability between 28 and 77 days among the pasture treatments (P > 0.05). No significant variations were observed in the carcass and internal organ weights among pasture types (P > 0.05). Additionally, while the dry matter content (P < 0.01), TBA value (P < 0.05), and fatty acid profiles differed (P < 0.01), the protein, ash, water holding capacity, and oxidation stability of broiler breast meat did not differ among pasture groups (P > 0.05). Moreover, while the values of breast meat lightness (L*) and brightness (b*) differed (P < 0.05), redness and pH did not differ between the sexes (P > 0.05). Furthermore, sex significantly affected ash, protein content (P < 0.05), and TBA value (P < 0.01) of breast meat but did not affect dry matter, water holding capacity, and peroxide value of breast meat. Also, there was a significant difference in the weight of the neck, breast, thigh, live weight, hot carcass yield, heart, liver, abdominal fat, and digestive system between sexes (P < 0.05). However, breast meat fat content and fatty acid profiles were not influenced by the sex of the broilers (P > 0.05). It was concluded that access to the studied pasture species has no effect on the growth performance traits but results in notable variations in the fatty acid profiles in broiler breast meat.

Keywords: Fatty acid composition; Free-range; Pasture plants; Pastured poultry; Slower-growing broiler.