Effect of intramuscular fat level on carcass composition, physicochemical characteristics, texture, and microstructure of breast muscle of broiler chickens.

This research aimed to determine the effect of intramuscular fat (IMF) levels in m. pectoralis major on carcass weight and composition, meat of male broiler chickens. Whole eviscerated necked carcasses of Ross 308 male broiler chickens aged 42 days were purchased from a commercial poultry slaughterhouse. After the carcasses were dissected, m. pectoralis major was sampled to determine their basic chemical composition, physicochemical and sensory characteristics, texture, and microstructural characteristics. The IMF content of the m. pectoralis major evaluated male Ross 308 broiler chickens at 42 days of age ranged from 0.88 % to 4.64 %. The majority (about 66 %) carcasses contained pectoral muscle containing no more than 2.04 % IMF. Male broiler chicken carcasses differed (P < 0.05) in IMF, water, and protein content of m. pectoralis major. Breast muscles of Ross 308 chickens with the highest IMF levels (2.05-4.64 %) had significantly less water and protein compared to those of chickens with the lowest (0.88-1.60 %) and medium (1.61-2.04 %) IMF levels. IMF level had no effect on carcass weight and composition, physicochemical characteristics, texture, and microstructure of m. pectoralis major. To date, there have been no studies determining the effect of IMF level on microstructure and texture traits of m. pectoralis major (except WB shear force) and electrical conductivity in Ross 308 broiler chickens. The results obtained indicate the need for future research in this area with consideration of males and females and research material from multiple sources.