Abstract

Consumers’ interest of indigenous chicken meat is increasing. An experiment was conducted to determine the effect of vitamin D₃ supplementation on meat quality of indigenous male naked neck chickens. Different supplementation levels of 0, 2000, 4000, 6000 and 8000 IU of vitamin D₃ per kg dry matter (DM) of feed were examined. 13 weeks old male naked neck chickens with a mean live weight of 1200 ± 3 g were supplemented with vitamin D₃ for a period of seven days before slaughter. A 2 (cooking or not) × 2 (postmortem agings of 0 or 24 h) × 5 (vitamin D₃ levels) factorial arrangement in a complete randomized design was used for shear force analysis of raw or cooked naked neck chicken meat. A 2 (postmortem agings of 0 or 24 h) × 5 (vitamin D₃ levels) factorial arrangement in a complete randomized design was used for sensory evaluation of the meat. A quadratic equation was used to determine vitamin D₃ supplementation levels for optimum shear force value and sensory attributes. Vitamin D₃ supplementation did not improve (P>0.05) shear force values of unaged or aged raw and cooked naked neck chicken meat. Shear force values of unaged raw or cooked meat were optimized at different levels of 3735 (r²=0.832) and 2512 (r²=0.669) IU of vitamin D₃ per kg DM feed, respectively. Shear force values of aged raw or cooked meat were optimized at different levels of 6728 (r²=0.274) and 4249 (r²=0.873) IU of vitamin D₃ per kg DM feed, respectively. Vitamin D₃ supplementation had no effect (P>0.05) on unaged meat tenderness, juiciness and flavour. However, vitamin D₃ supplementation improved (P<0.05) aged meat tenderness and flavour. Tenderness, juiciness and flavour of aged naked neck chicken meat were optimized at supplementation level of 6830 (r²=0.839), 6894 (r²=0.683) and 9795 (r²=0.657) IU of vitamin D₃ per kg DM. It was concluded that vitamin D₃ supplementation improved tenderness and flavour of aged naked neck chicken meat. However, shear force values of unaged or aged raw or cooked naked neck chicken meat were not improved by vitamin D₃ supplementation.

Key words: Shear force, postmortem aging, calpains, connective tissue, tenderness, juiciness, flavour.