Effect of hulled whole-grain rice substituted corn diets on the growth performance, meat quality and sensory evaluation in meat-type Nagoya breed and broiler chickens

The present study was conducted to determine the effects of hulled whole-grain rice substituted corn diets on the growth performance, meat quality, and sensory evaluation in meat-type Nagoya breed and broiler chickens. In experiment 1 (Ex1), nine hundred chickens of the meat-type Nagoya breed (10 weeks old) were divided into two experimental groups (N_group 4wks and N_group 8wks) and a control group (N_control group). The experimental groups were fed a diet containing 64.3% hulled whole-grain rice with no corn for 4 weeks (14-18 weeks of age) and 8 weeks (10-18 weeks of age). The diet fed to the control group was a practical corn-based diet. In experiment 2 (Ex2), two hundred and forty broiler chickens (3 weeks old) were divided into two experimental groups (B_group 2wks and B_group 4wks) and a control group (B_control group). The experimental groups were fed a diet containing 66.0% hulled whole-grain rice for 2 weeks (5-7 weeks of age) and 4 weeks (3-7 weeks of age). The control group was fed a practical corn-based diet. The following results were obtained. 1. There was no significant difference in the growth rates among the three groups in Ex1 and EX2. In Ex1, the feed conversion rate was the lowest in the group N_group 8wks, but in Ex2, the feed conversion rate was significantly higher in the group B_group 4wks than in the control group (B_control). 2. In meat color, in Ex1, increase in the values of lightness and decrease in the values of yellowness of breast meat, thigh meat, and abdominal fat were observed in N_group 8wks. In Ex2, similar results were observed in B_group 4wks but only for breast meat. 3. Oleic acid content in the fat of breast meat was significantly higher in N_group 8wks than in N_control. Linoleic acid contents in the fat of breast meat were significantly lower in N_group 8wks and B_group 4wks than in the control group. 4. In the sensory evaluation of soups prepared using breast meat, there was an aftertaste in the soup made from the meat of N_group 4wks group birds, and the soup made from B_group 2wks group meat had a weaker flavor than that made from the control group meat.