Effects of Feeding Rancid Rice Bran on Growth Performance and Chicken Meat Quality in Broiler Chicks

A total of 225 day-old broiler chicks (43.08 g initial body weight) were allotted to three dietary treatments for a 6-week feeding trial. The treatments were 1) Control (defatted rice bran; DFRB), 2) fresh rice bran (FRB) and 3) rancid rice bran (RRB). Rice brans were intentionally spoiled by two degrees of rancidity by the values of free fatty acids (FFA): 7.6% (FRB) and 16.3% (RRB). Diets were prepared on an isonutrient basis, and defatted or rancid rice brans were included 5 and 10% for starter (0-3 week) and finisher (3-6 week), respectively. At the end of the feeding trial, six chicks per treatment were sacrificed, and thigh meats were ground and stored at $1^{\circ}C$ for thiobarbituric acid reactive substances (TBARS) and peroxide value (POV) analyses. For a digestibility, 48 growing chicks (4 weeks old) were employed in cages (3 replicates/treatment, 2 birds/cage) according to the experimental design: FRB, RRB, pelleted and extruded rice bran. Some of the FRB were pelleted ($70^{\circ}C$) or extruded ($110^{\circ}C$). There was no significant difference in growth performance during the starter period, but chicks fed a diet containing DFRB grew faster (p<0.05) with increased feed intake (p<0.05) than those fed diets containing rice brans, FRB or RRB, during the finisher period. Feed conversion ratio in the RRB was inferior (p<0.05) to the DFRB. Between rice bran groups, weight gain was higher (pco.os) in FRB than in RRB during finisher period. There was a similar trend in growth performance of chicks for the overall period (0-6 week) as the finisher period. Dry matter and energy digestibilities were higher (p<0.05) in extruded than in RRB group. Protein digestibility was improved (p<0.05) when rice bran was extruded, but not pelleted. The chicken meats from RRB showed higher (p<0.05) TBARS than those from FRB during storage for 4 weeks at $1^{\circ}C$. In conclusion, it would appear that feeding rancid rice bran gave negative effects on growth performance and lipid stability of meat in broiler chicks.