This study was conducted to investigate the effects of chromium from chromium propionate (CrPro) on serum lipids, carcass traits, and breast meat quality in heat-stressed birds. A total of 210 1-day-old male broilers were randomly allotted by initial body weight (BW) into 5 treatments with 7 replicates with 6 birds per replicate pen for 42 days. The treatments included a basal corn-soybean meal diet and basal diet supplemented with 0.2, 0.4, 0.8, or 1.6 mg Cr/kg diet. Birds had ad libitum access to feed and distilled-deionized water at normal conditions for 1-3 weeks with little or no stress, and then birds were housed under heat stress conditions with 35 ± 2 °C ambient temperature for 4-6 weeks. Results showed that serum triglyceride (TG) (P = 0.0006) and low-density lipoprotein cholesterol (LDLC) (P = 0.0038) concentrations were decreased linearly as Cr dose increased. Compared with other groups, birds receiving 0.8 or 1.6 mg Cr/kg had lower TG (P = 0.0015). Compared to control birds, birds fed diets with 0.2, 0.4, 0.8, or 1.6 mg Cr/kg supplementation had lower LDLC (P = 0.0006). However, the total cholesterol (TC) and high density lipoprotein cholesterol (HDLC) concentrations in serum were not affected by treatment (P > 0.05). No difference was observed in BW, the relative weights of breast muscle, thigh muscle and abdominal fat (P > 0.05), and breast meat quality (Ph15min, Ph24h, L*, a*, b*, cooking loss, shear force) among the treatments (P > 0.05). Results from this study indicated that CrPro supplementation could be beneficial to serum lipids metabolism of heat-stressed broiler chickens by decreasing TG and LDLC contents, but had no impacts on meat quality and carcass traits of the heat-stressed broilers.
Keywords: Carcass traits; Chromium; Heat-stressed broilers; Meat quality; Serum lipids.