Effect of Dietary Inclusion of Gynura divaricata (L.) on Growth Performance, Hematology, and Carcass Fat Deposition in Broilers

抄録

The objective of this study was to examine the effect of Gynura divaricata (Jakr-Na-Rai, JNR) on the growth performance, hematology, and carcass fat deposition of broilers. A total of 240 male Cobb-500 birds, 22 d old, were randomly allocated into five treatment groups of six replicates. Each group was raised at a high stocking density of 28kg of body weight/m² until day 43. The treatments consisted of (i) a basal diet, or the basal diet supplemented with (ii) 2.5mg/kg avilamycin (T2), (iii) JNR crude ethanol extract at a flavonoid level of 1.3g/kg (T3), and (iv and v) JNR powder at a flavonoid level of 1.3 (T4) or 2.6g/kg (T5). Dietary supplementation with JNR powder at both flavonoid levels decreased the heterophil/lymphocyte ratio compared to the other groups (P < 0.001). Birds in the T5 group presented decreased blood glucose (P < 0.005) and cholesterol (P < 0.002) levels and a numerically (P = 0.056) decreased triglyceride level. The total bile acid concentration increased (P < 0.001) in all the JNR-fed groups, but there was no significant effect on the digestibility of ileal protein or fat. At 1.3g/kg of diet, JNR increased the final body weight and feed intake (P < 0.05), but the average daily gain and feed conversion ratio were not different among groups. The carcass and abdominal fat percentages were lowest in chicks fed on the diets supplemented with 2.6g/kg JNR powder (P < 0.007 and P < 0.025, respectively). Drip loss and malondialdehyde concentrations in the breast meat did not change. In conclusion, JNR powder improved several hematological parameters, increased total bile acid concentrations, and decreased the percentage of abdominal fat. The powder form of JNR elicited better results than the ethanol extract form at the same flavonoid inclusion level.