| Two experiments were conducted to investigate effects of ginger root and ginger oil on growth performance of broilers.Exp.1 The objective of the experiment was to study the effect of ginger root and ginger oil on growth performance, antioxidant status, immunity, carcass characteristics and meat quality of broilers. A total of 720, one-day-old Arbor Acres broiler chicks were used in this study. Broilers were randomly allotted to 6 treatments. Dietary treatments were as follows: 1) control corn-soybean meal basal diet (BD), 2) BD + antibiotic (40 mg/kg bacitracin zinc and 8 mg/kg colistin sulfate), 3) BD + 0.5 % of ginger powder, 4) BD + 1 % g/kg of ginger powder, 5) BD +2 % g/kg of ginger powder, 6) BD + 100 mg/kg of ginger oil.The result of this experiment indicated: at 21 days of age, ADG, ADFI and FCR were similar among treatments (P>0.05). Both ginger root powder and ginger oil increased the TAOC, TSOD and GSH-Px activties in the serum or liver of broilers (P<0.05), whereas decreased the MDA content (P<0.05). Broiler addition of 0.5 % or 1 % ginger powder had higher activities of TSOD and GSH-Px in serum than that of antibiotic group (P<0.05). The proliferation of blood T and B lymphocytes in the ginger powder and ginger oil group were significantly greater (P<0.05) than that in the control group but similar to the antibiotic group (P>0.05). Broilers with 1 % ginger had higher T lymphocytes than diets with 2 % or ginger oil group. All supplement groups significantly increased (P<0.05) the breast meat yield. The abdominal fat content was reduced (P<0.05) by supplemented with 1 % or 2 % ginger root powder. At 42 days of age, dietary ginger root powder and ginger oil slightly improved the BW of broilers. Birds in the ginger oil or antibiotic supplemented groups had higher BW and ADG compared to the control (P<0.05). Broilers addition of 2 % had a lower ADFI than that of antibiotic or addition of 1 % groups. Ginger root powder at the level of 1 % decreased (P<0.05) the FCR over the entire experimental period. The activities of TSOD, GSH-Px and TAOC in serum were improved by supplemented with ginger powder and ginger oil (P<0.05). However, serum MDA concentration was decreased (P<0.05). Dietary ginger increased the TAOC in liver (P<0.05). There was no effect on activities of TSOD and GSH-Px in liver (P>0.05). Diets supplemented with 0.5 % or 1 % ginger powder increased thymus index and bursa of Fabricius index of broilers (P<0.05). Dietary ginger oil also increased thymus index of broilers. Spleen index was improved by dietary 1% and 2% ginger powder. Intermediate cell and leukocytes were improved by dietary ginger oil or 2 % ginger root. Ginger group (the dosage of 1 % or 2 %) increased the breast meat yield and leg muscle yield. The abdominal fat yield was reduced (P<0.05) by the group with 0.5 % or 1 % ginger powder. Supplementation with ginger product or antibiotic increased the redness (a*), and reduced the yellowness (b*) of meat color (P<0.05) while lowered (P<0.05) drop loss and the water loss rate of breast meat. There was no difference in the pH value and lightness of meat.Exp.2 The objective of the experiment was to assess the effects of dried ginger root that was processed to different particle sizes on growth performance, antioxidant status and serum metabolites of broiler chickens. 144 d-old Arbor Acres broilers were used and divided into 6 treatments. Dietary treatments were non-ginger supplementation (Control) and supplemented with ginger root processed to 5 particle sizes (300, 149, 74, 37 and 8.4μm denoted as: G300, G149, G74, G37 and G8.4) at the level of 0.5 %.The result of this experiment indicated: all broilers had similar ADFI or FCR over the entire experimental period. However, broilers supplemented with ginger powder tended to have higher ADG and had greater (P=0.014) eviscerated carcass yield as compared with that of control. A slightly lower (P=0.096) abdominal fat content was observed in ginger group than the control birds at 42 d. At d 42, carcass yields of birds in G74 and G37 were higher (P<0.05) than that of birds in control, G300, or G8.4. Supplementation of ginger powder significantly increased activities of TSOD and GSHPx, but reduced MDA content in the serum at ages of 21 and 42 days. Reducing particle size (from 300 to 8.4μm) of ginger powder linearly reduced (P < 0.05) cholesterol (d21), linearly increased (P<0.05) GSHPx (d21) and TSOD (d42). In contrast, activity of GSHPx in the serum of birds supplemented with ginger tended (P=0.065) to be quadratically increased at 42 d of age. Ginger supplemented broilers had higher (P=0.002; 42 d) TP concentration, and higher (P=0.025) concentration of globulin at 42 d as compared with that of control broilers. In contrast, concentration of cholesterol in serum was significantly reduced by supplementation of ginger powder. Concentrations of TP and globulin in ginger supplemented broilers were linearly increased (P<0.05) at both ages as the particle sizes of ginger powder decreased from 300 to 8.4μm. In contrast, quadratic responses (P=0.010) of serum cholesterol concentration occurred at 21 d with decreasing particle sizes of ginger powder.It was concluded that ginger root powder and ginger oil could improved the growth by elevating antioxidant status and immunity effect. The optimal levels used in the broilers diet were 0.5 % or 1 %. The efficacy of ginger is mediated by its particle size that exerted the greatest effect on most of the responses when ginger was processed to approximately 74-37μm. |
