Effects Of Ginger Root On Dietary Oxidation Stability And Antioxidant Status, Immune Function And Laying Performance Of Laying Hens

Two experiments were conducted to investigate the effects of ginger root on dietary oxidation stability and antioxidant status, immune function and laying performance of laying hens.Exp.1 The objective of the experiment was to study the effect of ginger powder on dietary oxidation stability. The dietary treatments were corn-soybean meal based diets supplemented with 0, 5, 10, 15 and 20 g/kg diet of ginger powder (denoted as Control, GP5, GP10, GP15 and GP20) replacing equivalent amount of wheat bran in the diet formulation. 3 diets (1.0-kg) of each treatment were transferred into separate airtight plastic bags and stored in an incubator with constant temperature of 20 oC. Subsample of 120 g was taken from each bag at d 0 and every 10 d after till d 60 for determination of peroxide value (PV) and acid value (AV).The result of this experiment indicated: supplementation of ginger powder to diet at the levels up to 20 g/kg diet enhanced diet stability by linearly increasing (P < 0.05) PV but reducing (P < 0.05) AV of the diet during the first 30-d storage.Exp. 2 The objective of the experiment was to study the effect of ginger powder on laying performance, egg qualities, antioxidant status and immune function of laying hens. 675 Hy-Line brown laying hens at 27 wk of age were randomly allocated into 5 treatments with 5 replicates in a complete randomized design. Laying hens were fed corn-soybean meal based diets and supplemented with 0, 5, 10, 15 or 20 g/kg diet of ginger powder respectively. The experiment comprised of a week of adaptation and 10 weeks of measurement period. ADFI, laying rate, average egg weight, egg mass and feed conversion were calculated each week and egg qualities, antioxidant status, serum antibody titer and blood index were determined on d 35 and d 70.The result of this experiment indicated: there was no significant difference in ADFI, laying rate, feed conversion, eggshell thickness, egg index, egg yolk weight and egg albumen weight among treatments (P > 0.05). However, laying hens supplemented with ginger powder had higher (P < 0.05) average egg weight during the second 5-wk period and higher (P < 0.05) egg mass during the entire period. Among the ginger powder supplemented groups, GP5 appeared to contain the highest (P < 0.05) average egg weight during the second 5-wk period. Laying hens of GP10 had higher (P < 0.05) egg mass than that of control birds during the entire period. Besides, supplementation of ginger powder also increased (P < 0.05) the percentage of crude fat and dry matter in eggs and the activities of SOD, GSH-PX and T-AOC in serum or egg yolk at d 35 and d 70, increased (P < 0.05) the New castle disease antibody titer at d 35 and egg yolk colour, percentage of egg yolk, Avian influenza H9 and H5Re-5 antibody titer and the number of granulocyte at d 70. However, MDA concentration at d 35 and d 70 and the percentage of egg albumen, crude protein in eggs and cholesterol in egg yolk at d 70 were decreased (P < 0.05). Among the ginger powder supplemented groups, eggs of GP10 laying hens appeared to contain the highest (P < 0.05) nutrient content. As the levels of ginger powder increasing from 0 to 20 g/kg diet, serum and egg yolk antioxidant status were linearly and/or quadratically increased (P < 0.05) at d 35 and d 70 of the experiment. Laying hens consuming diet GP15 had the highest (P < 0.05) egg yolk colour and egg yolk percentage, but lowest (P < 0.05) egg albumen percentage at d 70. However, among the ginger powder supplemented groups, eggs of GP20 laying hens appeared to contain the lowest (P < 0.05) cholesterol content. As the concentration of ginger powder increased from 0 to 20 g/kg diet, Avian influenza H9 antibody titer and the number of granulocyte were linearly and/or quadratically increased (P < 0.05) at d 70.In conclusion, laying hens responded to ginger powder supplementation in a dose dependent manner and the results indicate that the optimum dietary ginger powder concentrations are 10 to 15 g/kg diet in terms of improved diet oxidative stability, enhanced birds'laying performance, egg qualities, antioxidant status and immune function of laying hens.