Genistein improves the reproductive performance and bone status of breeder hens during the late egg-laying period.

Genistein (GEN), a type of soy isoflavones, is similar to estrogen structurally and functionally. The effects of dietary gen on the reproductive performance and bone status of breeder hens were investigated. A total pf 720 laying broiler breeder (LBB) hens were randomly allocated into 3 groups with supplemental dietary GEN doses (0, 40, 400 mg/kg). Each treatment has 8 replicates of 30 birds. The results indicated that supplemental GEN significantly improved the egg production and eggshell strength of LBB hens. Dietary GEN was deposited into the egg yolk, which decreased malonaldehyde in the follicle and egg yolk. The levels of vitellogenin (VTG), progesterone, and follicle-stimulating hormone in the serum of GEN-treated groups were elevated compared with the control group. Furthermore, GEN treatment downregulated the mRNA expression of insulin-like growth factor binding protein in the fallopian tube, whereas 40 mg/kg GEN treatment upregulated estrogen receptor α expression. Both the mRNA expression of VTG-II in the liver and mRNA expression of amphiregulin in the fallopian tube were upregulated after 40 and 400 mg/kg GEN treatment. In the 400 mg/kg GEN-treated group, the levels of calcitonin and alkaline phosphatase in the serum were increased compared with the control group, which was consistent with the increased levels of calcium and phosphorus in the tibia. Supplemental GEN (400 mg/kg) improved the tibia strength of LBB hens, whereas 40 mg/kg GEN had better effects on laying performance. In summary, dietary GEN could improve the egg production and quality, as well as the bone status of LBB hens during the late egg-laying period.

Glucose and lipid metabolism disorders in the chickens with dexamethasone-induced oxidative stress.

The purpose of this study was to investigate the effects of long-term treatment with dexamethasone (DEX) on the antioxidation and nutrition metabolism in broiler chickens. Broilers were placed on a high-nutrient diet for 41 days, and half were given orally DEX-supplemented water at 20 mg/L every other day from 19 to 41 days of age. DEX treatment downregulated superoxide dismutase activity as well as the mRNA expression of CuZn-superoxide dismutase and glutathione peroxidase with a decrease in GSH/GSSG ratio and an increase in malondialdehyde level in the liver of broilers. DEX treatment aggravated oxidative damage in the liver and, therefore, increased the sensitivity of broilers to ascites syndrome with higher mortality and reduced growth performance. Serum metabolomics analysis showed that DEX treatment significantly increased the levels of glucose, intermediates in protein metabolism (valine, proline, serine, threonine and urea) and lipid metabolism-related products (palmitic acid, stearic acid and cholesterol) while decreasing the levels of ß-hydroxy butyric acid, succinic acid and malic acid, demonstrating that DEX treatment inhibited the Krebs cycle and the oxidation of fatty acids, and promoted the de novo synthesis of fatty acids as well as protein decomposition in the liver of broilers. Additionally, detection of metabolism-related enzymes revealed that DEX treatment inhibited glycolysis and promoted glycogen decomposition. In summary, DEX treatment resulted in oxidative stress and glucose and lipid metabolism disorders in the broilers.