The present study aimed to evaluate the effects of excess dietary fluoride (F) on laying performance, egg quality, tissue retention, serum biochemical indices, and serum reproductive hormones of laying hens. A total of 384 Hy-Line Gray hens, 37 wk old, were treated with sodium fluoride added to a corn-soybean meal basal diet at 0, 400, 800, and 1200 mg fluorine/kg feed. The results showed that dietary F levels at 800 and 1200 mg/kg markedly decreased ADFI, laying rate, average egg weight, and increased feed conversion ratio (FCR) (P < 0.05). Dietary F levels at 800 and 1200 mg/kg dramatically decreased the egg quality of albumen height, yolk color, eggshell strength, and eggshell thickness, and on the 49th D, 400 mg/kg F group significantly decreased the eggshell strength, compared to those of control group. Fluoride residues in tissues of hens were increased significantly with the increase of dietary F supplemental levels (P < 0.05). Fluoride concentrations were generally high in feces, eggshell, tibia, kidney, and ovary, and the highest in feces, following with eggshell and tibia, lower in kidney and ovary, and the lowest in serum. Serum uric acid levels and alanine aminotransferase activity increased significantly (P < 0.05), and glucose, triglycerides, and phosphorus decreased significantly (P < 0.05) in response to dietary F concentration, compared to those of the control group, respectively. Dietary F supplementation at 1200 mg/kg significantly decreased (P < 0.05) the estrogen concentrations in serum, compared to those of the control group. Concentrations of progesterone in the fluoride-treated groups were significantly (P < 0.05) decreased relative to those of the control group. In conclusion, these results indicated that the excessive ingestion of F has had a detrimental effect on egg laying rate and quality of eggs by damaging the function of the liver, kidney, and ovary of laying hens.

中文翻译：

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过量的日粮氟化物会影响蛋鸡的产蛋性能、蛋质量、组织保留、血清生化指标和生殖激素。

本研究旨在评估过量日粮氟化物 (F) 对蛋鸡的产蛋性能、蛋质量、组织保留、血清生化指标和血清生殖激素的影响。总共 384 只 37 周龄的 Hy-Line Grey 母鸡在 0、400、800 和 1200 mg 氟/kg 饲料中添加了添加到玉米-豆粕基础日粮中的氟化钠。结果表明，800 和 1200 mg/kg 的日粮 F 水平显着降低了 ADFI、产蛋率、平均蛋重，并提高了饲料转化率（FCR）（P < 0.05）。日粮 F 水平在 800 和 1200 mg/kg 时显着降低蛋品质的蛋白高度、蛋黄颜色、蛋壳强度和蛋壳厚度，并且在第 49 天，与那些相比，400 mg/kg F 组显着降低蛋壳强度的对照组。随着日粮F添加量的增加，母鸡组织中的氟残留量显着增加（P < 0.05）。氟化物在粪便、蛋壳、胫骨、肾脏和卵巢中的浓度普遍较高，在粪便中最高，其次是蛋壳和胫骨，在肾脏和卵巢中较低，在血清中最低。与对照组相比，随着膳食 F 浓度的增加，血清尿酸水平和丙氨酸氨基转移酶活性显着增加（P < 0.05），葡萄糖、甘油三酯和磷显着降低（P < 0.05）。与对照组相比，1200 mg/kg 膳食 F 补充剂显着降低（P < 0.05）血清中的雌激素浓度。氟处理组的孕酮浓度显着（P < 0. 05) 相对于对照组降低。总之，这些结果表明，过量摄入F会损害蛋鸡的肝脏、肾脏和卵巢功能，从而对产蛋率和鸡蛋质量产生不利影响。