ABSTRACT This study was conducted to evaluate the effects of stocking density on productive performance, egg quality, and antioxidant capacity in laying ducks. A total of 720 20-week-old Jinding laying ducks were randomly assigned to 5 stocking densities (4, 5, 6, 7, and 8 birds/m2) with 8 replicate pens each treatment. The results showed that increasing stocking density linearly increased egg production and egg mass and linearly decreased FCR of laying ducks (P < 0.05). The eggshell strength and thickness decreased linearly (P < 0.05) and quadratically (P < 0.05) with an increase in stocking density. Increased stocking density linearly decreased concentrations of estradiol-17β and follicle-stimulating hormone, activities of superoxide dismutase, glutathione peroxidase, and total antioxidant capacity in plasma (P < 0.05), but linearly increased plasma and hepatic malondialdehyde content (P < 0.05). The results suggested that high stocking density adversely influenced laying performance and egg quality of ducks, which is associated with impaired antioxidant capacity. Under our experimental conditions, we recommend that the stocking density of laying ducks should be kept to 4 or fewer birds/m2 to avoid the negative effects of high stocking density on performance and egg quality of laying ducks.

中文翻译：

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饲养密度对产蛋鸭生产性能、蛋品质、生殖激素和抗氧化能力的影响

摘要 本研究旨在评估饲养密度对蛋鸭生产性能、蛋品质和抗氧化能力的影响。720 只 20 周龄金顶蛋鸭被随机分配到 5 个放养密度（4、5、6、7 和 8 只/平方米），每个处理 8 个重复围栏。结果表明，增加饲养密度线性增加产蛋量和产蛋量，线性降低蛋鸭的FCR（P < 0.05）。随着饲养密度的增加，蛋壳强度和厚度呈线性（P < 0.05）和平方（P < 0.05）下降。饲养密度增加会线性降低雌二醇-17β 和促卵泡激素的浓度、超氧化物歧化酶的活性、谷胱甘肽过氧化物酶和血浆中的总抗氧化能力（P < 0.05），但血浆和肝脏丙二醛含量呈线性增加（P < 0.05）。结果表明，高饲养密度对鸭的产蛋性能和蛋质量产生不利影响，这与抗氧化能力受损有关。在我们的实验条件下，我们建议蛋鸭的放养密度应保持在 4 只或更少的鸟/平方米，以避免高放养密度对蛋鸭的性能和蛋品质产生负面影响。