This study assessed the impact of the dietary inclusion of L-ascorbic acid and organic zinc (Availa-Zn) on heat-stressed Japanese quails. Growth performance, antioxidant status, immune status, heat shock protein 70 (HSP70), and some blood biochemical parameters were assessed. One-day-old, unsexed Japanese quail chicks (n = 240) were randomly allocated into 4 dietary treatments (6 replicates per treatment; 10 birds per replicate). Birds were fed a basal corn-soybean meal diet (control treatment) with different supplemental levels of L-ascorbic acid and/or Availa-Zn (200 mg L-ascorbic acid/kg diet, 62 mg Availa-Zn/kg diet, and 200 mg L-ascorbic acid + 62 mg Availa-Zn/kg diet) from July to August 2020 for 35 days. The average minimum and maximum ambient temperatures varied from 85.4 to 98.8 °F, and the relative humidity was between 69 and 74%. Supplemented L-ascorbic acid and Availa-Zn, either as separate supplements or as combined supplements, increased bird growth performance, blood hemoglobin, thyroid hormones, total protein, globulin, total antioxidant capacity, HSP70, catalase, superoxide dismutase enzyme activity, and immunoglobulin A and G (P < 0.05), while heterophil/lymphocytes decreased (P < 0.01) during the entire rearing period (1-35 days). Most of the assessed parameters showed stronger responses when L-ascorbic acid and Availa-Zn were added together, which may suggest a synergistic effect. In conclusion, the combined supplementation of L-ascorbic acid and Availa-Zn at 200 and 62 mg/kg, respectively, could be considered an efficient dietary supplement to enhance Japanese quail growth performance, antioxidant capacity, immune status, and general health under heat stress conditions.

中文翻译：

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锌和 L-抗坏血酸膳食补充剂影响热应激条件下日本鹌鹑的抗氧化状态、热休克蛋白 70 和一些免疫球蛋白。

本研究评估了日粮中添加 L-抗坏血酸和有机锌 (Availa-Zn) 对热应激日本鹌鹑的影响。评估了生长性能、抗氧化状态、免疫状态、热休克蛋白 70 (HSP70) 和一些血液生化参数。1 日龄、无性别的日本鹌鹑小鸡 (n = 240) 被随机分配到 4 个日粮处理中（每个处理 6 个重复；每个重复 10 只鸡）。给鸡只饲喂基础玉米-豆粕日粮（对照处理），添加不同水平的 L-抗坏血酸和/或 Availa-Zn（200 mg L-抗坏血酸/kg 日粮、62 mg Availa-Zn/kg 日粮和200 mg L-抗坏血酸 + 62 mg Availa-Zn/kg 饮食）从 2020 年 7 月至 8 月，持续 35 天。平均最低和最高环境温度从 85.4 到 98.8°F 不等，相对湿度在 69% 到 74% 之间。补充 L-抗坏血酸和 Availa-Zn，无论是作为单独的补充剂还是作为组合的补充剂，都可以提高家禽的生长性能、血红蛋白、甲状腺激素、总蛋白、球蛋白、总抗氧化能力、HSP70、过氧化氢酶、超氧化物歧化酶活性和免疫球蛋白A 和 G (P < 0.05)，而在整个饲养期间 (1-35 天)，嗜异性/淋巴细胞减少 (P < 0.01)。当 L-抗坏血酸和 Availa-Zn 一起添加时，大多数评估参数显示出更强的响应，这可能表明存在协同效应。总之，分别以 200 和 62 mg/kg 的 L-抗坏血酸和 Availa-Zn 联合补充剂可被认为是提高日本鹌鹑生长性能、抗氧化能力、免疫状态、