van Niekerk T, Garber T K, Dunnington E A, Gross W B, Siegel P B
Department of Poultry Science, Virginia Polytechnic Institute and State University, Blacksburg 24061.
Poult Sci. 1989 Dec;68(12):1631-6. doi: 10.3382/ps.0681631.
This study was undertaken to assess the effects of dietary ascorbic acid on the growth and immunoresponsiveness of chickens when subjected to particular types of stress. White Leghorn chicks were fed diets containing no supplemental ascorbic acid, and ascorbic-acid diet (330 ppm) for 2 days or for 19 days before challenge. Then, half of the females were inoculated with Escherichia coli; half of the males were challenged with dietary corticosterone (30 ppm) for 12 days; and the remaining chicks were maintained as controls. These chicks, reared under "good" husbandry procedures, did not realize advantages in growth or feed efficiency due to the short- or long-term consumption of diets containing ascorbic acid. Incubation with E. coli resulted in considerably higher heterophil-to-lymphocyte ratios 24 h after inoculation, and E. coli-induced mortality was higher for pullets on short-term ascorbic acid than for those on long-term or no ascorbic acid. Dietary corticosterone caused differences in body weight and the relative weights of certain organs, regardless of dietary levels of ascorbic acid. The antibody response to red-blood-cell antigens from sheep was enhanced in unchallenged cockerels (no dietary corticosterone) fed ascorbic acid on a long-term basis, but dietary corticosterone overshadowed the advantageous effects of dietary ascorbic acid. These data showed that the effects of supplemental ascorbic acid on growth and on immunoresponsiveness were related to the quality of the husbandry, length of supplemental feeding, age of the chicks, endogenous-exogenous balance for ascorbic acid, and the relationship with corticosterone.
本研究旨在评估在特定类型应激条件下，日粮抗坏血酸对鸡生长和免疫反应性的影响。给白来航雏鸡饲喂不含补充抗坏血酸的日粮以及抗坏血酸日粮（330 ppm），持续2天或在攻毒前持续19天。然后，一半雌性雏鸡接种大肠杆菌；一半雄性雏鸡用日粮皮质酮（30 ppm）攻毒12天；其余雏鸡作为对照。这些在“良好”饲养程序下饲养的雏鸡，并未因短期或长期采食含抗坏血酸的日粮而在生长或饲料效率方面体现出优势。接种大肠杆菌后24小时，其异嗜性粒细胞与淋巴细胞比值显著更高，且短期采食抗坏血酸的小母鸡因大肠杆菌诱导的死亡率高于长期采食或不采食抗坏血酸的小母鸡。日粮皮质酮导致体重和某些器官相对重量出现差异，与日粮抗坏血酸水平无关。长期采食抗坏血酸的未攻毒公鸡（无日粮皮质酮）对绵羊红细胞抗原的抗体反应增强，但日粮皮质酮掩盖了日粮抗坏血酸的有利影响。这些数据表明，补充抗坏血酸对生长和免疫反应性的影响与饲养质量、补充饲喂时间、雏鸡年龄、抗坏血酸的内源性 - 外源性平衡以及与皮质酮的关系有关。
