Animal Nutrition, Life Sciences, Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan.
Phytobiotics Futterzusatzstoffe GmbH, 65343 Eltville, Germany.
Poult Sci. 2021 Feb;100(2):957-963. doi: 10.1016/j.psj.2020.11.050. Epub 2020 Nov 30.
Broiler chickens reared under heat stress (HS) conditions have decreased growth performance and show metabolic and immunologic alterations. This study aimed to evaluate the effect of supplementation with a standardized blend of plant-derived isoquinoline alkaloids (IQ) on the growth performance, protein catabolism, intestinal barrier function, and inflammatory status of HS-treated chickens. Three hundred sixty 0-day-old Ross 308 male broiler chickens were randomly distributed into 2 treatment groups: control diet (no additives) or diet supplemented with 100 ppm IQ. At day 14, the chicks in each diet group were further divided into 2 groups, each of which was reared under thermoneutral (TN) (22.4°C) or constant HS (33.0°C) conditions until day 42. Each group consisted of 6 replicates with 15 birds per replicate, and chickens were provided ad libitum access to water and feed. During days 15-21, the body weight gain (BWG) and feed intake (FI) were significantly lower in the HS treatment group than in the TN group, and feed conversion ratio was higher (P < 0.05); these factors were not alleviated by IQ supplementation. During days 22-42, the final BW, BWG, and FI of the HS birds were better among those administered IQ than those that were not (P < 0.05). HS treatment increased plasma lipid peroxide, corticosterone, and uric acid concentrations as well as serum fluorescein isothiocyanate-dextran, a marker of intestinal barrier function, and decreased plasma total protein content (P < 0.05). These changes were not observed in the IQ group, suggesting that IQ supplementation improved oxidative damage, protein catabolism, and intestinal barrier function of chickens under HS. Isoquinoline alkaloid supplementation inhibited the expression of intestinal inflammatory factors, IL-6, tumor necrosis factor-like factor 1A, and inducible nitric oxide synthase under HS treatment (P < 0.05). These results suggest that IQ supplementation can improve the growth performance of broiler chickens under HS conditions, which may be associated with amelioration of oxidative damage, protein catabolism, intestinal barrier function, and inflammation.
热应激条件下饲养的肉鸡生长性能下降，表现出代谢和免疫改变。本研究旨在评估补充标准化植物源性异喹啉生物碱（IQ）混合物对热应激处理鸡的生长性能、蛋白质分解、肠道屏障功能和炎症状态的影响。将 360 只 0 日龄罗斯 308 雄性肉鸡随机分为 2 个处理组：对照组（无添加剂）或日粮添加 100 ppm IQ。在第 14 天，每组鸡进一步分为 2 个组，每组在热中性（TN）（22.4°C）或持续 HS（33.0°C）条件下饲养至第 42 天。每组包括 6 个重复，每个重复 15 只鸡，鸡自由饮水和采食。在第 15-21 天，HS 处理组的体重增重（BWG）和采食量（FI）明显低于 TN 组，饲料转化率更高（P<0.05）；IQ 补充并未缓解这些因素。在第 22-42 天，接受 IQ 处理的 HS 鸡的最终 BW、BWG 和 FI 优于未接受 IQ 处理的鸡（P<0.05）。HS 处理增加了血浆脂质过氧化物、皮质酮和尿酸浓度以及血清荧光素异硫氰酸酯-葡聚糖，一种肠道屏障功能的标志物，同时降低了血浆总蛋白含量（P<0.05）。在 IQ 组中没有观察到这些变化，这表明 IQ 补充改善了 HS 下鸡的氧化损伤、蛋白质分解和肠道屏障功能。IQ 补充抑制了 HS 处理下肠道炎症因子 IL-6、肿瘤坏死因子样因子 1A 和诱导型一氧化氮合酶的表达（P<0.05）。这些结果表明，IQ 补充可以改善 HS 条件下肉鸡的生长性能，这可能与改善氧化损伤、蛋白质分解、肠道屏障功能和炎症有关。
