Istiteh Rahaf, Abuajamieh Mohannad, Al-Qaisi Mohmmad, Abedal-Majed Mohamed A, Abdelqader Anas
Department of Animal Production, School of Agriculture, The University of Jordan, 11942, Amman, Jordan.
Vet World. 2025 Apr;18(4):1059-1069. doi: 10.14202/vetworld.2025.1059-1069. Epub 2025 Apr 30.
Heat stress (HS) significantly compromises broiler performance, intestinal health, and immune responses, posing a growing threat under climate change. Probiotics (PROs) have been proposed as a nutritional intervention to mitigate HS effects, yet their efficacy through drinking water remains understudied. This study aimed to evaluate the effects of water-supplemented PROs on growth performance, physiological responses, intestinal morphology, and inflammatory biomarkers in broiler chickens under thermo-neutral (TN) and HS conditions.
A total of 192 one-day-old Ross 308 broiler chicks were randomly allocated to four treatment groups (6 replicates/group): TN with control (CON) water, TN with PRO-supplemented water, HS with CON water, and HS with PRO-supplemented water. PROs ( and ) were administered in drinking water at 50 mg/L from day 1 to 35. Birds in the HS groups were subjected to 3 h daily heat exposure (33°C ± 2°C) from days 31 to 35. Growth performance, physiological indicators, intestinal histomorphology, and blood biomarkers were assessed.
HS significantly increased rectal temperature (Tr) (1.6°C; p < 0.01) and respiratory rate (57 breaths/min; p < 0.01). PRO supplementation reduced Tr by 0.17°C (p = 0.01) but did not affect performance metrics (feed intake, body weight gain, feed conversion ratio). HS reduced villus height (VH) and surface area in the jejunum and ileum (p < 0.05), while PROs partially ameliorated VH under HS. No significant effects of PROs were observed on serum amyloid A or tumor necrosis factor-alpha levels. However, PROs tended to reduce diamine oxidase levels (24%; p = 0.09). HS also decreased albumin and glucose levels (p ≤ 0.02).
HS adversely affected intestinal integrity and selected blood metabolites. Although PRO supplementation had limited effects on performance and inflammatory biomarkers, it conferred modest thermoregulatory benefits and tended to improve intestinal permeability. Further research is warranted to optimize PRO formulation and assess synergistic strategies for HS mitigation in poultry.
热应激（HS）严重影响肉鸡的生产性能、肠道健康和免疫反应，在气候变化的背景下构成了日益严重的威胁。益生菌（PROs）已被提议作为一种营养干预措施来减轻热应激的影响，但其通过饮水的功效仍未得到充分研究。本研究旨在评估在热中性（TN）和热应激条件下，通过饮水补充益生菌对肉鸡生长性能、生理反应、肠道形态和炎症生物标志物的影响。
总共192只1日龄的罗斯308肉鸡随机分为四个处理组（每组6个重复）：热中性条件下饮用对照水（CON）组、热中性条件下饮用补充益生菌的水组、热应激条件下饮用对照水组、热应激条件下饮用补充益生菌的水组。从第1天到第35天，以50 mg/L的浓度将益生菌（ 和 ）添加到饮水中。热应激组的鸡在第31天到第35天每天接受3小时的热暴露（33°C ± 2°C）。评估生长性能、生理指标、肠道组织形态学和血液生物标志物。
热应激显著提高了直肠温度（Tr）（1.6°C；p < 0.01）和呼吸频率（57次/分钟；p < 0.01）。补充益生菌使直肠温度降低了0.17°C（p = 0.01），但对生产性能指标（采食量、体重增加、饲料转化率）没有影响。热应激降低了空肠和回肠的绒毛高度（VH）和表面积（p < 0.05），而益生菌在热应激条件下部分改善了绒毛高度。未观察到益生菌对血清淀粉样蛋白A或肿瘤坏死因子-α水平有显著影响。然而，益生菌有降低二胺氧化酶水平的趋势（24%；p = 0.09）。热应激还降低了白蛋白和葡萄糖水平（p ≤ 0.02）。
热应激对肠道完整性和某些血液代谢物有不利影响。虽然补充益生菌对生产性能和炎症生物标志物的影响有限，但它具有适度的体温调节益处，并倾向于改善肠道通透性。有必要进一步研究以优化益生菌配方，并评估减轻家禽热应激的协同策略。
