Ji Woonhak, Kim Tae-Yong, Lee Chae Won, Kim Z-Hun, Jung Ji Young, Ban Byeong Cheol, Kong Changsu, Kim Myunghoo
Department of Animal Science, College of Natural Resources & Live Science, Pusan National University, Miryang 50463, Republic of Korea.
Department of Animal Science and Biotechnology, Kyungpook National University, Sangju 37224, Republic of Korea.
Poult Sci. 2025 Jan;104(1):104572. doi: 10.1016/j.psj.2024.104572. Epub 2024 Nov 22.
This study evaluated the effects of Parachlorella sp. KSN1 (PA) supplementation on the gut microbiota and intestinal immunity of broilers of different ages. A total of 180 Ross 308 broiler chicks were weighed and divided into early (1 to 10 days post hatch) and late (11 to 28 days post hatch) periods, with six replicates of 10 chicks per cage assigned to two dietary groups. The experimental diets included a corn-soybean meal-based control diet and a treatment diet supplemented with 0.5% PA, replacing corn or corn starch, and fed ad libitum for the assigned experimental period. On days 10 and 28, two broilers from each of the six replicate cages, with 7 broilers per cage in each group, were selected and euthanized, and cecal feces and intestinal tissue samples were collected. PA supplementation did not significantly affect broilers growth performance during both the early and the late periods. However, PA supplementation altered the cecal microbiome, with Clostridiaceae and Clostridium exhibiting prominent and consistent changes. In terms of intestinal immunity, PA supplementation significantly increased the number of CD3+ and CD4+ T cells when administered only during the early period. Cecal IgA levels were significantly increased by PA supplementation during both the early and late periods. A significant positive correlation was observed between IgA, Clostridiaceae and Clostridium during the early and late periods. Gene expression analysis identified 40 upregulated genes, including polymeric immunoglobulin receptor (pIgR), and 142 downregulated genes, including marginal zone B and B1 cell specific protein and immunoglobulin lambda-like polypeptide 1 that were associated with the IgA response in PA-treated broilers during the early period. This study demonstrated that PA supplementation promotes gut microbial colonization and intestinal immunity development during the early age of broilers. These findings suggest that the early growth period of broilers is the optimal time for dietary immunomodulation to promote gut health in broilers.
本研究评估了添加小球藻属KSN1（PA）对不同日龄肉鸡肠道微生物群和肠道免疫的影响。总共180只罗斯308肉鸡雏鸡称重后分为早期（出壳后1至10天）和晚期（出壳后11至28天），每个时期的两个日粮组每个笼子有6个重复，每个重复10只鸡。实验日粮包括以玉米-豆粕为基础的对照日粮和添加0.5% PA的处理日粮，PA替代玉米或玉米淀粉，在指定的实验期内自由采食。在第10天和第28天，从六个重复笼子中的每个笼子中挑选两只肉鸡（每组每个笼子7只肉鸡）进行安乐死，并收集盲肠粪便和肠道组织样本。在早期和晚期，添加PA均未显著影响肉鸡的生长性能。然而，添加PA改变了盲肠微生物群，其中梭菌科和梭菌属表现出显著且一致的变化。在肠道免疫方面，仅在早期添加PA时，显著增加了CD3 +和CD4 + T细胞的数量。在早期和晚期，添加PA均显著提高了盲肠IgA水平。在早期和晚期，IgA、梭菌科和梭菌属之间均观察到显著的正相关。基因表达分析确定了40个上调基因，包括多聚免疫球蛋白受体（pIgR），以及142个下调基因，包括边缘区B和B1细胞特异性蛋白以及免疫球蛋白λ样多肽1，这些基因与早期PA处理的肉鸡的IgA反应相关。本研究表明，添加PA可促进肉鸡幼龄期肠道微生物定植和肠道免疫发育。这些发现表明，肉鸡的早期生长阶段是通过日粮免疫调节促进肠道健康的最佳时期。
