Insawake Kittisak, Songserm Thaweesak, Songserm Ornprapun, Plaiboon Atthawoot, Homwong Nitipong, Adeyemi Kazeem D, Rassmidatta Konkawat, Ruangpanit Yuwares
Department of Animal Science, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand.
Department of Pathology, Faculty of Veterinary Medicine, Kasetsart University10900, Thailand.
Poult Sci. 2025 Jan;104(1):104671. doi: 10.1016/j.psj.2024.104671. Epub 2024 Dec 12.
This study investigated the effect of isoquinoline alkaloids as an alternative to bacitracin on growth performance, oxidative stress, inflammatory status, and ceca microbiome of broilers raised under high stocking density (HSD). A total of 1,500 one-day-old male Ross 308 chicks were randomly assigned to five treatment groups, with 10 replicate pens per group and 30 birds per pen, for 37 days. The treatments included normal stocking density (NSD, 10 birds/m²), HSD (15 birds/m²), HSD with 50 ppm Bacitracin (BCT50), HSD with 80 ppm isoquinoline alkaloids (IQA80), and HSD with 100 ppm isoquinoline alkaloids (IQA100). From days 11 to 24, HSD birds had lower feed efficiency (P < 0.05) compared to those in other treatments. The heterophil-to-lymphocyte ratio and malondialdehyde levels were lower in NSD and IQA80 birds compared to HSD and BCT50 birds (P < 0.05). HSD birds had higher IL-6 and a lower villus height and villus height-to-crypt depth ratio compared to birds in other groups (P < 0.05). Serum TNF-α was lower in NSD and IQA80 birds compared to those in the HSD group. Alpha diversity was not affected by the treatments; however, beta diversity was lower in HSD birds compared to other treatments. HSD birds showed reduced microbial diversity, with a higher prevalence of Enterococcaceae and Peptostreptococcaceae. NSD enhanced the abundance of Lactobacillaceae, Clostridiaceae, and Rikenellaceae. BCT50 increased and decreased the abundance of Enterococcaceae and Rikenellaceae respectively. IQA80 and IQA100 increased the abundance of Lachnospiraceae, Leuconostocaceae, and Coriobacteriaceae. HSD altered metabolic pathways related to carbohydrate and lipid metabolism, and amino acid biosynthesis. BCT50 modulated microbial functions, particularly those related to cell wall synthesis, while isoquinoline alkaloids upregulated pathways involved in energy production, secondary metabolite biosynthesis, and antioxidant production. Both Bacitracin and isoquinoline alkaloids were effective in mitigating the negative effects of HSD on immunity, gut health and microbiota in broilers. Given the concerns about antimicrobial resistance, isoquinoline alkaloids are a potent alternative to bacitracin, with IQA80 being particularly recommended.
本研究调查了异喹啉生物碱作为杆菌肽的替代品，对高饲养密度（HSD）下饲养的肉鸡生长性能、氧化应激、炎症状态和盲肠微生物群的影响。总共1500只1日龄雄性罗斯308肉鸡被随机分配到五个处理组，每组10个重复栏，每栏30只鸡，为期37天。处理包括正常饲养密度（NSD，10只鸡/m²）、HSD（15只鸡/m²）、添加50 ppm杆菌肽的HSD（BCT50）、添加80 ppm异喹啉生物碱的HSD（IQA80）和添加100 ppm异喹啉生物碱的HSD（IQA100）。在第11至24天，与其他处理组相比，HSD组的肉鸡饲料效率较低（P<0.05）。与HSD组和BCT50组相比，NSD组和IQA80组的肉鸡异嗜性粒细胞与淋巴细胞比率和丙二醛水平较低（P<0.05）。与其他组相比，HSD组的肉鸡IL-6水平较高，绒毛高度和绒毛高度与隐窝深度比率较低（P<0.05）。与HSD组相比，NSD组和IQA80组的肉鸡血清TNF-α水平较低。处理对α多样性没有影响；然而，与其他处理组相比，HSD组的肉鸡β多样性较低。HSD组的肉鸡微生物多样性降低，肠球菌科和消化链球菌科的患病率较高。NSD组提高了乳酸杆菌科、梭菌科和理研菌科的丰度。BCT50组分别增加和降低了肠球菌科和理研菌科的丰度。IQA80组和IQA100组增加了毛螺菌科、明串珠菌科和棒状杆菌科的丰度。HSD改变了与碳水化合物和脂质代谢以及氨基酸生物合成相关的代谢途径。BCT50调节微生物功能，特别是与细胞壁合成相关的功能，而异喹啉生物碱上调了与能量产生、次生代谢物生物合成和抗氧化剂产生相关的途径。杆菌肽和异喹啉生物碱均能有效减轻HSD对肉鸡免疫力、肠道健康和微生物群的负面影响。鉴于对抗菌素耐药性的担忧，异喹啉生物碱是杆菌肽的有效替代品，特别推荐IQA80。
