The present study investigated the influence of dietary threonine (Thr) levels and ajwain seed (AS) on the growth performance, immunity, blood metabolites, ileal microflora and jejunum morphology of broiler chickens. A total of 600‐day‐old male broiler chickens (Ross 308) were randomly allocated among five replicates of eight dietary treatments according to a 4 × 2 factorial arrangement of treatments, including four different levels of Thr (100, 105, 110 and 115% of requirements) and two inclusion rates of AS (0 or 10 g/kg of the diet). Body weight gain and FCR improved in broiler chickens fed 105% Thr supplement during the starter, finisher and whole periods of the experiment (p < .05). The broiler chickens fed AS supplemented diet had a greater weight gain (25–42 days) and better FCR (1–10 and 25–42 days) than those without AS (p < .05). A significant interaction was observed between Thr and AS supplementation for lymphocyte, heterophil/lymphocyte (H/L), bursa and spleen (p < .05). The liver enzyme activity of aspartate aminotransferase (AST) was higher in the chicks that received diet without AS supplement than those fed AS diet (p < .05). Inclusion of 105% dietary Thr and 10 g/kg AS increased the viable cell counts of Lactobacilli and decreased the population of the Escherichia coli in broilers (p < .05). In jejunum morphology, the broiler chickens fed 105% Thr diet had a greater villus length, width and crypt depth (p < .05). Also, the villus length was longer in broilers that received AS supplemented diet (p < .05). It is concluded that the dietary 105% of Thr and AS supplement individually improved growth performance, ileal microbial population and jejunum morphology of broiler chickens.

中文翻译：

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日粮苏氨酸在分级水平上的苦艾种子（Trachyspermum ammi L.）对肉鸡生长性能，血清代谢产物，肠道形态和微生物种群的功效。

本研究调查了日粮苏氨酸（Thr）水平和a丝种子（AS）对肉鸡生长性能，免疫力，血液代谢产物，回肠微生物区系和空肠形态的影响。根据4×2处理顺序，将总共600天大的雄性肉鸡（罗斯308）随机分配到八种饮食疗法的五份重复样本中，包括四种不同水平的苏氨酸（100、105、110和115） ％的要求）和两种AS的添加率（0或10 g / kg的饮食）。在试验的开始，结束和整个试验过程中，饲喂添加了105％Thr的肉鸡的体重增加和FCR均得到改善（p <.05）。与不添加AS的肉鸡相比，添加AS饮食的肉鸡体重增加（25-42天）和FCR（1-10和25-42天）更好（p  <.05）。观察到Thr和AS补充之间的淋巴细胞，异嗜性/淋巴细胞（H / L），滑囊和脾脏之间存在显着的相互作用（p <  .05）。在不添加AS饲料的雏鸡中，天门冬氨酸转氨酶（AST）的肝酶活性高于饲喂AS的雏鸡（p  <.05）。105％的膳食苏氨酸和10g / kg的AS增加的活细胞计数的夹杂物乳杆菌和人口减少大肠杆菌肉鸡（p <.05）。空肠形态下，饲喂105％Thr饲料的肉鸡的绒毛长度，宽度和隐窝深度更大（p  <.05）。同样，接受AS补充饮食的肉鸡的绒毛长度更长（p  <.05）。结论是，饮食中105％的Thr和AS补充剂分别改善了肉鸡的生长性能，回肠微生物种群和空肠形态。