The influence of different calcium source and calcium levels on the growth performance, immune organ indexes, intestinal microbiota and morphology of broiler chickens was studied. We used scallop shells to produce active dicalcium phosphate (ADP), shell powder cleaned by acetic acid (SCAC), and shell powder cleaned by distilled water (SS). A total of 300 1-d-old broiler chickens were randomly assigned to 6 treatments. The broiler chickens received a basal diet supplemented with 0.95% or 1.05% ADP, SCAC, and SS treatments until d 42. Compared with broiler chickens fed SCAC and SS, a diet with 1.05% ADP supplementation is more effective. It exhibited a greater average daily weight gain and lower feed conversion ratio (P < 0.05). The leg muscle yield were increased and the abdominal fat rate was decreased (P < 0.05). The length of the duodenum, jejunum, and ileum as well as the weight of spleen, thymus, and bursa immune organs and the activities of digestive enzymes were increased (P < 0.05). Harmful bacteria were inhibited and beneficial bacteria were increased. (P < 0.05). Furthermore, it increased the villus height and villus height to crypt depth ratio and decreased the crypt depth (P < 0.05), thereby improving intestinal development. Therefore, ADP is a potential calcium source as a kind of feed additive.

研究了不同钙源和钙水平对肉仔鸡生长性能，免疫器官指标，肠道菌群和形态的影响。我们使用扇贝贝壳生产活性磷酸二钙（ADP），用乙酸清洗过的贝壳粉（SCAC）和用蒸馏水清洗过的贝壳粉（SS）。总共300只1日龄的肉鸡被随机分配到6种处理中。到第42天，肉鸡接受基础饮食，同时补充0.95％或1.05％ADP，SCAC和SS处理。与饲喂SCAC和SS的肉鸡相比，添加1.05％ADP的肉鸡更为有效。它表现出更大的平均日增重和较低的饲料转化率（P <0.05）。腿部肌肉产量增加，腹部脂肪减少（P <0.05）。十二指肠，空肠和回肠的长度以及脾脏，胸腺和法氏囊的免疫器官的重量和消化酶的活性均增加（P <0.05）。有害细菌被抑制，有益细菌增加。（P <0.05）。此外，它增加了绒毛高度和绒毛高度与隐窝深度之比，并降低了隐窝深度（P <0.05），从而改善了肠道发育。因此，ADP作为饲料添加剂是一种潜在的钙源。