Effects of Calcium Source and Calcium Level on Growth Performance, Immune Organ Indexes, Serum Components, Intestinal Microbiota, and Intestinal Morphology of Broiler Chickens

Abstract

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.