Spirulina platensis (Sp) or Amphora coffeaeformis (Am) are good candidates as an in-feed antibiotic substitute for broilers. This work was performed to investigate the effects of Sp and Am on the growth performance, intestinal microbial population, physiological responses, and blood biochemical constituents in broiler chickens. Fifty-one-day old Cobb broilers (with initial body weights 50-55 g) were allocated to five groups. Each treatment group had five replicate pens with two birds each. The experiments lasted for 35 days. The 1st group had basal diet (control group). The 2nd and 3rd groups received basal diet, along with 5- or 10-g/kg Sp as a feed ingredient, respectively. While the 4th and 5th groups received basal diet, along with 5- or 10-g/kg Am as a feed ingredient, respectively. Data analysis revealed significantly higher body weight gains (P ≤ 0.05) with higher Sp or Am levels and, in turn, linear improvements (P ≤ 0.05) in feed conversion values. In addition, intestinal Lactobacillus sp. was increased, and Escherichia coli populations were decreased by both dietary Sp levels or Am levels. Furthermore, the liver (% body weight) was significantly decreased (P ≤ 0.05) and the heart (% body weight) was significantly increased (P ≤ 0.05) with higher Sp or Am levels in comparison with untreated control. In conclusion, dietary inclusion with 10 g/kg of Sp and Am could improve the growth performance, serum biochemical parameters and intestinal microbial population in broiler chickens.
Keywords: Amphora; Broiler; Dietary supplement; Growth factor; Spirulina.