Dietary Spirulina inclusion in low-protein diets modulated the proportion of cecal propionic acid with a marginal effect on jejunal morphology in broiler chickens

This study assessed the effect of dietary Spirulina (SP) on the growth performance, cecal short-chain fatty acids, and the jejunal morphology of broiler chickens fed an adequate (195 g/kg) or low crude protein (LCP) diet (160 g/kg). Birds were fed a starter diet from d 1 to 8 post-hatching. Birds were assigned to 4 dietary treatments in a 2 × 2 factorial arrangement with two crude protein (CP) levels (195 or 160 g/kg CP) and two added SP levels (0 or 50 g/kg) from d 8 to 20 post-hatching. There were 8 replicate cages per treatment with 8 birds per cage. Dietary SP addition increased (P < 0.05) villus height to crypt depth ratio and ileal digestible energy in broilers, regardless of CP level. There was a tendency (P = 0.091) for an SP × protein level interaction on the jejunal villus area of broiler chickens. Moreover, there was an SP × CP level interaction (P < 0.05) on the proportion of propionic acid in the cecal digesta of birds. In conclusion, the study demonstrates that an LCP diet with dietary Spirulina inclusion altered cecal short-chain fatty acid proportion and marginally induced changes in jejunal morphology in broiler chickens.