Physicochemical properties of raw potato starch and its protective effect on bone quality in meat ducks with...

Compromised bone quality predisposes domesticated birds to fractures in meat ducks, leading to pain and bad welfare. As a fermentable type II resistant starch, raw potato starch (RPS) probably supports gut health and potentially mitigate this inflammatory bone loss. Accordingly, the physicochemical properties of RPS were characterized, and its protective effect on bone quality in meat ducks were evaluated in the present study. The outcomes from electron microscope and X-ray diffraction showed that RPS possessed a round or oval granules with a smooth surface and a B-type crystalline structure. Subsequently, a total of 60 1-day-old meat ducks were randomly assigned to two treatment groups and fed either a basal diet or a diet containing 12% RPS until 21 d (Animal trial 1). The results revealed that dietary supplementation of RPS increased (P < 0.05) tibial ash content of meat ducks, which negatively correlated gut leak and serum inflammatory status. To confirm the protective role of RPS in enteritis-induced bone loss in meat ducks. Ducklings were allocated to a phosphate-buffered saline control group, dextran sodium sulphate (DSS) oral administration group, and DSS treatment and fed a 12% RPS diet group with 8 repetitions of 10 birds each to 21 d (Animal trial 2). Duck challenged DSS exhibited increased bone resorption and compromised tibia density and mechanical properties (P < 0.05). DSS treatment downregulated the expressions of tight junction proteins and triggered intestinal inflammation in ileum, whereas failed to change the composition of caecal microbiota. In meat ducks with DSS-induced enteritis, feeding a diet of RPS reversed inflammation-induced bone loss. This effect was accompanied by increased serum phosphorus levels (P < 0.05) and reduced pro-inflammatory cytokines in the bone marrow microenvironment, leading to decreased osteoclastic bone resorption. These findings support that a diet with 12% RPS might be one of promising holistic approaches for mitigating systemic inflammation and consequent bone loss in meat ducks.