Effects of commercial premix vitamin level on sternum growth, calcification and carcass traits in meat duck.

The present study was conducted to investigate the effects of dietary vitamin level on sternum growth, calcification and carcass traits in meat duck. A total of 432 1-d-old mixed-sex Cherry Valley ducks (216 males and 216 females) were randomly allocated and fed low-vitamin level diet (70% NRC vitamin regimen), high-vitamin level diet (DSM vitamin regimen) or medium-vitamin level diet (50% low-vitamin level diet and 50% high-vitamin level diet). Sternum and serum were harvested after 49 d of feeding. Compared with the low-vitamin level group, dietary high-vitamin level increased body weight (BW) at d 49 (p = 0.029) but did not alter all parameters of carcass trait (p > 0.05). Medium- and high-vitamin level increased sternum defatted weight, density, ash and calcium (Ca) concentration (p < 0.05). Meanwhile, the medium and high-vitamin level group significantly decreased the relative proportions of the keel cartilage at 49 d (p < 0.05) and decreased the sternum length and height (p < 0.05) in meat ducks at 49 d. Likewise, high-vitamin level improved serum Ca and phosphate (P) content (p < 0.05) and declined serum Alkaline phosphatase (ALP) activity (p = 0.003) compared with the low-vitamin level group. Our study indicates that high-vitamin level did not affect the examined carcass traits; however, high-vitamin level improved growth performance and sternum calcification.