Calcium is often oversupplied in pig diets because limestone, the main source of Ca in pig diets, is an inexpensive feed ingredient and is often used as a carrier in premixes or a diluent in feed ingredients. However, excess Ca may be detrimental to P digestibility and pig growth performance. It was recently reported that commercial pig and poultry diets sold in Europe contain significantly more Ca than formulated, but it is not known if the Ca concentrations in commercial pig diets in the United States also contain more Ca than formulated. Therefore, a survey of commercial diets from the United States was conducted to compare analyzed and formulated values for Ca. A total of 103 diets were collected from feed mills, feed companies, or swine integrators in the United States between 2019 and 2021. Samples were analyzed for total Ca and total P. Results from the regression model used to evaluate the data indicated that diets on average contained 0.19 percentage units more total Ca and 0.06 percentage units more total P than expected. Thus, more attention needs to be paid to the inclusion of Ca in pig diets to avoid Ca oversupply and the negative effects of Ca on pig growth performance.

Read the full article in the Journal of Animal Science.