Link To:

Study Looks at Calcium in Canola Meal as Part of Pig Diet

18 Mar 2014

US - When formulating diets for pigs, it is more accurate to use values for standardized or true nutrient digestibility than values for apparent nutrient digestibility because the former are additive in mixed diets. Research at the University of Illinois is helping to determine the true digestibility of calcium in swine diets.

Hans H. Stein, a professor of animal sciences at the U of I, led the team that conducted the study. "We know that there are endogenous losses of calcium in cattle and chickens, and our hypothesis was that the same is true for pigs," Stein said. "We also wanted to determine if adding microbial phytase to the diets would affect endogenous losses of calcium."

Stein's team set out to determine the apparent total tract digestibility (ATTD) and true total tract digestibility (TTTD) of calcium in canola meal without and with microbial phytase. They fed growing pigs four diets containing 0.08, 0.16, 0.24, or 0.32 percent calcium. All of the calcium in the diets came from canola meal, which is one of the few ingredients that contain both phytate and appreciable amounts of calcium. In addition, they fed four diets that were identical to the first four except that they also contained 1,500 units per kilogram of microbial phytase.

In diets both with and without added phytase, the ATTD of calcium increased as the calcium level in the diets increased. This indicated that there was endogenous loss of calcium. Using regression equations, the researchers estimated that the total endogenous loss of calcium was 0.160 g/kg dry matter intake (DMI) for pigs fed diets with no added phytase, and 0.189 g/kg DMI for pigs fed diets containing microbial phytase. These values were not statistically different, demonstrating that phytase doesn't affect endogenous loss of calcium, Stein said.

See detail, please visit