Levels and Sources of Vitamin D for Pigs Fed Diets Containing Varying Quantities of Calcium

Abstract

When the level of calcium was increased from 0.48% to 0.88% and to 1.32% in the diet of young pigs, average daily gain and efficiency were decreased significantly, but there was not a significant effect on feed intake. The highest level of calcium significantly decreased the apparent digestibility of calcium and dry matter. The inclusion of 220 or 880 I.U. of vitamin D2 per kg. of diet significantly increased calcium absorption over the unsupplemented control group and the group subjected to ultraviolet irradiation. Average daily gain, feed intake and apparent digestibility of dry matter were not influenced significantly by vitamin D treatment. Neither calcium nor vitamin D treatment significantly affected apparent phosphorus digestibility or percent bone ash. Significant calcium × vitamin D interaction occurred only when apparent digestibilities of protein and ether extract were used as response criteria.