Mineral and vitamin supplementation of diets for growing pigs. 2. Barley, oats, sorghum and maize-based diets

Abstract

The response of growing pigs to supplementation with minerals, vitamins, or both, when fed diets bassd on barley, oats, sorghum or maize was examined in six factorial experiments involving 192 pigs. In two of these experiments meat-and-bone meal (with some fish meal up to 32 kg liveweight) was used as a protein concentrate with barley and oats. In the other four experiments, soybean meal (SBM) was used with each grain. A base supplement of vitamins A and D3 was added to all diets, The pigs were restrictively and individually fed between 18 and 73 kg. Mineral supplementation of the animal protein (AP) diets did not affect pig performance, but improved that of pigs fed the SBM diets. Lack of supplementary minerals in the SBM diets caused slow growth, broken bones, foot abnormalities and failure of many pigs to reach slaughter weight. Some results indicated there were differences in mineral availability between grains. Vitamin supplementation, over and above vitamins A and D3 did not affect performance of pigs fed AP diets. Despite a number of apparent vitamin deficiencies in the SBM diets, there was little or no response to vitamin supplementation. The lack of response suggests the vitamin requirements of growing pigs currently estimated by the Agricultural Research Council are high for restrictively fed pigs.