The nutritive value of white- and dark-flowered cultivars of pea for growing-finishing pigs

Abstract

The nutritive value of two white- and one dark-flowered cultivar of pea was determined in eight growing pigs weighing 31–55 kg. Each diet was given to two animals according to a replicated 4 × 4 Latin Square design. The apparent digestibility coefficients of organic matter, neutral detergent fibre, crude fibre and energy were significantly lower ( P < 0.05) for the dark-flowered cultivar than for the white-flowered cultivars. All pea cultivars differed significantly with respect to the digestibility of crude protein, whereas the dark-flowered cultivar had considerably lower digestibility coefficients than the other cultivars. The mean content of metabolizable energy in the dark-flowered cultivar was only 13.6 MJ kg −1 of dry matter, which was 1.5–2.1 MJ less than the contents of the two white-flowered cultivars. The differences in nutritive value between the white- and the dark-flowered cultivars of pea can be explained by a higher content of tannins and other “anti-nutritional factors” in the latter cultivar, which results in low digestibility of nutrients and energy and consequently, a lower content of metabolizable energy in the feed. The apparent digestibility coefficient of nutrients and energy and the metabolizable energy content of the diets increased with increasing weight and age of the animals. This is probably due to increased fermentation activity in the caecum-colon, as the efficiency of N retention and NPU were not influenced by changes in live weight.