Isoquinoline alkaloids and keto-fatty acids of Argemone ochroleuca and A. mexicana (mexican poppy) seed.II. Concentrations tolerated by pigs

Abstract

Two batches of Mexican poppy seed were fed to pigs in several experiments to determine tolerable concentrations in pig diets. One batch, botanically identified as Argemone ochroleuca, was split and one half exposed to sunlight after milling. Sunlight rendered A. ochroleuca seed non-toxic at 4% in the diet, whereas 1% of freshly milled seed was toxic within 3-4 weeks. Signs of toxicity were pronounced reductions in feed intakes, lethargy, reddening of the skin and mild diarrhoea. The relative toxicity of the sunlight-exposed and freshly milled seed could not be explained in terms of the contents of the alkaloids sanguinarine, chelerythrine, protopine or berberine, but may be explained by the total isoquinoline alkaloid contents, of which the major components are dihydrosanguinarine and dihydrochelerythrine. These latter alkaloids were previously thought to be non-toxic. Based on pig performance data and alkaloid contents of different batches of A. ochroleuca, we suggest a safe tolerance of 0.2% in the diet of grower pigs, and up to 1% for finisher pigs. Similar concentrations of A. mexicana should be tolerated, based on alkaloid contents.