The objective of this study was to determine the effect of sulphur feed content on sulphur retention and excretion by pig. The sulphur content of 76 different feedstuffs commonly used to formulate pig diets was evaluated from INRA-AFZ database.
Total sulphur content varied between 0.5 and 15.3 g S/kg dry matter. For most of the feedstuffs, protein sulphur contributed to most of the sulphur content. However, inorganic sulphur was also found at a high level in some feedstuffs, especially in by-products from industrial process. In vivo experiments were conducted on fattening pigs individually housed in metabolic cages for collection of excreta. Eleven experimental diets, mainly based on wheat and on soybean meal, were compared. They differed by their protein content and the incorporation of feedstuffs with different total sulphur content (wheat, dried distiller’s grains with solubles, sugar beet pulp or rapeseed meal). Sulphur supply varied between 3.1 and 8.3 g S/pig/day. Sulphur retention by animals was not affected by the diet and amounted to 1.1 g S/pig/day on average. Sulphur excretion was highly affected by the diet and varied from 1.5 to 6.9 g/pig/day. Sulphur digestibility was 79% on average and urinary sulphur excretion represented 55% of intake. Sulphur was excreted as 100% sulphate speciation form in urine, 50% in faeces and 90% in slurry.
The results from this study indicate the feed composition may have a marked effect on sulphur excretion, with a specific contribution of some feedstuffs with high inorganic sulphur content.
P. Peu , J.-Y. Dourmad, S. Picard, P. Dabert. Contrôler les formes soufrées présentes dans les lisiers de porcs en utilisant l'approche alimentaire. 2012. Journées Recherche Porcine, 44, 127-132.