Effect of proteinate or sulphate mineral sources on trace elements in blood and liver of piglets

Four hundred piglets were housed in 20 pens and offered for 42 days a pre-starter and then a starter compound supplemented with trace elements given as sulphates (SULF) or proteinates (PROT) at a common level (100) or at a reduced level (20) of inclusion. The common level supplied 278, 148, 315 and 98 mg/kg and the reduced level supplied 128, 38, 135 and 50 mg/kg of iron (Fe), copper (Cu), zinc (Zn) and manganese (Mn), respectively taking into account the natural food contents. Proteinates used in the trial were analysed and described in terms of content and quality of different potential ligands. Piglet growth was not affected by any treatment. At the end of the trial blood samples were collected from eight pigs for each treatment. These animals were slaughtered and their livers were removed, weighed and analysed. Compared with SULF, PROT increased significantly plasma levels of Fe (25.1 v. 15.7 mu mol/l), haemoglobin (10.9 v. 10.4 g/dl) and the number of red blood cells (6.4 v. 6.1 millions per mu l) but the liver recovery of Fe was not affected by any treatment. In piglets receiving PROT the liver content of Cu and Zn increased significantly compared with those receiving SULF On reducing the dosage, CEI in the liver significantly decreased with SULF but not with PROT and the amount of Zn decreased move with SULF than with PROT. The results may reflect a better availability of Cu and Zn when proteinates rather than sulphates were used as mineral supplements.