Bioavailability of iron from amino acid complex in weanling pigs

The objective of the study was to evaluate the iron bioavailability of iron amino acid complex, Availa-Fe compound, as compared to the iron from feed grade ferrous sulfate in weanling piglets. Seventy-two 30-day-old three-way cross piglets, with an average live-weight of 6.41 kg, were randomly allocated into 12 groups of six dietary treatments and two replicates. The control diet (C) included 100 mg kgÿ1 iron from ferrous sulfate heptahydrate into a basal corn±soybean±whey diet. The other dietary treatment groups were supplemented an additional 30, 60, 90, or 120 mg kgÿ1 of iron from Availa-Fe into the control diet. An additional diet supplemented with 120 mg kgÿ1 of iron from ferrous sulfate heptahydrate into the control diet was used as a positive control. The piglets fed Availa-Fe as an iron source did not demonstrate a statistically signi®cant improvement in live-weight gains or feed-conversion ratio. The monitored parameters that responded to increases in the level of Availa-Fe supplementation, included pack cell volume, hemoglobin concentration, plasma iron and total iron binding capacity in the blood, hemosiderin and ferritin iron in the liver and spleen. Skin redness with an `a' value in color measurement increased signi®cantly as the level of Availa-Fe supplement increased (p<0.05). The total iron content, heme-iron concentration in the muscle and skin color responded to increases in the level of Availa-Fe supplementation. The bioavailability of iron from Availa-Fe is signi®cantly better compared to ferrous sulfate supplementation. # 2000 Elsevier Science B.V. All rights reserved.