Biodisponibilidade de ferro em diferentes compostos para leitões desmamados aos 21 dias de idade Bioavailability of iron in different compounds for piglets weaned at 21 days old

Abstract

Avaliou-se a biodisponibilidade de ferro de diferentes compostos visando sua utilização em dietas para leitões desmamados. Utilizaram-se 44 leitões (7 não-anêmicos e 37 anêmicos) desmamados aos 21 dias de idade (7,3 ± 1,8 kg) e distribuídos em dois grupos: grupo não-anêmico e grupo anêmico. Durante sete dias, os animais do grupo não-anêmico receberam dieta com FeSO4.7H2O (sulfato ferroso hepta-hidratado) na dose de 100 mg/kg e os do grupo anêmico, dieta sem ferro (Iron bioavailability from different compounds was evaluated to be used in diets for weaned piglets. Forty four piglets (7 non-anemic and 37 anemic) weaned at 21 days old (7.3 ± 1.8 kg) were distributed into two groups: non-anemic group and anemic group. During seven days, the animals from non-anemic group were fed diet with ferrous sulfate hepthydrate (FeSO4.7H2O) in the dose of 100 mg/kg and of the anemic group, diet without iron (<15 mg/kg diet). On the seventh day, after the determination blood hemoglobin concentration and diagnosed with anemia, piglets were grouped according to product of the weight (kg) × hemoglobin (g/dL) and individually housed, for 13 days in cages for digestibility studies, where they were fed with six diets based on corn and powdered milk: three standard diets with FeSO4.7H2O in equivalent amount of 80, 150 and 200 mg Fe/kg diet; two experimental diets, one with iron (150 mg/kg) in form of FeSO4 microencapsulated with carboxymethylcellulose and other chelated with methionine, and a control diet with iron (100 mg/kg). In the days 0, 3, 6, 9 and 13 of the repletion period, the animals were weighed for performance evaluation and blood was collected to determine the hemoglobin concentration. At the end, the animals were slaughtered and liver was collected for determination of total iron concentrations, Fe-heme and Fe non-heme. Liver concentrations of Fe-heme, Fe non-heme and Fe-total did not differ among animals, however, the control group showed excess of Fe-total in the liver, related to iron injected dose in the piglets after weaning. Compared to FeSO4.7H2O not encapsulated, iron compounds microencapsulated with carboxymethylcellulose and iron chelate with methionine promote better feed conversion in weaned piglets.

Keywords

• absorção
• hemoglobina
• ingrediente alternativo
• absorption
• alternative ingredient
• hemoglobin