Minerais orgânicos: suplementação de cobre, ferro, manganês e zinco na dieta de poedeiras comerciais

Abstract

The objective was to evaluate the effects of replacing inorganic Fe, Cu, Mn and Zn minerals (sulphates) with organic ones (chelated methionine) in different layers in the laying diet, comparing zootechnical parameters, digestibility of nutrients and minerals, in addition to quality variables and mineral composition of the egg. 240 Dekalb White laying hens at 67 weeks were used, with 48 birds per treatment, 12 per repetition. The diets were isoenergetic, isonutrients, without phytase and with a 10-week diet consolidation period. The treatments were constituted by the origin and inclusion of minerals, being: inclusions made commercially with inorganic (MI100) and organic (MO100) minerals, and decreasing inclusions of 65%, 45% and 35% of organic mineral premix (MO65, MO45 and MO35 ). It was evaluated: production index, egg per housed bird (OAA), viability, egg weight and mass, percentage of bitten and lost, digestibility of food and nutrients, retention and excretion of minerals, physical chemical characteristics and traces of these minerals in the shell, yolk and albumen. The birds in the MO35 and MO45 treatments had a lower production index, and regardless of inclusion, those fed with organic minerals had a higher egg weight, and the egg mass did not differ between the MI100, MO35 and MO45 treatments, although larger masses had observed for MO65 and MO100. The digestibility of food and nutrients, and the quality of eggs were not influenced by the source or inclusion of minerals. Fe showed the highest retention index followed by Cu, Zn and Mn. Mn and Zn showed higher bioavailability in relation to inorganic origins and the reduction in the inclusion of organic minerals did not alter the retention, which was confirmed by the decreasing excretion of these minerals. The deposition of organic Zn in the bark increased with the increase of inclusions, and in the yolk it decreased. It is concluded when considering the zootechnical indexes of economic importance, OAA, viability, weight and egg mass, that the supplementation of 2.8 mg / Kg of Cu, 17.7 mg / Kg of Fe, 24.5 mg / Kg of Mn and 17.5 mg / Kg of Zn, chelated methionine minerals (MO35) meets the demand for micro minerals for the performance and production of good quality white laying eggs in the last third of the laying cycle.