Effects of Mineral Supplements on Bioproductive Results in Egg-Laying Hens Farmed in Organic Systems

Abstract

The experiment on mineral supplementation of feed, in egg-laying hens, was carried out in concordance with the national and common legislation, with the feeding and maintenance conditions specific to the organic system. According to the experimental organization scheme, a group of 90 egg-laying hens, with the age of 19-34 weeks, was randomly distributed in three experimental variants and fed on a basic CM; the differentiating nutritional factor was represented by the level of microelement supplementation, as follows: -V₁ – fed on CM, without mineral premix; the micromineral participation was provided by the CM basic components, determined according to specific chemical analyses, at the level of 60.68 mg Fe, 20.33 mg Mn, 28.16 mg Zn, 7.73 mg Cu, 0.12 mg Co, 0.06 mg I, 0.26 mg Se/kg SU – CM; -V₂ – fed on CM, with supplementation of mineral premix; the microelement participation was adapted to the extensive breeding and the supplementation was 70.68 mg Fe, 40.33 mg Mn, 48.16 mg Zn, 9.23 mg Cu, 0.24 mg Co, 0.26 mg I, 0.36 mg Se / kg SU CM; -V3 – fed on CM + mineral premix with double microelement supplementation, reaching the level of 80.68 mg Fe, 60.33 mg Mn, 68.16 mg Zn, 10.73 mg Cu, 0.37 mg Co, 0.46 mg I, 0.46 mg Se / kg SU CM. In this experiment, we determined nutritive indices and also bioproductive indices related to egg quantity and quality. The results prove the necessity of feed supplementation with microminerals in the egg-laying hens bred in organic systems as well, but with levels reduced with 50% compared with the intensive systems.