Model setting of the micromineral supplementation values in laying hens raised in organic system.

摘要

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 were used per replicate making ten birds per treatment. The hens were randomly distributed in three experimental variants and fed on a basic CM (concentrate mixture); the differentiating nutritional factor was represented by the level of microelement supplementation, as follows: G₁ (30 hens) fed on CM, without mineral premix; the micromineral participation was provided by the CM basic components, determined according to specific chemical analyses, Fe 60.68, Mn 20.33, Zn 28.16, Cu 7.73, Co 0.12, I 0.06 and Se 0.26 mg/kg DM of CM; G₂ (30 hens) fed on CM, with supplementation of mineral premix; the microelement participation was adapted to the extensive breeding and the supplementation was Fe 70.68, Mn 40.33, Zn 48.16, Cu 9.23, Co 0.24, I 0.26, Se 0.36 mg/kg DM of CM; G₃ (30 hens) fed on CM+mineral premix with double microelement supplementation, adapted to the intensive breeding, reaching the level of Fe 80.68, Mn 60.33, Zn 68.16, Cu 10.73, Co 0.37, I 0.46, Se 0.46 mg/kg DM of CM. In this experiment, we determined the nutritive indices and also the bioproductive indices related to egg quantity and quality. Mineral supplementation of feed in egg-laying hens for an extensive growth significantly influenced on the egg-mass, the feed conversion ratio, and from the egg quality indices, the albumen index and the Haugh index. The results prove the necessity of feeding supplementation with microminerals in the egg-laying hens bred in organic systems as well, but with levels adapted to the extensive breeding.