PERFORMANCES OF LAYING HENS IN CONDITIONS OF EXPLOATATION IN AVIARIES

C. Spridon, Paula Druc, Carmen Gavrilescu, M.G. Usturoi

Abstract
   The predictions regarding exploitation of laying hens in cages show a possible renounce of this working principle, so the specialists are improving the nowadays alternative rearing systems; those technical solutions must allow greater densities on square unit and to assure a suitable free movement for birds. In the current paper are presented the performances realised by laying hens in conditions of exploitation in aviaries, during 20-60 weeks age period. Investigations were carried out on 36343 ISA Brown hens accommodated into a shelter of 2642 m² equipped with a Natura Nova Twin aviaries, and for comparison were utilised 10346 ISA Brown hens exploited in Big Dutchman cages, Eurovent type. The assured microclimate factors presented lower or higher variations, function of several factors, but especially due to the utilised rearing system, but without leaving the zone of physiological comfort. Body weight of the studied hens was higher than the standard of utilised hybrid, consequence of a photo-stimulation process applied in the host unit, sustained their very good egg production. During studied period, hens reared in aviaries obtained a production of 254.49 eggs/head, and the ones from cages obtained 258.08 eggs/head (face to a theoretical value of 246 eggs), at a mean laying intensity of 88.66%-aviaries and respectively 89.88%-cages (88.51% being the theoretical intensity). Maximum intensity of laying was reached at age of 31 weeks and was of 93.3% for the hens in aviaries and 93.85% at the ones from cages (theoretical performance being 96%). During whole studied period, mean daily consumption of mixed fodders was 120.17 g m.f./head/day respectively, of 115.29 g m.f./head/day, while feed conversion index was situated at levels of 135.34 g m.f./egg in the case of hens reared in aviaries and of only 127.66 g m.f./egg at the ones from cages. In conclusion, we could say that rearing system in aviaries assure optimal conditions for productive potential of laying hybrids, at comparable levels with the ones realised at rearing in cages.

Key words: rearing, aviaries, hens, production, eggs