STUDIES REGARDING THE INFLUENCE OF REARING SYSTEM FOR LAYING HENS (LOFT vs. BATTERY) ON QUALITY OF EGGS

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

Abstract
    Research was focused on quality of eggs provided by ISA Brown hybrid exploited in two different systems: Natura Nova Twin loft; Eurovent battery. Eggs were gathered at for different ages of birds (20, 31, 40 and 60 weeks). Abnormal morphological eggs were into a mean rate of 1.43% at hens reared in battery and of 1.36% at the ones from loft. Mean weight of eggs was 58.99 g at the hens from battery and 59.23 g at the ones from loft, format index was 77.97% for hens from battery and 78.42% at the ones from loft. Mean thickness of mineral shell was 0.363 mm for the eggs of the hens reared in battery and 0.381 mm at the ones from loft, shell breaking resistance was 0.329 kgf/cm2 respectively 0.332 kgf/cm2. Regarding eggs’ structure, at the ones gathered from the hens in loft was founded a higher rate of yolk (30.33-32.99%) and shell (10.17-11.82%), while at eggs of the hens from battery, albumen was predominant (56.90-57.97%). Albumen index was at mean levels of 0.211 (rearing in battery) and 0.221 (rearing in loft), yolk index was 0.455 respectively 0.472, and Haugh index was, in average, of 96.09 HU (battery) and 96.66 HU (loft). Yolk colour was of 9.88 colour units at eggs provided by rearing in battery and 9.99 units at the ones from loft. The conclusion of our study was that loft rearing system offers optimal conditions to laying hens for evolution of metabolic processes specific for egg formation, materialized in superior qualitative and physical metabolic indexes.

Key words: hens, rearing, loft, eggs, quality