CONTRIBUTIONS ON THE QUALITY KNOWLEDGE OF THE EGGS LAID BY HENS REARED WITHIN VERSIONS OF PERMANENT LITTER TECHNOLOGICAL SYSTEM
M.G. Usturoi, R.M. RADU-RUSU
The investigations focused on the establishment of quality for those eggs issued from certain versions of the permanent litter technological system. The biological material comprised 2025 hens belonging to the "Hisex Brown" hybrid, allocated in 2 groups (Lc-permanent litter hall, in an environment controlled compartment; Lexp-rearing on permanent litter, in a compartment opened toward an outer paddock). Quality traits were assessed through conventional methods, using eggs sampled from the 4 main moments of the laying curve (onset, peak, plateau and ceasing). In those birds which acceded to the external paddock (Lexp group), the proportion of eggs with morphologic anomalies was 0.08% lower; moreover, the eggs presented better levels for the quality parameters, which were 1.31% higher for weight, with 5.47% higher for shell thickness, 2.36% higher for shell breaking strength, 0.28% more yolk and 0.36% more shell proportion in whole egg structure. The achieved data indicated that, at least for egg quality, the "free range" was better than the conventional one (isolated houses, permanent litter); that advantage was provided by the free access of the laying hens to the outer environment, which contributed to enhance egg formation processes and better D3 synthesis, knowing its involvement in the calcium metabolism.