Various hen housing systems determine different egg quality

The aim of this study was to evaluate the effect of enriched cages and aviary housing system on egg quality. A total of 2520 eggs (180 eggs per age and housing system) were analysed. The egg quality parameters were measured in eggs from 44, 48, 52, 56, 60, 64 and 68-week-old hens. The analysis of the technological value included the evaluation of egg weight, shape index, surface area, volume, eggshell proportion, thickness, strength, colour, index, albumen proportion and index, Haugh units, yolk proportion, index, colour and yolk to albumen ratio. The significant interactions between housing system and age of hens were found in all observed parameters except for the egg shape index. Considering the eggshell strength, 52-week-old hens from aviary and from enriched cages had the highest values (46.90 and 46.87 N cm-2, resp.), whereas the lowest values had eggs from 64-week-old hens housed in aviary (31.90 N cm-2). Moreover, Haugh units were the highest in enriched cages from 48, 52 and 56-week-old hens (90.63, 89.80 and 89.28, resp.) and the lowest in aviary system from 64-week-old hens (75.38). Bearing in mind the results, the most of the highest and lowest values in eggshell quality were observed in enriched cages, while in internal quality of eggs, the most of the highest values were seen in enriched cages. That could indicate an unbalanced quality of eggshell and relatively stable internal quality depending on housing system. Regarding to the effect of age, higher quality was found in the first half of studied laying period.