Chemical features, cholesterol and energy content of table hen eggs from conventional and alternative farming systems
This study was carried out to investigate the effect of conventional farming systems for laying hens (standard cage batteries) and new alternative systems (improved cages and free range), approved by European Union (EU) poultry welfare legislation, on the chemical and nutritional quality of table eggs. The biological material consisted of eggs laid by 1200 Lohmann Brown hens, aged 27 weeks, fed similarly (a corn-wheat-soymeal diet). Conventional AOAC methods were used to analyse the eggs, and gross energy was calculated based on organic matter energy. All data were subjected to ANOVA statistical computation. The eggs produced in conventional cages compared with those laid in free-range farming conditions, presented significantly higher concentrations of total lipids (11.40 ± 0.65 g/100 g vs. 10.78 ± 0.87 g/100 g), cholesterol (211 ± 6.31 μg/egg vs. 202 ± 7.79 μg/60 g egg) and gross energy (0.36 ± 0.007 MJ/egg vs. 0.35 ± 0.012 MJ/egg). Consequently, it could be stated that under similar dietary conditions, the cage-free system influenced hens to produce eggs with a higher nutritive value than in the other systems.
Keywords: Battery cages, chemical composition, dietetic value, improved cages, free-range, laying hens