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The increasing public concern for animal welfare has pushed the poultry sector to progressively replace conventional battery cages (CC) for laying hens with alternative systems such as enriched cages (EC) and aviaries (AV). The aim of this study was to compare laying performance, egg location, and egg quality associated with these three housing types. The experiment was conducted in twelve pilot-scale chambers fitted out with one of the three treatments. Each chamber housed 30 Lohmann LSL-Lite laying hens from 23 to 32 weeks of age. The available area was 492, 780, and 1120 cm²/hen for CC, EC, and AV, respectively. The EC and AV chambers were equipped with nest boxes, perches, and a pecking/scratching area (PSA). In the AV chambers, hens had free access to a space arranged in three levels with a wood shaving litter on the ground level as a PSA. Hen-day production was recorded and egg quality assessment included egg cleanliness, weight and proportion of each component (albumen, yolk, and shell) but also pH, Haugh unit, and meat spots for albumen; color intensity and blood spots for yolk; thickness and resistance for shell. The laying rate and egg weight were similar for CC and EC (around 96.5% and 59.5 g; P > 0.05). For AV, these parameters were significantly lower (77.2% and 58.6 g; P 0.05) but there was a lower yolk proportion for eggs laid in AV (25.2% versus 25.7% for cages systems; P

The effect of dimeric DNA intercalating compounds was assayed on a purified AP endonuclease from Microccoccus luteus using apurinic supercoiled PM2 DNA as a substrate. Binding on apurinic sites was estimated through the competition with the intercalating compound, 9-NH2-ellipticine, which displays great specificity for apurinic sites. An acridine dimer with a spermine linker is at 0.1 μM the best inhibitor of cleavage at the apurinic site induced either by the AP endonuclease or by 9-NH2-ellipticine. Bisintercalating agents are more effective inhibitors of AP endonuclease than monointercalating ones. Most effective inhibitors among dimers have acridine residues.