Non-beaked laying hens housed in aviaries. I: Production performance in cages and three types of aviaries.

摘要

Non-beak-trimmed commercial white hens were housed in Marielund (M), Laco-Voletage (V) or tiered wire floor (TWF) aviaries or a commercial 3-tiered battery cage system (C) installed in the same building. Production results, plumage condition and percentage of mislaid eggs were recorded from 3 full laying cycles (hens aged 20-75 weeks) for 6000 hens per cycle. System C had the highest egg production per hen per day (50.2 g), followed by M (48.7 g), while hens in V and TWF produced 48.1 and 47.5 g respectively. The mean feed conversion ratio in TWF was higher than in C (2.63 vs. 2.17 kg feed/kg egg mass, P<0.05). There were no differences in egg shell strength, albumen height and blood spots between eggs from cages and aviaries. The average percentages of mislaid eggs ranged from 3.7% (M) to 13.8% (TWF), while the average cumulative mortality rate was 11% in C, 13% in M, 13% in V and 22% in TWF. About half of the mortality in TWF was due to cannibalism. Feathering score at 42 weeks of age was lowerfor TWF and V than for C and M (P<0.05). [For Pt. II see pp. 425-436 of the same number of the journal].