Non-beaked laying hens housed in aviaries II: Behaviour of cockerels and their effects on hen performance
1996
Kathle, J. | Braastad, B.O. | Langstrand, H. (Norges Landbrukshoegskole, Aas (Norway). Inst. for Husdyrfag)
1. Non-beak trimmed white egg layers (Norbrid41) were housed in a three-tiered battery cage system (C) and in two aviaries of the types Marielund (M) and Laco-Voletage (V) for four laying cycles. About 1500 hens were included per system. In the first three cycles the aviary hens were without company of cockerels while the effect of two densities (1m/30 ff vs. 1m/130 ff ) and two types of cockerels (Nordbrid41 vs. Jaerhons) were studied in the fourth cycle. The hens' production and the cockerels' behaviour were recorded. 2. Production results, plumage condition and percentage of mislaid eggs of the first three full laying cycles (20-75 weeks) from M, V and C were compared with the successive fourth cycle. In the last cycle the average egg production per hen and day was: 51.9 g (V), 51.8 g (M) and 51.3 g (C). The differences between C and M, and C and V in egg production were significantly changed in favour of aviaries compared to the mean of the first three cycles. The cumulative mortality rate was about 10 in all systems and no cannibalism was recorded in contrast to the three first cycles. The cumulative percentages of mislaid eggs were 3.5 (M) and 8.4 (V). Pens with a high density of cockerels had somewhat lower frequency of mislaid eggs until 30 weeks of age than pens with few cockerels (16.3 vs. 18.6). 3. Few differences in cockerels' behaviour related to cockerel type or density were observed. However, cockerels with high social rank crowed more, received more pecks from the hens, and had more interrupted mating than cockerels with low social rank. 4. To conclude: The presence of cockerels seems to have a favourable impact on production level, frequency of mislaid eggs and cannibalism. More knowledge about interactions between cockerels and hens may be applicable when improving aviary systems.
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