Abstract #T336

# T336
The production performance of egg layers in different rearing systems.
Bilgehan Yilmaz Dikmen*1, Aydin Ipek1, Ümran Sahan1, Arda Sözcü1, 1Department of Animal Science, Faculty of Agriculture, University of Uludag Bursa, Turkey,.

Today alternative rearing systems for caged hen egg production has gained importance. The objective of this study was to determine the production performance of laying hens kept in different rearing systems (conventional, enriched cages and free-range system). A total of 480 egg layer strain (Lohmann Brown) were weighed and randomly allocated into 3 rearing system (n = 160, 4 replicates of 40 hen per group) as conventional cage, enriched cage and free range pen at 17 wk of age. The 3 rearing systems were located on a single farm and experienced identical seasonal temperature fluctuations and photoperiod (16L:8D). Feed and water were given ad libitum until 66 wk of age. Live weight was measured at the beginning and at the end of the study. Egg production as hen day, number of damaged eggs, dirty eggs and mortality were monitored daily. Feed intake and egg weight were recorded on weekly basis. The data were analyzed with using ANOVA, and significant means were separated using Duncan Multiple Range Test. The final live weight of hens were found similar in conventional and enriched cage system (1.95 vs. 1.94 ± 0.03 kg, respectively), but was higher in free-range system (2.09 ± 0.02 kg; P < 0.001). The earliest 5% egg production age was found in enriched cage system (138.3 ± 1.75 d; P < 0.05). The latest 50% egg production age was found in free-range system (159.25 ± 1.75 d; P < 0.01). The highest mean egg production ratio was found in free range rearing system (89.27 ± 0.87%; P < 0.05). The egg mass was higher in free-range system, but was similar in conventional and enriched cage systems (59.76, 56.80 vs. 56.66 ± 0.34 g/d/hen, respectively; P < 0.001). The feed intake was found to be higher in free-range system, but similar between conventional and enriched cage systems (124.58, 117.06 and 118.06 ± 0.56 g/d/hen, respectively; P < 0.001). The damaged egg ratio was low but dirty egg ratio was higher in free-range systems (0.35 ± 0.07% vs. 3.30 ± 0.15%, respectively; P < 0.001). The mortality ratio was higher in enriched cage system (6.25%; P < 0.05). It was concluded that free-range system has a positive effect on egg production and egg weight, but feed intake and dirty egg ratio were higher than the caged system.

Key Words: rearing system, egg production, egg layer