The effects of 2 genetic lines on spatial distribution and use and preference of perch and nest area in an aviary system

The objective of this trial was to evaluate spatial distribution, nest and perch usage, and preference of Lohmann Brown (BH) and Bovan White (WH) Leghorn hens raised in an aviary system. At 5 wk, 400 floor raised pullets, BH and WH strains, in equal numbers, were placed into 8 modified Big Dutchman Natura aviary units. Each aviary unit had 3 tiers with perches and an indoor litter area. At 25 wk, the number of birds was recorded by scan sampling every 4 h. The number of birds perching in each aviary unit was recorded every 4 h at 15, 25, and 35 wk. The number of eggs laid was recorded daily from 22 to 53 wk. A split-plot factorial design with Poisson distribution was used for analysis of spatial distribution and perch preference. Nest and perch usage was analyzed using a split-plot factorial design with binomial distribution. There was an interaction (P < 0.0001) indicating that during late afternoon and night, a higher number of WH were observed in the middle and top tier while a higher number of BH were observed in the litter area and bottom tier at 25 wk. The odds of observing WH perching were higher than the odds of observing BH perching during late morning, late afternoon, and night at 15 wk, from early afternoon to night at 25 wk, and during all afternoon at 35 wk. WH had higher nest usage than BH expressed by the higher odds of observing eggs from the nest area (P = 0.071). There was a strain and egg location interaction (P < 0.0001) for number of eggs laid indicating that WH were laying more eggs in the nest area and litter floor area compared to BH, whereas BH were laying more eggs in the metal aviary wire tiers in comparison with WH. In conclusion, WH showed greater degree of adaptation to aviary systems than BH expressed by greater usage of perches and nest areas and elevated tiers.