Modification of perchery system: Preference for ramps rather than ladders during early adaptation period for cage-reared pullets

Poor early adaptation in aviaries has adverse effects on welfare and the later production. Effects of system modification by ramps and ladders on early adaptation of birds were investigated. A total of 240 pullets and 24 cockerels of Yukou Jing Pink II parent stock were allocated into six perchery compartments at the age of 83 days from conventional cages. Three compartments were modified with ramps of different angles, 30°, 40° and 30° & 50° combination. The other compartments were fitted with 2 ladders, with 22 cm steps and 33 cm steps. Spatial distribution of birds and eggs, as well as the data of ramps and ladders utilization were used to assess birds’ adaptation and the effectiveness of modification facilities. A higher proportion of hens got onto the tiered platforms in ramp group (p<0.001) and engaged in feeding (p=0.002). Inversely more than 85.0% of hens dwelled on the system floor in the ladder group for the whole observation period. The proportion of birds feeding increased over time (p<0.001), with the proportion of birds lying decreasing (p<0.001). A higher frequency of utilization of ramps was found compared with ladders (4.5-25.8 vs. 2.8-14.7 times/40 birds per hour). For ramp use, 79.3% of hens negotiated level change by using 30° ramp and behavioral process was also found related with the type of ramps. On the contrary, very few successful level changes were observed via ladders and 60% of ladder use was ended with birds backing to the system floor. Besides, a higher proportion of non-nest eggs was recorded in ladder group in the early laying period. These results indicated that modification of ramps is more applicable for improving birds’ early adaptation and later production in perchery system of multi-tier, especially for pullets reared in conventional cages.