Effect of perch provision in rearing cages on pullets’ adaptability to perch system before and after transfer

As people pay more attention on animal welfare, the alternative systems, like perch systems, usually with multi tiers, are increasingly used for poultry production. Pullets need good spatial capabilities to utilize resources distributed on different tiers and display certain behaviour in such systems. However, the majority of pullets in China are housed in conventional cage systems which are considered adverse for the development of spatial skill since the performance of behaviour like perching, jumping and flying are restricted. A lack of such exercises weakens pullets’ ability to negotiate the level changes and results in poor adaptability in multi-tier systems, which contributes to problems of behaviour, such as disproportionate distribution in different space, high ratio of floor laying and injures. 240 Jingfen No.2 parent layer breeders were used in present study to investigate the effect of perch provision during rearing period on pullets’ adaptability before and after transfer into the multi-tier perch system, aimed at improving pullets’ adaptability in such cage-free system from traditional rearing cage system. Each rearing cage accommodates 8 pullets, providing each pullet with 487.5 cm2 cage floor area. 2 factors including manipulation time (age of 63 days and 73 days) and positions of perch addition (along the width of the cage and along the depth of the cage) were taken into account. Each treatment was replicated in 6 cages and the rest 6 cages were used as control groups. Altogether 30 cages were used. All pullets were transferred into the perch system on the ages of 83 days and pullets from 5 different cages were put together and put on the system floor. The number of roosting pullets after light off and individual behaviours during the daytime were observed in cages. Distributions of pullets and individual behaviours during the daytime in perch unit were compared. The results showed that: 1. the addition of perches in rearing cages significantly affected on the number of roosting pullets at the first night (Ptime*position<0.01). Utilization of width perches on the age of 63 days was significantly higher than that on the age of 73 days (P<0.01) and higher than that of depth perches (P<0.01). Averaged 4.5-5.3 pullets roosted on the perches on the 10th night with the ratio of perch use ranging from 75% to 88%, and no significant difference was found among treatments. 2. The accumulative frequency of standing, lying and preening on the cage floor decreased in perch cages, along with increased feeding and locomotion and decreased pecking behaviours of the whole group. The proportion of perching behaviour during the daytime was 12.8%-21.6%, and more pullets preferred to stay on perch, with heads toward to the wire mesh of the cage. 3. In the ramp perch units, the proportions of pullets from perch groups were 74.2% and 65.6% respectively on elevated platforms in the perch system for the 2 ages during the initial 5 days after transfer, and it is 59.2% for the control group, which is significant difference compared with perch group of 63 days age (P<0.05). However, perch utilization was rare in 2 modified perch units. Overall, the results indicated that the provision of perches in rearing cages is advantageous for pullets’ adaptability to the stereo space in the perch system after transfer, and earlier experience of perch during rearing period is better. It is suggested that perches should be provided in pullet rearing cages as early as possible in order to improve the adaptability of pullets after being transfered to perch system.