The ability of laying hens to negotiate perches of different materials with clean or dirty surfaces

摘要

Increasingly, perches for laying hens are being made from metals and plastics. There is nothing in the literature regarding how easily birds jump between perches of different materials, or how their ability to do so changes with faecal contamination of the perches. Forty-four medium hybrid brown hens negotiated perches of wood (5 cm x 5 cm, rounded edges), metal (half-round section, diameter 4 cm) or poly-vinyl-chloride (PVC. circular section, diameter 4 cm), which were either clean or dirty (poultry manure 0.5-1.0 cm deep). The time to jump to the destination perch (0.75 m from the start perch), number of squats (pre-jumping behaviour), slips, failures to jump (in 300 s) and crashes were recorded. Compared to wood and metal perches, birds took significantly longer to jump from PVC perches when they were clean, but there was no difference when the perches were dirty. Birds slipped significantly more on clean metal or PVC perches compared to clean wood perches. The birds took significantly longer to jump from metal or wooden perches when they were dirty compared to when they were dean. These data may suggest that PVC is not a suitable material for perches. Slipperiness is important. The birds apparently found the metal and PVC perches more slippery than the wooden perch, although the metal perch did not cause the birds to delay jumping. A slippery perch may deter the birds from attempting to jump. Manure on the perches reduced the slipperiness of the metal and PVC perches. Once perches become dirty, any welfare issues concerning the risk of injury from slippery perches cease to be as important as the potential slipperiness of the manure itself.