Early access to perches in caged White Leghorn pullets

Abstract

Osteoporosis, a progressive decrease in mineralized structural bone, causes 20 to 35% of all mortalities in caged White Leghorn hens. Previous research has focused on manipulating the egg laying environment to improve skeletal health, with little research on the pullet. The objective of the current study was to determine the effect of perch access on pullet health, bone mineralization, muscle deposition, and stress in caged White Leghorns. From 0 to 17 wk of age, half of the birds were placed in cages with 2 round metal perches, while the other half did not have perches (controls). Bone mineralization and bone size traits were determined in the tibia, femur, sternum, humerus, ulna, radius, and phalange (III carpometacarpal) using dual energy x-ray absorptiometry. Muscle weights were obtained for the breast and left leg (drum and thigh). A sample of pullets from each cage was evaluated for foot health, BW, right adrenal weight, and packed cell volume. Most measurements were taken at 3, 6, and 12 wk of age. Access to perches did not affect breast muscle weight, percentage breast muscle, percentage leg muscle, bone mineral density, bone length, bone width, adrenal weight, packed cell volume, and hyperkeratosis of the foot-pad and toes. There were no differences in BW, bone mineral content, and leg muscle weight at 3 and 6 wk of age. However, at 12 wk of age, BW (P = 0.025), bone mineral content of the tibia, sternum, and humerus (P = 0.015), and the left leg muscle weight (P = 0.006) increased in pullets with access to perches as compared with controls. These results suggest that perch access has beneficial effects on pullet health by stimulating leg muscle deposition and increasing the mineral content of certain bones without causing a concomitant decrease in bone mineral density.

The effect of perch availability during pullet rearing and egg laying on the behavior of caged White Leghorn hens

“…There was a distance of 18 cm (7 in) between the 2 perches, between the front perch and the feed trough, and between the rear perch and the back of the cage. This figure and caption were published previously by Enneking et al (2012a). b) Two round metal perches, 32 mm in diameter, were installed in laying cages (18 to 72 wk of age) in parallel arrangement to each other.…”

“…A starter diet was fed from hatch to 3.9 wk, a grower diet from 4 to 17.2 wk, a prelay diet from 17.3 to 18 wk, and a laying hen diet from 18 wk through the end of the study. Diet specifications can be found in Enneking et al (2012a) for the pullet phase and in Hester et al (2013b) for the laying phase.…”

“…Perches were manufactured by Big Dutchman (Holland, MI) and were smooth, round, 32 mm in diameter, and made of galvanized steel (Figure 1a). Number of birds per cage, treatment assignment, tier arrangement, cage dimensions, perch placement ( Figure 1a) as well as floor, perch, and feeder space/bird are described in detail by Enneking et al (2012a). At 17 wk of age, 324 birds were transferred to 36 cages in a room in the Purdue University Layer Research Unit.…”

“…In a companion paper of the current study (Enneking et al, 2012a), pullets were given access to 2 perches in a rearing cage from day of hatch to 16.9 wk of age, when they were transferred to laying cages for the current study. Use of the front perch in pullet cages closest to the feed trough during scotophase increased from less than 0.1% at 6 wk of age to 31% at 12 wk of age.…”

The welfare of layer hens in cage and cage-free housing systems

“…Enneking et al (2012) provided pullets with perches from one day to 17 weeks of age. Birds with perch access had greater bone mineral content of the tibia, sternum and humerus, as well as greater muscle deposition at 12 and 71 weeks of age compared to birds without access to perches (Enneking et al, 2012;Yan et al, 2014). In cages, perches also give reprieve from standing on a sloped wire floor (Hester, 2014 (Lay et al, 2011;Heerkens et al, 2016).…”