Cage-Free Pullets Minimally Affected by Stocking Density Stressors

Area of Science:

• Animal Science
• Poultry Science
• Animal Welfare

Background:

• Pullet rearing management impacts long-term bird health and welfare.
• Extensive housing systems require specific evaluation of pullet phase management.
• Limited research exists on pullet phase stocking density effects in cage-free environments.

Purpose of the Study:

• To investigate the effects of stocking density and strain on pullet welfare and performance.
• To evaluate bird-based measures including appearance, blood parameters, organ weights, and production values.
• To assess the impact of different stocking densities on uniformity and feather coverage.

Main Methods:

• A 2x2 factorial randomized complete block design was used.
• Two Lohmann strains (LB-Lite and LSL-Lite) were housed at high and low stocking densities (2-16 weeks of age).
• Evaluated bird appearance, blood parameters, organ measurements, and production values.

Main Results:

• Stocking density significantly affected relative bursal weight, with lower weight at high density.
• High stocking density decreased uniformity and feather coverage in the brown strain but improved them in the white strain.
• Low stocking density improved feed conversion ratio (FCR) by 0.07 for both strains.

Conclusions:

• Stocking density effects on pullet welfare are strain-dependent but generally minimal in cage-free systems.
• Cage-free pullets showed few negative welfare impacts across tested stocking densities.
• Strain and age were primary drivers for most evaluated parameters, not stocking density.