Fig. 1From: Age-related changes in the shell gland and duodenum in relation to shell quality and bone strength in commercial laying hen hybridsProduction data (means) for the entire poultry house in weeks 1–57 in the production period of the laying hens. Lohmann Brown (LB) (n = 61) cages and Lohmann Selected Leghorn (LSL) (n = 61) cages. a Rate of lay (%), number of eggs laid/day and hen ×100 [significantly higher for LSL hens (P < 0.0001)]. b Egg weight in grams [significantly higher for LB hens (P < 0.0001)]Back to article page