Effects on plumage condition, health and mortality of dietary oats/wheat ratios to three hybrids of laying hens in different housing systems

The effects on plumage condition and health when feeding diets with varying oats/wheat ratios to different non‐beak‐trimmed hybrids housed in various systems were studied in two experiments. In experiment 1 (Expt. 1) 1146 Lohmann Selected Leghorn (LSL) and 1006 Lohmann Brown (LB) birds were housed in eight aviary pens; four in each of the systems Lövsta (L) and Marielund (M), or in six groups of 24 conventional cages each (C). Two diets with a high proportion of either oats or wheat were used. Experiment 2 (Expt. 2) included 1740 LSL and 1632 SLU‐1329 birds housed in 6 pens each of system M. Diets with varying proportions of oats and wheat were given. In Expt. 1, LB hens housed in C showed better plumage condition compared with those housed in the aviaries, whereas LSL birds showed the opposite trend. Housing system affected most health traits, showing superior results for system C regarding, for example, bumble foot, cleanliness of feet and keel bone lesions. In Expt. 2, feather cover deteriorated in LSL birds when the oats/wheat ratio was decreased but no such effect was found in the SLU‐1329 birds.