GERMANY - Rather than providing the desired effect of improving plumage condition, dustbathing in feed particles increases the build-up of lipids on feathers, according to a new study at the Friedrich-Loeffler-Institut.
Feed is not a suitable litter material for laying hens because it leads to the accumulation of lipids on the plumage, according to Britta Scholz and colleagues at the Friedrich-Loeffler-Institut in Celle.
Within the European Union, dustbathing material in cage-housing systems for laying hens became compulsory in 2012, they explain in their paper in the latest issue of Poultry Science. In practice, most producers use feed as a litter substrate. The feed is dropped in small amounts on scratching mats by an automatic transporting system. However, because dustbathing behaviour is meant to remove stale lipids from hens’ plumage, feed particles may not be a suitable substrate due to their fat content.
The study at Celle analysed feather lipid concentration (FLC) of laying hens with access to feed particles (F) or lignocellulose (L) as litter substrates.
In each of two identical trials, 84 laying hens of two genotypes (Lohmann Selected Leghorn and Lohmann Brown) were kept in 12 compartments of seven birds each. Compartments were equipped with a grid floor and additionally contained a closed dustbathing tray holding F or L.
Feather samples (150 feathers) were taken twice during the experiment. At 23 weeks of age, four hens per compartment were sampled after they were allowed pair-wise access to a dustbath for 2.5 hours and three hens were sampled without access to a dustbathing tray (control). After 10 weeks of free access to the dustbathing trays, all hens were sampled again.
In trial 2, an additional third sampling was made after dustbaths had been closed again for six weeks. Here, six hens per compartment were sampled immediately before and after a dustbath.
Dustbathing in F resulted in higher feather lipid concentration than with L and control (P<0.001); no significant difference was found between L and control (P=0.103).
When open access to litter was provided, hens had higher feather lipid concentration in F than L (P<0.001).
The feather lipid concentration immediately after dustbathing in F was higher than before dustbathing (P<0.001), whereas it was lower after dustbathing in L (P=0.006).
Scolz and colleagues concluded their results show that F are unsuitable litter material for laying hens because they lead to lipid accumulation on the plumage.
Scholz B., J.B. Kjaer, S. Petow and L. Schrader. 2014. Dustbathing in food particles does not remove feather lipids. Poultry Science. 93(8):1877-1882. doi: 10.3382/ps.2013-03231
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