Risk factors associated with leg disorders of gestating sows in different group-housing systems: a cross-sectional study in 108 farrow-to-finish farms in France.

Group-housing, rather than individual-housing systems, is mandatory for gestating sows in the European Union (2008/120/EEC). However, leg problems occur more frequently in group-housing than in individual-housing systems and are a welfare and health concern. A cross-sectional study involving 108 farms in western France was carried out to see whether the type of the 4 main group-housing systems (i.

Stable individual profiles of daily timing of migratory restlessness in European quail.

Temporal characteristics of migratory behavior in birds are usually studied at the species and population levels, and rarely at the individual level. Variations among species and populations of the seasonal onset of migratory behavior have been widely investigated, but very little is known about its daily organization or whether birds are conservative in their behavior. The determination of intra- and inter-individual variability is important for the study of genetic variations and can reveal the existence of different adaptation capacities within populations.

Daily laying time in free-living European starlings: solar noon, a potential synchronizer.

Reproduction is generally controlled by important temporal constraints involving complex adaptive mechanisms. Birds, in temperate zones, present marked breeding seasonality as well as marked daily organization of reproductive behavior, especially laying. Intra-specific variability and determinants of this pattern have been investigated mainly in domestic non-passerine birds.

Inter-individual variability during morning choruses in Japanese quail males (Coturnix coturnix japonica).

We compared the organization of dawn choruses in five groups of Japanese quail, Coturnix coturnix japonica, males (four groups of kin-related males and one group of unrelated males). We documented the structure of chorus groups: one male sang much more than the others during the dawn peak in four of the five groups, and this regardless of the number of males in the group. The dominant singers were then removed from two similar-sized groups, one of kin-related (K3) and the other of unrelated (NK) males.

Effect of a cranium-directed daily illumination cycle on the laying rhythm in Japanese quail.

This study tests the effect on the laying rhythm of a light cycle reaching directly the encephala via a diode in Japanese quail maintained in constant darkness. In DD, all the birds expressed their free-running laying rhythm (period close to 25 h). When the diode is switched on 14 h per 24 h cycle, females showed the same organization as in LD with the same laying time.