Development of furnished cages re-using conventional cages for laying hens: Behaviour, physical condition and productivity.

Furnished cages for laying hens have advantages in allowing normal behaviors and maintaining productivity. As the cost of introduction is a barrier for farms, we developed furnished cages that re-use conventional cages. To determine the minimum and functional cage design, we compared six designs, combinations of two floor designs (artificial turf or wire cage floor) and three screening designs in the integrated area (no screening, one entrance side or four sides). In total, 144 hens were used, and we measured behavior, physical condition and productivity. Comparing the floors, the percentages of hens performing dust-bathing and laying eggs in the integrated area were higher in cages with turf than wire floor (P < 0.05 for both). Comparing the screening, dust-bathing, litter-exploring and active behavior tended to be more frequent in cages with the integrated area screened on one side than four sides. Feather damage was lower in cages with the integrated area screened on one side than with no screening (P < 0.05). These results suggest that the cage design with an integrated area with artificial turf floor, screened on one side, was effective for furnished cages that re-use conventional cages.

Why should we care about nonhuman animals during times of crisis?

Incentives to care for nonhuman animals derive in part from the extent to which people depend on animals for food, for livelihood, and for cultural and psychological reasons as well as from the duty to protect animals in their care. When attention is turned to solving and preventing animal welfare problems at times of crisis, it becomes clear that those problems are also associated with problems for human welfare and environmental impact. The incidence and spread of animal diseases is affected by how animals are treated, and this can have very important effects. Similarly, during disasters caused by either natural or human-made events, outcomes for animals are important both in themselves and for their effects on humans and the environment. The need to plan and prepare to care for animals in advance of disease pandemics and disasters - and then to provide coordinated, measured management in response when such crises occur - requires collaboration between all agencies involved as well as increasing attention and resources.

The European Union ban on conventional cages for laying hens: history and prospects.

Since the publication of Animal Machines (Harrison, 1964), there has been widespread public pressure in Europe--supported by European institutions--to "ban the battery cage." The European Union (EU) and national governments (particularly in Northern Europe) funded research on noncage systems for egg production and enriched cages. In 1986, the EU passed a Directive specifying a minimum size for cages, but public opinion--again particularly in the North--continued to require more. A market sector emerged that would pay more for noncage eggs. Denmark, Sweden, and Switzerland passed more stringent legislation than the rest of Europe. A 1999 Directive with details based on advice from the EU's Scientific Veterinary Committee will phase out conventional laying cages but allow enriched cages. Implementation depends on various factors, including negotiations in the World Trade Organization. In the next 10 years, however, major changes to the housing of most laying hens in Europe almost certainly will occur. Similar changes in other countries will follow. As in Europe, change probably will be piecemeal, affected both by public pressure and by all sectors of society: producers, retailers, consumers, legislators, and the media.

NATURAL SELECTION ON QUANTITATIVE TRAITS IN THE BOMBINA HYBRID ZONE.

Observations on the means, variances, and covariances of quantitative traits across hybrid zones can give information similar to that from Mendelian markers. In addition, they can identify particular traits through which the cline is maintained. We describe a survey of six traits across the hybrid zone between Bombina bombina and Bombina variegata (Amphibia: Discoglossidae) near Pescenica in Croatia. We obtained laboratory measuments of the belly pattern, skin thickness, mating call, skeletal form, egg size, and the developmental time of tadpoles. Although offspring from hybrid populations showed no evidence of reduced viability, a third of the F1 families failed completely, irrespective of the direction of the cross. All traits differed significantly between the taxa. Clines in belly pattern, skin thickness, mating call, and skeletal form were closely concordant with clines in four diagnostic enzyme loci. However, the cline in developmental time was displaced towards bombina, and the cline in egg size was displaced towards variegata. This discordance could be because the traits are not inherited additively or because they are subject to different selection pressures. We favor the latter explanation in the case of developmental time. We show that moderate selection acting directly on a trait suffices to shift its position; rather stronger selection is needed to change its width appreciably. Within hybrid populations, there are significant associations among quantitative traits, and between traits and enzymes. Phenotypic variances also increase in hybrid populations. These observations can be explained by linkage disequilibria among the underlying loci. However, the average magnitude of the covariance between traits is about half that expected from the linkage disequilibria between enzyme loci. The discrepancy is not readily explained by nonadditive gene action. This puzzle is now unresolved and calls for further investigation.