Laying hen breeding systems and hygienic status of the eggs

Abstract

Due to the expected ban in 2012 of conventional cages for laying hens, new breeding systems are being developed. The impact of these systems on the hygienic status of the eggs was studied.

The contamination of the egg shell by bacteria is significantly higher in free-range systems compared to furnished or conventional cages. These differences are lower in commercial conditions than in experimental studies. This could be explained by differences in breeding practices in the different breeding sites compared. The differences observed between furnished and conventional cages are lower and not constant. The percentage of eggs laid in the nest but also the disposition of the furniture (nest, perch and scratching area) may significantly affect the bacterial load of the egg shell. Many other factors such as cracks or dirt on the shell, dust concentration in the rooms or season may also influence bacterial egg shell contamination.

Studies also show that it is highly unlikely that a move from conventional cages to alternative cage systems and non-cage housing systems for laying hens will result in an increase in Salmonella infection and shedding, rather the opposite is expected.