In every floor housing system for broiler breeders, a certain number of floor eggs will be produced. The actual number depends on a lot of various things, from health status of the birds, housing system in rearing, agressiveness of males to nest design, slat area, feeding time, drinking system, light distribution, house lay out in production etc. Its not always possible to determine why certain flocks or certain houses do give more floor eggs, although some general recommendations can be given.
Normally we see that at the start of production the percentage of floor eggs is rather high, 10% or more, and then it should go down towards peak production. Not everybody will have the same norms for acceptable levels of floor eggs, but usually we estimate floor egg levels of less than 2% to be acceptable, 2 to 4% to be not a problem but more than we like, and more than 4% to be considered as a problem.
Floor eggs are having higher levels of contamination, as they are located in a dirty environment during the process of cooling down, which allows bacteria to penetrate the pores. Cleaning and disinfection afterwards are having very limited effects, as it is difficult to remove the bacteria from the pores.
The importance of this cooling effect can be easily demonstrated by a simple test. When clean floor eggs are placed separatedly in an incubator, the number of bangers and the loss of hatchability will not differ much from the situation when dirty floor eggs are placed. However, when clean nest eggs are cooled down and than are placed on the litter for several hours, incubating these eggs will show that there is hardly a difference in hatchability with clean nest eggs that are placed in the machine. This demonstrates that the problem is not so much the bacteria and manure on the shell, but much more the bacteria in the pores.
Floor eggs will have a reduced hatchability, usually about 20-30% less than the hatchability of clean nest eggs. Also the number of exploders (bangers) will increase, giving an increased risk of contamination of other eggs and chicks, and resulting in a reduced chick quality