Combating Floor and Slat Eggs in the Breeder House

Hatching eggs laid on the floor or slats of the breeder house can present a significant problem for the hatching egg producer as well as the integrator. Most eggs laid on the floor or slats are unacceptable as hatching eggs because of the increased likelihood of being cracked and/or contaminated. Unfortunately, often these eggs are, at most, gently wiped off and placed with nest clean eggs in the egg cooler. Once delivered to the hatchery, it only takes a small few contaminated eggs placed in the setter to further contaminate the environment and many of the surrounding eggs. The best case scenario is that only those eggs placed near the floor eggs in the incubator racks will be affected. Therefore, floor and slat eggs are costly to the contract breeder grower as they may cause reductions in overall hatchability of eggs from their own flock. More importantly, these contaminated eggs that somehow "slip in" with nest clean hatching eggs are often very costly to the integrator as they can affect hatchability and chick quality from eggs of other flocks placed nearby in the setters. The incidence of floor and slat eggs in the breeder house can range from moderate to severe with reports of floor and slat eggs exceeding 25 percent in some cases.

Laying and Nesting Behavior

The basic nature of the breeder hen tells her to find a nesting site where she can feel safe, secure and comfortable. She is searching for a place where she feels will be suitable to incubate and raise chicks. Obviously, commercial broiler breeders will never incubate and brood young, but their basic instincts tell them they should find an appropriate site to do so.

Manufacturers of nesting equipment, as well as those involved in designing breeder houses, have attempted to provide ideal nesting areas for breeder hens. However, ease of gathering and handling hatching eggs is of equal if not greater concern to the hatching egg producer. Therefore, the nature of the commercial poultry industry and the design of breeder houses in general, allow for egg laying in other than designated areas of the breeder house. Proper flock training and management, as will be discussed, can encourage hens to use the designated nest sites for egg laying.

What Causes Floor Eggs?

Floor and slat eggs are not a new problem to the poultry industry. Recently, this problem was readdressed with a group of hatching egg producers and a list of causes for their increase in the incidence of floor eggs was identified. As these areas were addressed, the percentage of flocks with floor egg problems was reduced by more than one half. Further improvements continue for this group of hatching egg producers.

The first area identified was poor initial training of the birds by the grower. This is a preventive measure in combating the incidence of floor/slat eggs in the breeder house. As a preventive measure, it is critical that training of the birds be performed prior to the onset of the chores of gathering hatching eggs. It is not uncommon for growers to want to extend their "resting time" after house preparation until the first eggs appear because they never had a floor egg problem before. Indeed, they deserve the time off as the demands are heavy for hatching egg producers. However, late training of birds is not effective once floor/slat eggs become a problem since birds are creatures of habit and tend to reuse the same nesting sites day after day.

To properly train breeders to use the nest boxes, it is important that birds be "walked" several times each day prior to egg production. It is recommended that the slats and scratch area are walked at least six and up to 10 times each day prior to egg production. This will encourage hens to find the nests and acclimate them to the breeder house and the associated human activity. However, rapidly "walking" the breeder house and not "training" the birds to use the nests and get up on the slats is not effective. Rapid walking tends to startle the hens and scare them away from the nests. Walk the hens slowly, especially during the training period. Walk the houses in a pattern that will force the birds toward the nesting sites, not away from them. If the pattern of grower traffic forces birds into corners, they will be introduced to improper potential nesting sites. The slat area should be walked close to the side walls and corners to encourage bird movement away from the edges and toward the nest boxes. Walking the birds should be continued through their peak in egg production although less often as the birds become trained.

As previously discussed, housing design and equipment layout coupled with bird management protocol can often encourage floor and slat eggs. For instance, placing too many hens in the breeder house places limits on each hens access to proper nesting sites. Although the nest manufacturers suggested number of hens per nest hole will vary, the industry average is 5.5 hens per nest hole. Further complicating the matter is the fact that hens, being creatures of habit, will generally choose the same nesting site day after day to lay their eggs. That is why many times multiple hens will pile in one nest box when a neighboring box is empty. Each hen feels that box "belongs" to them and it is the same place they were the day before. If access to their specific box is denied, they may choose an alternative nest site such as the floor or slat area. Make sure that the number of birds housed does not exceed the recommendations for the nest type in the breeder house. Also, make sure that all nest boxes are accessible to the hens. Take into account hen houses that may be partially used for housing surplus males and consequently are rendering a number of nest boxes inaccessible to the hens. This setup can create additional dark spots and corners within the house at an impressionable age of the young hens.

Another similarly associated factor was ease of access to the nest boxes and ease of going from the floor to the slat area. If a hen cannot see the nest boxes or they are difficult to get into she is less likely to enter. This problem can actually increase as birds age. Older birds are heavier and often have reduced mobility due to physical limitations caused by foot and leg problems. Ramps or perches on the fronts of the nests or slanted slats at the front edge of the nests have proven to be helpful. Slat height should also be kept to a minimum. It is recommended that slat height not exceed 20-22 inches from the ground to the front edge of the slat. As birds scratch in the litter below the slats, the slat height is often exceeded in houses with older flocks. Coincidently, this is also the time when birds are often less mobile.

Another area identified was poor nest sanitation and preparation prior to egg production. Dirty belts and manure buildup on nest pads tend to discourage hens from entering the nest hole. Every factor needs to be attended to in order to encourage hens to use the appropriate nest sites. From a sanitation standpoint, eggs which are laid in dirty nests will be similar to many of the floor and slat eggs. Additionally, worn nest pads tend to be uncomfortable to the hens and may discourage them from using the proper nesting sites. Birds prefer a clean and dry area to lay their eggs. Clean and comfortable nest sites will assist in enticing hens to find and continue using the nest boxes provided for them.

A fourth factor was poor feeding methods and equipment problems that caused birds to spend too much time at the feeders. Excessive time intervals between feeder run times causes birds to spend extra time on slats near the feeders waiting for feed. In adequate feeder space for the number of hens housed will also cause birds to hover around the feed lines for longer than necessary. Feed spills over the slats not only create serious pest control problems and are costly to the integrator, they cause shortages in feed and, after accumulation under the slats cause additional areas where hens will hover. Time spent eating, looking or waiting for feed is time that should be spent in or around the nest boxes. Increases in slat eggs are often related to feed or water problems. Also, male feeders running for prolonged periods of time tend to attract hens to the scratch area during the peak egglaying times of the day. Male feeder problems are confounded when feed spills occur. When hens are excessively drawn to the scratch area at this time of day, an increase in floor eggs usually results.

Poor ventilation was also found to contribute to the incidence of floor and slat eggs especially in the newer houses, such as tunnel ventilated houses. When air movement within the house is insufficient, birds have a tendency to migrate to a more comfortable area of the house. One additional problem identified was late transfer of pullets to the breeder house. Some producers feel that maintaining pullets in the pullet house several extra days will improve bird fleshing and conformation.

This has been a somewhat recent trend within certain areas of the poultry industry. Producers believe they can hold birds in the pullet house longer in order to improve uniformity of sexual maturity within the flock. Although in many cases their desired results have been achieved, there have been several side effects of this practice. Obviously, the pullets have a shorter period of time in the hen house before egg production begins. This practice decreases the time available for training the flock and increases the likelihood that some hens will choose alternative nest sites as they come into production in their new and unfamiliar environment.

Summary and Conclusion

If floor and slat eggs are a problem, evaluate your management practices and housing conditions as soon as the problem is detected. The longer the problem persists, the more difficult it is to correct. Remember, birds are creatures of habit and habits are difficult to break. Observe your birds to try and determine the cause of them not choosing the provided nesting sites. Record and tabulate what time of day most of the floor or slat eggs are laid. What percent of the eggs are laid at first lighting, after feeding, late in the afternoon, etc. Keep a record of where they are found. What percent of the eggs are found against the walls, next to the slats, near the fans, on the slats and next to the feeders, etc. Managing to prevent a problem is always preferred. However, if a problem does exist, diagnosing where and when the problem is occurring will greatly increase the likelihood of correction.


By Dr. R. Keith Bramwell, Extension Poultry Specialist
AVIAN Advice newsletter (Volume 2, Number 2)
Center of Excellence for Poultry Science, University of Arkansas