This article appears in the August issue of Poultry International. View all of the articles in the digital edition of this magazine.
Taking laying hens out of cages makes a big difference. The extra freedom allows them to move around expending energy and putting pressure on their bones. Cage-free hens also compete more for their daily ration, and they come in contact with their excreta. All of these facts make traditional layer feeding rather obsolete, or more eloquently put, in need of revising to ensure bird health, welfare, productivity and, of course, profitability are not sacrificed at the expense of consumer preferences.
Cage-free systems can take several different forms. Open aviaries are similar to cages with feeders, waters and nests provided inside the aviary, and the birds can leave the aviary to access the floor scratch areas. Of course, the traditional floor housing system, with perches and nests, remains a lower-density alternative, whereas free-range access remains a niche, albeit a popular one when hens are allowed to graze.
Let us examine how extra freedom given to the cage-free hen changes its requirements for nutrients and feed allocation management. The following tips arise from experiences in the European Union, where cage-free housing has been adopted as the standard means of keeping hens in many countries.
1. Energy. The whole idea of removing layers from their traditional cages is to give them enough freedom to move around and exhibit all their natural behaviors. It is to be expected that all this new activity requires additional energy. As such, energy requirements will increase from 5-15 percent, depending on the facility’s layout. Of course, open-range hens will require even more energy.
There are two ways to increase energy intake. One is to increase daily allowance based on previous records (from battery cages). It would be advisable to begin with a 10 percent extra allotment of feed towards this new "expenditure" on layer welfare, and as long as body weight for age remains within established targets, there is no reason to alter this allotment. For the first few cycles, it is best to keep weighing hens throughout their lives to establish a reliable relationship between feed intake and body weight.
The other method is to keep feed intake volume at established levels (important for genetic lines with limited appetite) and increase dietary energy concentration by adding a lipid source. This second method avoids overspending on expensive additives, but protein concentration might need a slight increase to allow for somewhat heavier musculature and its maintenance; this remains to be quantified.
2. Wastage. Feed in battery cages was wasted mainly when hens were over-consuming out of boredom. This was, of course, true in heavier birds with more generous appetites than in lighter strains of white-egg layers. Cage-free layers should not suffer from boredom as they are expected to have a great number of ways to keep themselves busy. But, as these new housing/feeding systems are relatively new, it is possible that feed can be wasted due to insufficient feeder design. A high-quality equipment manufacturer should have already taken this into account in their product design.
3. Competition. Keeping four layers in a cage allows little room for competing during feed time. But, keeping hundreds if not thousands of layers roaming about without enough access to feeding spots may reduce feed intake for the lower-ranking birds and increase body weight for those at the top of the pecking order.
This is a feed wastage and an under-feeding problem — both causing reduced productivity and increased feeding cost. Increasing feed allowance to the level of satisfying the low-ranking birds is equally wasteful. It is best to consult with housing and manufacturing experts to establish the correct number and positioning of feeders and watering points to ensure all birds have ample chances of being nourished properly.
4. Productivity. Some preliminary reports indicate that hens in enriched colony cages might be able to reach higher productivity by 2-3 percent than in conventional cages. This has been attributed to enhanced welfare and health status, but again, this is based on a limited number of studies. The same cannot be said about floor-housing and open-range systems.
It is best to be a bit generous during the first couple cycles to re-establish a new productivity curve with any new housing/feeding system. In other words, do not change feeds before you see an actual cumulative drop of 2-3 percent productivity.
5. Excreta. Traditional and enriched cages offer the advantage of keeping birds away from their excreta. Floor-housing and aviaries and, to a lesser extent, open-range systems, bring birds in contact with their feces. As such, their health might be impaired if litter is not handled properly, especially if it is allowed to become wet. Here, experiences from the broiler industry can be extremely useful. At the very least, health additives should be marshaled to keep gut health and systemic immunity as high as possible. Coccidosis control in cage-free birds is of much greater importance.
6. Bones. Bone strength has always been a problem with traditional cage systems. Plainly, hens never had enough calcium to sustain their bone structure and their genetically determined high productivity. Cage-free hens get more weight-bearing exercise, which strengthens bones, but living in three-dimensional environments that require hopping and flying also increase the chance of injury.
All measures should be taken to ensure enough calcium (and phosphorus and vitamin D) become available to the hen. This remains especially important not only for the aging hens, but also for the developing pullets. Calcium management has never been as important as with cage-free systems, and we still have a long way to go to ensure we fully covered this issue.
7. Open-range. This requires some extra attention. If hens simply have access to a dry paddock, then little more than a small energy increase in their daily ration is required. But, if they have access to pasture, then we should look into ruminant nutrition and how to combine dry feed and fresh pasture. Organic poultry farming has already looked into this feeding puzzle and there are recommendations on how to feed hens depending on season and type of pasture. The traditional dry feed in its all-nutrient inclusive form can still be used, but it will lead to over- or under-feeding, and as such one or two new feeds (supplements) are needed.
8. White versus brown. Quite often, cage-free and especially open-range is associated with farm eggs, for which, in some countries, brown is the assumed correct color. If an egg producer switches from white to brown layers, then a new whole set of feeds is required as the latter are heavier in body weight and they produce fewer but heavier eggs. There is nothing secretive in feeding brown versus white layers, but in certain markets they are as alien as corn versus wheat. They can both be used, but not without rebalancing. The same is true for white versus brown layer genetics.
It should be evident by now that we are still uncertain how to design a single accurate feed program for layers housed outside cages, especially in aviaries and in open-range systems. Of course, under commercial settings, each operation is already testing various strategies depending on observed problems and available means. This is a new area in layer feed management that is custom-tailored to each production facility based on empirical knowledge and some trial and error.