Although there are no regulations in Argentina that require the identification of eggs for consumption with respect to their production systems, this requirement does apply in Europe and registers incipient initiatives in nearby countries such as Colombia or Chile.
In this sense, the veterinarian Bernardo Kojic Rousseil, independent consultant of laying farms and head of the course on Animal Welfare in Poultry at the Faculty of Veterinary Sciences of the National University of La Plata, explains that ” egg production systems they are the same all over the world and they will end up being categorized unfailingly in the country, because the public wants to know what they eat and how it is produced, and that is a basic right ”.
It details the four existing systems: the most widespread, in confinement in cages, the old traditional system or in batteries of cages on several floors, inside air-conditioned sheds, called automatic in the country, when referring to its egg collection and evacuation system guano.
To this are added the so-called alternative: confined to the ground or floor, which normally work in old broiler chicken rearing houses, with manual or automatic nests. There the birds can walk and perch on perches, which improves their bone structure; he camper, similar to the previous one since the hens are raised on the ground, with the addition of accessing an external park, protected with woven wire mesh. And the ecological, established by Senasa regulations, which accepts a maximum of 6 birds per square meter, while the free-range allows 9 birds per square meter.
In these models, animal welfare is higher but they assume more costs that should be recognized in the gondola for these systems to be viable.
Regarding confined systems, Kojic Rousseil points out that in Europe the cage enriched with nest is used, a place that the animal needs for 30 to 40 minutes, to lay the egg, which improves its performance. “The enriched cage has a nail file, inexplicably not mandatory in Argentina, a kind of sandpaper under the feeder that takes away the sharpness of the nails, since they do not wear out when in cages. It has 2 perchitas of about 18 cm and a trough front that is double what is used in Argentina. And instead of the 420 cm2 per animal that is used in the country, it has 600 cm2 per bird, “he said.
The battery cages that in Argentina are used in automatic sheds, the most modern installed in the country, and that house between 10 and 12 birds per cage, with an area per animal of between 380 and 420 cm2, were definitely banned in Europe in 2012, after a process of migration to systems more friendly to animal welfare, which the EU started in 1999. Based on these standards, in its member countries it is mandatory to identify the eggs according to the type of production system from which they come, classified as 0, ecological; 1, campero, 2, floor, and 3, cage.
Temperature, one parameter
Since hens have a normal body temperature of 41 degrees and that they produce an egg that they lay at 37 degrees, the thermal and humidity conditions are key for them to produce in conditions of animal welfare and to the maximum of their potential.
Kojic Rousseil explains that “the ideal room temperature for that to happen is between 17 and 24 degrees. But this is not always the case and the hens, if they are confined, are limited to receiving the temperature that exists and not the comfortable one. These birds do not have sweat glands, they cannot perspire to regulate their temperature. They lose heat through 4 mechanisms, 3 of which work up to 35 degrees ambient temperature ”. They are: radiation, conduction and convection.
In cages, chickens have a hard time lowering their body temperature in hot weather.
The radiation It is the loss of heat through its environment, so it must be cooler than the animal. The temperature of the skin should be higher than that of the air around it. The driving it is the possibility of losing heat by direct contact against a cooler surface. Birds in cages, standing on a wire, find it extremely difficult to lose heat through this system.
“On the other hand, an animal that is on the ground or in the country system, where it goes outside, when it is hot, lies down with its abdomen on the ground and thus 65% of its body is in contact with the ground and loses heat from support on the floor. This possibility is not available in the cage system ”, Kojic Rousseil points out.
The convection It occurs when the air that is in contact with the animal heats up and rises and then another mass of cooler air circulates. For this system to work and be effective, there must be a large air current so that it is renewed with speed.
These three mechanisms are quite efficient as long as the ambient temperature does not exceed 35 degrees. Upon reaching that mark and depending on the age of the animal, its last resort is panting, loss of temperature through the evaporation of its own water. It keeps its beak open and exposes lung moisture to the environment. For panting to function as a cooling system, there must be an important difference between the humidity that the animal has to lose and that of the air to receive. There must be a dry environment.
“Panting is not free for the hen. It requires you to have water and energy to lose in this operation, which also produces metabolic alterations in the animal. When panting, the animal hyperventilates and thus loses CO2 through the lungs and the ability to fix calcium in the blood, which affects lower quality of eggshell that it produces ”, he specifies.
In response to heat, birds consume more water and less feed, thereby produce fewer eggs, of smaller size and thickness of shell, that this way they will be more fragile. That egg carries a logistics problem, because it breaks more easily, which translates into a commercial disadvantage because it receives a lower price.
The hen is faced with climatic variations and its adaptation will depend on itself and its ability to find out about changes in external temperature, which will be reflected in its production. In response to heat there is acclimatization. The animal does not die of heat but of dehydration.
Kojic Rousseil explains that even if there is a cooling system in every battery cage house, the temperature is not uniform. It is not the same in the corridors that divide different sectors of cages, than within them. And neither on the upper and lower floors, nor closer to the corridors than further into the cages.
“The bigger the house, the more uneven is the temperature, which means that average values are handled, which differ from the real temperature at different points in the houses. It is difficult there to maintain a uniform temperature. And that requires different types of nutrition ”, He explained.
Beyond the influence of the temperature of the birds on their animal welfare, for Kojic Rousseil it is necessary to make the Argentine State understand that there must be rules. The alternative egg producerAlthough it is a minority, it exists. And the only way to survive it has is to transfer its higher cost, which it necessarily has for a matter of scale and manpower. You will not be able to have it as long as you cannot differentiate or identify it, that is why rules are needed. “Senasa must oblige producers to declare, in addition to the origin, color and expiration date of the egg, which of the four production systems have: if the hens are caged, on the ground, if it is free-range or organic ”, he insisted.
“It is not an argument that because the State cannot control, the producer cannot declare how it produces. The best way is for the producer to be within the system, registered with Senasa and to declare within that framework and on the day he is found in an error he will be sanctioned ”, concluded the specialist.