If Grade A quality chickens are to be produced at the processing plant, the broilers coming from the farm must be of high quality.
There is a well known saying that illustrates this well - “You put garbage in –ie poor quality live birds – you get garbage out”.
The processing plant is not a beauty salon where the poor appearance of low quality birds sent by the farm can be improved – and bird quality can have a major impact on performance. When poor quality birds arrive at the processing plant they have to be rejected, so reducing the volume of Grade A chicken that can be sold. Consequently, processing costs rise, and the competitiveness of the plant decreases.
There are, however, a number of steps that can be taken during the rearing, collection and transport of birds that will help to improve the quality of chickens sent to the processing plant.
Impact of litter on meat
The liter on which broilers are raised will have an impact on the meat they produce.
For good litter management, the poultry house floor should be made of concrete. Onto this base, a layer of absorbent natural materials is spread, for example rice husks, wood chips, or wheat straw. Litter should generally 5-10 cms deep.
One of the main challenges for those responsible for rearing chickens is to ensure, as far as is possible, its good condition and so prevent any possible harm to the broilers that could arise from keeping them on poor litter. To achieve this, daily inspection of the litter is something that should never be overlooked. The inspection should concentrate on the litter’s consistency and how damp it may be, and it is worth bearing in mind that once the litter has become damp, it is very difficult for it to dry out.
A number of factors can contribute to the litter becoming too wet. There include:
- Leaks from the drinking system due its poor maintenance;
- Poor water absorption by the birds, which is evident in the consistency of fecal material;
- Poor ventilation or inappropriate heating. It is worth remembering that cold air sinks quickly and so damp air is not effectively removed.
- Differences in the intensity of light. In those areas of the poultry house where there is stronger lighting the quality of the litter will be affected. This is because birds will be more active in these more brightly lit areas and consequently, the amount of urine and fecal material increases. As a result, the litter quickly becomes damp and compacted.
- If water and feed contain high levels of salts or minerals, the chickens will drink more water. This can lead to the litter quickly becoming damp.
- Should the birds develop any type of diarrhea there will be increased evacuation of fecal material, and it is important to remember the high content of uric acid and ammonia present.
There a number of ways in which the carcass can be affected by poor quality litter.
Problems with the legs usually emerge in the form of a callous – podermatitis – and this usually starts to emerge during the second week of rearing.
However, it does not emerge critically at this point, rather it becomes more apparent when the birds begin to grow quickly, form the fourth week and even more so from the fifth, when their legs have to support ever more weight each day. The pressure exerted against the litter is great, and if the litter is in poor condition the feet come into contact with a slimy surface, increasing footpad inflammation and leading to pain. This condition can make it difficult for the birds to reach the feeders, and because of this they will eat less and their growth rate will be reduced. These two aspects contribute to the quality of the flock being poor.
Breast meat damage
This part of the bird traditionally has the greatest value can be affected in two ways – partial skin burns and an overall redness.
These two costly problems occur in this area because the feather coverage is thinner, and consequently the breast skin enters into direct contact with the litter. This increases as the birds grow and gain weight, forcing them rest for more time on the litter.
Where there is a total reddening of the skin, the feathers around this area are also likely to be dirty, and this is how birds will arrive at the processing plant.
Influence of high density stocking
The skin problems that are most commonly observed on plucked carcasses are deep cuts, which have often not had sufficient time to heal, and scratches which affect the skin’s integrity.
To help prevent this, as birds grow, divisions should be installed in the poultry house to prevent birds crowding together. Eight to 12 divisions per 12 meter by 12 meter house are recommended. It is also important to ensure that drinkers and feeders are uniformly disitributed, as birds must have easy access to these.
Additionally, when staff responsible for collecting dead birds enter the poultry house, they must move slowly to prevent the birds from clumping together, which would result in them climbing over each other, causing scratches primarily to their backs. To help prevent this, staff should regularly walk the poultry house during the growth period so that birds become accustomed to the presence of humans and stress levels are reduced. Preventing birds becoming stressed due to the presence of humans is particularly important when birds are harvested.
There is another important factor that contributes to birds crowding together, in both open and in closed houses. In open houses, if the sides are not properly protected from sunlight, birds start to crowd together to avoid the heat of direct sunlight, whereas in closed houses, should there be any cracks in the walls that allow the entry of cold air, birds will avoid these areas, resulting in crowding in the warmer areas.
Care at harvest
It should be remembered that the broiler flock will live in the poultry house during their growth and fattening periods in relative comfort, with a temperature of 22-26 C and relative humidity of approximately 60 percent. Additionally, there will have been a continuous air-flow to prevent overcrowding.
Unfortunately, the harvesting crew is unaware of these carefully controlled conditions. When the birds are collected and placed into cages, these cages must be adequately ventilated. Mobile fans can be directed over the birds to dissipate the heat from the neck, wattle and comb, which act somewhat like a car radiator. If this is not done properly, birds can die from heat stress.
In short, if the poultry house is properly set up to receive chicks, and proper monitoring is carried out during their rearing, fattening and harvest, then the quality of birds arriving at the processing plant will be high, so increasing the amount of Grade A chicken produced.