Prof Robert Bragg, Veterinary Biotechnology Dept Microbiology and Biochemistry, University of the Free State offers his opinion
Challenges in SA Poultry Industry
the local poultry industry has been hit with a major bird flu epidemic. The ongoing load shedding and power disruptions have put tremendous pressure and additional costs on the industry, leading to a huge increase in price. One company (Astral Foods) has spent an additional R919 million as a result of load shedding alone. This has obviously had a significant impact on the profitability and sustainability of the company and the pocket of the consumer.
Bird Flu or Avian Influenza
Avian Influenza (AI) is a viral bird disease, including poultry. This is a devastating disease can wipe out a poultry flock in just a few days. Bird flu is the most widely-studied poultry disease as it has been causing major problems across global poultry industries for many years. The rise in this viral bird disease has increased since 2013 and can also infect people, pets and other animals.
Reluctance to vaccinate
In the past, (five to 10 years), AI was pretty much the only serious poultry disease South Africa (SA) was free of. There have been cases of what is called low pathogenic Avian Influenza in ostriches for some time. However, the commercial poultry industry was, for a long time, free of this highly pathogenic strain of the virus. This is now, unfortunately, no longer the case.
In the past, Veterinary Services was reluctant to allow vaccination of poultry in against AI in SA. Most of the major international vaccine manufacturers have highly effective vaccines against AI, which are widely used in many countries where AI has become well-established. There were two reasons for this reluctance. Firstly, there is a well-organised and -run surveillance system in place for AI in SA. The basis of this monitoring programme is routinely looking for antibodies against AI in commercial poultry. This surveillance system is only possible if the birds are not vaccinated. The control policy in the past was a “stamping-out” policy. In other words, when AI is detected in a flock, the flock is destroyed. Secondly, AI has not been a major problem in SA in the past and previous outbreaks were successfully controlled with the stamping-out policy which was in place. All this has now changed and AI is running rampant. The consequences of this will be severe.
Layers and Broilers
The commercial poultry industry is based on two types of birds – the layers and the broilers. The layers, as the name suggests, are the birds which lay eggs for human consumption. The broiler birds are the meat birds. In order to maintain the supply of both meat and eggs, there is a complex system of breeder birds, grandparents and great grandparents.
These breeder birds are genetic line birds and play a critical role in keeping the market supplied with poultry products. If these breeder birds contract AI, they will die, either from the virus infection or from control efforts. When this occurs, the constant supply of hatching eggs needed to keep the layer and broiler farmers supplied with chickens to meet the constant demand for poultry products will be gone. In other words, there will be a major shortage of poultry. As poultry is the most affordable source of protein, this will cause major food shortages and growing hunger problems.
Antibodies vs Viruses
There are now efforts to import vaccines against AI. This will assist with the control of the disease in the long term, but will unfortunately, not do much to control the current problem in the short term. The reason for this is that it takes time for vaccinated birds to develop antibodies against the virus. As soon as the birds are vaccinated, their immune system will start to produce antibodies. Only when there are enough antibodies, will the birds be protected. It can take up to two weeks to get sufficient antibodies. Even then, if there is too much virus in the field, the immune response of the birds can still be overwhelmed.
In simple terms, if the bird has a number of antibodies of 10 antibodies and there are nine viruses, the antibodies win and the birds are safe. If there are 10 antibodies, but 11 viruses, the viruses win and the birds die. (These numbers are not the real numbers and are merely used as explanation.) During the major Newcastle Disease (NCD) outbreak in the late 1990’s, the birds had very high levels of antibodies against NCD and should have been protected. However, there was so much circulating virus that the immune systems of the birds were overwhelmed, making this outbreak very difficult to control.
Biosecurity
The only short-term option for control of AI in the current situation is good biosecurity. It is essential that this is in place on poultry farms. Only high-quality, registered disinfectants must be used for biosecurity efforts. The ideal product would be one which is non-toxic to the birds and can be used to continually reduce the levels of viruses in flocks. Until the vaccination programme can take effect, the only control option is a full continual disinfection programme which would include using the disinfectant in the drinking water, provided that the product is registered for this application and also to regularly spray the birds – again only if the product is registered for this application. The registration of a product ensures that the label claims are substantiated and there is valid scientific evidence to support the claims made by the producers of the product.
The long-term consequences of this Bird Flu infection coupled with the constant problems with load shedding will be the death blow to many small- and medium-sized poultry farmers. It may even become very difficult for even large poultry companies to survive the current crisis. In order to meet the demand for poultry products, SA will most likely become even more reliant on imported poultry products, another bone of contention. According to SAPA’s 2021 report, in 2021, SA produced 1.91 million tonnes of poultry meat and consumed 2.3 million tonnes, with imports making up 19% of consumption, compared to 21% the prior year. In the same year, chicken imports made up 18% of chicken meat consumption, dropping from 20% in 2020.
*Edited and additional data supplied by Alex Rose-Innes, editor Greening Afrika
