Paradigm Shift: Industry changes present disease challenges

People in the poultry industry can be forgiven for believing that things have changed in recent years and not for the better, Jean-Pierre Vaillancourt, of the University of Montreal, said at the Poultry Industry Council’s annual poultry health conference in Kitchener.

People in the poultry industry can be forgiven for believing that things have changed in recent years and not for the better, Jean-Pierre Vaillancourt, of the University of Montreal, said at the Poultry Industry Council’s annual poultry health conference in Kitchener.

Vaillancourt said the avian influenza outbreak in British Columbia and the recent reminder in Saskatchewan lend credence to the idea. But changes and challenges are nothing new, he said.

Some seem recurrent and some seem to be emerging.

New changes and challenges may seem particularly frequent in the poultry industry, but the poultry industry, as we know it, is young and its expansion over the past 40 years has been phenomenal.

Dr. Jean-Pierre Vaillancourt says that before we look at the possible role of new production systems in the emergence of disease epidemics, it is important to review what effect the increase in regional density of commercial poultry farms has on infectious conditions in poultry.

“But keep in mind that since 1978 the poultry world has seen the emergence or re-emergence of at least one new disease or new variant of a known disease per year,” he said.

The disease breaks are occurring when there are more restrictions on veterinary drugs and when the public is increasingly concerned about the safety of the food supply, he said.

Some vocal and politically active people are questioning the morality of commercial poultry production. In response, new production systems are being proposed. These include: organic, antibiotic free, indoor and free range.

“This is not likely to be just a fad,” he said.

The changes are motivated by shifts in people’s attitudes towards well-being, their own and the animals’. They are also having consequences.

“In France, standard broiler production of whole birds is expected to decline by as much as 10 per cent per year,” he said.

Two types of production will replace this. One type will be labelled certified, which will be similar to classic production but the growers will have to show how the birds were raised and will include the capacity to trace the birds back to the farm. The other type will be organic, which will grow by 15-to-20 per cent per year.

The new production systems will create challenges, but Vaillancourt said it is important to understand the challenges that are already out there.

Vaillancourt said the poultry populations in parts of the U.S. are at “insane levels.” “Production diseases are more than likely the result of an increased infection pressure at the farm and the regional levels,” he said.

Greater regional farm densities have contributed to increasing the number of pathogens on any given production site and can affect poultry performance and, at times, “they may even become a lethal combination.”

At the same time large grocery chains and large fast food chains are in a position to dictate to producers not only what products they want, but also how these products will be produced.

For example, the Quebec restaurant chain Rotisseries St-Hubert wants, within a few years, to be able to offer antibiotic-free chicken to its customers. St-Hubert needs 110,000 whole chickens per week and thousands of kilograms of other poultry products, he said.

“So, marginal production systems are now emerging because of opportunities that far exceed the small niche markets they used to hold,” he said.

The challenge, he said, will be to manage growth of the new production systems.
“Indeed, the emergence of organic farming, antibiotic-free production, and other production models may also contribute to changes in the epidemiology of some diseases. If changes occur, they will be in terms of incidence and risk factors associated with their spread,” he said.

But it would be wrong to assume this will always lead to more disease problems. Meanwhile it must be recognized that pathogens aren’t necessarily confined to a single species.

“When we look at emerging production systems we tend to just think poultry, but we can share bugs,” he said.

For example, a novel H2N3 has been isolated from pigs in the U.S.

“This is not a typo,” he said. “You are probably aware of H3N2 in pigs and its ability to affect turkey breeder flocks. H2N3 is much different,” he said. H2N3 has an avian origin and is similar to an H2N3 found in mallards and other waterfowl.

“The concern here is not only that we have an avian connection to this virus, but its H receptor binding is very similar to the H of the H2N2 influenza virus associated with the 1957 human pandemic.”

This H2N3 causes two to five per cent mortality in pigs and tests on rodents have shown it can spread to other mammalian species.

To date there have been no human cases reported but the Centre for Disease Control is monitoring the situation.

The appearance of new diseases and the re-emergence of old diseases combined with new production systems, increased livestock density and increased consumer activism and public attention, argues for greater diligence.

Because diseases can be regional and studies in the Netherlands and Italy have shown that greater regional density increases disease risk, Vaillancourt said, “management of infectious disease risk must include a regional approach in terms of disease prevention
as well as disease containment.”

But improvements in regional biosecurity must be paralleled by improved communications. “The stigma attached to having an infectious disease is real and often leads to people to keep this information from others,” he said.

“But silence has been shown to be even more costly. . . . Pointing fingers has never been an effective disease control strategy,” he said.

Compensation is a hot topic in Canada, he noted. Changing production systems will tend to keep it on the front burner, he said. In other countries compensation levels take into account the level of biosecurity employed on the farm.

For example, in Australia the higher the biosecurity standards the higher the government compensation if a disease is found on the farm.

In the U.S., there is a program for surveillance of low pathogenic avian influenza. Producers in the program receive a substantially higher payout if the flock is depopulated. The program also includes payments for lost production.

The bottom line is the industry needs more surveillance and enhanced communication particularly in areas with high density. This is particularly true for emerging production systems.

“An increase in such production systems could have a significant impact on the epidemiology of poultry diseases,” he says. “However, this impact could be transient and eventually not significant as professional producers involved in these productions adapt to the reality of going from being a marginal production to a more mainstream one. But this will require a high degree of vigilance on their part regarding infectious diseases coupled with a willingness to work with neighbouring producers.”