Most people welcome the onset of summer, but for poultry producers it brings the threat of a fly population explosion. No matter how careful you are, flies will migrate and find their way into the sheds, and once they start breeding they can very quickly become a problem.
Fly control should be an integral part of every poultry producer’s management program. Flies spread disease and filth, area nuisance to employees, and can become problems for nearby farms and residences. As the number of producers decrease and the size of remaining poultry operations increase, larger units may provide the opportunity for flies to concentrate and therefore create even larger problems.
Flies pose a health risk for humans and poultry. They are carriers of Salmonella, Pasteurella, Campylobacter and E. coli which have a negative effect on poultry flocks and farm personnel. The speed of fly reproduction can vary depending on environmental conditions such as warmth, moisture and food sources, but it is not uncommon to have 5 – 6 generations during a single summer breeding season.
The little house fly is smaller than the house fly; however, the size difference is difficult to distinguish. Breeding sites for the little house fly are drier than for the house fly and poultry manure is preferred over most other materials. This fly prefers shade and cooler temperatures and even circles aimlessly beneath hanging objects in the poultry house, egg room, and feed room. The little house fly is less likely to crawl on people and food than is the house fly. lt is, however, usually the fly that causes the most complaints from residents near the poultry farm. Large numbers of these flies may gather in garages, breezeways, and homes because of their preference for shade.
The house fly is known to breed in many types of organic material such as decaying plant material, spilled grain and feed, and in all kinds of animal manure. ln caged layer houses the manure is a very good location for breeding. In houses where sanitation is poor and where water spills keep the manure moist, fly breeding may especially be a problem. The house fly prefers sunlight and is a very active fly, which crawls over filth, people, and food. Because of these habits it is the most important species from the standpoint of spreading human and poultry diseases and fly-specking eggs.
Large numbers of flies can negatively impact poultry farms operations including:
- Increased biosecurity risk
- Loss of poultry production
- Uncomfortable work environment
- Increased time and cost for fly control
- Damage to equipment
- Extra cleaning costs between flocks, to remove fly excrement from equipment and building surface
Flies can sometimes act as vectors of food-borne diseases such as Salmonella and E. coli bacteria, as they are able to transfer pathogens from one location to another when they land to feed, rest or defecate.
Pakistan Environmental Protection Act,, 1997, (PEPA) was created to address nuisance complaints related to odor, noise, dust, light, smoke, vibration and flies from farming operations.
As well as reducing the risk of public complaints against fly nuisance, controlling flies on the farm will also decrease the risk of disease.
“Poultry producers have to control flies as they carry hundreds of diseases and if you have a disease you don’t want to pass it onto a neighboring farm.” In addition, fly spots on eggs can often result in them being downgraded to seconds.
Flies like warm, semi-moist conditions for breeding, so poultry litter is ideal, especially under drinkers or where there has been a water leak.
Fumigating the shed to kill any adult flies before bringing in the new flock is also essential. “If you leave any adult flies around they will be straight into the new flock.”
The treatment for adult flies and larvae will depend on the breed of fly. “In maggot form the treatment for lesser and common house flies is exactly the same, but once in adult form it’s about locating the adulticide correctly as they contain pheromones to attract the flies to the bait.”
Health Risks of Flies
Flies are known to be vectors for many diseases of both humans and livestock, and are considered a sign of unsanitary conditions. Flies may transmit disease by carrying viruses, bacteria, parasites, and fungi on their bodies, or through their mouthparts after contacting or ingesting infectious materials. Chickens may eat flies at any life stage, and can become infected by ingesting the insects or by direct contact. Fly populations may also create a reservoir for disease on poultry farms, making disease treatment and elimination more difficult.
Fly control strategies
Developing an effective fly control program is important for the success of any poultry operation. The most successful programs combine multiple control methods with diligent monitoring to minimise the economic and health threats posed by flies.
Chemical Control
There are four basic types of chemical insecticide fly control: larvicides, residual adulticides, baits, and contact adulticides. Larvicides include contact larvicides and insect growth regulators (IGRs). They may be sprayed onto maggot infested areas directly, or, when manure is very wet, may be applied as a dry granule.
In insect growth regulators cyromazine is from triazine class with application in poultry as feed additive through feed for fly control in chicken feed and feces. Because of its novel and specific mode of action, the toxicity is of a very low order.
Start feeding Cyromazine 1% feed premix early in the spring before flies begin to appear and continue feeding throughout the summer and into the fall until cold weather inhibits fly development.
As the maturing larvae feed on the treated manure, they become unable to develop into adult flies because cyromazine, the active ingredient in Artemazine, Artevet inhibits formation of chitin. Chitin is the base of the fly’s exoskeleton.
Kaolin is the carrier of Artemazine. The use of kaolin, act as an inert ingredient in feed. Kaolin shows a significant effectiveness of adding kaolin in the feed on performance, litter moisture and intestinal morphology of poultry. It shows improvement in nutrients digestibility by reducing the digest transit in laying hens and broiler chickens and reduction of the free moisture of feces due to its antidiarrheal action. Poultry litter when moist is a propitious environment for the growth of bacteria and fungi; and also the main cause of ammonia emissions, one of the most serious environmental factors that affect the production of broiler chickens. Kaolin absorbs moisture and reduces the level of Ammonia in house and ultimately lessens the odor.
Role of Flies as Vectors of Foodborne Pathogens
Flies are “pests” of great medical and veterinary significance and are one of the most important vectors of human diseases worldwide. Houseflies are important nuisance pests of domestic animals and people, as well as the main fly vectors of foodborne and animal pathogens. Due to their indiscriminate movements, ability to fly long distances, and attraction to both decaying organic materials and places where food is prepared and stored, houseflies greatly amplify the risk of human exposure to foodborne pathogens. Houseflies can transport microbial pathogens from reservoirs (animal manure) where they present a minimal hazard to people to places where they pose a great risk (food). Stable flies are bloodsucking insects and important pests of domestic animals and people and can cause great economic losses in the animal industry, and they can also play a role in ecology of various bacteria originating from animal manure and other larval developmental habitats.
Most bacteria associated with insects include foodborne pathogenic bacteria such as Escherichia coli, Salmonella spp., Shigella spp. Naturally occurring association between insects and Salmonella spp. occurs in synanthropic flies. There is also concern that flies may also contribute to the spread of avian influenza. Potential of the dominant Musca domestica flies to act as vectors for circovirus carriage, and this potential may also be true for many nonenveloped viruses. Moth fly is a potential mechanical vector of bacterial pathogens associated with nosocomial infections.
Additionally, the development of antibiotic resistance among clinical bacterial isolates and commensal bacteria of people and animals, as well as bacteria in other habitats, raises a concern that flies may be vector competent not only for specific pathogens but also for nonpathogenic bacteria carrying antibiotic resistance genes.
