Keeping it Simple

Like the U.S., Latin America and Asia, Europe is finding vaccination to be an effective "and convenient "method of managing coccidiosis in broilers

Applying Paracox-5 to feed in the UK. A spray cabinet option will be available in the near future.

The European broiler market is discovering that vaccination is not only an effective way to manage coccidiosis, but that it simplifies logistics at the feed mill and processing plant.

"Extensive studies in the lab, on floor pens and in the field show that in standard broilers, just one dose of vaccine given to day-old chicks controls coccidiosis," says Dr. Luciano Gobbi, Verona, Italy, a veterinary consultant who has been involved with coccidiosis vaccine testing.

Vaccination against coccidiosis, he explains, prevents coccidial infection by initiating the development of immunity. In contrast, in-feed coccidiostats prevent coccidial infection by suppressing the parasite's life cycle, but resistance to in-feed products has been a worrisome and growing problem.

Vaccination Results

To illustrate the impressive results obtained with vaccination, Gobbi points to several carefully controlled commercial trials conducted in Spain with male and female broilers (Ross, Cobb, Hybro-G). The birds received either a coccidiosis vaccine or traditional in-feed coccidiostats (nicarbazin + monensin or nicarbazin + salinomycin) and were assessed for as long as 51 days.

"There were either no significant differences in live weight between birds in both treatment groups, or the vaccinated birds were significantly heavier than the coccidiostat-medicated chickens," he says.

Similar observations come from Dr. Michael Francis, director of biological research and development, Schering- Plough Animal Health, which manufactures the Coccivac and Paracox brands of coccidiosis vaccines.

In controlled field trials conducted in France, the U.K. and Italy, there were no reported coccidiosis outbreaks in birds that received coccidiosis vaccination, he says.

In addition, laboratory studies with vaccinated birds exposed to coccidial infection showed "significant protection" determined several ways, including oocyst output and lesion development, Francis says.

Simplifies Management

In addition to effective coccidiosis control, vaccination has other important advantages, according to Gobbi. "It greatly simplifies feed-mill management," he says.

Currently, feed mills manage several in-feed coccidiostats and provide different diets for broilers of different ages. This is necessary because coccidiostats must be rotated periodically to help minimize the coccidiostat resistance problem, he says.

"Considering that one feed mill may serve 200 to 300 farms, it can be difficult to be sure each farm gets the correct diet, with the correct coccidiostat," Gobbi says.

There is always a risk that the wrong diet will be sent to a farm, or a diet without an in-feed coccidiostat at all. Such errors can result in a coccidiosis outbreak in unvaccinated birds.

"The vaccine, however, eliminates these potential problems by eliminating the need for in-feed coccidiostats," he adds. "Feed mills also will have fewer regulatory worries since they will be managing fewer in-feed drugs."

Processing Flexibility

Dr. Charlie Broussard, a veterinarian with Schering-Plough Animal Health, cites other advantages of vaccination.

"It eliminates concerns about toxicity, residues and withdrawal times," he says. "This is particularly helpful at a time when there is increased consumer demand for more natural food."

Vaccination also gives producers more processing flexibility. Farmers often process birds based on market need. But if in-feed coccidiostats are used and a withdrawal period is necessary, they cannot always supply birds when supermarkets need them.

"The vaccine will better enable producers to process birds on short notice, meeting the demands of clients and the public," adds Broussard.

Growing Track Record

The coccidiosis vaccine now available for broilers in Europe is Paracox™-5, which is also marketed in Israel.
In the United States, Latin America and Asia, a coccidiosis vaccine for broilers called Coccivac-B is applied to chicks at the hatchery with a spray cabinet.

"These vaccinse are producing excellent results in studies and in the field. Their use has increased tremendously in light of growing coccidiostat resistance and the increased public demand for drug-free, natural birds," Broussard says.

Gobbi agrees and predicts that coccidiosis vaccination will provide an effective and easy way to manage coccidiosis in broilers far into the future.

"It is clear that vaccination can provide comparable or possibly better performance than traditional in-feed coccidiostats," he says.

"In fact, immunological prophylaxis with coccidiosis may provide broiler producers with a way to keep coccidiosis under real control for decades."

Boosting Vaccine Performance

Broiler producers can boost the effectiveness of coccidiosis vaccination by practicing "good management," say Drs. Charlie Broussard and Luciano Gobbi.

For instance, food and water provided before or after vaccination must not contain any anticoccidials or other drugs that have anticoccidial activity, which would destroy the oocysts provided in the vaccine and prevent the development of immunity, Broussard says.

Steps should be taken to reduce the chances of coccidial challenge to vaccinated flocks. "One way to do this is with good sanitation. Litter should be removed and the chicken houses thoroughly cleaned between rearing cycles," he says.

Gobbi says it is important to keep broiler houses dry through proper ventilation and with proper maintenance of watering systems, which will control the proliferation of coccidial oocysts in litter.

"Coccidial oocysts in broiler populations is impossible to eliminate because they are hardy organisms, and it is virtually impossible to raise completely coccidia-free broilers under commercial conditions," he says.

"But producers can effectively control coccidiosis by combining use of coccidiosis vaccination with these management strategies, as well as meet market demand for poultry meat free of chemical additive residues."

Source: CocciForum Issue No.2, Schering-Plough Animal Health.