“There seems to be an increasing consensus that these products are established methods of control and can be relied upon with great confidence,” says Dr. Martin Shirley, director of the Institute for Animal Health, UK. “Live-coccidiosis vaccines appear well able to protect against the spectrum of background species and strains of coccidia, and the industry is not seeing the emergence of parasites that are uncontrollable by vaccination.”

Poultry producers have taken note. From 2000 until 2008, the use of the coccidiosis vaccines Coccivac-B (available in the US and Canada) and Paracox-5 increased 250%, according to their manufacturer, Intervet/Schering-Plough Animal Health.

Improved administration is one of the major reasons that the efficacy of coccidiosis vaccination has been realized.

Instead of administering the vaccine via water or by spraying the vaccine onto feed, the vaccines are increasingly being administered with an innovative piece of equipment known as the SprayCox spray cabinet, developed by Intervet/Schering-Plough Animal Health, explains Dr. Charlie Broussard, US poultry technical service director for the company.

The innovation enables producers to vaccinate up to 100 day-old chicks with one pass. A dye in the vaccine lets hatchery managers monitor vaccine coverage; the dye also encourages chick preening, which helps ensure ingestion of the live vaccinal oocysts that help stimulate natural immunity to coccidiosis, he says.

“We also now know from numerous studies,” Broussard adds, “that broilers vaccinated with Coccivac-B or Paracox-5 perform as well or better than birds treated with traditional, in-feed anticoccidials.”

In the latest edition of Poultry Coccidiosis: Diagnostic and Testing Procedures, veterinary parasitologists Donal P. Conway and M. Elizabeth McKenzie say that coccidiosis vaccines “provide a very practical and important alternative to the exclusive use of anticoccidial drugs...”

Over the years, coccidiosis vaccination has evolved from a relatively simple, dependable way of controlling the disease into a broad management tool with multiple advantages for poultry producers:

Restoration of anticoccidial sensitivity

Rotating live-coccidiosis vaccines such as Coccivac-B or Paracox-5 into the coccidiosiscontrol program has been shown to restore anticoccidial sensitivity by reseeding poultry houses with Eimeria that are still sensitive to anticoccidials; this has been documented in several studies.

“It’s been good to see how vaccination decreases the number of anticoccidial drug-resistant isolates [in conventional flocks] and this effect seems to last for several growout periods,” notes Dr. Wil Landman of the Animal Health Service in Deventer, the Netherlands.

The restoration of sensitivity is an important benefit, notes Dr. Charles Hofacre, poultry veterinarian and professor, University of Georgia, because it’s going to be increasingly difficult to get new in-feed anticoccidials approved for use in food animals. “Not having the resistance problem is a fantastic thing for the industry,” he says.

Sustainable coccidiosis control

When coupled with good flock management, coccidiosis vaccination can be used as the sole method of coccidiosis control to enhance food safety — a major bonus for producers who want to meet growing consumer demand for drug-free birds and get premium prices for their products.

“Today’s coccidiosis vaccines offer the opportunity for real-world protection that provides an opportunity to meaningfully withdraw drugs from the diet and achieve optimal performance,” says Dr. Robert Teeter, a nutritionist at Oklahoma State University who has conducted extensive metabolic studies pinpointing the effects of coccidiosis on growth.

Relief from residue worries

Broussard points out that when vaccination is used instead of in-feed anticoccidials, producers no longer need an anticoccidial-withdrawal diet nor do they need to be concerned about drug residues in the poultry meat they produce.

“There’s an advantage for feed mills, too, because when birds are vaccinated, you don’t have to clean out manufacturing lines and equipment to prevent unwanted carryover of in-feed anticoccidials,” he says.

Flexible marketing

Coccidiosis vaccination brings tremendous marketing advantages to producers who thin their flocks, Broussard continues. Thinning is a practice common in Europe and used by some North American producers; birds, usually females, are removed to leave more space for growing larger males.

“Because there’s no withdrawal feed, producers have the flexibility they need to pull light or heavy birds as needed to meet market demand. They don’t have to keep medicated and non-medicated birds separate and they make better use of their poultry houses,” he says.

Indirect disease-control benefits

Necrotic enteritis, a disease caused by clostridium that is controlled in conventional flocks with in-feed antibiotics, is a greater threat to drug-free flocks. However, field experience indicates that effective coccidiosis control coupled with good management can help prevent necrotic enteritis by maintaining a healthy gut, which is less vulnerable to bacterial attack, Broussard says.

Another indirect benefit has been improved control of gangrenous dermatitis. Both field experience and trials suggest that late coccidial cycling predisposes birds to the development of this costly disease, he says. Dermatitis tends to be seen in flocks on chemical-to-ionophore or straight ionophore programs, which allow late coccidial cycling. In contrast, dermatitis tends not to develop in flocks that are vaccinated against coccidiosis at 1 day of age, presumably because they develop immunity early instead of late.

“Coccidiosis vaccination itself is not effective against gangrenous dermatitis,” Broussard emphasizes, “but by preventing late coccidial cycling, it reduces the severity of gut epithelial damage from coccidia or shifts the time at which it occurs. This could be an important means of preventing or at least reducing the prevalence of gangrenous dermatitis,” the veterinarian says.

Focus on nutrition

Coccidiosis vaccination enables producers to focus on improved nutrition for broiler chicks.

At Fisher Feeds in Listowel, Ontario, which produces drug-free feed for Bert Fisher Farms and contract growers, CEO and veterinarian Dr. Rae Fischer says, “With antibiotics, you can have some insult to the livestock and still not have a visible disease problem. When you go drug-free, you have to remove all those stresses that antibiotics might protect you from.”

He recommends that producers vaccinating birds against coccidiosis focus on nutrition the first 7 days of life, which are critical to the development of immunity. This is extremely important in antibiotic-free production. “You carry that thought process out a little farther, extend it for the life of the birds and do absolutely everything you can to minimize any insult that might be thrown in their way,” he says.

The importance of good nutrition and the development of early immunity has been confirmed by research. Teeter’s metabolic studies show that when broilers develop immunity early in life, as occurs with coccidiosis vaccination, it costs producers less because coccidiosis has less overall impact on the bird’s energy utilization. In contrast, when birds develop immunity against coccidiosis later in life, the impact on energy utilization is greater and so is the cost because it’s the same time that birds eat and grow the most.

“Producers today have a choice of how and when to develop bird immunity against coccidiosis. This is critical since birds consume approximately 50% of their feed during the last couple weeks, and to utilize feed effectively, intestinal health must be achieved,” he says.

Although coccidiosis vaccination has matured into an easy and reliable coccidiosis-control method, producers have learned from experience that good results require proper vaccine administration and attention to management.

“Properly administer these vaccines while they’re still fresh, and to get optimal results, adjust management as necessary. For instance, we’ve found that keeping chicks warm after they’re sprayed and exposing them to just 5 or 6 minutes of bright light promotes preening and uniform vaccine administration,” Broussard says.

When moved to the farm, chicks should be on litter with a moisture level in a range of 15% to 30%. Stocking density should be reasonable; if it’s too high, litter moisture problems and high litter-oocyst density may occur, Broussard cautions.

“By coupling coccidiosis vaccination with good early nutrition and some simple management changes, we can achieve excellent results in broiler flocks,” he says.