On The Chopping Block

After a revealing 'conversation' with his broilers, Dr. Mueez Ahmad put his neck on the line to benefit their intestinal health and performance

For as long as anyone can remember, it was always the chicken that put its head on the proverbial chopping block for the good of man. Now, at least one production veterinarian for a US poultry company has shown that he's willing to make the same sacrifice for the good of his birds.

After 5 years of success using a coccidiosis vaccine in the company's line of antibiotic-free birds, Dr. Mueez Ahmad of Draper Valley Farms, Mount Vernon, Washington, wanted to pull the in-feed anticoccidials used in the company's commercial broilers and start vaccinating all birds year round. It wasn't a spontaneous decision. The company, which places about 600,000 birds a week from its farms in Washington State and Oregon, had

been vaccinating chicks in its antibiotic- free line - about 15% of total production - with Coccivac-B instead of medicating with a traditional ionophore antibiotic.

The program worked well, so in 2005 Draper Valley began using the vaccine in its commercial birds for three cycles, usually from April through September. For the other three cycles, Draper Valley kept the birds on an ionophore. All commercial birds received an antibiotic to keep necrotic enteritis in check.

Then they started asking questions.

Inquiring minds

Impressed with the excellent performance of the commercial broilers that had been on the vaccine, production manager Dave Wilson kicked off the inquisition by asking Ahmad why they stopped vaccinating after three cycles. Wilson also noted that the vaccinated birds didn't suffer from spiking mortality syndrome. He also thought that frequent changes in medications might be stressing the birds and making them more susceptible to this condition.

Ahmad initially defended the vaccine- ionophore rotation in the commercial birds, explaining to his inquiring production manager that a lot of poultry operations had used this regimen with good success. He also noted that using the vaccine for several cycles helped to restore the sensitivity of coccidial organisms to traditional ionophore antibiotics and chemicals.

In time, however, Ahmad started questioning his own rationale.

"Our strategy had been to put the birds on Coccivac-B for three cycles and then switch to an ionophore for the next three," he says. "But in reality, we were getting only one good cycle from the ionophore. Production dropped off in the second cycle and become even worse on the third. We got to talking about it further and concluded that if the birds were doing so well on the vaccine, maybe we should just leave it in there and go with it year round."

Besides thinking that this was the best approach for the birds, Ahmad and Wilson also felt that any efforts to reduce or even eliminate drug usage was consistent with the Draper Valley's commitment and vision to distinguish its brand and add value to its product line.

'Talking to the birds'

But not everyone at Draper Valley shared their enthusiasm for vaccinating commercial broilers all year long. Some thought it was fine to use the coccidiosis vaccine from spring through fall, when there was better air circulation and presumably less of a coccidiosis challenge. But the idea of dropping ionophores and chemicals in winter initially met some stiff resistance. In fact, one influential advisor was so convinced the plan would fail, he threatened to resign if the company took the plan forward.

Ahmad dug in his heels, too. Reflecting on the showdown, he says, "I almost lost my job over this decision to vaccinate the birds all year, but I was confident in our plan and felt it was the best way to go - for both the company and the birds."

To support his case, Ahmad brought in a team of experts to speak objectively on the vaccination program's behalf. It wasn't a panel of veterinarians or nutritionists, however. Ahmad asked for input from the chickens themselves. "I'm posting birds every month, and every month they're telling me their gut is better when they're on the coccidiosis vaccine," he remembers telling the company's management. "The birds are telling me this program isn't going to fail."

"The birds are telling you?" asked one company decision-maker in disbelief. "You're actually talking to the birds?"

Lesions don't lie

At that point, Ahmad concedes with a smile, "some people thought I had some psychological problems." He held firm to his position, though, and provided more tangible evidence - in this case, the results of post-mortem exams of birds taken randomly from all houses in Draper Valley's system. The posted birds ranged from 14 days to market age.

The investigation showed that vaccinated birds had minor but manageable coccidiosis lesions early in the bird's life, before 21 days, versus the medicated birds, which showed had more serious lesions caused by wild strains of coccidiosis at 34 or 35 days.

Ahmad says that seeing lesions in birds is not unusual - or at least that was the accepted paradigm at the time. In his 15 years of commercial poultry production, he can't recall posting birds without lesions from Eimeria tenella, a major cause of coccidiosis. The one exception was the first time he used Clinacox (diclazuril), a synthetic anticoccidial that initially provided outstanding control until resistance issues made it necessary to significantly limit the product's usage.

"Other than that, seeing some lesions in your birds is perfectly normal," he says. "It's just a matter of how bad they are and when they occur."

'The birds will be fine'

After much debate, Draper Valley's management decided to try Ahmad's vaccination plan in October of 2005 - a time when the company normally would have rotated its commercial broilers back to the ionophore. But still, the high-stakes showdown wasn't over.

In late December - shortly after one advisor made good on his promise to quit - Ahmad stuck with his longstanding plans to take an extended vacation to visit his family in Pakistan. "They will be fine, nothing will happen," Ahmad confidently told his management before packing his bags and leaving Wilson in charge.

And apparently, Ahmad was right. "It was the best winter we ever had since starting with this program," Wilson recalls. "And by March or April, everyone realized that our commercial broiler operation didn't collapse and that performance had, in fact, improved."

Now, after more than 24 months of using coccidiosis vaccination in all the commercial birds, Ahmad says he's hardly seeing any lesions. He thinks that continued use of the Coccivac-B, which provides a controlled, balanced dose of live oocysts that naturally stimulate immunity, has caused the population to shift away from tenacious wild strains to those that can be more easily managed.

"If we see lesions in the birds today, it's usually associated with another management problem or possibly clostridium, not coccidiosis," he says. In its commercial birds, Draper Valley uses either BMD (bacitracin methylene disalicylate) or Stafac (virginiamycin) to help keep enteritis in check. If there's an enteritis break, Ahmad will bring it under control by adding penicillin to the water for 2 or 3 days.

No gangrenous dermatitis

Ahmad says Draper Valley's use of Coccivac-B yielded two other unexpected benefits, both related to the vaccine's ability to halt late coccidial cycling.

First, Ahmad and Wilson have not seen a single incidence of gangrenous dermatitis, a clostridium-related health problem that results in high mortality, carcass condemnations and trimmed parts since birds are on cocci vaccine. Economic losses have been estimated to be as much as $1.31 per affected bird.

Recent reports suggest that late coccidial cycling predisposes birds to this costly condition. Gangrenous dermatitis also tends to occur in flocks on chemical-to-ionophore and straight ionophore programs, which allow late coccidial cycling. In contrast, field experience shows that flocks vaccinated against coccidiosis have lifelong immunity against coccidiosis, do not experience late coccidial cycling and tend not to develop gangrenous dermatitis.

"Gangrenous dermatitis is a very expensive disease - one that hits birds close to market age, usually around 38 to 40 days - and it doesn't respond to treatment very well. Even if you do treat, you need to be very careful about withdrawal times at that age," Ahmad says.

"If your birds don't die from dermatitis, you can lose them on the processing line, where they'll be condemned," he continues. "Given the choice, I would much rather deal with the risk of necrotic enteritis than gangrenous dermatitis. Enteritis is definitely the lesser of two evils, and you can keep it under control with good management."

Ahmad also thinks that late coccidial cycling suppresses birds' immunity to other diseases. "Immunity suppression is an expensive phenomenon," he says. "The way I see it, anytime you have a stressful environment for the birds, it compromises their immunity and makes them more susceptible to other disease problems. Gangrenous dermatitis is one good example of that, but there's also staphylococcus and Escherichia coli.

"There's a group of bacteria out there just sitting and waiting for another bacterium to create an insult in the skin," he continues. "It could be that our new program results in better intestinal health, which in turn suppresses these bacteria."

Flexible formulations

While coccidiosis vaccination has allowed them to reduce drug usage, it has also given them more flexibility in formulating rations - for the simple reason that they no longer have to work around a predetermined drugrotation schedule. As a result, Draper Valley now invests more in its starter rations to ensure optimum intestinal health but saves on the back end because birds are moved to the lowcost finisher or withdrawal ration 7 to 10 days sooner.

"Our nutritionists can make changes in the needs of the birds, without having to work around the medication program," Ahmad says. "Having the anticoccidials out of the feed gives them a lot more freedom."

The feed mill enjoys the freedom, too, because it now has fewer medications to track and doesn't have to worry about flushing drug residues from the mill.

As for the economic side of the picture, Ahmad says Draper Valley's medication costs appear higher than the Agri Stats' national average, but that's because that category includes the vaccine, which Ahmad says is misleading.

"When you look at the cost variance of the different ionophores you'd have to use throughout the year if we didn't vaccinate, the cost tends to even out," he says. One other way to look at it: "If you divide the vaccine cost back into the cost of the feed given to those birds, you'd see that the cost of the vaccine isn't a big factor. The price of the vaccine is offset by its benefits. I think it's a wash."

Managing litter and light

Managing the birds' environment also helps build immunity and reduce disease pressure. Wilson says they prefer raising birds on "built-up litter" for 3 or 4 years without a lot of cleanout. "We just go in and de-cake it for every grow-out," explains Wilson.

This strategy, adds Ahmad, helps to stimulate bird immunity at an early age. "Our salmonella numbers over the last 2 years are dropping very rapidly," he adds, pointing to the decline from an USDA standard of 6% to 7% to about 2%."

Wilson thinks the lower salmonella numbers are a byproduct of the company's diligent efforts to control enteritis without drugs.

"We've made a lot of changes to our management, not just to the litter but also to ventilation, cleaning out our wells and water lines and so on. We knew clostridia were going to be our number one challenge as we reduced or eliminated drugs. Any time we fail it always goes back to an issue that occurred in the first 7 to 10 days. In our antibiotic-free program, we knew that if we made it to 21 days without an outbreak, it would be clear sailing."

Lighting also came into play. Ahmad and Wilson decided to give vaccinated chicks more light intensity in the first 7 days to help them develop a stronger immune system, more easily see the food and water, and get off to a fast start.

Once they're in what Ahmad calls "their comfort zone," usually around day 14, they reduce the light intensity to slow down the birds' growth - a practice recommended by Cobb, which provides their genetics. "It's a stepup/ step-down program," Ahmad says.

"Without that, they will continue to eat and grow their muscles, but at a faster pace than their skeletal and the cardiovascular systems."

Faster growth rate actually became a problem for Draper Valley after all of the company's birds were put on Coccivac-B. He fixed it by reducing light.

The future is now

The new emphasis on better nutrition, environment, management, and fewer drugs has also helped Draper Valley's production team better prepare for future market trends. In fact, in March 2007, Draper Valley also decided to drop the growth-promoting antibiotic from its commercial birds' rations in favor of an experimental competitiveexclusive product that helps promote better intestinal health.

Reflecting on their recent changes, Ahmad says that raising some of the company's birds without antibiotics has forced them to become even better managers.

"When you go antibiotic-free, you can't use drugs and Band-Aids to cover up our mistakes," he says. "That experience, I think, has had a profound effect on the management of our commercial birds as well. The use of the coccidiosis vaccination, for example, has helped us develop a better understanding of how birds grow. I don't look at vaccination as a disease-management program. To me, it's more of an animal husbandry approach.

"When the company came to me and said it wanted all of our birds to be totally antibiotic-free, I told them we could do it with the next cycle of birds Five years ago, I probably would have told them we needed 15 years," he adds, smiling.

Vaccination: 'Now it's a smooth ride'

What advice does Draper Valley share with other producers thinking about vaccinating for coccidiosis?

"I tell them it's like anything else that's new," says Ahmad. "You may hit a few bumps when you start out, and sometimes that causes people to give up. But once you get over the hump - say, once you're past the first two or three cycles - it's a smooth ride from there. More than anything, you have to be willing to become a better manager."

Wilson agrees. "I wanted to quit vaccinating several times because I wasn't comfortable with it after the first cycle. And besides, medications seemed so much easier.

"Then I had Dr. John McCarty (a consulting veterinarian for Schering- Plough) here and he said, 'Dave, you have to be patient and to stay on it a little longer.' I told him he was full of it," Wilson adds, smiling. "But you know what? Dr. McCarty was right, and I'm glad I listened to him. Change can be uncomfortable at first, but it's usually for the better."

Source: Cocciforum, isuue 13