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Canadian producer reaps benefits of coccidiosis vaccination — all year long

In the early 2000s, Fischer Family Poultry, Ltd., Ontario, Canada, devised a simple plan for breathing new life into its coccidiosis-control program:

Give the resistance-prone, in-feed anticoccidials a rest and use a live coccidiosis vaccine for three successive cycles. Then, when winter arrives, switch back to the medication program for three more cycles and continue with that rotation.

At the time, switching to vaccination for a few flocks offered one other intriguing benefit. Because the vaccine* contained a controlled, balanced dose of coccidial oocysts to stimulate the flock’s natural immunity, using it in successive flocks would eventually reseed broiler units with oocysts that were susceptible to ionophores and other traditional anticoccidials.

Unexpected results

To everyone at Fischer involved with the decision, the 3-3 rotation seemed like a reasonable and balanced strategy — one that allowed them to try a new approach to coccidiosis control while restoring the effectiveness of in-feed medications that had begun to sputter.

But something unexpected happened during Fischer Family Poultry’s rotation experiment.

Performance improved with each successive flock that was vaccinated. In fact, the second and third vaccinated flocks showed better performance than what had ever been seen with traditional anticoccidials. When Fischer switched back to medications in winter, flock performance leveled off or declined.

“At that point, we realized how much untapped performance there was in our birds and concluded that vaccinating year-round would work, provided we made small changes in nutrition and management,” said Derek Detzler of Fischer Poultry Consulting, a sister company of the broiler operation.

“We reviewed all the literature and distilled the science, which underscored the importance of early nutrition and its effect on intestinal development and immunity.”

It quickly became clear, he added, that good management and nutrition were prerequisites for a healthy gut and the production of healthy microflora. Furthermore, any delay in feed consumption could negatively affect growth and immunity.

“We were finding retained yolks, indicating stress and insufficient feed consumption, and concluded that our birds weren’t eating enough,” Detzler said.

“When I was a child growing up on a broiler farm,” he added, “my father would make me put out a lot of water trays for the first 12 hours, but now I realize that feed is more important than water. Villus growth and enterocyte differentiation depend in part on oral intake.”

No stone unturned

Continuing its investigation, the company also reviewed its hatchery records and learned that in a typical hatch window, up to 35% of chicks at placement could already be 24 hours of age or older. “The scientific literature suggested that these chicks were at risk for compromised intestinal development and immune function,” Detzler said.

To help accelerate feed intake, Fischer Family Poultry added Redvantage, a patent-pending, red coloring agent, to the feed so it would be more visible to chicks in their new environment. The operation also introduced a novel pre-starter ration that was formulated to increase digestibility by about 15% to 20% for a total of 90% to 95% digestibility, he said.

“Our average weight increased approximately 40 g (0.09 lb) at 7 days of age,” Detzler said.

The brooding environment was yet another variable that could be used to enhance intestinal health and the performance of the coccidiosis vaccine. In-house scale data revealed that growth improved to day 2 and then stalled. This problem was resolved by adding a brooder guard to confine chicks to the “comfort zone” with feed and water.

Growth stalled again when supplemental feed was discontinued on day 4 of age, which was corrected by continuing the supplemental feed on paper until day 7, he said.

Coincidentally, Detzler added, holding birds in the partial house until day 7 improved the uniformity of coccidiosis vaccine recycling, which was determined by measuring oocyst-shedding curves.

Measurable improvements

Looking back on their efforts to improve intestinal health, Detzler said the switch to feed containing Redvantage alone increased the 7-day-old weight by 4.8 g (0.01 lb). Other management changes added another 10 g (0.02 lb) and the adjustment in nutrition increased weight by over 28 g (0.06 lb).

In concert with these improvements, levels of oocyst shedding in vaccinated flocks dropped from a peak of about 80,000 oocysts per gram (OPG) of feces to less than 20,000, thereby reducing coccidiosis pressure with each cycle.

“We attributed the decline in OPG counts to a reduction in the wild-strain coccidial challenge in our broiler units, as well as to the more uniform flock response to vaccination that resulted from the changes in brooding management,” Detzler explained.

“The lower you can make your coccidial cycling, the better your performance,” he said. “Prolonged use of vaccine results in lower, earlier and more consistent oocyst cycling, flock after flock.”

Of particular note was a 10% increase in weight at 40 days of age, after these changes were made in flock management and coccidiosis control.

“Since 2005, we’ve never been off coccidiosis vaccination,” Detzler said. “We’ve taken control and are now managing coccidiosis for the long term. Our birds are healthier and more profitable.”

*Birds were immunized with Coccivac-B, a live coccidiosis vaccine.

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