Vaccination followed with feed medication gives pullets added protection against coccidiosis
Inadequate coccidiosis protection in pullets can lead to health issues ranging from uneven weight gain to mortality. Recent trials show an improvement in protection when a coccidiostat is used in combination with coccidiosis vaccine, according to Tak Niino, VMD, Zoetis.
“Vaccination is by far the most common method for controlling coccidiosis in pullets,” Niino said. “We see variable results with vaccination due to inconsistencies in immunization against coccidiosis. If birds aren’t protected, they might get a challenge that ultimately leads to inconsistent body weight and mortality, at its worst.”
Success with bio-shuttle program
Some poultry companies are running experimental trials to find a way to boost coccidiosis control for pullets. Some of the successful trials involve a bio-shuttle program using a coccidiosis vaccine in the hatchery followed by a coccidiostat — either an ionophore or a non-ionophore anticoccdial such as zoalene — later in the bird’s life. It’s important to time these medications carefully, however, so they don’t kill the coccidia oocysts in the live vaccine.
Zoalene has a unique label that allows a dose range of 36.3 grams per ton to 113.5 grams per ton to be used in pullets. This allows producers to fine-tune the dose, so shedding can still occur without causing clinical issues.
“I’ve been working with some companies to closely monitor their pullet coccidiosis program,” Niino said. “I am monitoring fecal-oocyst outputs on a weekly basis to make sure there’s adequate cycling and to make sure it doesn’t go out of control and cause clinical issues with the flock.”
The one-two punch of the bio-shuttle program has produced good results, Niino added. “They’ve had a lot of success getting the mortality under control and improving body uniformity.”
Oocyst counts better diagnostic tool
The oocyst counts Niino prefers to use for coocidiosis monitoring provide a quantitative result with coccidia oocysts reported per gram of feces. He collects feces throughout the bird house for a better representation of the flock. The samples are processed and oocysts counted by a hemocytometer.
“Because you count oocysts, the test is objective rather than subjective,” he stated. “It allows you to detect coccidia before the birds display signs.”
The most common method to diagnose coccidiosis today requires a sacrificed bird for observation of the coccidia in the intestinal lining. The oocyst counts do not require a sacrificed bird, which allows more frequent monitoring of the flock.
“With more frequent monitoring in the same flock, you hope to get a better understanding of the shedding profile and what times are peak challenges in an operation,” Niino explained. “Exposure and cycling patterns can vary quite a bit, depending on many factors that exist in the environment as well as management style.
“While oocyst counting does require a little more effort and time, if you don’t look, you’ll never know,” he said.
Posted on July 2, 2018