Paying attention to changes in turkey barns is key to successfully using ionophores, one of the industry’s older tools against the ubiquitous threat of coccidiosis, according to two industry experts.
Ionophores, feed additives that are classed as antibiotics and produced via fermentation, have been commercially available since the early 1970s. They remain the industry’s most common option for controlling coccidiosis.
Two facets of cocci control, two options for farmers
Ionophores work by modifying the cell walls of the Eimeria protozoans that cause the disease. This means that while water can get into cells, it can’t get out, ultimately killing the parasites. Not all of them are killed, however, and it is this “leakage” that allows birds to develop immunity naturally.
“It’s kind of a two-part control program. It’s long-term immunity, and [in the] short term, we’re controlling the oocysts. And the test is during that critical time during early grow out,” Steven Clark, DVM, Huvepharma’s veterinary technical services manager, explained during an appearance on the Iowa Turkey Federation’s Turkey Talkshow podcast.
There are only two ionophores available for commercial use in turkey flocks: monensin and lasalocid. Ionophores are fed through the whole life cycle of turkeys, but more commonly their use lasts from day 1 until the birds are between 8 and 12 weeks old.
Dose is always critical, but the drugs can have differing impacts under varying environmental conditions, influencing when they are used.
Different weather, different ionophore?
Monensin was singled out by Terry Olson, DVM, an Iowa turkey veterinarian who joined Clark on the podcast to share his experiences using ionophores with clients. He noted that although the drug can have great efficacy, in hot weather, using sulphonamides as well as monensin can be a “terrible triad” that can cause paralysis in turkeys. This becomes evident when fully alert birds are trying to pull themselves along by their wings.
“We need to be very careful about using some of these products during hot weather, because they can be toxic,” he added.
Clark pointed to producers using monensin when they have challenges keeping dry litter in the wintertime and shifting to lasalocid in the summer. He also noted the importance of paying attention to multiple factors in the field and adapting management accordingly.
“[In hot weather], we need to make sure that we have the right dose, [usually a low level], or we’re not using a sulpha drug,” he explained.
“When we’re moving birds, we need to be considerate of how long the birds are off feed and water, whether they’re going to gorge or if they’re going to have good access to water when they get moved, because all those things can combine into a situation where we might get knockdown [syndrome].”
Producers can also do their best to control the turkey house environment by ensuring water is available at the right height for birds and ensuring ventilation systems are working optimally.
A matter of rotation
Beyond making choices to avoid adverse reactions under certain conditions, rotating the two ionophores available is key to preserving their efficacy, the experts agreed.
Usually, signs of resistance will come in the form of reduced levels of control, and producers will make their own judgments about how their current program is performing, Olson noted. Although the option is there to conduct wider sensitivity trials with coccidia isolates, this is “not commonly done,” he said.
With sufficient attention to detail and timely rotations, substandard outcomes can be avoided, Clark added. However, he emphasized that in conventional turkey production, where they are used, ionophores should not be considered alone, but as part of a broader coccidiosis control program. This includes chemical anticoccidials and vaccines.
“We’re going to pick the best time when we’re going to focus on using ionophores in the correct dose and duration, then we’re going to include a chemical for rotation, and then some of us are going to include vaccination in our program. After that, we can come right back around again,” he said.
Farmer-veterinarian connection key
To ensure that programs continue working successfully, Olson highlighted the importance of communication between farmers and veterinarians.
“The feedback is critical. Anytime that turkey producers are doing their daily chores, they should note anything that’s unusual and specific to cocci control and report back to the veterinarian,” he said.
“That could be some depression, pulling off water or some loose droppings. Sometimes we see reddish-orange droppings, but anything unusual should be reported [so it] can be investigated.”
Managing birds’ vulnerabilities
Typically, coccidiosis is observed causing effects in the brooder house when birds are between 3 and 4 weeks of age, Clark said, which is a vulnerable time for birds, particularly with immunosuppressive pathogens like avian metapneumovirus appearing with greater frequency in the US.
“Now it is even more critical than ever that we must have the right program at the right time,” he added. “We’re all trying to define and fine-tune these comprehensive programs now so that we have the best immune response, the minimal reaction and the least disease in the flock during this time.”
To listen to the full episode, visit the Turkey Talkshow podcast website or scan the QR code:
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