Fine-tuning rotation plan can improve coccidiosis management
Broiler producers have made important strides in managing coccidiosis but could further improve control and cut losses by rethinking their strategy for anticoccidial rotation, say veterinarians who have worked extensively with the costly parasitic disease.
Coccidiosis remains the leading cause of intestinal problems for the world’s commercial poultry industry. In one recent report, the annual global economic impact cited due to coccidiosis production losses as well as prevention and treatment costs are an estimated US $2.4 billion annually.
“Coccidiosis is still one of the biggest headaches for broiler producers in Europe,” confirms Dieter Vancraeynest, DVM, a Belgium-based veterinarian with Zoetis Inc. who works with broiler producers throughout the European continent.
Full-blown coccidiosis outbreaks characterized by classic clinical signs such as bloody droppings and mortality are seldom seen. Coccidiosis more often presents in its subclinical form, and therein lies the problem, he says.
“When producers don’t see clinical signs, they mistakenly believe the disease is under control, but coccidiosis is slowly eroding their profits, primarily due to reduced bodyweight gain and poor feed conversion,” Vancraeynest says.
The situation is similar in the US, where coccidiosis usually presents as a subclinical instead of clinical disease and may go unrecognized, says Don Waldrip, DVM, a senior technical services veterinarian with Zoetis who has years of production experience.
In the Asia Pacific region, coccidiosis is described as “a continuous enteric challenge for broilers in all production circumstances” by ChoewKong Mah, DVM, a Zoetis veterinarian familiar with the disease in this territory. It’s a challenge that occurs regardless of the bird’s stage of life or its breed, which is generally the white commercial or indigenous yellow broiler.
As in Europe and the US, subclinical coccidiosis is common and clinical coccidiosis is less-often seen. “Nowadays, we seldom see wet and/or bloody droppings, loose feces, feed passage, cuddling, ruffled feathers, dirty birds, anemia and mortality. Overall, farms affected by coccidiosis complain about an overall loss in performance and poor feed conversion,” he says.
There’s no doubt that coccidiosis is still a major concern for broiler producers and that it has a serious economic impact, Mah says, particularly in production systems where birds are housed on deep litter but also among birds on slatted, raised floors.
The best defense against coccidiosis, Mah says, is a well-planned anticoccidial-rotation strategy designed to manage, not eradicate, the disease. “Producers need to learn how to manage anticoccidials for long-term performance. Be proactive rather than reactive,” he says.
It’s widely accepted that coccidia cannot be eliminated from the poultry environment, so the goal must be to minimize its economic impact while using anticoccidials responsibly so they maintain their efficacy, Mah notes.
Rotation plans can vary. With a so-called “shuttle” program, one in-feed anticoccidial is used in the starter feed and another in the grower/finisher feed until it’s time to withdraw the drug in preparation for marketing the broilers. Another type of rotation is a “full” program, where the same flock receives the same in-feed anticoccidial from day 1 until withdrawal, and the in-feed anticoccidial used on the farm is changed about every 3 to 6 months.
Guard against resistance
Broiler producers need to guard against the development of coccidial resistance to in-feed anticoccidials, which is a universal problem, Vancraeynest cautions.
“Many producers have done a good job managing coccidiosis with their anticoccidial-rotation programs, but from time to time, we have resistance issues if they use the same products for too long,” he says.
One of the biggest problems he sees involves independent producers who encounter resistance, then turn to water-soluble anticoccidial products for treatment — which is a costly approach as the producer pays twice: first for a failing in-feed product, then for a water-soluble treatment product to try and solve the issue. “The better solution is to change the in-feed molecule,” Vancraeynest advises.
Marco Quiroz, DVM, a technical services veterinarian at Zoetis who has worked extensively with producers in Mexico and Latin America, says that “Ideally, an anticoccidial-rotation program should be tailored to each company or production complex based on its history of success or failure with various anticoccidials, as well lesion scoring and anticoccidial sensitivity testing (AST). That will reveal which coccidial species are the greatest problem and which anticoccidials are going to be the most effective.”
Maintaining a database for monitoring the species of coccidia that may be affecting a farm and the level of control with various in-feed products is also recommended, he says.
Like Vancraeynest, Quiroz has observed that one of the biggest mistakes producers can make with their rotation programs is using the same product for too long. The class of product must also be rotated, he emphasizes.
“If you use salinomycin, don’t then switch to monensin or narasin because they are all monovalent ionophores and work similarly,” he explains. “If resistance develops to one, it’s likely to develop to another. Switch instead to a divalent ionophore such as lasalocid or to a synthetic anticoccidial or a coccidiosis vaccine.”
Although effective coccidiosis management in commercial poultry operations must rely primarily on ionophores, an annual cleanup with a synthetic anticoccidial or the use of a vaccine is often necessary, Mah and Quiroz say. They both caution, however, that while the synthetics are highly effective and excellent for cleanup programs, they should be used only once yearly or even every 2 years since resistance to them can develop quickly.
Role of vaccination
Vaccination is another tool that can play an important role in the coccidiosis-management strategy.
The initial cost and concern about an initial performance setback discourage some producers from including coccidiosis vaccination in their coccidiosis-management programs, Vancraeynest says. Vaccination, however, can be very helpful for producers who encounter multi-resistant populations of Eimeria.
He explains that vaccination gives in-feed anticoccidials a rest. It also seeds the poultry house with coccidia that are still sensitive to the in-feed products, and in that way restores their efficacy.
In case a drop in performance associated with initial use of a coccidiosis vaccine is observed, it will often be largely recovered in subsequent production cycles with in-feed products since the efficacy of these products will have improved, thanks to the vaccine, Vancraeynest says.
Waldrip adds that research indicates coccidiosis vaccination may help manage the risk for Salmonella in poultry. In a challenge study, coccidiosis vaccination numerically reduced the environmental load, the prevalence and cecal number of Salmonella Heidelberg, a food-borne cause of Salmonella poisoning in people.
He strongly advises anticoccidial-rotation planning for the long term — at least 12 and preferably 18 months into the future — to get the best results.
Sometimes, Waldrip continues, producers resist long-term planning because they are under economic pressure to get optimal short-term results, and sometimes they simply find it difficult to break old habits. However, short-term planning can backfire by inviting coccidial resistance.
“To have a sustainable coccidiosis-control program, we have to prevent resistance, and to do that, we must rotate enough different products and give each one an adequate rest. That takes time and long-term planning,” Waldrip says.
Zoetis has put these principles of rotation into action via its Rotecc™ Coccidiosis Management program, which is a science-based strategy to help poultry producers develop cost-effective, sustainable programs for combatting coccidiosis. The program draws on published research, field and pen trials, and the experience of Zoetis veterinarians in more than 70 countries. It includes all field-proven anticoccidial tools available, not just Zoetis products, he says.
Waldrip adds that the Rotecc rotation strategy, especially when coupled with good husbandry, should result in fewer problems with resistance, more effective coccidiosis management and fewer losses. “We see increased live weight gain, improved feed efficiency and reduced mortality, and that translates into better profits for poultry producers.”
 Quiroz-Castaneda R, et al. Control of Avian Coccidiosis: Future and Present Natural Alternatives. BioMed Res. Int. 2015;2015:430610. doi:10.1155/2015/430610.
 Coccidiosis can play a role in Salmonella control. WATTAg Net.com http://www.wattagnet.com/Coccidiosis_can_play_a_role_in_Salmonella_control.html
Accessed July 21, 2015.
Posted on September 29, 2015