Coccidiosis remains widespread in the EU and elsewhere, reportedly costing producers €2 billion (US $ 2.9 billion) annually — more than any other disease.
DR. LUCIANO GOBBI

Besides keeping the disease in check, coccidiosis-vaccination programs can help producers restore the sensitivity of in-feed anticoccidials; they can also complement the practice of thinning flocks and enhance marketing, reduce costs, simplify work at the feed mill and improve food safety, Dr. Luciano Gobbi, a veterinarian and technical service manager with Intervet/Schering-Plough Animal Health, said at VIV Europe 2008 — Moscow Edition.

The primary means of controlling coccidiosis has been in-feed anticoccidials, which accounted for 87% of coccidiosis control in the EU, according to a 2007 report. Yet coccidiosis remains widespread in the EU and elsewhere, reportedly costing producers €2 billion (US $2.9 billion) annually — more than any other disease — primarily due to lost performance that results from subclinical coccidiosis, said the Italy-based Gobbi.

One of the main problems with anticoccidials is the development of coccidial resistance, which has resulted from the overuse of the products, he said. Gobbi cited studies from the US, South America, Germany and the Netherlands documenting resistance. In the Dutch study, for instance, testing of 15 Eimeria isolates showed that 78% were resistant to diclazuril, 72% were resistant to monensin, 68% were resistant to nicarbazin and 64% were resistant to salinomycin.

Vaccine benefits

A major benefit of coccidiosis vaccination, he said, is the restoration of Eimeria sensitivity, which can be accomplished by rotating a vaccine with anticoccidials. Gobbi showed an example demonstrating that in flocks where ionophore sensitivity had declined, the use of the coccidiosis vaccine Paracox-5 for three consecutive flocks restored ionophore sensitivity.

“One hypothesis is that vaccinal Eimeria lines conjugate with wild lines and render Eimeria strains less pathogenic and more sensitive to anticoccidials. Conjugation means an exchange of genetic material, leading to less pathogenicity and a restoration of sensitivity to anticoccidial drugs,” he explained.

In trials designed to assess bird performance when a coccidiosis vaccine was rotated with anticoccidials, performance was within the normal range, whether the birds were light or heavy, although the best results were achieved in heavy birds raised to 2.0 kg or above, Gobbi said.

Compensatory growth occurred by day 30 onwards and performance improved with continuous vaccination of successive flocks because the challenge of natural coccidiosis declined. In addition, good results were achieved when flocks returned to in-feed anticoccidials, he said.

Enhances thinning

Continuous use of a coccidiosis vaccine not only provides complete control of the disease, it also can enhance the practice of flock thinning, Gobbi said. With thinning, male and female birds in one house are divided by a barrier. For the first thinning, females are usually removed and the barrier is taken away, leaving the whole house to grow larger males. Thinning also makes it easier to grow heavy birds in hot summer months.

Coccidioisis vaccination complements thinning because there is no anticoccidial drug in the feed and, consequently, no withdrawal time, which enables producers to pull light or heavy birds as needed to meet market demand, he said.

“Vaccination makes it easier to thin flocks, which in turn helps increase meat production per square meter,” Gobbi explained.

With more birds raised in the same house, costs are reduced for transporting feed and for moving chicks to the house and transporting them to market. In fact, transportation costs can decrease by as much as 20% to 30%, he said.

Since integrators pay farmers on the basis of kg of meat per square meter, which is improved with coccidiosis vaccination, farmers have reduced fixed costs, while integrators have a reduction in variable costs. “Hence, the integrator has reduced remuneration to farmers per kg of meat produced by each square meter,” Gobbi said.

Life at the feed mill is simplified, too, with coccidiosis vaccination, he said. There is no need for cleaning the manufacturing lines and equipment to reduce or prevent the unwanted carryover of anticoccidials, Gobbi said.

Another important benefit of coccidiosis vaccination is the reduced risk for drug residues in broiler meat that can result from the use of anticoccidials or therapeutics administered when coccidiosis outbreaks occur.

“Consequently, finished-meat products are from a traceable, clean production chain and can be guaranteed as safer for consumers,” he said. “This is particularly important for producers growing drugfree birds who want to differentiate their product.”

Regresar a European Edition (#2)