Anticipation of Damage / Post-Vaccinal Treatment with Baycox

The objective in poultry production is to keep challenge infection as low as possible in order to fully exploit the growth potential of the birds, although in practice this aim cannot always be realised entirely as the success of any prophylactic programme depends on factors related to the product, animal and environment.

Baycox can successfully support and improve existing prophylactic programmes and thus prevent coccidiosis and the economic losses related to the disease.

The most common ways to use Baycox in order to anticipate damage caused by coccidiosis are:

• Cross-over therapy in broilers to reduce damage associated with varying degrees of unpredictable coccidiosis caused by ionophore-tolerant Eimeria strains.This approach is useful during periods of high risk during the production cycle.
  
  
• As a transitional product in dual coccidiostat programmes (bridge concept), due to the fact that during the period of transition from the in-feed product during the first weeks of age and the one used during the late stage of the productive cycle there is a higher risk of developing clinical and subclinical coccidiosis problems.
  
  Tamas and Ostlind (Tamas Tamas, Phd y D.A. Ostlind, Ph D., Laboaratorios de Investigación Merck, Estados Unidos, Industria Avicola, 07/1996) challenged and compared the productive parameters of chickens treated with a dual system and chickens that were treated with the same coccidiosis control programme but also included the use of Baycox as a transitional product between the other two products. In their trial the group that included the transitional product obtained higher daily weight gain, lower intestinal lesions and lower levels of oocysts shedding.

Post-vaccinal programme.- Baycox may be also used 10 to 12 days following live vaccine administration due to the fact that Baycox does not impair the development of immunity, but actually boosts it.   

In fact chickens that were immunised against coccidiosis and treated with Baycox (Toltrazuril) afterwards had a stronger specific humoral antibody response  against sporozoite antigens (indirect immunofluorescence, Ig G) than chickens that were immunised only (Greif G., 2000, Parasitology Research 86: 787-790).

The reasons behind this are:

• Baycox is not active against extracellular stages responsible for the development of coccidia immunity (attachment/invasion). Hence at this stage it cannot interfere negatively with the immune response.
  
  
• Despite the high activity of Baycox against intracellular coccidia stages, it does not impair the development of coccidiosis immunity and even enhances the immunity due to the fact that at the intracellular level damaged coccidia trigger better the immune system. 
  
  
• Baycox does not negatively interfere with the production of cytokines IFN-g and IL-4, two important components of the cell-mediated immunity (CMI) response (Steinfelder et al., 2002). As coccidiosis immunity is governed almost exclusively by CMI the latter feature of the drug is a very important asset for a coccidiosis control programme.