Health: Coccidiosis

Coccidiosis is endemic to all commercial turkeys. Although they rarely
cause clinical lesions, anti-coccidials in the feed or vaccines to
hatchlings are still needed to control this protozoan disease in
commercial turkeys.

Coccidiosis is endemic to all commercial turkeys. Although they rarely cause clinical lesions, anti-coccidials in the feed or vaccines to hatchlings are still needed to control this protozoan disease in commercial turkeys. Vaccines are now routinely used in turkey breeders where they give lifelong protection. However, as a disease, coccidiosis is often ignored or considered unimportant to turkey production because it is often not seen or difficult to diagnose. The classical coccidiosis lesions are seldom present or often missed and with little or no signs in the live birds to suggest intestinal problems. However, the fact that intestinal epithelium is where the coccidia grow and replicate suggests that infection is likely going to impair nutrient absorption. This resultant malabsorption that can lead to the impairment of feed efficiency is therefore a reasonable assumption.

Performance of two paired-barn studies on turkey toms, one vaccinated and one medicated against coccidiosis 16 years apart, are compared here to show that feed efficiency can be directly linked to the different methods of coccidiosis control and the same observation is also supported by the performance data of commercial turkeys produced in Ontario.

Similar differentials in average body weight and feed conversion (Table 1 ) were maintained for both studies even though they were conducted 16 years apart and with poults growing on different formulation of feed as well as genetics. Antibiotics (Virginiamycin) or prebiotics (Immustim) (Table 1) when used were provided to both barns of each study and therefore should not be a factor in creating the differentials observed. These differentials could therefore only be the result of using different methods of coccidiosis control with vaccination performing 19 points better in feed conversion than medication (Tables 1 and 2). Both methods showed specifically that feed efficiency is directly related to coccidiosis control. With vaccination, by the nature of its cause and effect, we see  even more clearly that to obtain a better feed efficiency requires better coccidiosis control.

The same magnitude of differential in performance or feed efficiency was maintained even for the many years in between (Table 3 and Figures 1 and 2) 1989 and 2005.

When averaged body weights and feed conversions after 1998 were charted out flock by flock, and compared to 2002 USA standards (Figures 1 and 2), the same differentials were consistently present. One notable exception was when there was a specific disease situation at one farm, the feed efficiency increased to 3.3.

Economically, there is roughly a $20 per tonne savings based on 2005 paired-barn results (Table 3) at a $300 per tonne average feed price. With ever increasing feed prices this benefit will be even more substantial in the future and therefore should warrant attention. n