Efficacy in Turkeys

Several trials have been performed to evaluated the tolerance, safety and efficacy of Baycox® when it is used to control turkey coccidiosis.

A trial performed by Greuel (Greuel, E., Aus dem Institut für Anatomie, Physiologie und Hygiene der Haustiere der Universität Bonn und dem Geschäftsbereich Veterinär, Institut für Veterinärentwicklung, Bayer AG, Leverkusen, 1989) involved 160 female (Big 6) 10-day-old poults. The birds were infected with a pool of E. adenoides (190,000 oocysts), E. meleagrimitis (90,000 oocysts) and E. gallopavonis.

During the trial, two treatment regimens with Baycox® were evaluated.

•   25 ppm
• 125 ppm

The results of the trial showed that the infected control groups developed severe clinical coccidiosis, while the treated groups did not show any clinical sign, lesions or oocyst excretion. It is also important to mention that during the five weeks of the trial the growth rate and water intake were not affected in the Baycox® groups.

In another trial Greuel (Greuel, E., Deutsches Tierärtzliches Wochenschreiben, 1991 April; 98(4):129-32) compared three sulphonamide preparations and Baycox® following an experimental infection of caged turkeys with a mixed oocyst suspension of E. meleagrimitis, E. adenoides and E. gallopavonis based on clinical and parasitological parameters.

The infected control group showed severe clinical signs, the sulphonamides groups developed mild signs and the Baycox® group remained free of any clinical signs. These results correlated with the level of oocyst excretion that was 0% for the Baycox® group and about 50% of the oocyst count of the infected control for the sulphonamide group.

Greif and Froyman performed comparative efficacy trials against turkey coccidiosis between Baycox® given in three dose regimens (7 mg/kg per two days, 15 one day and 20mg/kg one day) and amprolium (250 ppm for 5 days), challenging with a mixed inoculum of drug-sensitive E. adeneides (Ead 3,000 oocyst/bird) and E. meleagrimitis (Eme 10,000 oocyst/bird) in ten-day-old turkeys raised in floor pens (2 replicates). Negative and positive control groups were also included in the trial.  

The challenge control group showed severe clinical signs including 60% mortality and oocyst counts in the fecal samples were of 544,000/gram, whereas all treated turkeys survived.  In the case of the amprolium group the oocyst counts were 51,000/g and no oocyst were shed in the Baycox® treated groups. Mean lesions scores (on scale of 0-4) for Ead/Eme were 3.5/3.3 and 1.7/2.2 in the positive and the amprolium group. A mean score as low as 0.1 was observed for Ead in the Baycox® 7 mg/2 days and Eme in the 15 mg/1 day. In the Baycox® group the Eme mean score was 0.6.

Weight gain was also measured from the day of infection until 7 days p.i.. The challenge control and amprolium groups' weight gain was severely depressed (161 gram and 162 gram approx.) in comparison with the negative control group (303 gram approx.). Growth was unaffected by coccidiosis in all Baycox® treated groups (300 to 320 gram approx.). Palatability was unimpaired with the regular Baycox® dosing, but slightly affected in the single dosing groups.

In conclusion, Baycox® cured turkey coccidiosis better than amprolium, limiting the duration of Baycox® treatment to a single day, whilst maintaining the total therapeutic dose did not diminish efficacy. (Greif and Froyman, Proceedings of the 9th International Coccidiosis Conference, Paraná, Brazil, September 19-23, 2005.)

Similar efficacy of Baycox® was shown by Roux (Roux, V.J., Phd Thesis, École Nationale Vétérinaire d'Alfort, France, 1997) in challenge trials that involved  200 and 300 male turkeys (BUT 9). The challenge inoculum involved in these trials were the following:

• E. meleagrimitis; strain PM3 (Ploufragan, 1992); 200,000 oocysts/bird
• E. adenoeides; strain Pad1 (Ploufragan, 1991); 100,000 oocysts/bird

Baycox® was administered to the birds at different dose levels: 7, 14, 21 mg/kg BW (50, 100, 150 ppm) on day 2 and 3 post infection (over approx. 8 h per day). 

Positive and negative control groups were included in the trials. Weight gain, oocyst excretion, lesion scores and variation in water intake were evaluated during the trial.

The results of the trials demonstrate that:

• Baycox® is highly effective for controlling turkey coccidiosis and preventing the detrimental effects of the disease (decrease in weight gain, damage of the intestines, mortality, etc) at the different dose levels.
• Baycox® is safe and well tolerated by the birds even at high inclusion levels.
• Baycox®  is highly effective for controlling turkey coccidiosis at a dose level of 7 mg/kg. An incremental increase in the dose rate does not boost efficacy. The correct dose of the product must be given in order to ensure the optimal results of the treatment. 

Due to the aforementioned facts, its wide spectrum of activity and unique mode of action, Baycox® is a highly efficacious and suitable option for treatment and control of turkey coccidiosis outbreaks.