Hd. Chapman et E. Saleh, Effects of different concentrations of monensin and monensin withdrawal upon the control of coccidiosis in the Turkey, POULTRY SCI, 78(1), 1999, pp. 50-56
The efficacy of different concentrations of monensin in turkeys exposed to
field isolates of Eimeria and the effect of the withdrawal of monensin from
their diet were investigated. Results of a battery study indicated that 66
ppm monensin was effective against three species of Eimeria in the turkey.
In floor pens in which poults were exposed to infection, use of 59.5, 79.4
, and 99.2 ppm monensin resulted in reduced mortality and improved feed con
version at 3 wk of age compared with birds that had received no medication.
Poults given 59.5 ppm monensin weighed more and had a better feed conversi
on at 3 wk than poults given 79.4 or 99.2 ppm monensin, but at 10 wk no dif
ferences in the body weight or feed conversion of poults given different co
ncentrations of drug were apparent. At 14 wk (and from 10 to 14 wk), poults
that had been given 99.2 ppm monensin had a lower feed intake and weighed
less than birds that had been given 59.5 ppm of the drug but there were no
significant differences in feed conversion. There was no significant differ
ence in the weight gain or feed conversion of poults from 10 to 14 wk of ag
e whether monensin was present in the feed or had been withdrawn. No eviden
ce of compensatory growth was found in the present study.