Coccidiosis is a protozoan disease that negatively affects animal production and can result in economic losses. Emeria spp. is the most common parasite. Infection occurs mainly in young cattle and can lead to gastrointestinal problems and clinical signs as bloody diarrhea and hemorrhagic enteritis. The objective of this study was to evaluate fecal infestation and average daily gain of 100 Nelore heifers (Average weight of 191.22 kg) randomly distributed, as a completely randomized design, in 1 of 2 treatments: (1) Control (C, no coccidiostat), and (2) Treatment (T, dosage of 15mg/kg of Toltrazuril 5%, dosed once at weaning, 210 d after birth). The experiment was conducted in the Arrojo Farm (Teófilo Otoni, MG, Brazil). Animals were weighed in the first day of the experiment and then 30 and 60 d after. Fecal samples were collected for laboratory analysis in the first and last days of the experiment, for counting oocysts per gram of feces (OOPG). Data were analyzed using the MIXED procedure of SAS and Tukey as post hoc tests for separation of means. Friedman nonparametric test was done for repeated analysis and count of OOPG. There was no difference between treatments for average daily gain (596 g/d for C and 656 g/d for T, P > 0.05). However, presence of OOPG was lower for cattle in the treatment group after 60 d when compared with samples from the beginning of the experiment (P = 0.01), which did not happen with the control group (P = 0.86). Results of this experiment suggest that Toltrazuril 5% in the dose of 15mg/kg can reduce parasite infestation in the gastrointestinal tract. Infestation in the beginning of the experiment was not deleterious enough to cause changes in average daily gain. Table 1. Effects of dosing 15 mg/kg of Toltrazuril 5% to cattle

Item	Group		SEM	P-value
Control	Treatment
ADG, g/d1	596a	656a	247.67	NS
Oocysts per gram of feces, d1	982.76a,A	988.89a,B	108.94	0.91
Oocysts per gram of feces, d 60	786.21a,A	730.56a,A	113.34	0.30

^{a,b, A,B}Values with lowercase letters indicate differences between treatments; those with uppercase letters indicate difference between d1 and 60 (Friedman nonparametric test). ¹Tukey post hoc test.