Nicarbazin ( NCZ ) is largely used to reduce coccidiosis effects in broilers. Combinations of NCZ with ionophores improves anticoccidial efficacy. A study evaluated NCZ associated with ionophores using a total of 2,310 one-d-old male Cobb 500 chicks distributed into 7 treatments with 11 replicates of 30 birds each. Treatments were an Unchallenged Control ( birds not inoculated with Eimeria spp. and without anticoccidials), whereas the other treatments were Eimeria spp. inoculated: Challenged Control (without anticoccidial), NCZ+maduramicin (40 + 3.75 ppm), NCZ+monensin (50 + 50 ppm), NCZ+narasin (50 + 50 ppm), NCZ+salinomycin (50 + 50 ppm), NCZ+semduramicin (48 + 18 ppm). Coccidia were orally gavaged at 14 d using live oocysts of Eimeria acervulina, E. maxima , and E. tenella (80,000, 80,000 and 40,000 oocysts per bird, respectively). Evaluation on the week post inoculation, (which is critical since it is when the peak of parasite replication and intestinal damage occurs) showed birds from the Challenged Control having significant reductions in BWG (60%) and feed intake (26%), as well as worsening in FCR (86%) (P 0.05). Mortality was reduced in the unchallenged control relative to the challenged control (0 vs. 29.3%) in the wk post inoculation, but treatments could not reduce mortality in the Challenged groups. Orthogonal contrasts, on the other hand, showed glycosidic ionophores (maduramicin and semduramicin) having reduction in mortality (29.1 vs. 34.1%) (P<0.029) vs. non-glycosidic ones (salinomycin, monensin and narasin). This also occurred in the cumulative period (1 to 28 d) (P<0.012). Lesion scores at 21 days showed higher values for all the Eimerias spp. in the Challenged Control compared to the Unchallenged Control, but without effects of the anticoccidial combinations; values for Eimeria tenella were numerically higher than the other coccidia.
Vieira et al. (Wed,) studied this question.