monensin and arprinocid

Three floor-pen trials have confirmed the high anticoccidial activity of CL 259,971 as first reported in batteries. The optimal dosage level was shown to be 5 ppm in the diet. At this level, excellent anticoccidial activity was observed with no adverse effect on weight or performance. The results indicated that 5 ppm of CL 259,971 provided efficacy and performance comparable to arprinocid or monensin, which were used for comparison in these trials.

Topics: Adenine; Animal Feed; Animals; Body Weight; Chickens; Coccidiosis; Coccidiostats; Energy Metabolism; Ethers; Female; Food Additives; Male; Monensin; Poultry Diseases

Sporozoites of Eimeria tenella were treated with different anticoccidial drugs in vitro and their subsequent viability was tested by inoculating them into chicken embryos. Monensin, salinomycin, lasalocid, and arprinocid, at concentrations between 0.01 and 1.0 micrograms/ml, greatly reduced sporozoite viability as judged by mortality, hemorrhage and specific lesions in the embryo chorioallantois. Monensin was also effective in reducing the viability of sporozoites of E. mivati and E. tenella as judged by oocyst production occurring in embryos; activity of monensin was greater against E. tenella than against E. mivati. Monensin (0.1 mg) inoculated into embryos inhibited development of E. tenella. Oocysts which were produced in the presence of the drug sporulated normally and sporozoites obtained from them were fully infective. By initiating treatment of chickens with monensin at different times in relation to infection, it was shown that the drug exerts its anticoccidial effect on the primary invasive stage and on the gametogonous stage of E. tenella and E. necatrix. The effect of gametogony was tested by initiating infections with second generation merozoites of E. tenella. Significant reduction in oocyst production occurred in three of four strains of E. tenella tested. Medication with monensin initiated before merozoite inoculation was effective in inhibiting oocyst production, but medication starting 5 hr after merozoite inoculation was not. This differed from the effects of arprinocid and sulfaquinoxaline which were expressed both before and 5 hr after merozoite inoculation. The results show that the ionophorous anticoccidial drugs exert their anticoccidial action primarily against the invasive stages of Eimeria.

Topics: Adenine; Animals; Chick Embryo; Coccidiosis; Coccidiostats; Eimeria; Furans; Ionophores; Lasalocid; Monensin; Pyrans; Temperature

Monensin, lasalocid, salinomycin, nicarbazin, halofuginone, or arprinocid were fed to 1-week-old male broiler chicks at recommended levels and 1.5, 2, 2.5, and 3 times the recommended level, for 3 weeks. Pair-feeding experiments also were conducted to investigate the extent that growth depression with medicated diets could be attributed to the drop in feed consumption. At the recommended level of drugs, growth and feed conversion were not significantly affected. At elevated drug levels, performance was impaired; the adverse effects of drugs became more pronounced with increasing the concentrations in the diets. Weight gain was significantly depressed at 1.5X with arprinocid, halofuginone, and salinomycin, at 1 to 2X with monensin, at 2X with lasalocid, and at 2.5X with nicarbazin. Feed conversion, however, was adversely affected by 2X with halofuginone or 2.5X with salinomycin, nicarbazin, arprinocid, monensin, or lasalocid. The results of the pair-feeding experiments with 2 to 3 times drug levels indicated that most of the growth depression with medicated diets could be attributed to reduced feed consumption, but all drugs except arprinocid caused some additional growth depression.

Topics: Adenine; Animal Feed; Animals; Body Weight; Chickens; Coccidiostats; Growth; Lasalocid; Male; Monensin; Nicarbazin; Piperidines; Quinazolines; Quinazolinones