Narasin is a poyether monocarboxylic acid or monovalent polyether ionophore produced by fermentation of Streptomyces aureofaciens & transport sodium Na+(Na+), K+ (Potassium), Rb+ (Rubidium) ion. Its also called methyl salinomycin due to it structurally similar to salinomycin or derivatives of salinomycin having methyl group presence in salinomycin in chemical structure of narasin. It’s used as feed grade coccidiostst which grayish brown to dark brown powder or particles. Narasin safe poultry at recommanded dose.
Narasin insoluble in water but soluble in ethyl acectate, chloroform,acetone,benzene, dimethylsulfoxide sparingly soluble in hexane and in petroleum ether etc.
Narasin is the narrow spectrum anticoccidial & antibacterial acts against selective Emeria species, some gram positive species e.g staphylococcus aureus, clostridium perfringenes, occationally acts against some enterobacteriace e.g salmonella typhimurium, Klebsiella pneumonia. Escherichia coli etc.Others uses in include Growth promoter, fattening of poultry by preventing cocciddiosis.
Mode of action
Narasin carries single alkali cation sodium Na+, K+, Rb+ ( Robidium) & act on Emeria species or coccidian parasites by altering transmembrane movement of monovalent thereby changed ionic gradients & disrupt physiological process or reproduction in Emeria species or coccidian parasites are inhibitated.
Endogenous stages affected of emeria spp
Like others Ionophores Narasin against first generation of sporozoites, tropozoites and early and late asexual stages of coccidian population in broilers.Narasin also is used for prevention of necrotic enteritis in broiler.
Absortion & Metabolism
Narasin well absorbed from gut of poultry. Its largely excrete by bile. Presence of narasin residue vary low in liver, musle, skin & fat that show in animal study. 5% of the total liver radioactivity and 50% of the total radioactivity in fat at zero withdrawal time was Narasin. None could be detected after 3 days
Narasin s effective for the prevention of coccidiosis @50-60 mg/kg body weight. Narasin has safety marin slight higher @70-80/Kg body without showing clinical signs. Narasin also used for prevention of Necrotic Enteritis @80mg/kg body weight applied in the field.
In Turkey, 20-40mg/kg safe without any adverse effect but cause adverse effect in higher doses.
Narsin overdoses causes congestive heart failure & cardiac muscle deformities above @125mg/kg body weight when applied. In Turkey, above 80mg/kg cause toxic effect cause 15-20% mortality if it used for fattening purpose.
Tiamulin may interfere with the metabolism of narasin in chickens and cause weight suppression at above recommended doses. Its strongly prohibited with tiamulin.
Narasin has lowest no observed effect (NOVEL) level identified @;5mg/kg in oral toxicity. It does not adversely affect egg production or egg quality. Narsin causes weight depression in slight over dosage in poultry. Transient & mild paralysis paralysis due to decreased feed consumption may occur if doses cross above 70 mg/kg bodyweight.
Narasin has no genotoxic, carcinogenic that tested in mouse,rat,rabbit. Does not adversely affect egg production or egg quality but not recommended in laying chicken due to excess ionic exchange effect hormonal regulation. Narasin may cause fatalities in horses that ingest it, and it should not be fed to adult turkeys (above 80 mg/kg). Narasin toxicity is probably occurred due to a disrupt ion balance or to oxidative damage in the host. Narasin may be dangerous to equines .
Narasin withdrawal period for egg & meat o days. Its suggested that narasin is acceptable without risk @ 50-60mg/kg body weight for the prevention & control of coccidiosis & fattening poultry subject to mention withdrawal period
Not for use in laying hens & adult Turkey in fatting stages; no withdrawal necessary.
Narasin has lowest Toxicity not only in host but also environment. Its readily acceptable for consumers without health risk & no withdrawal period are required.