Anticoccidial Efficacy of Narasin in Battery Cage Trials

Abstract

Narasin is a polyether monocarboxylic acid antibiotic produced by Streptomyces aureofaciens. An extensive series of battery cage trials was conducted to evaluate the efficacy of narasin against recent field isolates of the pathogenic species of chicken coccidia. Statistical analyses of the results of these studies revealed that each successive increase in the concentration of narasin produced a significant reduction in the severity of cecal and intestinal lesions when compared with those in infected nonmedicated controls. Increasing the concentration of narasin also produced significant improvements in weight gain and feed efficiency when compared to gain and feed efficiency of infected nonmedicated controls. Maximum weight gain of birds infected with Eimeria tenella alone was obtained at a narasin concentration of 60 ppm, but birds infected with E. tenella plus intestinal species of coccidia, when medicated with 80 ppm narasin had weight gains significantly greater than those of birds medicated with 60 ppm narasin. Weight gain improvement decreased at narasin concentrations greater than or equal to 100 ppm. Results of these studies confirm the effectiveness of narasin in controlling coccidial infections produced by recent field isolates of the pathogenic species of chicken coccidia.

Resistance to anticoccidial drugs of Dutch avian Eimeria spp. field isolates originating from 1996, 1999 and 2001

“…Most anticoccidial drugs (mainly ionophores) have growth-promoting properties, which may enhance the flock performance (Radu et al, 1987;Jeffers et al, 1988). Moreover, due to the occurrence of resistance, trickle infections that allow build-up of immunity take place.…”

Anticoccidial drugs of the livestock industry

“…Narasin (Fig. 1b) is a polyether antibiotic obtained from Streptomyces aureofaciens (Jeffers et al 1988). It is a derivative of salinomycin having an additional methyl group, therefore alternatively called (4S)-4-methyl salinomycin.…”

Statement on the update of the list of QPS‐recommended biological agents intentionally added to food or feed as notified to EFSA 1: Suitability of taxonomic units notified to EFSA until October 2014

“…There is a long record of using narasin as an anticoccidial additive (Peeters et al, 1981;Jeffers et al, 1988;Brennan et al, 2001) although the extent of usage is not comparable to that of other polyether ionophores such as salinomycin and monensin. Accidental narasin intoxication of rabbits and of some laboratory animal species may involve diarrhea and internal organ compromise, including respiratory stress, skeletal muscle degeneration and even death (Novilla et al, 1994;Salles et al, 1994;Oehme and Pickrell, 1999).…”