61 Oral Dosing Loline Alkaloid and Its Effects Against Mixed Infection of L4 Teladorsagia Circumcincta, and Trichostrongylus Colubriformis, and Adult Haemonchus Contortus

Abstract

Abstract Loline, an alkaloid produced by Epichloë endophytes in pastoral grass species, is considered non-toxic with suggested antimicrobial and anthelmintic properties. In vivo metabolism of loline suggests ability to reach the abomasum or intestine, and anthelmintic benefit is indicated in vitro when parasites are in either a developmental stage close to the gastric mucus layers or adult stage consuming blood. Therefore, the objective of this project was to investigate the validation of using a loline seed extract as a natural anthelmintic in parasitized lambs. Sixteen Coopworth lambs were individually penned, offered ad-libitum lucerne pellets and water and randomly assigned to 3 treatment groups; CON; no treatment, or treatment with a Festuca pratensis seed extract with (LOL) or without loline (NIL). Lambs were orally infected with 20,0000 L3 Haemonchus contortus on day 0, and 10,000 L3 Teladorsagia circumcincta, and Trichostrongylus colubriformis on day 14. Parasites then matured to determine lolines efficacy on blood feeding adult Haemonchus contortus and L4 mucosal browsers Teladorsagia circumcincta, and Trichostrongylus colubriformis. Loline was orally dosed at 52.5 mg/kg LW starting on day 13, and every other day until slaughter for worm enumeration on day 28. Feed intake and refusals were recorded daily, and fecal samples were taken prior to infection, on loline dose days and at slaughter. Worm and fecal egg counts were transformed to log10 and all data were analyzed in Genstat (18th edition). Significance was declared at P < 0.05. Worm burdens of T. circumcincta (P = 0.96), T. colubriformis (P = 0.43), and H. contortus (P = 0.15) were not different between treatments. No treatment difference (P = 0.39) was observed in fecal egg counts, weight gain (P = 0.51), or feed intake (P = 0.18). Average growth efficiency (kg LWG/ kg DM intake) was 0.18 in CON which was less (P = 0.01) than LOL (0.24) or NIL (0.23). In conclusion, limited evidence supported an in vivo anti-parasitic effect of loline.