Effect of various antiparasitic treatments on lamb growth and mortality

Abstract

Our objective was to compare the effects of a conventional anti-parasitic chemical drug and a lick block containing plant-based compounds on lamb growth and mortality. Ewes and their new-born offspring were allocated among three treatments: a group receiving standard drenching with an albendazole containing drug, a group supplied with a lick block containing essential oils from 10 plant species having anti-parasitic properties and a control group that was not dewormed. Lamb growth was evaluated as daily gain at various time periods between birth and 120 days-of-age. Lamb mortality was monitored in all groups. At the end of the fattening period, lamb meatiness and fatness were assessed by in vivo ultrasound measurement. Parasite infection of lambs at 28, 42, 56, 70, 100 and 120 days-of-age was assessed by examination of feces for parasite oocytes. Results established that the lick block, as did the chemical agent, effectively reduced coccidian invasion in lambs. It should be noted, however, that parasite infection in the experimental animals was relatively low, which allowed the use of moderately strong preparations as compared to conventional anti-parasitic drugs. The lick block treatment also had a beneficial effect on growth and body development of the lambs. Results suggest the need for further research on prophylaxis strategies with plant-origin anti-parasitic substances. Moreover, the provision of anti-parasitic substances in enriched lick blocks could be beneficial in optimal timing of treatments and for preventing weight gain declines after conventional drenching.