SAC Research

• Short term grazing on chicory results in reduced worm numbers.
• Lambs reared on chicory without anthelmintic drenches grow at similar rates as lambs reared on grass/clover with drenches. 
• Grazing on chicory improves the immunological response to gastrointestinal parasites
• Underfeeding lactating ewes results in increased excretion of worm egg counts
• Twin-rearing ewes are less resistant to parasites than single-rearing ewes
• Increased protein supply to twin-rearing ewes reduces nematode egg excretion and increases milk production within days
• The presence of body protein reserves reduces nematode egg excretion at times of limited protein supply from the diet.

The above present opportunities for designing feeding strategies that would reduce the reliance on anthelmintic drenches. Options to consider include the use of chicory in lambs, and protein supplementation to ewes.

There is a large body of evidence that protein supplementation to parasitized lambs increases weight gain (improved resilience), and SAC research showed that protein supplementation to parasitized lactating ewes resulted in an limited maternal weight losses and a 20-25% increased pre-weaning lamb weight gain. With such returns, protein supplementation to sheep can be economical attractive, whilst at the same time, there are benefits of improved worm control. Hence, feeding strategies as part of worm control programs should be seen as an investment, as they are likely to be cost effective in the long run! 

The right hand links provide further information:

• Technical note on Sustainable Control of Parasitic Gastroenteritis in Sheep in Scotland (TN577)
• Sheep and Beef notes for Drs Athanasiadou and Houdijk
• Powerpoint presentation of Dr Athanasiadou on chicory
• Powerpoint presentation of Dr Houdijk on nutritional effects on parasites
• List of publications with links to abstracts

Current work at SAC, funded by the Scottish Government, is investigating the interactions between two nutritional strategies for parasite control, i.e. periparturient protein supplementation and subsequent grazing on chicory until lambs have reached market weights. Preliminary results show that the combined use of protein supplementation around parturition and chicory until 10 weeks post-weaning results in additive results when compared to either of the effects alone. Furthermore, the interactions between strategic nutritional interventions and the breed of the animals are also being investigated.