Effects of Selective Deworming
A 3-year study (2006-2008) was conducted at the Appalachian Farming Systems Research Center in Beaver, West Virginia to determine the effects of selective deworming on performance and parameters associated with gastro-intestinal parasite management.
Suffolk and Katahdin wether lambs and Boer wether kids were finished on a mixed sward of orchardgrass, red clover, and white clover, with and without whole cottonseed supplementation. After the initial deworming with a combination treatment, lambs and kids were dewormed only if they had FAMACHA© scores of 3 or greater. FAMACHA© scores were determined bi-weekly. Suffolk lambs had a higher average daily gain (ADG) than Katahdin lambs. Goat kids had the lowest ADG. Overall 90-day ADG was increased with whole cottonseed supplementation. Fecal egg counts were variable, but not affected by supplementation. Supplementation did not affect FAMACHA© scores or need for deworming.
Katahdin lambs had lower fecal egg counts than Suffolk lambs which had lower fecal egg counts that goat kids. Katahdin lambs consistently had lower FAMACHA© scores than Suffolk lambs. Goat kids had the highest FAMACHA© scores.
Using FAMACHA© as a means to identify anemia resulted in a mean 56 percent reduction in deworming compared to a theoretical monthly dosing of each animal. After the initial dosing of dewormers, days to next treatment were fewest for goat kids (33 d), followed by Suffolk (67 d), and greatest for Katahdin (77 d). Conclusion: By considering the use of breed groups resistant to or having high resilience to internal parasites and coupling with the use of the FAMACHA©system to determine the need to deworm individual animals, producers can improve livestock performance and reduce overall cost of production.