Best Management Practices for Pasture Parasite Management


Source: Cornell University

General Management

  • Keep hay and grain off of the ground and in feeders. Keep animals out of the feeders.
  • Keep water high enough that your animals cannot defecate in it.
  • Feed 130% of daily protein requirement for a dry animal to ewes and does near parturition to strengthen their immune systems. A diet that is higher in bypass proteins would also be beneficial.
  • Separate kid and lambs in groups with no more than 2 weeks in age separating the youngest and oldest.
  • Keep young stock in clean, dry, uncrowded pens.
  • FAMACHA score your animals every 3 (warm weather) to 6 (dry or cool) weeks to determine if any of the animals are anemic, indicating barber pole worm infection.
  • If greater than 10% need to be treated based on FAMACHA, start checking more frequently.
  • Do Body Condition Scores and check that your animals’ coats look shiny.
  • Check animals for diarrhea.
  • Check animals for bottlejaw.
  • Watch which animals tend to be at the back of the herd or moving slowly.
  • Consider culling animals that require treatment 3 or more times a year. If the animal is not culled it should not be bred as it will pass on its genes for higher parasite susceptibility to its offspring.

Pasture Management

  • Have an appropriate number of animals in a pasture depending on the size and amount of forage in the pasture.
  • If possible, mix small ruminants with horses or cattle in the pasture to graze off the small ruminant parasites.
  • Move animals to a new pasture every 4 days if warm and wet, every 7 days if cool and dry, or whenever the forage is lower than 3 inches.
  • Keep all small ruminants off the pasture for at least 3 months to break the parasite lifecycle.
  • Disrupt the lifecycle of the parasites by putting another species in the pasture after small ruminants, mowing the pasture close to the ground, or baling the field.
  • If several groups of small ruminants will go through the same pasture, put the young recently weaned animals first, then lactating or pregnant, and then dry.
  • Consider planting high tannin forages such as birdsfoot trefoil, chicory, and Sericea lespedeza, which may reduce the effects of parasites.
  • If there is an area where animals are never rotated out of (barnyard, water area), prevent grazing by laying down gravel, providing hay in the barn, or making the area small enough that no grazing occurs. Another option is to leave the animals in rotated pastures overnight with portable shelters.
  • Fence off especially damp or wet areas of your pasture.

Deworming Protocol

  • Give all dewormers orally. Subcutaneous injection causes resistance to occur more quickly.
  • Deliver drench over the back of tongue so the full dose is delivered to the rumen.
  • Deworm adult animals that are FAMACHA score 4 or 5, kids and lambs at 3 -5, animals that are moving slowly, or have dull hair coat, diarrhea, or bottle jaw regardless of FAMACHA score.
  • Do not deworm all animals in a herd at one time. Leave some untreated animals so that parasites still susceptible to the dewormer are left in the herd to dilute the genes of the resistant worms.
  • Use correct dosage depending on the product you are using and the species of animal being treated (see chart for sheep and goat doses).
  • Weigh or use a weight tape rather than estimating weight to ensure proper dose is given.
  • Restrict feed intake for 24 hours to decrease the digesta flow rate and increase drug efficacy. Do not restrict feed in animals in late pregnancy.
  • Every two years or when you suspect a resistance issue have a Fecal Egg Count Reduction Test done to ensure the dewormer you use is working. This is done by having paired fecals run before and 2 weeks after deworming. Collect paired samples from at least six, but preferably ten to twelve, animals.
  • Give Copper Oxide Wire Particles (COWP) to adults (1-4 grams) and kids and lambs (0.5-2g) with high FAMACHA scores if recommended by your veterinarian. COWP should never be given more than 4 times during a worm season and doses should be at least 6 weeks apart. COWP should not be given with other sources of copper. The herd copper levels should be monitored with liver copper levels to avoid overdosing and toxicity.

New Animals

  • Quarantine all new animals for at least three weeks on a dry lot.
  • Deworm the new animal with a dewormer from two different classes at twice the normal dose, except Levamisole.
  • A fecal should be run before allowing the new animal to join the main herd to ensure no eggs are being shed.


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