Posted by Dr. Steve Dudley on May 30 2002 10:42

Why Do We Care About Parasites?

In a nationwide USDA survey, producers were asked to rank the most significant economic challenge facing cattle producers.

Internal parasites (67%) were ranked second only to external parasites (79%) as the most important

Internal Parasites: Damage and Effects on Animals

• Damage abomasum
• Damage intestine
• Disrupt nutrient digestion and absorption
• Diarrhea
• Poor response to respiratory vaccination
• reduced carcass weight
• reduced carcass quality
• reduced conception rates
• reduced immune system
• reduce feed intake
• reduced growth rate
• lower milk production
• lower body condition scores

Where do we find intenal parasites?

• 1% are in the cattle
• 99% are on the pasture

Preventative strategy for parasite control

• The goal is to maintain "parasite safe" pastures.
• Kill adult worms before grazing season begins.
• Kill immature worms before egg shedding.
• Time treatments to match seasonal grazing patterns.

Strategic Deworming- Kill worms before they start laying eggs

Timing is important

• Kill adult worms before grazing
• Kill immature worms before egg shedding
• Time treatment to seasonal grazing pattern

Use a Class II Dewormer 

Parasite Risk

• Native pastures = contaminated
• Improved winter pastures = contaminated
• Winter small grain pastures = parasite free
• Mountain Pastures = contaminated