Control of internal and external parasites is important for optimal growth, disease prevention and well-being of dairy replacements.

According to the Gold Standards III, having parasite-control protocols in place helps keep parasite populations from being a detriment to animal health, performance and well-being. They also can help prevent development of parasite resistance.

Eugene Myatt, 2011-2012 Dairy Calf & Heifer Association president, uses manure sampling to verify worm counts or infestations in the heifers that he raises with his two sons Adam and Justin. They raise heifers from four months of age until two months prior to calving.

During this time, heifers are dewormed about five times according to the farm’s written protocol.

“We have gone to a rotation using drenches and then injectables so that we don’t develop any resistance,” Myatt says.

To control flies, they use a feed-through insecticide to control fly larvae in the manure. They start feeding this before flies emerge in the spring. They also use fly tags, beginning in early June.

“The larger cattle all have access to headlocks, so it’s very easy to use some pour-on fly control on those cattle,” Myatt adds.

Guidelines in the Gold Standards III recommend that you develop a parasite-control protocol in consultation with your herd veterinarian and pest-management specialists. Pest-control strategies to include in your protocol will depend on your geographic location, climate and time of year.

Also be careful to avoid the use of products that are not labeled for parasite control in dairy heifers. Using products “off-label” may cause injury to livestock and people, as well as parasite resistance development and meat residue issues. This "Gold Standard" advice is supported by the best management practices outlined in section IV-A of the Dairy Animal Care & Quality Assurance Certification manual.

For more information on integrated pest management strategies for heifers, please see section IX in the Gold Standards III.