Spring weather can mean new challenges for sheep and goat producers, says David Fernandez, Extension livestock specialist at the University of Arkansas at Pine Bluff School of Agriculture, Fisheries and Human Sciences.
Warm, humid weather creates conditions favorable to the survival and production of many types of parasites.
“Sheep and goat producers should take special precautions against the barber pole worm,” said Fernandez, who is also interim assistant dean of academic programs.
“Barber pole worms are blood-sucking parasites that cause diarrhea, poor appetite, lethargy, anemia, bottle jaw and – if left untreated long enough – death.”
Barber pole worms live in the true stomach, or abomasum, of sheep, goats, llamas and alpacas. A sheep or goat carrying 5,000 barber pole worms can die in a little over a month from blood loss to these worms if not treated.
Barber pole worm eggs are shed in the feces. After hatching, larvae live for a period in the manure. Once they reach their third stage of development, they migrate away from the manure and climb up the grass.
“Larvae usually don’t travel further than 12 inches away from the manure, and only climb about 2 to 3 inches up a blade of grass, where they wait to be eaten,” Fernandez said. “Once inside the host, they complete their development, mate, and start to suck blood and lay the next generation of eggs.”
Minimalizing the rate of infection
In controlling these parasites, producers should focus on minimalizing the rate of infection in their animals.
“Because chemical dewormers are currently less effective due to overuse of products on the market, farmers should focus on using good management techniques that can help prevent infection in the first place,” Fernandez said. “Rotational grazing is one of the most effective ways to reduce the number of parasites livestock consume.”
Rotational grazing is the practice of regularly moving livestock from one pasture to another. By moving animals between pastures, the larvae of parasites don’t get eaten and eventually die.
“Producers should be careful not to overgraze their pastures,” he said. “It’s best to leave at least 3 or 4 inches of grass on a particular pasture when rotating to the next one.”
Where an animal eats its feed also plays a part in the number of parasites it consumes.
Hay or feed should not be put on the ground. Instead, a feeder should be used to make the animals eat with their heads elevated. As long as animals can be kept from grazing or eating close to the ground, they will consume fewer parasites.
“Remember that you cannot get rid of all of the worms in your herd or flock, no matter how hard you try,” Fernandez said. “Resistance to dewormers is a natural occurrence, so even though you deworm your animals, some parasites will still be alive and well.”
Considering the fact that all sheep and goats carry some parasites, producers should only treat animals that truly need to be dewormed. They can determine which animals need treating by using the FAMACHA score. They should then keep track of which animals require repeated dewormer treatments and cull them from the herd.
Though it may sound counterintuitive, producers should purposefully plan on leaving some parasites untreated, Fernandez said.
“Untreated worms are not resistant to a particular dewormer product,” he said. “When resistant worm eggs hatch, they are surrounded by a sea of worms that are still susceptible to the dewormer. When the worms mate, the resistant worms are more likely to encounter and mate with a susceptible worm, meaning their offspring will be less resistant to your dewormer.”
Test different dewormers
Fernandez said producers using chemical dewormers need to test different dewormers to determine the product that works best on their farm. Resistance to dewormers must be addressed on a farm-by-farm basis.
There are a few natural products available that can be used to control barber pole worms, he said. Plants high in condensed tannins, such as sericea lespedeza, chicory, sainfoin and birdfoot trefoil, can be effective. Copper oxide wire boluses have also been used to treat barber pole worm infestations.
Details: David Fernandez, 870-575-7214 or firstname.lastname@example.org.
The University of Arkansas at Pine Bluff offers all of its Extension and Research programs and services without discrimination.
— Will Hehemann is a writer/editor for the UAPB School of Agriculture, Fisheries and Human Sciences.