It’s a given that we have all been glued to the weather forecasts that seem to change daily. But another forecast beef producers should be informed about is the parasite forecast. In northwest Arkansas, a rainy spring will mean an increase in parasite activity. Take steps now to ensure your herd's health.
The Most Likely Candidate
Lance Kirkpatrick, Extension Agent with the University of Arkansas in Logan County, said the greatest parasite risk he sees is in those herds that are overgrazing pastures. "If you're running too many head and you're overpopulated, the cattle are grazing closer to the ground and picking up more larvae," Kirkpatrick said. Cattle will go out of their way to be away from manure when eating, but if you're overgrazing the closer to that manure the cows will have to get to those larvae sources.
Kirkpatrick also said spring and fall are the times of year when cattle are most susceptible to the internal parasites. Parasitic larvae thrive in the moist conditions the spring and fall bring.
Dr. Craig Payne, Extension Veterinarian with the Commercial Agriculture Program at the University of Missouri, said internal parasite levels are going to depend upon the environmental conditions present each year. “Although there are several parasites common to cattle, the one we are usually most concerned with is Ostertagia.”
Ostertagia is considered to be the most economically significant internal parasite in beef cattle. “Ostertagia is extremely active reproductively during the spring and fall of the year when cooler temperatures and adequate rainfall prevail,” Dr. Payne said. These conditions are needed for the adult parasite to reproduce.
When the parasite eggs are in their final stage of growth they are capable of infecting cattle. In this stage they are called larvae. “When cattle consume these larvae through grazing, they enter the abomasum and develop into an adult,” Dr. Payne said.
Although Ostertagia is the most common internal parasite in beef cattle, there are others to keep in mind. Trichostrongylus axei (stomach hairworm) and haemonchus sp. (large stomach worm) live in the abomasum. But there are many more that are present in the intestine. Here are a few: Bunstomum phlebotomum (hook worm), Oesophagostomum radiatum (nodular worm) and trichuris sp. (whipworm).
The Cost Effective Fix
Kirkpatrick says he recommends deworming twice a year, in the spring and in the fall. "If you do it in the winter they'll just pick up more larvae, more worms, in the spring. But if you do it in spring and fall, you can usually cut down on a lot of problems," Kirkpatrick said.
“Another time to consider deworming would be before cattle are moved to a “clean” pasture,” Dr. Payne said. “This will reduce the probability of that pasture becoming contaminated.”
Kirkpatrick cited research from Louisiana State University that said the minimum loss a producer will experience through herd infestations of worms will be right around a $25 per head loss. "That is the minimum you will lose. That is taking into account all the other problems parasites cause: calves not growing, challenges to the immune system and increased feed costs due to parasite pressure," Kirkpatrick said. With a $25 loss per head, he said a $5 to $6 deworming program is well worth it. "You are making yourself $18 to take care of the problem early."
