To Drench, or Not Drench

Dr. Reid Redden, Associate Professor and Extension Sheep and Goat Specialist, Texas A&M AgriLife Extension Service
(Reid’s Ramb-lings: July 2021)

This spring was cooler than most and some were fortunate to get a good healthy rain. As things start to warm up, we expect to have problems with internal parasites in sheep and goats. Fortunately, there has been some advancements in technology to help in the fight against these pesky parasites. The bad news is, strategic treatment is not simple, and the more science learns about parasites, the more we realize just how much we don’t understand!

For me, the complexity of life is part fascinating and part frustrating. The intricate process by which sunlight and water grow plants that are eaten by sheep and goats to sustain themselves, grow, and reproduce is truly incredible. It is amazing how they overcome challenges and thrive in the face of adversity. Unfortunately, parasites, predators, and pathogens that negatively impact sheep and goats are just as complex and resilient.

Therein lies the dilemma: how we make Continue reading

Are Parasites a Limiting Factor in your Operation?

Bill Fosher, Granite State Graziers coordinator and New Hampshire sheep producer
(Previously published in On Pasture: March 1, 2021)

The parasites that infest sheep can be an enormous drag on sheep production. Year in and year out, they probably cause more death and disease in some producers’ lamb crops than any other single factor, including predators.

The days when the answer to parasite management was to drench all the sheep every month are behind us. Parasites have started to evolve resistance to various classes of de-wormers. The problem with chemical resistance is so pronounced in some parts of the Southeast US that there are farms where no de-wormers work anymore, and there’s at least some degree of chemical resistance nearly every place where worms are a problem.

The first step in knowing how to manage parasites in your own farm is to know what’s going on in your flock’s guts and in the environment they inhabit. The second step is to know what environmental factors play into parasite reproduction and infectivity. In the final analysis, the answer for how to Continue reading

The Role of Fecal Egg Counting in Sheep/Goat Health

Susan Schoenian, Sheep & Goat Specialist, University of Maryland Small Ruminant Extension Program
(Previously published on the American Consortium for Small Ruminant Parasite Control: August 2020)

Although parasite burdens are low in many Ohio systems in the current moment, it is never too early to consider your 2021 parasite management plan. Many producers tend to treat for parasitic infection blindly and routinely, regardless of the true needs of their flocks or herds. For those interested in understanding the importance and implementation of fecal egg counting in your operation when it comes to parasite management be sure to take a peek at this quick read from Susan Schoenian.

A fecal egg count (FEC) is a quantitative measure of how many worm eggs a sheep/goat is passing in each gram of its manure. You get a number like 1000 EPG (eggs per gram of feces).

Fecal egg counts are performed by veterinarians, state diagnostic labs, and independent laboratories. You should only be willing to Continue reading

Prevent Parasites Through Grazing Management

Melanie Barkley, Livestock Extension Educator, Penn State Extension
(previously published with Penn State Extension: May 31, 2017)

Grazing management and genetic selection can help your flock minimize the impact of parasites.

Parasites continue to plague many sheep and goat producers throughout the grazing season. Internal parasites decrease growth rates and in high levels can even cause death. However, sheep and goat producers can follow several practices to minimize the impacts to their flock or herd. These practices center on grazing management, but can also include genetic selection principles.

Livestock pass internal parasite eggs in their manure. These eggs then hatch and go through several larval stages until they reach an infective stage. This can take as little as six days to go from egg to infective stage. Therefore, producers can use grazing rotations to Continue reading

An In-Depth Look at Ivermectin

Susan Schoenian, Sheep & Goat Specialist, University of Maryland Small Ruminant Extension Program
(Previously published in Wild and Wooly – Spring 2020)

(Image Source: Valley Vet Supply)

Recently, several media outlets reported the success of an in vitro study conducted in Australia regarding the antiviral effects of ivermectin on the virus that causes COVID-19. An in vitro study is performed outside the living organism, such as in a petri dish; where- as, an in vivo study is conducted in a living organism. A treatment may work in vitro but not in vivo or it may work in both or neither.

Ivermectin has shown in vitro activity against the zika virus, but its effect Continue reading

Best Management Practices for De-worming Sheep and Goats

With warmer weather projected in the near forecast and pastures beginning to become full and lush, many producers have or will soon be turning their stock out onto pasture. It is critically important that we monitor the health and well-being of our animals on a daily basis. For those that may need treatment due to parasitic infection, it is important to understand which de-worming products to use at the appropriate time and how to correctly incorporate them into your management system.

Parasite Management Starts with Genetics

Gail Keck
(Previously published in Ohio Farmer: February 24, 2020)

Ohio producer uses data to increase his sheep flock’s resistance to internal parasites.

For sheep producers with flocks on pasture, controlling internal parasites can be expensive and time-consuming, but the cost of not controlling the parasites can be even greater, in reduced performance and death losses. While it won’t eliminate the need to monitor and deworm entirely, building a flock with greater genetic resistance can help reduce losses and treatment expenses.

John Anderson, who raises Polypay sheep seedstock near Shreve,in Wayne County, Ohio, has been selectively breeding for parasite resistance for 10 years, and he’s seeing the benefits in his own flock and in the breeding stock he sells.

Continue reading

Larval Survival of Barber’s Pole Worm

Wormboss
(Previously published on Wormboss, Tests and Tools, Management Tools, Grazing Management)

(Image Source: Deb Maxwell)

Problem:
Many producers are unaware how long is required to prepare low worm-risk paddocks, although surveys show most are in favor of using them.

Solution:
Understanding the few conditions under which worm larvae will die is vital in creating low worm-risk paddocks.

Benefit:
Knowing the ‘required time’ for your property to create low worm-risk paddocks.

Under what conditions do worm larvae die?
A common misconception, based on having fewer worm issues in winter, is that frosts kill worm larvae on the paddock. This is a myth.

Continue reading

Using Refugia to Manage Parasites

Veterinary Practice New
(Previously published on the American Consortium for Small Ruminant Parasite Control web page, January 3, 2020)

With 2020 underway, the U.S. Food and Drug Administration (FDA) says it is continuing its ongoing effort to address issues related to antiparasitic resistance in livestock and horses across the country. Among these efforts are two videos on the subject, directed at large animal producers and owners.

Continue reading

Preparing Low Worm-risk Paddocks

Wormboss
(Previously published on Wormboss, Tests and Tools, Management Tools, Sheep)

Problem: Continuous re-contamination of the paddocks with worm eggs that develop to larvae is a major cause of ongoing worm problems for sheep or goats.

Solution: Preparing low worm-risk paddocks to prevent animals from becoming heavily infected with worms is a key strategy in effective and profitable worm control.

Benefit: Low worm-risk paddocks for key classes of stock at particular times of the year reduce both production loss and the need for chemical (de-worming) intervention. In turn, fewer [treatments] result in Continue reading