Impact of Selection and Breed on Resistance

Dr. Ken Andries, Kentucky State University
(previously published on wormx.info provided by the American Consortium for Small Ruminant Parasite Control)

Most producers of sheep and goats are experiencing resistant parasites to the common products utilized to control them. This continues to be a growing issue resulting in recommendations for change in management and selection practices. Selection for resistance can improve overall parasite status of a herd and reduce the need for treatment. Finding the individual within the breed that is more resistant is the issue when using selection.

For years, producers have been told they need to utilize selective treatment and cull animals that require greater numbers of treatments. Using the eye color score system (FAMACHA©), we are able to select for resilience, but there is little evidence of the impact on actual resistance using this method. There is also limited information on the impact of different parasites loads on performance of kids. Continue reading

De-worming Lactating Ewes May Contribute to the Development of Parasitic Resistance

Brady Campbell, Program Coordinator, OSU Sheep Team

Animal production losses associated with internal parasitic infection continues to be of great concern in the small ruminant industry. This is due to the development of parasitic resistance to chemical de-worming products.

For example, when a de-wormer is given at a lower dose than what is recommended on the manufactures label, the parasite in the treated animal may not receive an effective or lethal dose. A concern with treating lactating ewes is that Continue reading

A Decision Making Support Tool Now Available

Rory Lewandowski, OSU Extension Educator, Wayne County

Sorting through the information on sheep and goat parasite control: A decision making support tool is now available.

Farmers confronted with parasite infections in their sheep and goats soon realize there is no “magic bullet” or “one size fits all” solution. They can be quickly bombarded with a lot of information available on internal parasite control but with no help in sorting out which options they should consider in their farming operation.

OSU Extension personnel have developed a decision making support tool for farmers to develop Continue reading

Use FAMACHA Correctly for Best Results

Rory Lewandowski, OSU Extension Educator, Wayne County

An important component of summer management is internal parasite control.  By this point in the calendar year sheep, and/or goats on many farms have rotated through pasture paddocks at least a couple of times. Lactating ewes and does can shed large numbers of parasite eggs, effectively seeding pasture paddocks with parasite larvae that are waiting to be ingested with the next grazing pass.  As young lambs and kids learn to graze at the side of their mothers, they are very susceptible to acquiring large parasite infections. However, parasite loads are not equally distributed within the herd or flock.

Over the past several years targeted selective de-worming treatment of sheep and goats has been promoted as one way to avoid treating the entire flock or herd. Selective treatment can slow down the process of the parasite acquiring chemical resistance and thereby prolong the effectiveness of those chemical de-wormers available to sheep and goat owners. One tool that is being used to determine selective treatment is the FAMACHA system. Continue reading

Use FAMACHA Correctly

Rory Lewandowski, OSU Extension Educator, Athens County

A number of sheep and goat owners have been trained across Ohio in the use of the FAMACHA system, yet problems with internal parasites, in particular, with Haemonchus contortus continue. This is to be expected. The FAMACHA system utilizes an eyelid scorecard that can help a farmer make a decision to treat or not to treat the animal with a chemical de-wormer. The FAMACHA system is not a cure-all, or a silver bullet for dealing with internal parasites. It is one tool that can be a part of an overall parasite control strategy. In order for this tool to be effective Continue reading

Pasture, Parasites, and Risk Management

Rory Lewandowski, OSU Extension Educator, Athens County

May through early June is generally a time of good pasture growth and corresponding livestock production. However, if you are grazing sheep and goats this is the time of year that needs careful consideration in regards to internal parasites, in particular Haemonchus contortus, the barber pole worm. One way to approach this grazing season is to think in terms of risk management.

What can be done to reduce or minimize the risk of a heavy parasite infection while sheep and goats graze pastures? Continue reading

Breeding Season Preparation

Rory Lewandowski, OSU Extension Educator, Athens County

Reproductive performance is an important factor in determining profitability in the sheep flock. Most breeds of sheep have seasonal breeding patterns and the majority of flocks in Ohio are spring lambing. In this scenario, the peak fertility of the ewe is from late September through November. The breeding season will extend Continue reading

Parasite Management for Small Ruminants Begins… in the Fall?

Rory Lewandowski, OSU Extension Educator, Athens County

The biggest enemy of pasture based sheep and goat production has got to be internal parasites and especially, Haemonchus contortus, or the barber pole worm.  Its incredible reproductive capacity, an adult female can lay up to 5,000-10,000 eggs/day, combined with the fact that the infective third stage (L3) larvae can survive 60 to 90 days or more on pasture during Continue reading

Monitor Lamb/Kid Worm Burden

Rory Lewandowski, OSU Extension Educator, Athens County

July through September are critical times to closely monitor the internal parasite burden of lambs and kids. Preferably monitoring would start in June. The internal parasite of principal concern during the summer months is Haemonchus contortus, the barber pole worm. Lambs and kids grazing on pastures that are contaminated with large numbers of infective Haemonchus contortus larvae can go downhill very rapidly in July and August. It would not be uncommon that within a 7-10 day period Continue reading

Summer Parasite Management

Rory Lewandowski, OSU Extension Educator, Athens County

July and August are critical months to control the internal parasite, Haemonchus contortus in pasture based sheep and goat production. Often producers may find that lambs and kids seem to “stand still” during the summer, with little or no weight gain. There can be several reasons for this situation. Continue reading

Sudangrass, Could it Work for You?

Rory Lewandowski, OSU Extension Educator, Athens County

Raising sheep within a pasture based production system presents the manager with two challenges; internal parasite control and summer slump production of cool season pastures.  The use of a warm season annual like sudangrass may offer the pasture based sheep producer a parasite control option while at the same time filling in the forage production slump demonstrated by cool season pastures during the hot summer months.  In this article, I’ll draw on some of the results and lessons learned using sudangrass during the summer of 2007 on the Curt Cline farm in Athens County. Continue reading