Timely Topics for 2014
Sericea lespedeza: a "wiseman's alfalfa"
Tom Terrill, December 2014
Because of its ability to tolerate infertile, acidic soils and grow well on sloping land with minimal lime and fertilizer inputs, the perennial warm-season legume sericea lespedeza (SL; Lespedeza cuneata) has earned the nickname "Poor man’s alfalfa." With recent research on the potential health and environmental benefits of including SL in the diet of ruminant animals, it may be time for a new nickname.
For farmers trying to keep their livestock healthy during a period when anthelmintic drugs are rapidly losing their effectiveness, the excellent anti-parasitic properties of SL in fresh (grazed) or dried (hay, leaf meal, pellets) forms in the diet of sheep, goats, and other ruminants may be most important
The "silver bullet" of worm control in small ruminants
Paul Casey, November 2014
I manage a 60 ewe sheep flock at Heifer Project International’s Ranch in Perryville, Arkansas. About 10 years ago, we started looking at alternative methods of controlling gastrointestinal parasites in sheep. We tried garlic juice, papaya seeds, pumpkin seeds, an herbal dewormer, grazing chicory, grazing sunn hemp, and intensive rotational grazing. In the end, rotational grazing was the only practice we kept.
Why does it take so long for dewormers to become available on the market for small ruminants?
Adriano Vatta, October 2014
Some producers may be wondering: when are the drug companies going to bring out some new dewormers (anthelmintics)? What is the problem? Why are we having to rely on “old” drugs that, in many cases, are no longer working as they should?
Although we have seen the release of monepantel (Zolvix®, Novartis Animal Health) and the combination of derquantel and abamectin (Startect®, Zoetis) in some countries in recent years, the situation in the United States has not changed. There have not been any new classes of anthelmintics for livestock released on the market in the United States since ivermectin was developed more than 30 years ago.
Anne Zajac, September 2014
While many internal parasite infections of sheep and goats can only be diagnosed with the use of a microscope, tapeworm infections are all too apparent. Tapeworm segments, either individually or in long chains, can be seen in manure or even emerging from the host animal, and are a familiar sight to most sheep and goat owners.
The most common tapeworm of sheep and goats is Moniezia (pronounced Moe-knee-zee-ya) expansa. Adult tapeworms live in the small intestine. Of course, the important thing about tapeworms for the small ruminant producer is whether they affect animal health.
Should I consider using LongRange dewormer for parasite control in small ruminants?
Ray Kaplan, August 2014
LongRange™, a relatively new product from Merial Ltd. is gaining wide scale use in cattle, for which the product was developed. I often receive questions about whether this product would be good to use to control parasites in small ruminants.
LongRange™ contains the drug eprinomectin, which is also found in the cattle pour-on product Eprinex®. Eprinomectin is in the same family of drugs as ivermectin (Ivomec®). This family of drugs, the macrocyclic lactones (or MLs), also includes the drugs doramectin (Dectomax®) and moxidectin (Cydectin®).
High quality forage helps maintain resilience to parasites
Ken Turner, July 2014
Maintaining forages with high nutritive value (including increased protein levels by utilizing legumes in pastures) helps to increase resilience in sheep and goats to GI parasites. When grazing sheep and goats on pasture, resilience can be defined as the animal’s ability to tolerate higher GI parasite burdens and still remain productive (gain weight; produce milk).
In a 2012 study, meat goat kids grazing alfalfa or red clover (legumes, high protein) pastures gained more weight compared to goat kids grazing orchardgrass pasture despite an increasing fecal egg count in all animals. Meat-goat kids grazing alfalfa or red clover appeared to be more resilient to GI parasites than goat kids grazing orchardgrass.
Pine bark and other natural dewormers for small ruminants
Byeng Ryel Min, June 2014
Alternative methods of GI parasite control for animals raised primarily on forages are vital for the sustainability and profitability of sheep and goat farms in the United States.
Researchers at Tuskegee University found potential benefits of pine bark supplementation on anti-parasitic effects and improved feed efficiency. Pine bark is one of the abundant forest by-products in the southern United States and contains 11 to 13 percent condensed tannins on a dry matter basis.
Sericea lespedeza for natural control of coccidiosis
Susan Schoenian, May 2014
Sericea lespedeza (SL) has been scientifically proven to reduce barber pole worm (Haemonchus contortus) infections in sheep and goats. The condensed tannins contained in the lespedeza are credited with control, though the mechanism is not fully understood. Control has been achieved when animals consume SL as either fresh forage, dry hay, or leaf meal pellets.
During various studies, researchers noticed that SL-fed animals also had cleaner hindquarters and required fewer treatments for coccidiosis. This has led to more recent investigations into the effects of sericea lespedeza on Eimeria spp. (coccidia) infections in lambs and kids.
Haemonchus contortus and camelids
Lisa Williamson, April 2014
As is the case in sheep and goats, gastrointestinal parasites are a leading cause of illness and death in camelids. The blood-feeding nematode Haemonchus contortus is especially devastating in camelid herds living in endemic areas. Based on a survey conducted in the Athens, Georgia Diagnostic Laboratory last year, haemonchosis was the cause of death in 12% of the llama and alpacas submitted for necropsy.
Research conducted by the University of Georgia a few years ago on hundreds of llamas and alpacas living on 26 privately owned farms in the southeastern United States found that Haemonchus contortus was the most prevalent nematode parasite on the farms.
Do herbal dewormers work?
Dahlia O'Brien, March 2014
Internal parasite infections are a major cause for reduced productivity in the sheep and goat industry. Before the use of chemical dewormers became widespread, many livestock farmers used natural plant remedies in their herd/flock to control these infections.
With emerging dewormer resistance and an overall increase in the desire to promote sustainability, the use of non-chemical dewormers is desired and sometimes preferred. To this end, the use of commercially-available herbal dewormers might be a promising and viable alternative to chemical control. But, how effective are they in controlling internal parasites?
How can artificial insemination further parasite resistance in sheep?
Joan Burke, Stephan Wildeus, Roxanne Newton, & Kathy Bielek, February 2014
It is often difficult, especially for small flocks, to justify the purchase price of a superior ram, yet the success of these flocks, and the sheep industry as a whole, requires this advancement. The widespread use of artificial insemination (AI) in the cattle, swine, and poultry industries has resulted in accelerated genetic progress for economically important traits, while minimizing exposure to animal diseases.Historically, AI in the U.S. has been limited in sheep due to the complexity of the ewe’s cervix and because of difficulties in storing and thawing frozen semen.
Blueprint for selecting parasite-resistant sheep
Kathy Bielek, February 2015
The concept of selecting parasite resistant sheep is simple: consistently select the animals with the best resistance. Putting the concept into practice, however, can be more challenging. This paper will share some of the lessons learned over the last 10 years through several North Central Sustainable Agriculture Research and Education (NC SARE) grants and on-farm experience. A list of the SARE grants and the breeders involved is included at the end of this blueprint.