The Food and Drug Administration (FDA) today is announcing the approval of EAZI-Breed CIDR Sheep Insert (progesterone solid matrix) for induction of estrus in ewes (sheep) during seasonal anestrus. This progesterone Controlled Intravaginal Drug Release (CIDR) is a steroid hormone that allows out-of-season breeding in sheep.

The data to support this approval were gathered in collaboration with the National Research Support Project–7 (NRSP-7), a USDA program intended to support the approval of new animal drugs for minor species of agricultural importance.

“Members of the U.S. sheep industry have long cited this type of product as their top priority need,” said, Dr. Meg Oeller, Director, Center for Veterinary Medicine, Office of Minor Use and Minor Species Animal Drug Development. “And through efforts with our partners at NSRP-7 and the pharmaceutical firm, the FDA can now point to an approved drug product that is fulfilling a real need in the sheep industry.  It represents the true spirit of the MUMS Act.”

Clinical researchers funded by NRSP-7 grants conducted the studies to support the effectiveness, target animal safety, human food safety, and environmental safety of the progesterone CIDR.  These data were made available in a Public Master File in March of 2009.  The pharmaceutical company was able to use these data in conjunction with its own manufacturing, labeling, and other information to complete the new animal drug application.

EAZI-Breed CIDR Sheep Insert is manufactured by Pharmacia and Upjohn, a division of Pfizer, Inc., New York, NY.

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 somewhat beyond peak fertility for the late spring lambing system and begin somewhat before peak fertility for the late winter lambing system.  Some management attention given to the ewes and rams prior to the breeding season can pay dividends in terms of increased conception and lambing rate.

A primary consideration regardless of the lambing production system and timing used is nutrition of the flock.  The nutritional status of the ewe and ram at breeding is probably the primary factor that influences reproductive performance.  The nutritional status of the flock is also a factor that a flock manager has a lot of control over.  Evaluation of the body condition of the ram and ewe before breeding can tell the manager whether nutrient consumption should be increased or decreased.  Based on a scale of 1 to 5, with 1 being very thin and 5 being fat, the goal should be to have the ram and ewe enter the breeding season somewhere around a 3.5 body condition score.

One practice that is helpful with ewes that are below the target body condition score is to provide them with a diet high in energy that allows them to gain weight.  This practice is termed flushing and should be done 2 to 4 weeks before breeding.  The high energy diet can be provided by supplementing a high energy grain such as corn at a rate of one-half to one pound per ewe per day, or by providing a high quality pasture. Flushing can result in an increased lambing rate and a decreased number of open ewes.

One caution that is generally given if ewes are to be flushed using a high quality pasture is to keep them off pastures with a high content of legumes (clovers and alfalfa) and use grass pastures.  The reason given is that these legumes contain estrogen that leads to infertility and decreases the conception rate and pregnancy of the ewes.  Does this caution mean that ewes must graze pure grass pastures? Legumes typically help to boost the energy content of a pasture sward and generally are considered as a positive to improve pasture quality. What does high content of legumes mean?

Clovers and alfalfa contain compounds known as phytoestrogens.  In clover species the specific compounds are isoflavones.  These isoflavones exhibit estrogen like behavior in sheep, while cattle do not seem to be affected by them to the same degree.  I reviewed some of the scientific literature about this topic and it appears that sheep are more susceptible to the effects of isoflavones because as they are metabolized in cattle they are rapidly excreted in the urine, whereas in sheep they are not rapidly excreted and remain in their system longer.  In addition, the estrogen receptors in sheep appear to be more sensitive to these compounds as compared to cattle.

There are also other factors that influence the level or concentration of phytoestrogens in legumes.  The specific variety is one such factor.  Improved cultivars have been found to have lower phytoestrogen contents.  Environmental factors such as drought can increase the phytoestrogen content.  Finally, soil phosphorus levels can influence the amount of phytoestrogens in legumes.  Legumes grown in soil phosphorus deficient conditions have contained higher phytoestrogen concentrations as compared to legumes grown in non-deficient soil phosphorus conditions.

Still, the question remains, what is considered a high level of legumes with regard to this condition?  In the literature that I reviewed, the legume stands that produced a negative effect upon reproductive performance were either pure stands or predominantly legume stands.  I had a sheep farmer raise this question with me back in 2008 as he wondered about including clover in a grass pasture.  I wrote an email to Dr. Shulaw asking him about this issue.  He sent me some of the literature that I reviewed and summarized in this article and he also wrote, in part, “At this point in time, unless ewes are grazing pure stands of clover near breeding season I don’t have much evidence to make me concerned about infertility.”  As I am out and about on sheep farms and looking at pastures it is rare that I ever see a pasture that contains more than 35 to 40% clover.  The bottom line is that unless you have a pasture that is well over 50% clover, it should be fine to use in a flushing pass before the breeding season.

Some attention should also be given to the ram(s).  In addition to making sure that they are in good body condition, it is recommended that a breeding soundness exam (BSE) be conducted prior to breeding season.  The BSE consists of a physical examination, a reproductive tract examination and a semen evaluation.  Waiting until after the breeding season to discover a problem with your ram that shows up in the form of an extended lambing season or open ewes is costly.  Contact your veterinarian to schedule a BSE.  It is money well spent.

Finally, I need to close with a word about internal parasites.  One practice that use to be recommended was to deworm all the ewes and rams in the flock before the breeding season.  This practice is no longer recommended due to the resistance that parasites have developed to chemical dewormers.  Deworming all ewes and rams at one time is a method that will select for resistance.  Instead, deworm with a chemical dewormer based upon individual animal need.  This can be determined by using the FAMACHA eyelid color scoring system.  Those animals scoring a 3 or higher on this 1 to 5 scale should be dewormed with a chemical dewormer.  Animals scoring a 1 or a 2 should not be dosed with a chemical dewormer.  For more information about parasite control and use of the FAMACHA system, contact a member of the OSU Sheep Team.

The breeding season is upon the majority of flock owners in Ohio.  Some pro-active management action can insure that it is a successful and profitable breeding season.

OARDC Eastern Research Station in Caldwell, OH hosted the 2009 Ohio Sheep Day

The weather was absolutely gorgeous, with a glint of rain in the air all day, and finally it rained near the end of the program, which was very much appreciated in the drought stricken area of southeastern Ohio.  The air was filled with positive thoughts of an exciting Ohio sheep industry and the OSIA/OSWP/OSU coordinated Ohio Sheep Day was another overwhelming success.   Sheep producers from all over Ohio and other states flowed in to learn about several topics related to the sheep industry. The food served was generous and very well prepared.  There was just nothing to complain about during the day of Saturday, July 11, 2009 at the OARDC Eastern Research Station (EARS), in Caldwell, Ohio.

As the day progressed, nearly 150 sheep producers made their way to the 2010 Ohio Sheep Day event, several from outside of Ohio to learn about improved practices and research for the sheep industry.  Of course, many topics of interest to sheep producers were a valuable part of the day.  Many of the speakers entertained to crowds throughout the day as they spoke of topics from production of the sheep flock, lamb management to lamb cutting and cooking demonstrations.   There was something for everyone at the 2009 Ohio Sheep Day Program.  Welcoming the sheep producers to the OARDC-EARS Unit were Roger A. High, Executive Director of the Ohio Sheep Improvement Association and OSU State Sheep Extension Program Specialist, OSIA President, Susan Shultz, Dr. Steve Slack, Director, Ohio Agricultural Research and Development Centers and Dr. Jim Kinder, Chair, Animal Sciences, The Ohio State University.  Key speakers of the day included Wayne Shriver, Manager of the OARDC Eastern Research Station Unit and Clif Little, Guernsey County Extension Educator, who coordinates much of the sheep research done at OARDC-EARS.  Pasture management tours were once again popular as sheep producers were able to see the latest in annual and perennial forages; Bob Hendershot, USDA Grazing Specialist, and Rory Lewandowski, Athens Co. Extension Educator were the speakers for this part of the program.  One popular part of the program was Managing Coyotes and Black Vultures in Ohio by Chris Bartholomew, USDA Wildlife Services, David Schott, Monroe County SWCD Wildlife and Forestry Specialist and Mike Dyer, a private trapper, this discussion provided the attendees the opportunity to learn how to manage these major predators on their own sheep farms. Another popular topic area was Dr. Paul Kuber, OSU Animal Sciences, and Nick Forrest, American Lamb Board who provided the audience with a lamb cutting and lamb preparation demonstration; those in attendance stated that it was a “yummy” topic area. Daryl Clark, Muskingum County Sheep Producer discussed the type of sheep that works at OARDC-EARS using several sheep examples on the research farm.  The OARDC-EARS sheep handling facility was discussed by Chris Clark, EARS Animal Manager, and Wayne Shriver, Clif Little, and Kevin Stottsbury, of OARDC-EARS provided tours of the research grazing paddocks utilized at the station.  Another popular topic was a discussion by Katherine Harrison, of Blystone Farms, who discussed Marketing to the Ethnic Population.   Dr. Bill Shulaw, OSU Extension Veterinarian for Sheep and Beef discussed the parasite issue with sheep producers including managing the flock with FAMACHA scoring.   Of course, food is always an important part of any Ohio Sheep Day event, and OSIA member, Leslie Jordan and her family managed to serve a wonderful lamb meal.  The roast lamb sandwiches, prepared by Kris Doyle and served by OSIA serving crew of Lisa Rodenfels, Fannie Brill, and others were a popular hit for the lunch time meal.  Bottled water donated by David Betts, a Licking County Sheep Producer and President of the Amanda Hills Premium Bottled Water Company, was a much needed addition to Ohio Sheep Day as the weather was a bit warm.

Looking forward to 2010: Breeding Sheep for a More Profitable Flock will be the focus of a comprehensive seminar on defining and selecting traits that can increase profits in sheep production. What are the latest innovations in sheep genetics? How do we use modern selection criteria to increase profits? The seminar will include selection of traits, advantages of crossbreeding systems and evaluation of sheep breeds and their contribution to the commercial industry. Genetics for production systems ranging from grain based to total grass and marketing goals from selling roaster lambs to 140# finished lambs will be included in the discussions. Dr. Dave Notter (VPI), Dr. Dave Thomas (Univ. of Wis.) and Dr. Kreg Leymaster(USDA Marc) have been asked to be the keynote speakers. Breakout sessions will include live animal evaluations and a panel discussion with Dr. Charles Parker as the moderator.

This joint regional conference is sponsored by the ASI genetics stakeholders committee, the Ohio Sheep Improvement Association, the Ohio Sheep and Wool Board and the Ohio State University. It will be held July 10 and 11, 2010 at Riverwood Farms, Powell, Ohio. More detailed information will be available at the Buckeye Shephards Symposium in December.

The planning committee for this seminar includes Bill Shultz, Rory Lewandowski, John Anderson, Dr. Henry Zerby, Eric Bruns, Susan Shultz and Roger High.

Bill and Susan Shultz will be scanning their 2009 lamb crop on Friday, June 20, 2009 at their farm in DeGraff, Ohio. They have contracted with Bonnie Bradford, a skilled technician, to do the scanning of loin eye and back fat as she has done the past three years for the Shultz’s.

For any sheep breeder who is interested in scanning their lambs, the Shultz’s are willing for you to bring your lambs to their farm during the late morning on the 20th. Due to health concerns all lambs will need to be unloaded, processed and reloaded onto the truck or trailer as there will be no penning of animals at the site. The procedure for scanning is that a weighing scale will be available, and personnel will be available to shear each lamb between the 12th and 13th rib to provide adequate contact for the scanner. Bonnie charges $5.00 per head for scanning. For best results, lambs should weigh between 120 and 180 pounds.

If you are interested in scanning lambs please contact Bill or Susan at bunkerhillfarm@gmail.com and they will schedule you in for the morning of June 20th.