Livestock Update, January 1999
Scott Greiner, Extension Animal Scientist, Sheep, Animal and Poultry Sciences, Virginia Tech
Late Gestation Ewe Management
Proper management during the last four to six weeks of gestation are critical to ensure a healthy, vigorous lamb crop. Approximately two-thirds of the growth of an unborn lamb occurs the last six weeks of gestation. During this time, the ewe should gain approximately .5 pounds/day. Proper management during this last portion of gestation will help prevent pregnancy disease, promote strong lambs at birth, enhance milk production, and prevent disease. Following are a few points to consider during late gestation:
Energy/Protein:: Requirements for both energy and protein increase during the last 4 to 6 weeks of gestation. Mature ewes weighing 150 to 175 pounds require a diet of approximately 65% TDN and 11.5% crude protein. In most cases, energy is the deficient nutrient during late gestation. Feeding high quality grass/legume hays normally provide adequate protein concentrations for the late gestation ewe. However, hay samples should be analyzed to make appropriate ration formulations. General recommendations include supplementing 1 pound of corn or barley during the last 4 to 6 weeks of gestation. It is important to gradually work ewes up to the 1 pound/day: 1/2 pound per day 4 to 6 weeks prior to lambing increasing to 1 pound by 2 to 4 weeks prior to lambing. Grain should be introduced gradually to prevent enterotoxemia, and appropriate bunk space should be provided to prevent crowding and potential injury to unborn lambs. If hay supplies are short, 1 pound of corn may substitute for approximately 2 pounds of hay. It is important that ewes receive a minimum of 2 pounds of roughage per day to maintain rumen health. Additionally, supplemental protein will likely be necessary if grain is used to replace a significant portion of the roughage in the diet. Inadequate energy during late gestation may result in small, weak lambs at birth as well as decreased milk production in the ewe. Additionally, pregnancy ketosis may occur as a result of a diet deficient in energy during late gestation.
Selenium: Virginia is largely a selenium deficient state. Deficiencies in selenium result in weak lambs and white muscle disease. Ewes should have access to a selenium fortified trace mineral salt (up to 90 ppm selenium) during late gestation. Providing selenium mineral mixes specifically formulated for sheep should meet the ewes' requirements. If feeding a selenium mineral is not feasible, injections of selenium and vitamin E can be given. Ewes should receive 2.5 to 3 mg of selenium per 100 pounds of bodyweight. Injections of selenium/vitamin E are not recommended when a selenium mineral mix is being fed as high levels of selenium may be toxic.
Enterotoxemia and Tetanus: Vaccinate ewes for overeating and tetanus approximately four weeks prior to lambing. Vaccination at this time will provide passive immunity to the lambs at birth through the ewe's colostrum.
Antibiotics: Vaccines for prevention of abortion diseases (vibrio and chlamydiosis) have not been widely available. Chlortetracycline (Aureomycin) fed at a level of 80 mg/head/day (approved dosage) during the last six weeks of gestation has been shown to aid in prevention of these diseases. Injections of oxytetracycline (LA 200) at 2 week intervals the last 4-6 weeks of gestation have also been recommended as a preventative measure.
Deworming: Ewes should be dewormed 2 weeks prior to lambing. Research has documented that worms increase egg shedding just prior to and continuing after lambing. During this time, the ewe has a reduced ability to deal with the increased worm load. Therefore, deworming prior to lambing is an important aspect in an effective parasite control program.
Shearing: Shearing prior to lambing has several advantages: facilities remain cleaner and drier, ewes require less space, ewes about to lamb are easier to identify, and the newborn lamb and ewe are easier to manage. Shearing prior to lambing does require that adequate facilities be made available, especially immediately after shearing so that ewes have protection from adverse weather. Cold weather will increase the energy requirements of the ewe the first couple of weeks after shearing. Shorn ewes are more apt to seek shelter for lambing in adverse weather. Shearing can be done up to one week before lambing. Shearing ewes very close to lambing may result in some premature births. If shearing is not feasible prior to lambing, ewes can be crutched. Crutching involves the removal of wool around the dock and udder of the ewe. Although crutching enhances the shepherd's ability to manage the ewe and her newborn lambs, it will not enhance the lambing barn environment or reduce space requirements needed for the ewes.
Gary Hornbaker Named 1998 Roy A. Meek Outstanding Sheep Producer
Gary W. Hornbaker was named the recipient of the Roy A. Meek Outstanding Sheep Producer Award presented December 4, 1998, at the Virginia/North Carolina Shepherd's Symposium held in Blacksburg, Va. This award is presented annually by the Virginia Sheep Producers Association to recognize an outstanding sheep producer in the state. This year's recipient has been involved in sheep production since his first 4-H project in 1966. Since that time he has managed large flocks in Virginia and Maryland, and currently raises purebred Dorset as well as commercial sheep on his operation in Berryville, Va. Gary has been involved is almost every aspect of sheep production. He sheared sheep for 22 years for producers from North Carolina to Pennsylvania, and has been actively involved in the Loudoun County Wool Pool as a consignor, volunteer, and Extension agent. All of his wool is marketed through the Virginia Wool Pool system. Gary has combined his interest in sheep and people to assist many producers to get started or expand their sheep operations. He has been a supplier of purebred Dorset seedstock, 4-H club lambs, and western replacement ewes. Gary has also been actively involved in sheep marketing through leadership in organizing the Old Dominion Livestock Producers Association, which cooperatively markets lambs, goats, cattle, and breeding sheep. Gary has also served as a volunteer 4-H leader in Clarke County, and has judged numerous sheep shows throughout the Mid-Atlantic region. Gary's sheep enterprise is designed to make optimum use of available forage resources, while limiting dependence on purchased feed grains. Gary is employed full-time as the agricultural Extension agent in Loudoun County. He and his wife have six children and are actively involved in school, 4-H, sports, and community activities.