Thomas R. Thedford, Extension Veterinarian, Oklahoma State University
Bill Crutcher, Purebred Flock Manager, Oklahoma State University
Joe Hughes, Extension 4-H Livestock, Oklahoma State University
Gerald Fitch, Extension Sheep Specialist Specialist, Oklahoma State University
(Previously published online with Oklahoma State University Extension: February, 2017)
The key to any successful livestock health and management program is planning. The guidelines in this fact sheet were developed for your use with this concept in mind. All matters concerning disease prevention and diagnosis should involve your veterinarian. If health problems exist, a postmortem examination can be conducted and tissues selected for submittal to a diagnostic laboratory as an aid in securing a diagnosis. The veterinarian can also advise you about specific vaccination programs for your area.
- Maintain rams in good nutritional state all year long.
- Approximately 30-45 days before the breeding season, conduct the following:
- Shear rams.
- Check for internal and external parasites and treat if necessary.
- Have a veterinarian evaluate the semen, palpate the testicles for epididymitis, and conduct a general breeding soundness exam which should include examination of feet, legs, sheath, and mouth.
- Increase the feed to get rams into good physical condition.
- Mature rams may breed 30-50 head of ewes. Ram lambs (6-12 months of age) may be used to breed 15-25 ewes.
- If the days are hot, turn rams into the ewes only at night.
- Use a marking harnesses and record breeding dates. Change marker colors every 15-17 days on purebred rams and rotate commercial rams among commercial ewe groups each 15-17 days. A suggested marker color sequence is blue, red, and green. Using a marking harness will save you labor at lambing time since lambing dates are known. This will also indicate which ewes are recycling.
- Observe rams while mating and watch for any problems that may develop.
- Teaser rams (vasectomized rams) may be put in with ewes two weeks before the breeding season. Introduction of a teaser ram near the end of the anestrous period can induce estrus and ovulation earlier than would normally occur without the presence of a ram. The result is a grouping of breeding dates, although, lambing rate is not increased.
- Check for internal and external parasites and [treat if necessary].
- Ewes can be maintained on poorer quality feeds if the feeds are provided in adequate amounts.
- Two weeks before turning in rams, put ewes on good pasture or feed one-half to three-quarter pound concentrate per head per day. This increased level of nutrition or “flushing” can influence the ovulation rate early in the breeding season, and it should produce an increased lambing rate. Sheep should be fed in troughs and not on the ground to prevent the spreading of diseases and parasites.
- If you have had an abortion disease problem in your area, vaccinate ewes for sheep type vibrio (campylobacter) and enzootic abortion (chlamydia). Monovalent (vibrio) and bivalent (both diseases) vaccines are available. Consult with your veterinarian for any additional vaccine recommendations.
- To protect ewes from possible toxoplasmosis infection, keep cats as well as other animals out of the feed supply. Toxoplasmosis is caused by the ingestion of a coccidia from cats [and varmints]. If the ewe becomes infected while pregnant, abortion may occur.
- Producers may shear and then dip, spray, or pour-on, for external parasites. Commercial producers usually shear only in the spring. Dipping and spraying should be done after shearing to facilitate penetration of the insecticide to the skin.
- Ewes should be identified with either paint brands or ear tags.
- Keep good records by using a marking harness on rams and record breeding dates.
- Watch for repeat breeders! Do not wait until lambing season to find out ewes did not settle.
- Pre-lambing/Gestation (Average pregnancy length is 147 days.)
- After 40 days, ewes may be checked for pregnancy if equipment and expertise are available.
- Rams should be removed from the flock during late gestation in order to prevent injury to the ewes.
- Feed one-half to one pound grain per day for 120 pound ewe during the last 4-6 weeks of pregnancy to prevent pregnancy toxemia.
- Vaccinate ewes for Clostridium perfringens types C and D and Tetanus to protect ewes and lambs (two doses two weeks apart – second dose two weeks prior to lambing). Lambs will obtain antibodies through the milk of vaccinated ewes. Give a yearly booster two to three weeks before lambing in successive years.
- If practical, divide ewes into two groups – those close to lambing and others. This will permit feed conservation and closer observation.
- When a ewe is found in labor allow 30 minutes to one hour for normal dilation and delivery. Do not rush the lambing process. If lambing hasn’t occurred by the end of this time period, examine the ewe. Wash your hands and arms and the external genitalia of the ewe thoroughly before entering the ewe. If you cannot readily get into the uterus and feel the lamb, stop and call your veterinarian. If you cannot reposition and deliver a lamb in 15-20 minutes, stop and call your veterinarian. Cesarian section is economical in sheep if live lambs can be delivered. Don’t wait too long and handle with care.
- Navel cords should be clipped off about 2-3 inches long and treated with a seven percent solution of iodine to prevent navel ill. Make sure the ewe is milking by stripping out a small amount of milk. If the lamb has not nursed by two hours of age or if it is weak, use a stomach tube and feed it 60cc of warm colostrum. Frozen cow colostrum will work if gradually warmed to ~104 degrees Fahrenheit. Do not heat in a microwave oven.
- If it is necessary to pair up lambs with ewes or observe ewes, utilize lambing pens or “jugs” as needed. Allow 10 pens per 100 ewes as a minimum. If ewes are wild, use lambing pens only when necessary. Handle wild ewes as little as possible. Remove ewes and lambs from lambing pens as soon as they are paired up and by 3-5 days maximum. After removing the ewes and lambs from the lambing pens, they should be held in a restricted area for a few days to make sure that all lambs are nursing. Separate the ewes with singles from those with twins and triplets and feed accordingly.
- Identify ewes and lambs with wool branding paint or tags. Ewes that were twins or triplets are more likely to have multiple births than are ewes who were singles. Therefore, an ear notching system can be used in marking lambs that are twins (one notch) or triplets (two notches) so they will be recognizable at weaning. This information should be recorded in the “remarks” section of the record form.
- Observe lambs daily to insure that they are nursing and to detect diseases and other problems. Early treatment of starvation, pneumonia, and scours is necessary for survival.
- Observe ewes for vaginal discharge and udder infection (mastitis and sore teats).
- Dock lambs at less than two weeks of age if at all possible. One hundred to 300 I.U. tetanus antitoxin may be given at this time to prevent tetanus if the toxoid has not been given to the ewes. Castration may be done at this time, also. Purebred breeders may prefer to castrate later after ram selection has been done. If castrated more than two weeks after docking, re-administer antitoxin.
- Keep lactating ewes separate from pregnant ewes. Feed lactating ewes 1-2 pounds of grain per day and all of the high quality forage they can eat. Ewes with twins and triplets will require additional grain.
- Maintain a lambing record similar to the example provided in this publication.
- Lambs should be castrated prior to one month of age. Tetanus antitoxin should be given at this time unless the ewes were given a tetanus toxoid series prior to lambing.
- Lactation or pre-weaning
- A 16%-18% crude protein creep ration should be available to the lambs.
- Vaccinate lambs for Clostridium perfringens type D (enterotoxemia – pulpy kidney) at ~30 days of age. A second dose 2-4 weeks later is recommended.
- Remove grain from the ewe’s ration 2 weeks prior to weaning in order to reduce milk flow.
- Most lambs should be weaned at 60-80 days of age. Do not change rations or move the lambs to different pens. Move the ewes, not the lambs. This helps to reduce weaning stress on the lambs.
- Provide quality rations for the lambs to insure gain and growth at desirable rates.
- Ewes need to be taken off feed for 36-48 hours during weaning to reduce milk flow and stress on the udder.
- Check teeth, udders, and feet of ewes. Broken and smooth mouth ewes may be separated for additional feed or culled. Cull all ewes with bad udders.
- Watch for chronic wasting disease and cull the affected ewes.
- Evaluate production records and cull poor producers.
Ewe Lamb Management
Most spring born lambs will breed at approximately 8 months of age or when they reach about 65% of their mature body weight.
Management aids for ewe lambs are:
- Ewe lambs should be maintained separate from the ewes from the time they are weaned until their first lambs are weaned. This will permit ewe lambs to be fed proper rations in order to maximize growth and production.
- Breed to lamb at a different time than the ewe flock since ewe lambs will require more attention at lambing.
- Vaccination program should be very similar to the ewe program.
- Special attention should be given to the control of internal parasites because young sheep are more susceptible to stomach and intestinal worms.
- Provide clean water at all times.
- Provide salt and mineral mix at all times.
- Rotate pastures as necessary.
- Monitor parasite burden.
- Observe sheep daily while they are quiet. It is easier to detect sick sheep at this time, and early detection is very important to survival or recovery from sickness.
- Always utilize pasture for ewes if possible. High quality forage is necessary during periods of flushing and lactation.
- Keep good records and use them in selecting replacement ewes and in making other management decisions.
- Design a flock health program with the assistance of your veterinarian.
Editors Note: For more details regarding overall flock management, be sure to visit the Oklahoma State University webpage for additional management tools and factsheets.