Shelby Filley, Oregon State University, Regional Livestock and Forage
(Previously published on the Oregon State University Extension page: April, 2018)
Do you have your ewes nutritionally prepared for lambing and lactation? If not, that’s okay! There is still plenty of time to get this important task accomplished. Learn to put a nutrition plan in place early in the season so you can decrease problems with your ewes later.
Two phases of the ewe’s biological cycle need special dietary consideration when it comes to lambing:
- The first phase is the last four to six weeks of pregnancy, when 70% of fetal lamb growth occurs. In this late gestation period, ewes require significantly more dietary energy and protein than earlier in pregnancy. A good plane of nutrition here will help ensure that strong, healthy lambs are more easily delivered and have a good start in life. Ewes in poor nutritional condition are more susceptible to pregnancy toxemia, and may have weaker, lighter birth weight lambs to the point that lamb survival rate drops.
- The second phase of the ewe’s biological cycle for nutritional consideration is during lactation, especially during the first six to eight weeks after lambing when milk production is high. This is the time when the ewe has the greatest nutrient requirements for energy and protein.
Additionally, the size and productivity of your ewes also influence the requirements. Larger ewes pregnant with twins require more nutrients than smaller ewes carrying a single lamb. Ewes suckling twins need more nutrients because they produce 20% to 30% more milk than ewes suckling singles.
How much should you feed your sheep, and when? Let’s look at feed resources.
Although pastures may be nice and green, with high nutritional quality, the amount present will most likely be in short supply. Hence, the feed available from pasture may be too low to meet the demands of the ewe.
Many times, grass hay alone does not contain sufficient concentration of nutrients for the ewe. Low-quality grass hay does not meet the energy and protein requirements of ewes during various segments of the production cycle.
Since the forage examples used here don’t match the ewe’s requirements, supplementation would be necessary for optimal production. For example, a 154-pound ewe will eat about 4.5 pounds of feed per day of a late gestation diet. For a 130%–180% lamb crop, she would need a diet with 65% total digestible nutrients and 11.3% crude protein.
Expect delivery of lambs to begin approximately 142 days from when the ram bred the ewe. Count back 28 to 42 days (four to six weeks) to give you the date you need to start slowly introducing this diet. Rapid diet changes have the potential to cause digestive upset.
After lambing, move the ewe up to full feed (6-7 pounds) of a diet containing 65% total digestible nutrients and 15% crude protein (when suckling twins). An example diet that would meet this requirement could be 4 pounds of moderate quality alfalfa hay and 2 pounds of whole corn. Alternatively, you could feed 4 pounds of good quality grass hay and 3 pounds of grain.
Young lamb mothers need additional requirements for their own growth and may benefit from being fed as a separate group if circumstances allow. As the quantity of grass increases in your pasture, you can decrease the amount of supplemental feed offered to your sheep, eventually relying solely on grass.
Remember to allow the pasture to get a good start on its growth by not overstocking it, or beginning to use it too early. Don’t forget to offer a trace mineral salt mix made especially for sheep. You should also consider other pre-lambing practices such as vaccinating for enterotoxemia, trimming feet, and shearing or crutching/tagging ewes. Also, prepare the lambing barn, and check supplies and equipment.
Good luck with your new arrivals!