Ehrhardt: Winter nutrition is critical for pregnant ewes
“Proper winter nutrition is critical for pregnant ewes,” says Michigan State University Small Ruminant Extension Specialist Dr. Richard Ehrhardt during an American Sheep Industry Association podcast dated Feb. 24.
Ehrhardt explains winter is an important time of year as producers are managing and feeding ewes through some point of pregnancy.
He shares, producers need to understand pregnancy requirements, especially when the goal is to feed sheep to a productive state.
Risks caused by weight
“I rarely cross paths with someone who overfeeds their ewes,” Ehrhardt says. “Oftentimes, I find producers underfeeding ewes, causing an energy shortage during late pregnancy.”
“Ewes are at increased risks when influenced by weight,” Ehrhardt adds. “Being underweight, or even overweight, can cause risks during pregnancies.”
Underweight ewes are at higher risk of experiencing pregnancy toxaemia, more commonly known as Twin Lamb Disease (TLD).
TLD occurs when a lamb in utero requires more glucose than the ewe can provide, Ehrhardt explains. This disease commonly affects ewes carrying twins or triplets.
TLD can be treated by giving ewes an oral glucose solution twice a day. If one ewe is affected by TLD it can be assumed the rest of the flock is in danger. According to Ehrhardt, it is better to prevent TLD than to treat it.
Ehrhardt shares underfed ewes might experience other issues, as well.
“Most times, chronically underfed ewes will provide less milk,” Ehrhardt says. “Being underfed will also affect ewe behavior. Generally, these ewes will not be good mothers.”
Ehrhardt shares overfeeding breeding ewes usually isn’t an issue. It can be hard for producers to know the body condition score of their ewes, especially if they aren’t shorn.
He adds, “Ewes go from needing nine to 10 percent crude protein during pregnancy to needing 13 to 15 percent during lactation. The amount of protein needed during these times can be dependent on how many lambs a ewe has. If a producer has a higher protein forage, they might consider saving it for the lactation period.”
“Ewe requirements will vary throughout the duration of pregnancy,” says Ehrhardt. “Feeding ewes during mid-term pregnancy requires a maintenance diet.”
Ehrhardt continues to explain lambing in late spring results in feeding a maintenance diet throughout winter.
“About 40 days before lambing, producers should switch their ewes to a higher caloric diet,” Ehrhardt states. “It is essential to recognize late pregnancy is a critical time.”
Ehrhardt notes, ewe requirements are starkly different depending on the number of lambs they are carrying.
He adds it is crucial to acknowledge the number of lambs and size of an ewe is dependent on breeds. Producers should keep in mind the size of the ewe and the number of lambs carried during pregnancy when calculating feed requirements.
Ewes carrying one lamb require a 50 percent increase in calories, whereas ewes carrying three lambs require 130 percent more calories.
Wintering ewes outside requires more feed so ewes can maintain their body temperature. Wind protection and full fleece can also affect feed requirements, Ehrhardt shares. Full fleece can make up to a 25 percent difference in feed intake.
“Sheep are great at acclimating,” Ehrhardt explains. “They don’t stress as much once they are acclimated. However, they do stress when the temperature dramatically changes.”
Ehrhardt explains vitamins are crucial when it comes to maintaining pregnancy. Many ewes lack vitamins A, D and E.
“Sheep store extra vitamin A in their liver,” Ehrhardt says. “They can store six months worth of vitamin A.”
He shares vitamin D2 is found in sun-cured forages, such as hay, and vitamin D3 is from exposure of skin to ultraviolet light, such as sunlight. Because of this, keeping ewes in a lambing shed for a prolonged amount of time while on a diet low in vitamin D2 can cause a vitamin D deficiency.
Ehrhardt adds sheep kept in pastures don’t usually experience vitamin D deficiency like sheep kept out of the sun.
“Sheep don’t store vitamin E like they can vitamin A,” Ehrhardt shares. “This means sheep require a daily intake of vitamin E.”
Ehrhardt adds vitamin E supplements can increase lamb weaning weights, improve production and result in higher quality colostrum.
Feeding lactating ewes
“There are three different feed programs producers often use for lactating ewes,” says Ehrhardt. “Stockpiling pasture, grazing covered crops and silage are some common feeding practices.”
Stockpiling pasture or range has significant advantages and disadvantages. Ehrhardt shares, producers should do extensive research before implementing a feed program such as stockpiling. Limiting grazing on a pasture too early will provide tall, non-nutritious grasses whereas limiting grazing too late will provide nutritious grasses, but can raise concern due to not having enough feed.
Ehrhardt says cover crops can also be quality forage producers can feed lactating ewes. He adds, lambs may be finished out on cover crops with careful management.
“Producers may also feed ewes hay or silage,” Ehrhardt explains. “It is important to know the quality of feed. If the silage or hay being fed doesn’t have high enough quality, producers may have to supplement with grain.”
“Silage managed carefully will reduce the risk of diseases,” Ehrhardt notes. “The quality and cost can help sway a producer’s decision regarding feed.”
Ehrhardt says hay or silage may be a good option, especially for larger operations.
Madi Slaymaker is the editor of the Wyoming Livestock Roundup. Send comments on this article to firstname.lastname@example.org.