ASI reminds producers of the importance of pregnancy ketosis in small ruminants

Producers of small ruminants often learn about pregnancy ketosis the hard way, but with proper nutritional management, producers can increase lamb survival rates while enhancing ewes’ health throughout gestation.

On the July 26 episode of the American Sheep Industry Association (ASI) podcast, Host Jake Thorne, sheep and goat program specialist at Texas A&M AgriLife Extension, spoke with Michigan State University (MSU) Department of Animal Science Professor and Small Ruminant Extension Specialist Dr. Richard Ehrhardt about the effects of ketosis.

“Ketosis has another common name in sheep – pregnancy toxemia. Unique to sheep, it’s associated with late pregnancy,” Ehrhardt says. “It is a metabolic disease, which is different than an infectious disease.”

Ehrhardt explains ketosis is an energy crisis effecting ewes, mostly because lambs drain nutrients from ewesʼ bodies. 

“Principally, glucose is the major nutrient causing the problem. It wreaks a lot of havoc when ewes can’t regulate their energy metabolism properly,” he notes.

Signs of pregnancy ketosis include depression, lethargy, poor appetite, dull eyes, low fecal output, changes in behavior and general “slowness.” 

As the condition progresses, affected sheep may manifest tremors, circling, teeth grinding, blindness, wandering, stargazing, coma and death.

Economic losses because of this disease have been considerable, and it is the most commonly occurring metabolic disease of sheep.

Ketosis

According to Ehrhardt, sheep carrying multiple fetuses have a very high energy demand in late pregnancy and require adequate energy in their diet to ensure pregnancy requirements are met.

He notes this can be a challenge in females carrying two or more fetuses, as the metabolic needs of a large litter are difficult to meet.

“In late gestation, the liver increases gluconeogenesis to facilitate glucose availability to the fetuses which represents a substantial percentage of the ewe’s glucose production and which is preferentially directed to supporting the fetuses rather than the ewe,” he explains.

Mobilization of fat stores is increased in late gestation as a way to assure adequate energy for the increased demands of the developing fetuses and impending lactation.

The release of stored energy will address low blood glucose issues, but not without side effects.

“Byproducts of fat mobilization called ketone bodies can accumulate to toxic levels and suppress appetite, and without intervention, affected ewes may spiral downward in a fatal negative energy balance, taking their unborn fetuses with them,” he adds.

Additionally, twin-bearing ewes appear to have more difficulty producing glucose and clearing ketone bodies, thus increasing their susceptibility to pregnancy toxemia.

Ketosis prevention

Producers can monitor and diagnose individuals for ketosis through the use of urinary ketone detection strips, blood ketone tests and/or checking the breath for a fruity or acetone-like smell, although not every person can detect this.

In early cases where the ewe is still eating, she can be given more energy by means of more grain or better-quality hay, he notes.

Another solution Ehrhardt mentions is orally administering multiple doses of propylene glycol.

Detection of the first case of ketosis should motivate a producer to reevaluate the herd’s ration, assess body condition scores of all pregnant animals and make adjustments as needed.

“Producers should focus on prevention,” he states. “While there are options to detect and manage ketosis, producers can help prevent ketosis in the late gestation through nutrition.”

Prevention of pregnancy ketosis includes giving pregnant ewes a more energy-dense ration beginning in at least the last four weeks of pregnancy, he mentions.

“We don’t want ewes to be too fat in the last months of pregnancy,” he remarks. “Ewes with a body condition score of less than two or over four are at risk.”

He further notes ewes pregnant with twins and triplets will require a more energy-dense diet than those with singletons, so producers need to more closely monitor ewes pregnant with singles because they could grow excessively fat on the higher-energy ration required for twins and triplets.

Ehrhardt adds, “By utilizing ultrasound, ewes can be separated, managed and fed as a group, depending on the number of fetuses they are carrying.”

Given the close profit margins achieved by small ruminant producers, it is essential to understand pregnancy ketosis and how to prevent it.

Melissa Anderson is the editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.