Adequate minerals important for healthy sheep

URBANA, Ill. — Minerals are essential for normal function of sheep and deficiencies in any of them can negatively impact health and performance.

“Sheep require at least 14 minerals and they play a role in almost every biological system in the animal,” said Haley Linder, assistant professor in the Department of Animal Sciences at The Ohio State University.

“Minerals maintain the immune function for disease resistance and they are really important for growth and development,” she said during a presentation at the Illinois Lamb & Wool Producers annual meeting.

Most sheep operations today have a mineral feeder.

“The question is not if minerals are being offered, but whether that mineral program is intentional,” Linder said. “In many cases, people are selecting a mineral program based on habit, price or brand loyalty and they are not matched to the forage base, season or stage of production.”

She encourages shepherds to build and evaluate a mineral program that fits their system. For example, spring-lambing ewes that are grazing pastures have different risks than fall-lambing ewes grazing stockpiled fescue or eating hay.

Also, gestating or lactating ewes will have different needs and requirements than growing lambs.

Mineral intake by sheep is not only what is in the mineral feeder.

“It is the summation of multiple sources including forages, supplements and often forgotten about is water,” Linder said.

“In most systems, forage makes up the majority of dry matter intake for sheep, so if we do not know what the forage is contributing, we are formulating in the dark,” she said. “Forage mineral content is not uniform or static. It varies a lot on plant maturity, the species and the soil pH.”

Selenium levels vary across the United States.

“Some regions like a good chunk of Illinois have low selenium concentrations where others are adequate or even too high like in the Dakotas and the Great Plains,” Linder said. “If forage is grown in selenium-deficient soils, that deficiency starts in the plant and carries through to the sheep.”

Selenium is just one example; there are regional mineral patterns for other minerals like copper.

“Keep in mind where you live can change the mineral content of your forages,” Linder said.

Therefore, forage testing is essential to know how much the hay is providing in terms of minerals, as well as energy and protein.

“Test at different points in the year and over multiple years because forage mineral content varies due to plant maturity and there are year-to-year variations due to environmental variabilities,” Linder said.

“Test your water because it does contribute to mineral intake by sheep, particularly if you are in an area that has an antagonist like sulfur,” she said.

The amount of minerals in different types of feeds is variable.

“Forages tend to be relatively higher in calcium than phosphorus and grains tend to be higher in phosphorus and lower in calcium,” Linder said.

As shepherds change the diet formulation for their flock, they may also be shifting the mineral balance.

“In most cases we want the diet to provide a 2-to-1 ratio of calcium to phosphorus — that means twice as much calcium as phosphorus,” Linder said.

“This is important for proper bone development and overall mineral metabolism,” she said. “But one of the bigger reasons is because it helps reduce water belly or urinary calculi which is a concern in wethers and growing lambs because it can result in bladder rupture if it is untreated.”

Copper is essential for sheep, Linder said; however, sheep are more susceptible to copper toxicity than most other livestock species.

“When sheep consume excess copper, they are really good at holding on to it and storing it in the liver, rather than extruding it from their body,” she said. “Over time, that buildup of copper damages the liver tissue, and in some cases when sheep have a stressful event like weaning, shearing or transport, the liver releases all the copper into the bloodstream and in most cases causes death of the animal.”

Sheep can usually get their copper need from normal feed ingredients.

“Because of the delicate balance between the copper requirement and toxicity, it is really important to feed mineral supplements that are specifically formulated for sheep,” Linder said.

Feeding loose free choice minerals to flocks is convenient in many feed systems.

“But we need to recognize the variability because one ewe may eat 2 ounces per day and another ewe may eat almost nothing,” the professor said. “So, we need to monitor the intake of the animals.”

Salt is the driver of free choice mineral intake by sheep, Linder said.

“Sheep consume minerals to satisfy their salt appetite not to meet their mineral needs,” she said. “If you provide salt and minerals separately, sheep will likely just eat the salt and not the mineral.”

Minerals can also be hand fed or mixed into a total mixed ration, or TMR.

“A TMR is much more controlled and that consistency can be valuable in critical production stages, but there is additional labor cost associated with it,” the professor said.

Linder recommends one mineral feeder for every 10 to 12 sheep to ensure adequate access.

“Putting the feeder in a shaded area, loafing area or near water can encourage intake,” she said.

The professor talked about common myths with feeding minerals to sheep including the idea that if sheep are eating a mineral that means they need it.

“Sheep do not vary their mineral intake based on needs; therefore, offering minerals in a buffet style does not provide sufficient amounts of each mineral to meet requirements,” Linder said.

“Sheep do not have the nutritional wisdom to choose the right amount of minerals based on their physiological needs,” she said.

In addition, many minerals are poorly palatable which does not encourage sheep to eat them.

“Feeding more of a mineral does not necessarily improve performance — you only see that if you are correcting a deficiency,” Linder said. “Just because a little is good, more is not better. Overfeeding adds costs without adding a benefit.”

Price alone does not determine if a mineral program will be effective for a flock.

“The key is being strategic and not automatically choosing the highest-cost product,” Linder said. “The value is determined by the product fit, not the price tag.”

“Mineral supplementation is not about feeding more — it is about feeding the minerals correctly,” she said.