Rebecca Kern-Lunbery, Animal Scientist, Ward Laboratories Inc.
(Previously published online with Progressive Forage: December 22, 2025)
Sheep 
and goats have smaller rumens than cattle, limiting intake and increasing dependence on highly digestible forage. They need greater fiber digestibility and energy density, especially in lactation, making hay analysis distinct from cattle standards.
There is a lot of information available for forage analysis for beef and dairy cattle. And most of the advice given to small-ruminant producers is to apply what we know about cattle to their sheep or goats. They are all ruminants, right?
Not exactly. While forage is the base of sheep and goat diets just like it is for cattle, they are very different animals who share a similar gut structure. Their anatomical differences impact not just their physiology but also their grazing behavior and nutritional needs. First, let’s look at these differences in anatomy and what they mean for their nutritional requirements. Then, let’s see how that can guide our understanding of a hay analysis relative to their specific needs.
Comparative anatomy and grazing behavior
Cattle are grazers, and at the opposite end of the spectrum are goats, the only true browsing livestock species. Grazers typically have large wide mouths designed for taking in as much of the forage in front of them as possible. They also have a much larger rumen making up to 30% of their bodyweight. Conversely, browsers typically have small mouths and narrow muzzles designed for careful selection of leafy portions of plants and fruits on shrubs. Browsers also have a smaller gut and therefore lower capacity for high-fiber and -volume forages.
These anatomical differences impact their natural grazing behavior. While cattle graze two to three times per day, browsers like goats graze 10 to 15 times a day! This is because the grazer consumes higher-fiber plants, mostly grass. Therefore, they must spend a lot more time ruminating on their forage than a browser. Furthermore, to break down that high-fiber diet, forage must spend significantly more time in a cow’s rumen than in a goat’s rumen. Sheep are intermediate feeders, and their grazing behaviors fall somewhere between those of a cow and a goat, but more closely aligned with a cow. In addition to these digestive tract differences, small ruminants also have other anatomical and production differences that impact their nutritional needs.
Urinary calculi is a condition that occurs when mineral deposits are formed in the urinary tract and these small stones can then move into the urethra, causing blockage. Male ruminants have a sigmoid urethra; however, small ruminants also have an additional extension of the urethra known as the urethral process. While the sigmoid structure makes both cattle and small ruminants prone to developing urinary calculi, the urethral process is a common site for blockage to occur, making sheep and goats more prone to develop the issue.
Furthermore, unlike beef cattle whose primary production purpose is meat and/or producing one calf, sheep and goats can be raised for wool production and have multiple offspring. So what does all this mean for small ruminants primarily consuming hay?
Nutritional considerations for small ruminants
Due to these anatomical, physiological, behavioral and production differences, small ruminants have different nutritional requirements than cattle. However, during winter months, the base of their diet is hay. So here are four key factors to evaluate to ensure you provide adequate nutrition when grazing is not an option.
Fiber and fiber digestibility: Since small ruminants, especially goats, do not have the large gut capacity of cattle, they cannot handle high-fiber forages as well. They need forages lower in fiber content, and that fiber should be highly digestible. We like to see neutral detergent fiber (aNDF) below 60% for beef cattle; for sheep and goats, even lower values would be preferred. Digestibility of aNDF at 48 hours (NDFD48) should be on the higher side, so for most forages that means this value should be above 45% of aNDF. Remember, they have not adapted to spending large portions of their day ruminating and slowly breaking down fibrous feeds.
Additionally, sheep nursing multiples have higher energy requirements. The fiber and energy (total digestible nutrients, TDN) have an inverse relationship, meaning lactating ewes will require lower-fiber hay, and typically it helps to have higher fiber digestibility to come closer to meeting energy needs during this physiological state. For example: A 154-pound ewe nursing twins will require 64.5% TDN, while a 1,200-pound lactating beef cow requires just 57.3% TDN.
Protein: Typically, small ruminants will have a higher requirement for the concentration of crude protein in their hay, since when grazing they typically are more selective for parts of the plant with higher protein. This is due to a smaller gut capacity as well as higher reproductive performance goals when producing multiple offspring.
Again, reproduction for small ruminants with multiples also increases protein requirements relative to their beef cow counterparts. A 154-pound ewe nursing twins will require 14.8% protein, while a 1,200-pound lactating beef cow requires just 9.3% protein.
Furthermore, protein is a key component in wool. For quality fleece production, small ruminants need sufficient protein.
Calcium, phosphorus and magnesium: These minerals need to be provided in a delicate balance to rams, bucks, and wethers. Due to their urinary tract design, they are more prone to developing urinary calculi. Hay should be analyzed to ensure proper mineral supplementation can be supplied to these groups. Additionally, hard water can contribute to this condition, so testing new water sources is key for prevention.
Copper, sulfur, iron and zinc: These minerals are key to producing quality wool. Copper (Cu) is responsible for the color and texture of the fleece. Zinc (Zn) is also important to ensure wool is soft and not brittle. Sulfur (S) and iron (Fe) are both important to healthy hair and skin, yet excess can interfere with Cu absorption. So it is key that these four minerals along with molybdenum (Mo) are in balance for quality wool production.
So while we often find ourselves applying beef cattle information to sheep and goat nutrition, the fact remains that these are very different animals. They have a very different digestive tract anatomy adapted to their foraging and grazing behavior. They also have more rigorous production demands when we evaluate what it takes to produce wool as well as multiple offspring.
Understanding the unique anatomy, grazing behavior and production demands of sheep and goats makes it clear that small-ruminant nutrition cannot be managed the same as cattle. Using hay analysis to evaluate fiber, protein and key mineral balances allows producers to match forage quality to the higher nutritional demands of sheep and goats. By understanding how your hay aligns with these species-specific requirements, producers can support healthy productive animals through appropriate supplementation and diet strategies during non-grazing months.