Goats are ruminants, and ruminants must have roughage in their diet to keep the rumen functioning properly. Roughage is defined as any feed ingredient that has a high concentration of fiber that breaks down slowly. The best roughage is long coarse fiber. Long coarse fiber is plant material that is from 3/8 inch to 1-1/2 inches in length or longer. The goat's rumen works best when the roughage effect takes place. The coarse materials rub against the walls of the rumen, stimulating the muscles to contract and relax -- agitating the materials in the rumen. The resulting slurry of materials is more easily digested by the micro-organisms that inhabit the goat's rumen. Think of the rumen as a fermentation vat. Once the micro-organisms have done their initial work, the goat regurgitates and re-chews the coarse materials before the micro-organisms can metabolize them to benefit the goat. This is called "chewing its cud."
The rumen tends towards a slightly acidic level (6.8 pH). When saliva mixes with the cud, "buffers" in the saliva help keep rumen acidity down. Rumen micro-organisms work best in a neutral to slightly-acidic environment. When the producer feeds the goat sugars, starches, and other rapidly-digested feeds (grain-based feeds), the rumen becomes more acidic. Introducing long fiber into the rumen helps minimize this acidic effect by the longer chewing time that is necessary to break down and digest the fibrous materials. The longer fibrous material has to be re-chewed, therefore remains in the rumen longer -- adding to this buffering effect. This nutritional balance is critical to the good health of the goat.
What exactly is roughage? In terms of processed feed, roughage is made up of materials such as cottonseed hulls, soybean hulls, oat hulls, rice hulls, and "forage products," which are defined on feed tags as high-fiber ingredients that include any type of hay, silage, or fresh forage. (This writer recommends against feeding silage to goats; however, this is the subject of another article.) Roughage values can be found in the Ingredients section of the feed tag if the state in which the feed is produced requires such disclosure.
Grinding roughage into small particles greatly reduces the "roughage effect" on the rumen. For this reason, ground and pelleted feeds such as alfalfa pellets are not roughage. While containing fiber, alfalfa pellets do not provide roughage. Alfalfa -- either pelleted or in hay form -- is high in calcium and protein and low in energy and phosphorus, so it should not be fed exclusively but rather as part of a balanced nutritional program.Since the "roughage effect" does not occur with grain-based feeds and does take place with long fiber digestion, producers should deduce from this information that goats should not be fed grain at night in cold weather but instead should be given extra grass hay to keep the rumen functioning which in turn keeps the goat warm.
How much roughage does a goat need? Acid Detergent Fiber analysis measures digestible and non-digestible forms of plant materials. Without going into the technical aspects of WHY, producers should know that an ADF level of about 28% is appropriate for goats. If the ADF is over 40%, feeding grain-based materials is essential, because the fiber is low in energy. Most feed tags do not include ADF measurements, so the producer must ask the feed company's nutritionist to supply that information. When having hay tested for nutritional values, the producer should always ask for the Acid Detergent Fiber level in the hay.
Read feed tags for Crude Fiber values. Remember that goats in non-managed situations can vary their diets by selecting a variety of plant materials that keep the rumen acidity in balance.This is not the case in managed herds or in feed-lot situations. Most processed feed is either pelleted or ground to increase digestibility or to keep the goat from selecting the items it likes and leaving the rest. The latter is called "textured" feed and is not a desirable type of feed for goats. If the Crude Fiber level is low, then additional roughage needs to be added to the goat's diet. Remember that Crude Fiber in feed needs to come from roughage items like cottonseed hulls (see above). If Crude Fiber is high and roughage is low, then the fiber will not provide the roughage effect that the rumen requires and digestive problems may well occur. .
Always transition the goat's feed sources gradually -- over a period of at least 10 to 14 days. This rule holds true for both changes in grain-based feeds and for forage/browse/pasture rotation. Pulling a goat off pasture into a pen-fed situation must be done carefully. Grain-based feeds are lower in roughage than forage/pastures, which are 100% roughage. The rumen needs time to adapt to the new feed source so that acidosis and other rumen problems do not occur. Grain is also the source of starches. Starches are high in energy but they also reduce the digestion of long fiber.