Ruminant Food

From Dr. Marie Bulgin 

Ruminant animals are designed to eat forages. They can meet all of their energy needs to grow, reproduce and stay healthy with feed that consist of 100% good quality roughage (alfalfa, grass-hay or good pasture). 

However, supplementation during certain periods. with concentrates (whole corn, barley, wheat, oats or other high carbohydrate feeds) may be in order. Ruminant animals. have a stomach that is composed of four compartments - reticulum, rumen, omasum and abomasum. The rumen serves as a large fermentation vat in which bacteria and protozoa actually digest the cellulose (otherwise known as fiber) in the forage which mammals can not do. 

The ruminant adds saliva to this material as it chews and swallows and then rechews when it later regurgitates (belches up) this material. This process is called rumination. (People say the animal is chewing its cud.) The purpose of the saliva is to add bicarbonate molecules to the rumen which helps control the acidity of the fermentation that goes on in the rumen. 

Once the fiber is partially digested and the particle size of the material is right, the feed goes through the other stomachs including the abomesum, which is actually the true stomach, just like the stomach of other mammals. 

There are two types of forages commonly fed to ruminants; 

legumes and 

grasses. 

Alfalfa, clovers, peas and beans are all legumes. These plants provide quite a bit more protein than other grasses and plants. Thus, for hay, at least, alfalfa is preferred because it is considered to be a higher quality feed. 

Protein is especially important in growing animals since protein can be likened to bricks, building blocks used to build tissue and bone. When purchasing feeds, protein content usually determines price. Even so alfalfa hay is generally the cheapest source of protein. The only draw back to the protein in alfalfa is that it is not readily available to the young ruminant which really isn't a ruminant at all until it develops the rumen organisms it needs to digest cellulose. 

For the calf, this would be about 6-7 months of age, for the kid and lamb it would be 60-90 days of age. Milk protein (100% digestible) is definitely the highest quality of protein that can be fed to young stock, and soy protein becomes beneficial as the youngster gets a little older, 60 days for calves, 30 days for the smaller ruminants. TDN which stands for total digestible nutrients is a measure of the energy present in the feed and is particularly important when trying to fatten animals or late in pregnancy as it protects against "ketosis" and "pregnancy toxemia,"- higher the value the better. Energy can be likened to gasoline. 

It runs the heart, lungs, brain, legs, etc. When the amount of energy is greater than the needs of the body, it is stored as fat. Thus, energy and protein need to be balanced according to the individual. A growing animal, a pregnant animal or a lactating animal all need more protein than an adult who has weaned her offspring and isn't pregnant. 

A working animal (cutting horse, breeding bull or sheep dog) all need a lot of energy.—And of course, show animals and feedlot animals which should be fat, need a lot of energy. Most forages, including alfalfa hay, have TDNs of around 50-55%. 

Grains and seeds on the other hand tend to have TDNs of 75-85%. Thus, when a high energy diet is required, one of the grains, often corn, is added to the diet. The major problem feeding grains are their propensity for producing acid when fermented by the rumen organisms. When the amount of grain is relatively small, the bicarbonate in the saliva will buffer the acid produced and all is well. However, if the animal is suddenly exposed to a lot of grain all at once, the acid produced will overwhelm the buffering capacity of the saliva and the animal becomes sick or acidotic. 

This is a serious condition requiring veterinary help and has killed many an animal. However, grain can be increased by small increments over time and the rumen organisms will adapt and not produce so much acid. 

Other nutrients besides protein and energy, (there are a total of 5) that need consideration are minerals, vitamins and water. 

Minerals are divided into macro minerals which are measured in grams or ozs and microminerals, measured in parts per million (ppm). Calcium (Ca) and phosphorus (P) are macrominerals and are very important for the production of bone and milk. 

Alfalfa hay has a calcium content of 1.4% but only 0.23%. phosphorus so it is a good supplier of calcium. Grains, on the other hand, have calcium contents of 0.1% while the phosphorus content is 0.4%. So, grains are better suppliers of P. For the best utilization of both calcium and phosphorus the over all Ca:P ratio should be 2.5 to 1. 

Keeping these minerals balanced can prevent urolithiasis (stones) in steers, bulls, wethers, rams and bucks. A good trace mineral salt generally supplies all of the needed microminerals although microminerals needs differ according to the species of animals. Almost all animals need more copper than sheep. 

It is very easy to give sheep too much copper. Make sure that there is no added copper in a trace mineral salt that is going to be fed to sheep. All animals need selenium. Selenium is deficient in many parts of the country. In those cases animal owners should make sure there is at least 90 ppm of selenium in the mix. 

Two important vitamin needs are Vitamin A and Vitamin D. Vitamin A is essential for keeping the skin, hooves and interior body linings in good repair. It is needed in larger amounts by young growing animals, lactating and pregnant animals. It can be supplied by any nice green forage and green leafy hay that was put up within the last year. 

Vitamin A is stored in the liver and animals on pasture during the summer usually store enough to make it through the winter, even if feed is low in vitamin A. Vitamin D is needed for the absorption of calcium and phosphorus from the intestine and for the building and repair of bones. The action of sunlight on the skin of animals can convert certain compounds in the skin into vitamin D. 

During the summer when animals are outside in the sun, they will make all the vitamin D they need. When animals are kept inside most of the time, or they live in rainy cloudy conditions (western Oregon for example), vitamin D should be supplemented. 

Nice green leafy hay that has been sun cured is also high in vitamin D. Vitamin E and selenium are co-workers. Together they are important in the production of immunity against diseases, certain enzymes and the integrity of muscle and red blood cells. Deficiencies of these two cause poor growth, poor health and in severe cases, white muscle disease. Vitamin E is also high in green leafy plants and hays, but is not stored in the body. If poor quality hay is being used during the winter, vitamin E should be supplemented. 

Water makes up the fifth essential nutrient. Adequate clean water should always be available. Ruminants require large amounts of water daily to keep the contents of their rumens in a liquid phase. Otherwise, the bacteria can not optimally mix with the feed. As a matter of fact, when water is restricted, ruminants will restrict the amount of dry matter they take in. Thus, feed efficiency and gain will be markedly affected. 

Lack of water also encourages the formation of bladder stones in the male. Alfalfa and corn make up the most common ruminant diets, although any forage and any grain can be substituted depending on availability and price. 

Field or dent corn: is commonly fed whole to small ruminant as they are more apt to chew their feed than cattle. Cattle which tend to swallow their food whole, do not digest whole grain well and they pass through in the manure. Yellow dent corn is dried in the field, creating a "dent" at the top of the kernel. 

About 90% of it is used for animal feed as it has a very thick outer skin that doesn't soften much even if you cook it for hours. Bovatec, a coccidiostat, limestone to supply calcium, vitamin A, D, or E, thiamine, minerals, salt, bicarbonate, antibloat compounds, antibiotics or other supplementation may also be included in diets depending on the ratio of forage to grain and the current disease problems being experience by the animals.