Abomasum
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The fourth, true stomach of ruminants. It is located between the omasum and the small intestine. Its function is similar to the simple stomach of non-ruminant animals. |
| Acetonemia (ketosis) |
A condition characterized by an elevated concentration of ketone bodies in body tissues and fluids. It is more common among high-producing cows in a negative energy balance. |
| Acid detergent fiber (ADF) |
A measure of cellulose and lignin in forages and feeds. It is analyzed by boiling the sample in an acid-detergent solution. ADF is highly correlated with cell wall digestibility. ADF primarily consists of cellulose, lignin, silica, insoluble crude protein and ash, which are the least digestible parts of the plant. Because ADF percentage in forages negatively relates to digestibility, it has been used to calculate energy values. ADF is one of the most common analyses made, particularly on forages. Low ADF usually is preferred because it means higher net energy. As the plant matures, ADF increases. |
| Acidosis |
A condition in which pH of the rumen drops quickly following ingestion of a large meal of grain or forage of too small particle size. Symptoms of acidosis include: off-feed problems, low milkfat test, laminitis, poor body condition, poor reproductive performance, poor production. |
| Acidotic |
A situation in which a cow is experiencing acidosis. |
| Adipose |
Another name for fat, or relating to fat. See also lipid. |
| Adjusted crude protein (ACP) |
Adjusted crude protein (ACP) is a calculated protein value corrected for heat damage. It should be used in place of crude protein to balance rations whenever ICP/CP exceeds 0.1. Most laboratories will compute and report the ACP for forages analyzed for both protein and ICP( Indigestible Crude Protein. |
| Aflatoxin |
The toxic material produced by the fungi Aspergillus flavus in feeds during storage under certain conditions of temperature and moisture. |
| Amino acids |
The building blocks of proteins. They are extensively used for milk protein synthesis, muscle synthesis and glucose synthesis in the liver (termed gluconeogenesis) of dairy cows. |
| Ammonia |
A colorless nitrogen compound produced as a degradation product of protein and nonprotein nitrogen in the rumen that can be used to synthesize bacterial protein |
| Ammonia |
A colorless pungent gas, NH3, composed of nitrogen and hydrogen; its compounds are used as fertilizers |
| Anaerobic treatment |
The treatment of animal waste by predominantly anaerobic biological action using anaerobic or facultative organisms, in the absence of air, for the purpose of reducing organic matter in wastes. |
| Anion |
A negatively charged ion. Nutritionally important anions in dry cow rations are chloride and sulfate. |
| Antibody |
A protein (modified type of blood serum) developed or synthesized by lymphoid tissue of the body in response to an antigen. Each antigen elicits production of a specific antibody. |
| Antigen |
A high molecular weight substance (usually protein) which when foreign to the bloodstream of an animal, stimulates formation of a specific antibody. |
| Ash |
The mineral matter present in feeds. It is measured by burning the sample at 500 C until all carbon is removed. The material which burns off is termed organic matter. |
| Balanced Ration |
The daily food allowance of an animal mixed to include suitable proportions of nutrients required for normal health, growth, production, and well-being. A ration containing all the dietary requirements to meet the purpose for which it is being fed. |
| Beta carotene |
The precursor of vitamin A. Supplementation with beta-carotene may improve reproductive performance, although it is generally considered to be economically infeasible. |
| Bloat |
A condition in animals characterized by distension of the reticulorumen due to gas accumulation. Often caused by grazing succulent legume pasture or excessive, chronic overconsumption of starch. |
| Body condition |
The body condition score of a dairy cow reflects the amount of subcutaneous fat that is stored. In dairy cows the range in body condition score is from 1 (thin) to 5 (fat). The optimal condition score is 3.5 with less than 1 condition score loss during early lactation. |
| Bovine somatotropin (BST) |
A complex, biologically active protein secreted by the pituitary gland. It stimulates body cell growth and milk production. It is available as a synthetically produced product for use in cattle. Sometimes called "growth hormone" or BGH. |
| Brassica |
This is a group of plants belonging to the Mustard family, Cruciferae. Includes vegetables such as Broccoli, Brussels Sprouts, Cabbage, Cauliflower, Collards, Kale, Kohlrabi, Mustard, Rape, Rutabaga and Turnip |
| Buffer |
Chemical compound that resists changes in pH with the addition (or loss) of acid or base. Commonly, buffers such as sodium bicarbonate are supplemented to diets to reduce risk of rumen acidosis (low pH). |
| Butyrate |
The four-carbon volatile fatty acid produced by bacterial fermentation in the rumen. The other major volatile fatty acids are: acetate and propionate. |
| Bypass protein |
Refers to escape protein or undegradable intake protein. The fraction of the dietary crude protein that is not digested in the rumen, but excapes intact to the lower tract. Lactating dairy cows require about 35 to 40% escape protein (as a % of crude protein). |
| Byproduct |
Secondary product of less commercial value produced along with the principal product. For example, corn gluten feed is a byproduct of corn milling to produce sweeteners. The preferred term is coproduct because it implies that the secondary product is also valuable. |
| Calorie |
Unit of heat energy; amount of heat needed to raise the temperature of one gram of water from 14.5 to 15.5 C at a pressure of one atmosphere. |
| Cannula |
A plastic device introduced surgically into different body organs to collect samples. A common cannula is placed in the rumen to collect fluid samples for pH and volatile fatty acid analysis. |
| Carbohydrates |
Includes the sugars, starch, cellulose, gums and related substances. Carbohydrates are the largest component in the dairy cow diet and contribute 60 to 70 percent of the net energy used for milk production. Their abbreviation, CHO, indicates that they contain carbon, hydrogen, and oxygen. |
| Casein |
A major milk protein. |
| Cation |
A positively charged ion. Used in calculation of dietary cation-anion balance. A negative DCAD ration helps reduce the risk of hypocalcemia when fed for about two weeks prior to parturition. |
| Cellulose |
The most abundant plant constituent comprised of glucose molecules linked in beta 1-4 linkages. |
| Coliform bacteria |
Bacteria from the intestinal tract of warm blooded animals. Presence is considered indicative of fecal contamination. |
| Complete ration |
A blend of all feedstuffs (forages and grains) in one feed. A complete ration fits well into mechanized feeding and the use of computers to formulate least-cost rations. Sometimes called total mixed ration or TMR. |
| Concentrate |
A broad classification of food stuffs that are high in energy and low in crude fiber (less than 18 percent). Included are cereal grains, soybean oil meal, cottonseed meal, and by-products of the milling industry such as corn gluten and wheat bran. A concentrate may be low or rich in protein. |
| Crude fiber |
In proximate analysis it is the presumed analysis for fiber. It is very inaccurate and no longer recommended. |
| Crude Protein Crude Protein (CP) |
measures both true protein and non-protein nitrogen. Protein supplements often are expensive. Because CP tests are relatively inexpensive, they are justified for the benefits received. However, crude protein is a poor predictor of the productive energy value of a feed. (Nitrogen content *6.25) = CP |
| Digestible dry matter (DDM) |
Digestible dry matter (DDM) estimates the percentage of forage that is digestible. It is calculated from ADF using the equation: DDM (%) = 88.9 - [ADF (%) x 0.779) |
| Dry matter (DM) |
Dry matter (DM) is the percentage of feed that is not water. In contrast, moisture is a measure of the amount of water in the feed on an "as is" or "as fed" basis, and is important because moisture dilutes the concentration of all nutrients. Convert nutrient values to a dry basis to formulate rations. Then convert feeds in the ration obtained from the dry basis to an "as fed" basis to obtain amounts to feed or mix in the ration. |
| Forestripping |
Expressing streams of milk from the teat prior to machine milking to determine visual quality and to stimulate "letdown". |
| Grass tetany |
A magnesium deficiency in cattle characterized by hyperirritability, muscular spasms of legs, and convulsions. |
| Heat Damaged Protein |
Acid detergent insoluble nitrogen (ADIN), unavailable nitrogen, and heat-damaged protein all refer to nitrogen (or CP) that has become chemically linked to carbohydrates to form an indigestible compound. The overheating that causes this reaction is most common in silage stored at less than 65 percent moisture and in hay bales or stacks that contain more than 20 percent moisture. Heat-damaged feeds often have an amber, tobacco brown, or charcoal discoloration and a carmelized odor, but sometimes no discoloration occurs. Some Indigestible Crude Protein normally is present in feeds. When the ICP/CP ratio is above 0.1, excessive heating probably has occurred, causing reduced protein digestibility. When this occurs, crude protein values should be adjusted downward to more accurately balance rations for protein. |
| Ketosis |
See acetonemia. |
| Laminitis |
Inflammation of the laminae with resulting sore feet and ulceration of the sole. Laminitis is usually caused by excessive grain feeding and is made worse by having cows on concrete, poor stall comfort, and wet conditions. |
| Leaf:stem ratio |
The weight ratio of leaf and stem tissue in a legume plant such as alfalfa. Quality of a forage declines as the leaf to stem ratio decreases (more stems) because leaves contain highly digestible protein and stems contain less digestible fiber.
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| Legume |
Clovers, alfalfa, and similar crops that can absorb nitrogen directly from the atmosphere through action of bacteria that live in their roots and use it as a nutrient for growth. |
| Minerals |
Inorganic elements needed for growth and maintenance of bone, osmotic balance, muscle and nerve function, body enzymes, hormones and body cells. When calcium and phosphorus supplements are needed, or when control of their levels is important, periodically analyze feeds for tehse elements. An example is the control of calcium and phosphrous levels in the dry cow ration of a dairy herd plagued by milk fever. Trace minerals commonly are added as insurance against deficiencies. Because of high cost, trace-mineral analyses are not recommended routinely. However, trace minerals should be checked periodically, or when a specific case suggests the need. |
| Near Infrared Reflectance Spectroscopy (NIR) |
Near infrared reflectance spectroscopy is a rapid method for estimating the nutrient content of a feed or forage by interpreting the patterns of reflected infrared light from the sample. Most commonly, forage testing labs use NIR to predict the crude protein, neutral detergent fiber, and acid detergent fiber content of a forage. |
| NEL |
The most commonly used term for energy content of a feed or diet for lactating dairy cows. The NEL requirement for lactating dairy cows ranges from 0.73 to 0.80 Mcal of net energy for lactation per pound of ration dry matter.
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| Net Energy (NE) |
Net energy (NE) is the energy available to an animal in a feed after removing the energy lost as feces, urine, gas and heat produced during digestion and metabolism. NE is the most useful energy estimate for formulating rations. The net energy value of a feed depends on whether the feed is used for maintenance (NEm), producing weight gain (Neg), or milk production (NEL). |
| Neutral detergent fiber (NDF) |
Measures the cell wall - cellulose, hemicellulose, and lignin. NDF is highly correlated with intake. Dairy cows require a minimum amount of NDF in the diet of adequate particle length to avoid acidosis. Neutral detergent fiber (NDF) measures the structural part of the plant, the plant cell wall. NDF gives "bulk" or "fill" to the diet, and as a result limits intake. Because NDF can be used to predict intake, it is one of the most valuable analyses to have conducted on forages for dairy rations and can be useful for beef rations that rely on forages primarily. Low NDF usually is desired. As maturity of the plant at harvest increases, cell wall content of the plant increase, and NDF increases. |
| Relative Feed Value (RFV) |
RFV combines digestibility and intake into one number for a quick, easy, effective way to evaluate the quality of hays or haylages. It is used primarily with legume or legume/grass forages. Relative feed value is most valuable for animals using high-forage rations such as dairy cows and growing animals, because the RFV provides an index to rank a forage according to its digestible energy intake potential. RFV also has been used widely in hay marketing. |
| Rumination |
Another word for cud chewing. During rumination saliva is produced which helps to buffer the rumen and guard against rumen acidosis. A lactating dairy cow should ruminate about 7 to 8 hours per day. |
| Saturated fatty acids |
A completely hydrogenated fat, each carbon atom is associated with the maximum number of hydrogen; there are not double bonds. Saturated fatty acids are solid at room temperature. Tallow is a source of saturated fat. Saturated fats tend to have less detrimental effects on rumen fermentation than unsaturated fats. |