Dairynutrient 414 Ruminant Nutrition Dairynutrient 414 Ruminant Nutrition Glossary

The degree with which a measurement matches the actual, true or target value (see also Precision).

The growth of body parts at different rates, resulting in a change of body proportions.

Protein released in the blood that is generated in reaction to a foreign protein (antigen) that has entered the body. Antibodies produce immunity against certain micro-organisms or their toxins.

Any of a group of chemical compounds, including sugars, starches, and cellulose, containing only carbon, hydrogen, and oxygen, with a ratio of hydrogen to oxygen of 2:1.

A substance present in small amounts that increases the rate of chemical or biochemical reactions without being consumed in the process.

A measure of the concentration of matter per unit of volume (e.g., g/l or kg/m3)

A measure of the proportion of a feed that is digestible. The digestibility of a nutrient is often measured as the difference between the amount of nutrient ingested minus the amount of nutrient excreted in the feces, expressed as a percentage of the nutrient ingested: 100 x (intake - excreted)/intake.

A non-lactating cow. The dry period is the time between lactation, when the cow is not secreting milk.

That part of the feed which is not water. It is usually determined by the residual weight of a sample placed for a period of time in a drying oven that removes the water from the sample. Usually, the dry matter content of a feed is expressed as a percentage. For example, an hay of 85% dry matter contains 85 g of dry matter for each 100 g of fresh feed.

A method of expressing the concentration of a nutrient in a feed. For example, a feed containing 12% crude protein on a dry matter basis contains 12 g of protein for each 100 g of feed dry matter

Quantity of dry matter ingested by a cow in a 24 h period. For example, a cow eating 18 kg of grass silage of 33% of dry matter ingest 18 x 0.33 = 6 kg of grass silage dry matter.

An organism, animal or vegetal, at its early stage of development.

A measure of the concentration of energy in a feed or a ration usually expressed as a unit of energy (megacalorie or megajoule) per lb of dry matter or per kg of dry matter.

Usually a protein that accelerates a biochemical reaction at body temperature, without being used up in the process (see also catalyst).

A chain of carbon terminated by an acid (carboxyl) group (COOH). Fatty acids with less than 4 carbon units are volatile. Fatty acids with 5 to 20 carbon units are usually found as part of fats and oils.

Nutrient of low energy density present in large quantities in forages. Fiber is composed of structural carbohydrates (cellulose and hemicellulose) and phenolic compounds. Fiber is important for dairy cows because they stimulate rumination and promote a healthy rumen environment for bacterial growth. However, in large amounts in the diet, fiber may fill the rumen, limit intake of energy and constrain milk production.

Hemicellulose and cellulose that can be quantify by the neutral detergent fiber procedure.

A three carbon sugar which form the backbone of triglycerides and other fats.

A sun-dried forage. A method of preserving forage by cutting the plant and letting it dry in the sun.

Strong acid secreted by the abomasum that breaks down chemical bounds and thus contributes to the digestion of feeds.

Decomposition of a chemical compound by reaction with water.

One of the 20 amino acids constituting the building blocks of proteins. Animals have a high requirement for lysine, and it is often deficient in proteins of plants.

Morbidity is an incidence of ill health. It is measured in various ways, often by the probability that a randomly selected individual in a population at some date and location would become seriously ill in some period of time. Contrast to mortality.

is incidence of death in a population. It is measured in various ways, often by the probability that a randomly selected individual in a population at some date and location would die in some period of time. Contrast to morbidity.

The amount of energy in a feed which is available for milk production and body maintenance. Feeds generally are similar in total energy content but vary widely in the proportion of the total energy which is available for maintenance and milk production. The remainder of the energy in the feed is lost in the feces urine, gas belched form the rumen and excess heat production by the cow. In the cow, it takes 0.74 Mcal NEl to produce 1 kg of milk containing 4% fat and the net energy content of most feed range from 0.9 to 2.2 Mcal NEl per kg dry matter.

Carbohydrates that are not part of the neutral detergent fiber, but generally accumulate in the plant as energy reserve (e.g., starch). These carbohydrates usually are more rapidly and more completely digested than the fibrous carbohydrates (syn Non-structural carbohydrate).

(see non-fiber carbohydrate).

The taste and flavor property of a feedstuffs that make them more or less acceptable to be eaten.

The process by which the chlorophyll of plants converts carbon dioxide and water into simple sugars with the simultaneous release of oxygen.

Having more than one digestive cavity; Having a stomach divided into different chambers (e.g., ruminants).

The passage connecting the stomach (abomasum) to the duodenum.

The probability that a test is positive, given that the animal has the disease (See also specificity).

The probability that a test is negative, given that the animal does not have the disease (see also sensitivity).

(see Fibrous carbohydrate).

The intimate living together of two dissimilar organism in any of various mutually beneficial relationships.

A two-lobed gland located in the throat and secreting the hormone thyroxin, which regulates the iodine metabolism in the body.

A fat composed of three fatty acids and glycerol.

Digestive enzyme secreted by the pancreas and responsible for the break down of peptide bonds of proteins. Some plants contain a trypsin inhibitor that prevent trypsin from functioning properly.

Particles that carry cholesterol and fat throughout the bloodstream. These particles are released from the liver into the bloodstream. They are similar to chylomicrons which originate from the gut because they both carry cholesterol and triglycerides which are gradually released in the bloodstream to be absorbed by body cells along the way. In the process of losing triglycerides, the VLDLs grow smaller and turn into LDLs (Low Density Lipoprotein) which have lost all their triglycerides.

Products of fermentation of carbohydrates (and some amino acids) by the rumen microorganisms. Acetic acid, propionic acid and butyric acid are the primary volatile fatty acids which are absorbed through the rumen wall and used as an energy source by the cow.

The number of days between calving and first attempt to breed a cow. A typical voluntary waiting period is 45 days. However, it may varies from less than 40 to 80 days depending on farmer’s preference and reproductive protocol in place on the farm.

The liquid fraction that remains after the separation of curd in cheese making. Its main food use is in the preparation of whey cheese, whey drinks and fermented whey drinks. The main industrial uses are in the manufacture of lactose, whey paste and dried whey.