Dairynutrient 414 Ruminant Nutrition Dairynutrient 414 Ruminant Nutrition Glossary

Condition characterized by a low rumen pH (below 6). The normal rumen function are impeded usually because too much concentrates were fed.

Allometric equations take the general form Y = aM^b, where Y is some biological variable, M is a measure of body size, and b is some scaling exponent. See West et al. (2012) for more details.

One of the 20 building block units of protein. Amino acids contain both an amino group (NH₂) and an acid or carboxyl group (COOH).

A pungent gas. Ammonia is extensively used to manufacture fertilizers and nitrogen containing compounds. Also, ammonia is the end-product of protein degradation by ruminal bacteria.

The part of the metabolism in which metabolites are used in the growth and repair of body tissues.

A disease due to a deficiency in red blood cells or in hemoglobin that carries oxygen in the blood.

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.

Reproductive procedure by which semen previously collected from sires, packaged in “straws” and frozen in liquid nitrogen is thawed and manually deposited in the uterus of a cow in estrus, in the hope of conception. Artificial insemination is a technology that allows for genetic improvement based on selection and use of superior sires.(see also Timed Artificial Insemination).

A measure of protein quality. The percentage of protein in a feed which is not lost in the urine or the feces of the animal. Biological value is a reflection of the balance of amino acids available to the animal after digestion and absorption.

A bull used for natural mating after mutiple artificial insemination attempts have failed to establish pregnancy.

A gas produced by combustion or oxidation of organic matter. Carbon dioxide is also produced in large quantities during ruminal fermentation.

A polymer - long chain- of glucose units. Cellulose is the most abundant organic matter in the world. It is a major component of plant cell wall. Ruminant can use cellulose as an energy source because of fermentation by bacteria in the rumen.

Involving or based on direct observation of the patient (a clinical diagnosis). A clinical disease is a disease that can be diagnosed by examination because of signs / symptoms of discomfort, anomalies of the normal state

Feedstuffs usually rich in energy and coming from the part of the plant that accumulate nutrient reserves for an embryo (fruits, nuts, seeds and grains). The word concentrate is also used to refer to the mixture of minerals and other supplements used to feed dairy cattle.

Base of the stem where roots arise

A measure of the amount of protein in a feed determined as the amount of nitrogen multiplied by 6.25. The factor 6.25 is the average grams of protein that contains 1 gram of nitrogen. The word "crude" refers to the fact that not all nitrogen in most feed is exclusively in the form of protein. Because most feeds contain non-protein nitrogen (NPN), crude protein generally overestimates the actual protein content of a feed.

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.

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.

First part of the small intestine. The secretions of the liver and pancreas are discharged into the duodenum.

The seed-bearing part of a cereal plant. An ear of corn is composed of the grains, the cob, but not the husk, which are removed during harvesting.

The nutritive tissue of a plant seed, surrounding and absorbed by the embryo.

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.

Method used to select cows which are eligible for hormonal treatment (such as Ovsynch). For example, the enrollment plan may be defined by the voluntary waiting period or a negative pregnancy check.

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

The removal of a material from an organism. Example of material excreted include tears, urine, feces, sweat and carbon dioxide. Examples of an organism's organs involved in excretion include eyes, bladder, rectum, skins and lungs.

An animal that tests as negative but who is actually positive. The percent of false negative for a test can be calculated as 100 – SENSITIVITY.

The transformation of carbohydrates in absence of oxygen by rumen micro flora that produces volatile fatty acids such as acetic acid, propionic acid and butyric acid, and gases such as carbon dioxide (CO2) and methane (CH4).

Usually expressed as two percentages. The percentage of ration dry matter that is made up of forage and the percentage of ration dry matter that is composed of concentrates. The two total 100. For example a 50:50 forage to concentrate ratio means that a cow eating 20 kg of dry matter of that ration would eat 10 kg of concentrate dry matter and 10 kg of forage dry matter.

Is a polymer of fructose molecules generally, but not always, found as "carbohydrate storage in cool season grasses (C3 plants). Tall fescue and perennial ryegrass tend to have the highest levels of fructans when compared to other grasses under the same conditions. Fructan is stored in vacuoles inside cells throughout the plant where it is readily available as needed. In some species of grass the lower part of the stem is a carbohydrate storage organ.

The stomach and the intestine as a functional unit.

To begin to or to cause to grow (syn to sprout.

Seed from cereal plants.

Family of plants including rye grass, fescue, brome, timothy and other herbaceous plants often referred to as grass. Cereals are gramineous plants but often, they are considered apart from the grass because they are cropped for the grain rather than the vegetative parts of the plant.

An iron rich protein found in the red blood cells which function as a carrier of oxygen and carbon dioxide.

A strong desire for food.

The arrangement of flowers on a stalk that characterizes a plant species.

A unit of measurement of the amount of biologically active vitamin in a feed or required in a diet.

The whole grain of a cereal. The meats of nuts and drupes (single stoned fruits).

Inflammation of the sensitive vascular tissue of the hoof.

Indigestible phenolic compound which, as the plant matures, is deposited in the cell wall and is responsible for the decrease in digestibility of the cell wall carbohydrates.

A sedimentary rock, chiefly calcium carbonate (CaCO3), containing variable amounts of magnesium. It is used as building stone, but also as a source of calcium in ration of animals.

Protein coated packages that transport fats in the bloodstream

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.

A diet that supplies the nutrients required to maintain vital functions (heart beat, respiration) and assure a constant body temperature.

A physiological state in which the animal is neither gaining nor losing weight, performing work or expending nutrients for any type of production.

To grind or crush (food) with or as if with the teeth to prepare it for swallowing and digestion (Syn: Chew).

The mean of a normal distribution is the most likely value (the value that has the lowest probability of being "wrong"). The mean is the best measure of central tendency of a normal distribution. With a normal distribution, approximately one-half of the samples have values lower than the mean and one-half have values higher than the mean.

In ruminant nutrion, metabolizable protein, often abbreviated MP, is the amount of digestible protein that reach the small intestine, which is the source of amino acids absorbed into the blood. The three main sources of MP include rumen undegraded protein (the dietary protein fraction that has not been degraded in the rumen), the microbial (bacterial) protein synthesized in the rumen from the fermentation process, and the endogenous protein (intestinal digestive enzymes and sloughed cells from the gastro-intestinal tract). The latter source is minimal.

(see Microbe).

1. The inorganic chemical elements (e.g., calcium phosphorus magnesium) determined by combusting a sample in a furnace and weighing the mineral residue. 2. Minerals play major roles in numerous metabolic processes. (syn Ash).

Having one digestive cavity (i.e., one stomach).

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.

A measure of the amount of cell wall in a feed determined by a laboratory procedure. Neutral detergent fiber includes cellulose, hemicellulose and lignin.

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).

Nitrogen that comes from a source other than protein but may be used by a ruminant in the building of protein. NPN sources include compounds such as urea and anhydrous ammonia, which are used in feed formulations for ruminant only.

(see non-fiber carbohydrate).

The chemical substances found in feeds that can be used, and are necessary, for the maintenance, production and health of the animal. The main classes of nutrients are carbohydrates, fats, proteins, minerals, vitamins and water.

This refers to meeting the animal's need of the various classes of nutrients for maintenance, growth, reproduction, lactation and physical work.

Compounds composed of carbon oxygen hydrogen and nitrogen. All living organisms are composed primarily of organic matter. Fats, carbohydrates and proteins are examples of organic compounds.

Release of an oocyte (i.e., egg) from a mature follicle. In dairy cows, ovulation occurs 24 to 32 hours after the first standing event of behavioral estrous. Similarly, ovulation occurs 24 to 32 hours after an injection of Gonadotropin Releasing Hormone; (Gn-RH) administered in the presence of a dominant follicle.

An irregularly shaped gland that secretes pancreatic juice into the duodenum and produces insulin that is released into the blood.

1. Small projections on the inner surface of the rumen and the reticulum wall that increase the surface area of absorption of volatile fatty acids and other end-products of bacterial fermentation.

Protuberances at the surface of the tongue that detect the taste of a feed.

The act of giving birth (Syn Calving).

A digestive enzyme found in the gastric juice that breaks down proteins into peptides.

Organic substance in which the carbon atoms are linked together in a ring structure (also called aromatic structure). Lignin is an example of phenolic compound.

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

An organ that develops during pregnancy in female mammals. It lines the uterus and partially envelopes the fetus, to which it is attached by the umbilical cord. Following birth, the placenta, then called the after birth, is normally expelled. The retention of the placenta usually leads to bacterial infection of the uterus called metritis.

The set of individuals, items, or data from which a statistical sample is taken. In statistical terms, a population is defined as a larger set from which samples are obtained.

1. The degree with which a measurement is reproducible, that is, yielding similar results when repeated (see also Accuracy).
2. the number of significant digits to which a value has been reliably measured.

Having one or several fetus growing inside the uterus.

A chain or multiple chains of amino acids (more than 100). Proteins are composed of carbon, oxygen, hydrogen nitrogen (16% on average,found in the form of amino acids) and often sulfur. Proteins have important functions in the body. They are present in all plants and animals and they are essential in the ration of animals. See also Crude Protein.

Most primitive form of life in the animal kingdom composed of only one microscopic cell.

Reversal of the natural direction in which contents flow through a tube or a cavity in the body. During rumination, rumen contents are regurgitated through the esophagus in the mouth for further mastication.

The first two stomachs of a ruminant comprised of the reticulum and the rumen. A microbial population lives in the rumen and enable the cow to digest dietary fiber. The digesta in the rumen and the reticulum is being exchanged once about every 50 to 60 seconds under the influence of a rhythmic cycle of contraction which also results in passage of some digesta from the reticulum into the omasum through the reticulo-omasal orifice.

The large first compartment of the stomach of a ruminant from which food is regurgitated and in which cellulose in broken down by the action of the symbiotic bacterial, protozoa, and fungal populations.

The movement of a material from one place to another. Secretion is often required to move a material to the place where it can be excreted. Examples of materials secreted include all materials excreted (see Excretion above), plus enzymes, hormones and saliva. The organs that play a role in secretion include all those involved in excretion, plus the digestive glands like salivary glands, pancreas, liver and gallbladder and endocrine glands like the thyroid gland, pituitary gland, and ovaries and testes.

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

A cavity formed by a bending or curving; a dilated passage.

A ring-like muscle that maintains constriction of a bodily passage or orifice and opens upon relaxation.

Standard deviation (SD) is a measure of the dispersion of a set of data from its mean. If the data points are further from the mean, there is higher deviation within the data set. The SD shares the same unit as the mean. The SD is calculated as the square root of variance by determining the variation between each data point relative to the mean. The symbol for standard deviation is σ (the Greek letter sigma). Approximately, in a normal distribution,
38% of all observations are within ± 0.5 SD units of the mean;
68% of all observations are within ± 1 SD units of the mean;
95% of all observations are within ± 2 SD units of the mean;
99% of all observations are within ± 3 SDunits of the mean.

A calf born dead or that dies within 48 hours of birth.

Without clinical manifestations; said of the early stages or a very mild form of a disease, e.g. subclinical disease, infection, parasitism, or when a disease is detectable by biological tests but not by a clinical examination.

Highly complex phenolic compounds in plants that may play a role of defense again microorganisms and possible predators (the herbivores). Tannin binds and reduces the availability of proteins and carbohydrates to ruminal microbes.

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

Method of AI breeding in which the timing of artificial insemination (AI) is based on a hormonal protocol that synchronizes the timing of ovulation. This is in contrast to timing insemination based on direct or indirect detection of estrous behavior. Hormonal protocols for Timed AI were developed in 1995 and have been widely adopted by dairy producers for reproductive management.

Mixture of the forages, concentrates, minerals and vitamin supplements of a ration. The total mixed ration has the advantage of offering a balanced ration at each meal rather than on a 24 h basis.

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.

Usually refers to feeding insufficient energy.

Fat containing fatty acids that can accept hydrogen atoms to saturate their structure (e.g., oleic, linoleic, linolenic and arachidonic acids).

A nitrogen-containing organic compound found in urine and other body fluids. Urea is synthesized from ammonia and carbon dioxide. Urea can be used as fertilizer or as a source of nitrogen in the ration of ruminants.

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.

Complex organic substances occurring naturally in plants and animal tissue and essential in small amounts for the proper functioning of numerous metabolic processes.

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.