DS 825 Ruminant Nutrition Physiology DS 825 Ruminant Nutrition Physiology Glossary

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

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).

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).

Single-cell organisms living either independently or in close association with other living organisms. Often referred to as microbes or microorganisms because of their microscopic size. Some bacteria are beneficial, but others cause infectious diseases.

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 unit of heat that can be used to measure the amount of energy in a feed or a ration. A calorie is the amount heat required to raise the temperature of 1 gram of water from 14.5 ° centigrade to 15.5 ° centigrade.

(see Parturition)

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

The part of the metabolism in which metabolites are oxidized for the production of work and heat.

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

Fibrous structure that provides rigidity to the plant. The cell wall is composed of digestible fibrous carbohydrates (cellulose; hemicellulose and pectin) and an indigestible phenolic compounds (e.g., lignin and tannin).

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.

A plant in the grass family (gramineae), the seeds (i.e., grain) of which are used for human and animal food (e.g., maize, rice and wheat).

Glumes, husk, or other seed coverings, together with the plant parts, separated from seeds in threshing or processing.

To crush or grind (food) in the mouth by continued action of the teeth with the help of the tongue (syn to masticate).

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

The central core of an ear of corn.

The thick and yellowish secretion collected from the mammary gland at the first milking after calving. The colostrum is low in lactose but normally high in total solid (24%). It is rich in fat, proteins and antibodies that help the new born calf to fight infectious diseases. The secretion collected from the second to the eighth milking is referred to as "transition milk" because of it intermediate composition between colostrum and whole milk.

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 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.

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 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.

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.

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

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.

A sweet sugar occurring in many fruits and honey.

The stomach and the intestine as a functional unit.

A six carbon sugar which is the building block of starch and cellulose. Glucose is rapidly fermented into volatile fatty acids by ruminal bacteria.

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

A type of carbohydrate similar to cellulose except that it contain not only glucose but also other 6 carbon sugars and also 5 carbon sugars.

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

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

One thousand calories.

A disaccharide composed of a unit of glucose and a unit of galactose. Also known as milk sugar, lactose is produced commercially from whey.

Any compound that helps to prevent the accumulation of abnormal or excessive amounts of fat in the liver, control blood sugar levels, and enhance fat and carbohydrate metabolism.

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).

Abbreviation for Megacalorie.

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.

One million calories.

Animal or vegetal organism of microscopic dimension (syn Microorganism).

(see Microbe).

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

A cow that has given birth more than once.

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).

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.

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.

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.

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.

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

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.

1. A young cow that is pregnant for the first time. 2. A cow that has given birth once.

The part of a plant embryo that develops into the primary root.

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 second stomach of a ruminant in which folds of the mucous membrane form hexagonal cells. Also called honeycomb stomach. The reticulum is joined to the omasum by the reticulo-omasal orifice.

A deficiency disease resulting from a lack of vitamin D or lack of sunshine exposure, characterized by defective bone growth.

see diarrhea.

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.

(a) Any of the cells of a plant or animal except the reproductive cells. (b) Milk somatic cells are primarily leukocytes (white blood cells) and some epithelial cells shed from the lining of the mammary gland. The leukocytes are derived from blood and consist of macrophages, lymphocytes, and polymorphonuclear cells, primarily neutrophils (PMN). Normal milk does contain somatic cells, and the concentration of these cells is almost always less than 100,000 cells/ml in milk from uninfected/uninflamed mammary quarters.

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

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.

Carbohydrate found chiefly in seeds, fruits, tubers, roots, an stem pith of plants notably in corn, potatoes, wheat and rice. Warm season grasses (C4 plants) store starch in chloroplasts in leaf tissue. C4 grasses such as Bermuda Paspalum or Rhodes grasses grown under heat stress may contain considerable starch in leafy tissue. Nutritionally, it is referred to as non-structural carbohydrate as opposed to the carbohydrate found in the neutral detergent fiber of the plant.

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

(see Fibrous carbohydrate).

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.

Narrowly defined, SI refers to increase food production from existing farmland in ways that place far less pressure on the environment and that do not undermine our capacity to continue producing food in the future. However, Garnett et al. (2013) added the following four premises underlying SI: (a) The need to increase production; (b) Increase production must be met through higher yields because increasing the area of land in agriculture carries major environmental costs; (c) Food security requires as much attention to increasing environmental sustainability as to raising productivity; and (d) SI denotes a goal but does not specify a priori how it should be attained or which agricultural techniques to deploy.

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.

A fat composed of three fatty acids and glycerol.

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.

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.