DS 825 Ruminant Nutrition Physiology DS 825 Ruminant Nutrition Physiology Glossary

The fourth digestive chamber of the digestive system of most ruminants. The abomasum is located after the forestomachs (rumen, reticulum and omasum) and before the first segment of the small intestine (i.e., the duodenum); It is sometimes referred to as the "true" stomach because of its acid-secreting ability, which is found in most other mammalian species.

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

A latin word that means "to one's pleasure." In nutrition, ad libitum (abbreviated "ad Lib") refers to feeding management in which animals are fed without restriction. Cows are usually considered fed ad libitum when the refusals (orts) amount to approximately 5 to 10% of what has been offered the day before.

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.

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

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.

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).

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

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.

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.

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

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

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

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).

Membranous tissue, usually in a single layer, composed of closely arranged cells separated by very little intercellular substance. The epithelium forms the lining of the respiratory, intestinal, and urinary tracts and the outer surface of the body.

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).

the embryo of a plant present in the seed.

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

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.

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.

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

Inflammation of the sensitive vascular tissue of the hoof.

A plant of the family leguminosae which bears a pod that splits into two valves with the seed attached to lower edge of one of the valves (examples: pea, bean, clover, alfalfa, lespedeza). Also, legumes are characterized by the nodules on their roots that allow these plants to use atmospheric nitrogen reducing the need for nitrogen fertilizer and improving soil fertility.

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.

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.

A class of vertebrate animals distinguished by self-regulating body temperature, hair, and in the female (a) milk producing gland(s).

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

An infammation of the udder (often caused by a microbial infection) resulting in pain and the secretion of milk with a high count of white blood cells (referred to as somatic cell count).

Abbreviation for Megacalorie.

1. The episodes of feed ingestion throughout the day.
2. The edible seed or other edible part of a grain, coarsely ground (as opposed to flour which is finely ground).

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.

Refers to all of the changes that nutrients undergo after they are absorbed from the digestive tract. Metabolism is divided into anabolism and catabolism.

A product of metabolism of nutrients.

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.

Inflammation of the uterus.

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

(see Microbe).

Condition that occurs immediately or within the first day after calving. The cow has cold ears and a dry muzzle. This condition is due to a calcium imbalance. As opposed to what the name implies, there is no "fever", but rather a paralysis of the limbs.

1. A building equipped with the machinery for grinding grain into flour or meal. 2. A device or mechanism such as rotating millstones, that grinds grain.

To grind, pulverize or break down into smaller particle size in a mill.

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).

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.

A cow that has given birth more than once.

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

The third stomach of a ruminant between the reticulum and the abomasum. It is characterized by the presence of muscular leaves that may have an absorptive function.

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.

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.

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

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 type of bacteria that live in association with the roots of legume plants and make the nitrogen of the air available to the plants.

A root-like usually horizontal stem growing under or along the ground that sends out roots from its lower surfaces and leaves or shoots from its upper surface.

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 clear yellowish fluid obtained upon separating the clotted whole blood into its liquid and solid (red and white blood cells) components.

(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 main upward growing axis of a plant, usually above the ground and in direction opposite of the roots.

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

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.

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