Dairynutrient 414 Ruminant Nutrition Dairynutrient 414 Ruminant Nutrition 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.

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.

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.

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 chemical substances, such as sodium bicarbonate, that can maintain the pH of the rumen content around neutrality (pH = 6 to 7). The pH is maintained by neutralizing the volatile fatty acids and other organic acids produced by ruminal fermentation.

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

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.

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.

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.

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

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 unborn young.

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

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.

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

Outer covering of grain or other seed, especially when dry (syn: husk).

A strong desire for food.

Outer envelop, usually green, of fruits and seeds, as around an ear of corn (syn hull).

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

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 cow that has given birth more than once.

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

(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.

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.

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.

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).

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

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

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 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.

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.

see diarrhea.

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

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

To grow or to develop quickly (syn to germinate).

(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.

Mammary gland of a cow.

Ray in sunlight which enables vitamin D to be synthesized under the skin.

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.

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.