DS 825 Ruminant Nutrition Physiology DS 825 Ruminant Nutrition Physiology Glossary

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.

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

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 liver secretion that is necessary for proper digestion of fats.

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 swelling of the left side of the cow caused by a frothy material which prevents gases of fermentation from being eructed from the rumen. Occurs primarily when cows are grazing certain species of legumes especially, alfalfa. If not treated immediately, bloat can cause death in a matter of hours. More...

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)

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).

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 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 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.

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.

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.

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.

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

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.

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

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

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.

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).

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.

Inflammation of the sensitive vascular tissue of the hoof.

A feed or drugs that will induce bowel movements (defecation) and relieve constipation.

Structure, usually flat and green that grows from a stem or stalk of a plant and is responsible for photosynthesis.

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.

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.

An enzyme that breaks down fat.

Any of the numerous fat or fat-like materials that are generally insoluble in water, but soluble in common organic solvents. Nutritionally, lipids contain about 2.25 times more energy then carbohydrates.

Protein coated packages that transport fats in the bloodstream

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 large gland that has multiple functions, one of which is to secrete bile and digestive enzymes that are mixed with the digesta entering the duodenum.

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

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).

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.

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).

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.

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.

(see non-fiber carbohydrate).

Lipid, usually of vegetal origin, which is liquid at room temperature (as opposed to fats).

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.

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

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.

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.

To free from coarseness; to refine.

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.

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

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.

Method of preservation of fresh forages based on the partial fermentation of the sugars in absence of oxygen. Silage can be made in various silos.

Structure constructed to help preserving forages as silage. Different types of silos includes: Tower silo, oxygen limiting silo, trench silo, etc.

(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 stem of an herbaceous 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.

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.

A fat composed of three fatty acids and glycerol.

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

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.

Evaporating readily at normal temperature and pressure.

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.