Dairynutrient 414 Ruminant Nutrition Dairynutrient 414 Ruminant Nutrition Glossary

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.

The mixture of digestive secretion, bacterial population and feeds undergoing digestion in the gastro-intestinal tract (such as rumen content).

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 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.

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.

Feed that stimulate rumination due to their long particle size and their high content in fiber. Generally, forages are composed of the leaves and stems (stalk of plants. The bacterial population of the rumen allows the ruminant to digest forages.

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.

The stomach and the intestine as a functional unit.

the embryo of a plant present in the seed.

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

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.

An enlargement of the thyroid gland associated with iodine deficiency and visible as a swelling at the front of the neck.

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.

Any of the numerous plants of the family gramineae, characteristically having narrow leaves and hollow, jointed stems (e.g., orchardgrass, ryegrass, bromegrass).

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.

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.

One million calories.

(see Microbe).

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.

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.

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.

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

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

Having one or several fetus growing inside the uterus.

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.

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.

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

A fat composed of three fatty acids and glycerol.

Usually refers to feeding insufficient energy.

The parts of plants that are involved in the growth as opposed to the parts of plants involved in reproduction.

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.