Chapter 8. Feedstuffs

1. INTRODUCTION
2. AN INTERNATIONAL FEED NOMENCLATURE
3. THE SYSTEMATIC COLLECTION AND RECORDING OF DATA ON FEED COMPOSITION
4. CALCULATIONS USED IN SUMMARIZATION OF FEED COMPOSITION DATA
5. ENERGY FEEDS
6. PROTEIN SUPPLEMENTS
7. VITAMIN AND MINERAL SUPPLEMENTS AND MISCELLANEOUS ADDITIVES
8. REFERENCES

L. E. Harris
Utah State University
Logan, Utah

1. INTRODUCTION

1.1 International Network of Feed Information Centre (INFIC)

Feeding farm animals is a process of priority decision-making involving at least two general conditions. The first is an abundance of food material which is not in a usable form or aesthetically acceptable as human food, and the second is a surplus of food material accompanied by a standard of living sufficiently high that the nutrient losses involved in feeding animals are compensated for by the increased desirability and nutritional excellence of foods of animal origin.

Decisions relevant to the first set of conditions include determining the optimum numbers and kinds of animals that can be productively supported by the available feedstuffs. Efforts should be made to maximize production; but also to allocate nutrient supplies in a competitive situation for the maximum benefit to the society concerned. These decisions are among the most critical that civilization faces today.

Decisions can be made only on the basis of reliable information concerning the composition of all feed materials used in animal feeding. This information is fundamental in assigning priorities to the use of available feed supplies in animal agriculture.

1.1 International Network of Feed Information Centre (INFIC)

German documentation began in 1949 and the United States began in 1952. Although there was some contact between the two centres for several years, it was not possible to combine or adapt the systems to each other. Personnel at the Utah (United States) centre contacted FAO concerning the need for world cooperation. FAO, in turn, sent a consultant to review on-going international activities in the fields of feed data collection and methods for retrieval of these data, and to report on possibilities for collaboration on an international basis. The report (Alderman, 1971) enumerated the value of a collaborative effort in this field, both to developing countries and to animal production at the international level and recommended that FAO act as the coordinator for international activities in collection of data on feed composition and its summarization and dissemination.

The first consultation meeting was held in 1971, in Rome. At that time representatives from several feed information services formed the International Network of Feed Information Centre (INFIC Publication 1, 1977). Members (besides FAO) were: Australian Feed Information Centre, Sydney, Australia; Agriculture Canada, Ottawa, Canada; International Feedstuffs Institute, Utah State University, Utah, U.S.A.;. US AID Feed Composition Project, University of Florida, Gainesville, Florida, U.S.A., and Universität Hohenheim, Dokumentationsstelle, Stuttgart, Federal Republic of Germany.

Since then, meetings of the INFIC group have been held annually, and the following centres have joined INFIC: The Arab Centre for Studies of Arid Zones and Dry Lands (ACSAD), Damascus, Syria; College of Fisheries, Aquaculture Division, University of Washington, U.S.A.; The International Livestock Centre for Africa (ILCA), Addis Ababa, Ethiopia; Institute d'Elevage et de Médecine Vétérinaire des Pays Tropicaux (IEMVT), Maisons-Alfort, France; the Latin American Programme for Feed and Feeding Systems, at the Institute Interamericano de Ciencias Agricolas (IICA), San Jose, Costa Rica; and the Tropical Products Institute (TPI), London, United Kingdom. In the meantime, the US AID Feed Composition Project in Florida has been terminated and its responsibilities were transferred to the Utah Centre. Participation by other feed information services throughout the world is encouraged by INFIC. All centres function independently with regard to financing, personnel, data retrieval, research and publications.

2. AN INTERNATIONAL FEED NOMENCLATURE

2.1 Classes of Feeds by Composition and Usage
2.2 International Feed Description
2.3 Short Feed Names
2.4 Official Country Names

Naming and describing feeds for data processing must be carried out systematically. This means that a precise nomenclature had to be established. This nomenclature contains controlled terms (descriptors) which constitute the "International Feed Vocabulary". These descriptors are used for coining the international names of feed. Thus, the nomenclature can be expanded by combining the existing descriptors.

Many of the by-products arising from the preparation of human food are suitable for animal feeds. As new technology develops for processing human foods, additional by-products are constantly being introduced. Unless well-defined guidelines are established for naming these products, confusion will reign. Many grain products are changed by subjecting them to some form of mechanical process; e.g., blending, grinding, pelleting, and steam or dry rolling. This often results in an alteration in the nutritive value of feeds. Generally, these changes increase nutritive values resulting in increased efficiency of animal production. However, this complicates the task of precisely naming these materials. The names of many feeds are controlled officially by regulation in the U.S.A., Canada and the European Community. These names include descriptions of processes used in their manufacture and may include guarantees of quality. Such names, however, are usually common or trade names and do not describe the feed accurately.

In reviewing the literature, more than 20 percent of the common names were found to be different names (synonyms) for the same product from different areas of the world. This complicates the identification of feeds. A new international system was proposed by Harris (1963) and Harris et al. (1968) to overcome inconsistencies in naming feeds. This system was modified and is now known as the International Feed Vocabulary.

Using this vocabulary, over 18 000 feeds have been recorded and given International Feed Descriptions or Names in English, German and French. Portuguese and Spanish versions are being prepared. These International Feed Names are now in wide use.

The International Feed Vocabulary is designed to give a comprehensive name to each feed as concisely as possible. Each feed name is coined by using descriptors taken from one or more of six facets.

Facet 1: Origin. The origin or parent materials may be one of three types:

(i) plants

specific (barley, oats, coconut, soybeans)
non specific (cereals, grass, meadow)

(ii) animals

specific (cattle, chickens, swine)
non specific (animal, poultry, fish)

(iii) minerals, chemical products, drugs and others.

For specific plants and animals, each descriptor of this facet is composed of:

(i) scientific name
(ii) common name.

Feeds should be described by their common names at up to three levels as far as this is possible. The first level should be the generic name; e.g., cattle, fish, clover, wheat, etc. The second level should be more specific (such as breed or kind); e.g., Hereford, cod red (clover), winter (wheat), etc. The third level should list other important characteristics (such as strain; e.g., Delmar) (see Table 1).

Facet 2: Part Fed to Animals as Affected by Process (es). This component of the feed description represents the actual part of the parent material fed. In the past, the edible parts of plants and animals were obvious such as leaves, stems, seeds, meat trimmings, or bones. Today, due to the extensive fractionation of plant seeds and the reconstitution of many of the parts into new processed foods, innumerable by-products are available for animal feeding.

Each part has to be described unambiguously by a descriptor, the use of which is defined as far as necessary.

Table 1 International Feed Description: Origin (Examples)

With Specific Origin
genus	Bos	Gadus	Trifolium	Triticum
species	Taurus	Morrhua	Pratense	Aestivum
Level 1 generic name	Cattle	Fish	Clover	Wheat
Level 2 breed or kind	Hereford	Cod	Red	Winter
Level 3 strain	-	-	-	Delmar
With Non Specific Origin
Level 1 generic name	Animal	Grass	Poultry	Meadow plants
Level 2 breed or kind	-	-	-	-
Level 3 strain	-	-	-	-

The above are examples of feeds with specific origins. Some feeds may have no specific origin, and are described by their common name; e.g., animal, grass, poultry, meadow grass.

Minerals, drugs and chemicals are listed according to the nomenclature of CRC (1968). The chemical formula are designated where applicable.

Examples of International Feed Descriptions or Names with parts are given in Table 2.

Table 2 International Feed Description: Origin + Part (Examples)

genus	Bos	Gadus	Trifolium	Triticum
species	Taurus	Morrhua	Pratense	Aestivum
generic	Cattle	Fish	Clover	Wheat
breed or kind	Hereford	Cod	Red	Winter
strain	-	-	-	Delmar
part	Milk	Whole	Aerial part	Grain

Facet 3: Process (es) and Treatment (s). Many processes may be used in the preparation of a feed for consumption and some of these may significantly alter their nutritional value. Heat may damage some nutrients and, conversely, it may make others nutritionally more available. Pelleting increases consumption while grinding may affect digestibility of protein and carbohydrates.

It is important, then, that a feeder be aware of the processes to which a feed has been subjected. Also, the type of animal and its physiology must be considered relative to these factors. Therefore, origin and part terms are followed by those distinguishing the different methods of processing which are used alone or combined; such as separating, reducing size or thermal. The term dehydrated (descriptor: DEHY) when applied to AERIAL PART means feeds which are artificially dried. Similarly, FAN AIR DRIED indicates the AERIAL PART (hay) dried indoors by air convection.

The term, mechanically extracted (MECH EXTD) has been used rather than expeller extracted, hydraulic extracted, or old process.

Table 3 International Feed Description: Origin + Part + Process (Examples)

genus	Bos	Gadus	Trifolium	Triticum
species	Taurus	Morrhua	Pratense	Aestivum
generic	Cattle	Fish	Clover	Wheat
breed or kind	Hereford	Cod	Red	Winter
strain	-	-	-	Delmar
part	Milk	Whole or cuttings	Aerial part	Grain
process	Boiled	Mech Extd Dehy Ground	Ensiled	Ground

Examples of International Feed Descriptions with processes are given in Table 3.

Facet 4: Stage of Maturity or Development. Although stage of maturity may be unimportant or may not even apply to many feeds such as grain by-products, it is probably the most important factor influencing the nutritive value of forages. There is an optimal stage of maturity for forage crops beyond which lignification or the reduction of the ratio of leaf to stem greatly reduces digestibility. Examples of International Feed Descriptions with stage of maturity for plants and animals are given in Table 4.

Facet 5: Cutting. Many forage crops are cut and harvested several times during the year. Each cutting has a unique nutrient content as well as characteristic physical properties. The descriptor for cutting refers to the sequence of cutting from the first to the last during the year (cut 1, cut 2, etc.). The maturity terms refer to stage of growth or of regrowth and, therefore, must be considered within the limits of cutting.

In tropical and subtropical areas, crops may be cut throughout the year, particularly if they are irrigated.

Table 4 International Feed Description: Origin + Fart + Process + Maturity + Cut (Examples)

genus	Gallus	Gadus	Trifolium	Digitaria
species	Domesticus	Morrhua	Pratense	Decumbens
generic name	Chicken	Fish	Clover	Pangolagrass
breed or kind	Leghorn	Cod	Red	-
strain	-	-	-	-
part	Whole	Whole	Aerial part	Aerial part
process	Fresh	Boiled	Dehy	Ensiled
maturity	Day old	-	Early bloom	28-42 days' growth
cut	-	-	Cut 1	Cut 2

The time to start counting cuttings for non-irrigated forages would be the first rainy season. For irrigated forages, the count should start from the first crop.

Since stage of maturity is more important than cutting data, the various cuts for forages are sometimes combined with the stage of maturity when data are summarized for feed composition tables. Examples of International Feed Descriptions with cuttings are given in Table 5.

Table 5

genus	Glycine	Medicago	Gadus
species	Max	Sativa	Morrhua
generic name	Soybean	Alfalfa	Fish
breed or kind	-	-	Cod
strain	-	Ranger	-
part	Seeds without oil	Aerial part	Whole
process	Solv Extd	Dehy	Boiled
maturity	-	-	-
cut	-	Cut 1	-
grade	More than 44% protein	17% protein	-

Facet 6: Grade. Some commercial feeds and feed ingredients are given official grades on the basis of their composition and other quality characteristics. Such feeds are sold on a quality description basis in accordance with their official gradings. Thus, these grades and quality designations must be included as a definitive component in the description of the feed. These guarantees for various attributes are expressed in terms of "MORE THAN" (minimum) and "LESS THAN" (maximum) of some percentage of crude fibre, protein, fat, etc. LOW GOSSYPOL is an example of a quality grade. These guarantees and quality are used as descriptors in this facet. Examples of International Feed Descriptions with grade are given in Table 5.

2.1 Classes of Feeds by Composition and Usage

Feeds are grouped into eight classes on the basis of their composition in the way they are used for formulating diets (Table 6).

By necessity these classes are arbitrary, and in borderline cases the feed is assigned to a class according to the most common use made of it in usual feeding practice. For instance, some bran samples may contain over 18 percent fibre and more than 20 percent protein and yet are classed as forages because they are normally used in this way.

Table 6 Classes of Feeds by Composition and Usage

Code	Class Description 1/
1	Dry forages and roughages	Hay; straw; fodder (aerial part); stover (aerial part without ears, without husks or aerial part without heads); other products with more than 18 percent crude fibre (dry basis); HULLS
		This class includes all forages and roughages cut and cured. Forages or roughages are low in net energy per unit weight, usually because of the high fibre content. Thus, such products as SEED COATS, PODS, rice BRAN, etc. are included in this group.
2	Pasture, range plants, and forages fed green	Included in this group are all forage feeds either not cut (including feeds cured on the stem) or cut and fed fresh.
3	Silages	This class includes only ensiled forages (MAIZE, ALFALFA, GRASS, etc.), but not ensiled FISH, GRAIN, ROOTS and TUBERS.
4	Energy feeds	Included in this group are products with less than 20 percent protein (dry basis) and less than 18 percent crude fibre (dry basis) as, for example, FISH, GRAIN, mill by-products,
5	Protein supplements	This class includes products which contain 20 percent or more of protein (dry basis) from animal origin (including ensiled products) as well as oil meals, GLUTEN, etc.
6	Mineral supplements
7	Vitamin supplements (including ensiled yeast)
8	Additives	This class includes further feed supplements as antibiotics, colouring materials, flavours, hormones and medicants.

^1/ Short feed names are used with or without the genus, species or variety

2.2 International Feed Description

An international feed description is composed of the previously described six facets and descriptors within the facets. The feed descriptions are maintained in an "International Feed Description Name File".

A six-digit "International Feed Number" (IFN) is assigned to each feed description. The first digit of this IFN denotes the class of feed. This reference number is used in computer programmes to identify the feed for use in calculating diets, summarization of the data, for printing feed composition tables and for retrieving on-line data for calculating diets for maximum profit.

A complete International Feed Description consists of all descriptors applicable to that feed. It is numerically identified by the IFN. This is illustrated by examples in Table 7.

Table 7 Examples of International Feed Descriptions

Components	Feed no. 1	Feed no. 2	Feed no. 3	Feed no. 4	Feed no. 5	Feed no. 6
Specific Origin
	Class 1	Class 2	Class 3	Class 4	Class 5	Class 6
genus	Trifolium	Avena	Medicago	Zea	Box	Magnesium
species	Pratense	Sativa	Sativa	Mays	Taurus	Carbonate
variety	-	-	-	Indentata	-	-
generic	Clover	Oats	Alfalfa	Maize	Cattle	Magnesium
breed or kind	Red	-	-	Dent	Guernsey	Carbonate
strain	-	-	-	Yellow	-	MgCO3
part	Aerial part	Aerial part	Aerial part	Grain	Milk	-
process	Sun-cured	Fresh	Ensiled	Dehy	Spray dehy	Ground
maturity	Late vegetative	Early bloom	Early bloom	-	-	-
cutting	Cut 2	-	Cut 1	-	-	-
grade	-	-	-	Grade 2 695 G/L	-	-
International Feed Number	1-02-395	2-03-287	3-07-844	2-03-931	5-08-626	6-02-754
Non Specific Origin
	Class 1	Class 2	Class 3	Class 4	Class 5	Class 6
genus	Meadow plants	Grass	Legume	Bakery	Animal	Rock phosphate
species	Inter-mountain	-	-	-	-	-
variety	-	-	-	-	-	-
Non Specific Origin	Class 1	Class 2	Class 3	Class 4	Class-5	Class 6
generic	Meadow plants	Grass	Legume	Bakery	Animal	Rock phosphate
breed or kind	Inter-mountain	-	-	-	-	-
strain	-	-	-	-	-	-
part	Aerial part	Aerial part	Aerial part	Waste	Blood	-
process	Sun-cured	Fresh	Ensiled	Dehy	Spray dehy	Ground
maturity	Late bloom	Early bloom	-	-	-	-
cutting	Cut 1	-	-	-	-	-
grade	-	-	-	-	-	-
International Feed Number	1-09-176	2-08-431	3-07-796	4-00-466	5-00-381	6-03-945

2.3 Short Feed Names

Short names are used for Feed Composition Tables, compiled for use in particular countries or regions, when it is inconvenient to use the longer and more precise International Feed Description; however, the Short dame cannot be used for describing a feed when adding material to the feed data bank.

2.4 Official Country Names

In some countries feeds have been given official names. Usually, these names are not used as international feed descriptions because they are either incomplete or do not begin with the origin or parent material. However, they are used as additional names to relate the country name to the international feed description. In feed tables, these names may be listed after the short feed names for a given country or region. Examples of country names are given in Table 8.

3. THE SYSTEMATIC COLLECTION AND RECORDING OF DATA ON FEED COMPOSITION

3.1 The International Source Form
3.2 Information Provided In Source Form

3.1 The International Source Form

A system for recording data on an "International Source Form" was first devised by Harris et al. (1968) and Harris (1970) . This form has been revised by INFIC so that data on additional attributes such as toxic constituents, fertilizer and pollution can be recorded.

Figure 1 illustrates one type of source form in use. Each INFIC Center may devise other source forms appropriate to their needs. The example source forms are used to record nutritional data about a feed. Items that may be recorded on the source form are outlined below. However, only those which are applicable to the particular feed sample are recorded (Figure 2 for example of completed source form).; Completed source forms are forwarded to regional INFIC Centres where the information is coded for entry into the databank. Each source form is designed so information may be punched directly into 80 column computer cards or onto magnetic tape. A description of information to be filled in for each area of the source form follows.

Table 8 International Long and Short Names and Country Names (Examples)

Components	Feed no. 1	Feed no. 2	Feed no. 3	Feed no. 4	Feed no. 5	Feed no. 6	Feed no. 7
International Feed Descriptions
genus	Animal	Linum	Avena	Fish	Medicago	Triticum	Zea
species	-	Usitatissimum	Sativa	-	Sativa	Aestivum	Mays
variety	-	-	-	-	-	-	-
generic	Animal	Flax	Oats	Fish	Alfalfa	Wheat	Maize
breed or kind	-	-	-	-	-	-	-
strain	-	-	-	-	-	-	-
part	Livers	Seeds without oil	Groats by product	Whole or cuttings	Aerial	Flour by product	Gluten with bran
process	Dehy ground	Solv extd ground	-	Boiled mech extd ground	Sun-cured	-	Wet milled dehy
maturity	-	-	-	-	Early bloom	-	-
cutting	-	-	-	-	-	-	-
grade	-	-	-	-	-	Less than 4.5% fibre	-
Short Feed Names 1/
genus	Animal	Linum	Avena	Fish	Medicago	Triticum	Zea
species	-	Usitatissimum	Sativa	-	Sativa	Aestivum	Mays
variety	-	-	-	-	-	-	-
generic	Animal	Flax	Oats	Fish	Alfalfa	Wheat	Maize
breed or kind	-	-	-	-	-	-	-
strain	-	-	-	-	-	-	-
part	Livers	Seeds	Groats by product	-	Hay	Red dog	Gluten with bran
process	Meal	Meal solv extd	-	Meal mech extd	Sun-cured	-	-
cutting	-	-	-	-	-	-	-
grade	-	-	-	-	-	Less than 4.5% fibre	-
Country Name
	Animal liver meal (CFA)2/	Solvent extracted linseed meal (CFA)	Oat feed (CFA)	Fish meal (CFA)	-	Middlings, less than 4.5% fibre (CFA)	Corn gluten feed (CFA)
	Animal liver meal (AAFCO)3/	Linseed meal, solvent extracted (AAFCO)	Oat mill by-product (AAFCO)	Fish meal (AAFCO)	-	Wheat red dog less than 4.5% fibre (AAFCO)	Corn gluten feed (AAFCO)
International Feed Number	5-00-389	5-02-048	1-03-332	5-01-977	1-00-059	4-05-203	5-02-903

^1/ Short feed names are used with or without the genus, species or variety
^2/ Canada feed act name
^3/ American Association of Feed Control Officials name

Fig. 1 International Source Form

Fig. 2. This is an illustration of source form to record only a few analyses where the sample is not described in detail. Also it shows how to record ratio values. The unit code factor will convert the ratio data to arginine as per cent of feed; acetic acid as % of feed; and butyric acid as % of feed, respectively.

3.2 Information Provided In Source Form

3.2.1 Card 10

Origin of Data, Origin of Sample and Description of Feed

Project No. This number is filled in by the project leader.

Country. Give the country where the laboratory is located that analyzed the feed sample.

State, province or department. Give the state, province or department within the country where the laboratory is located that analyzed the feed sample.

Laboratory sample number. Give the number assigned to the sample. When source forms are prenumbered, this number could be used as the laboratory number; however, other numbers may be used. For example, the first sample collected in 1977 could be 77-1, the second 77-2, etc.

Origin of Sample

Date originally collected. Record date the sample was collected. This is especially important for forages as the nutritive value is influenced by the age of the plant.

Country. Give name of the country where feed originated. For example, anchovy fish meal may have come from Chile and be fed to livestock in Brazil. In this case, enter Chile for country.

Climatic zone. To be filled in by the Feed Centre. This is a geographic area within a country (or countries) with similar altitude, latitude, and rainfall.

Fishing area. Give the nearest state, province or department within a country where the fish were caught. This includes rivers, lakes or the oceans.

State, province or department. Give name.

Country, district or region. Record name. This will assist in identifying areas where plants exhibit nutritional deficiencies and/or toxic levels of materials when fed to animals. When sufficient data are collected, maps can be drawn outlining these areas.

Literature reference No. This is primarily used at the Centre when data are collected from the literature. However, if the data being reported have been published, fill in literature reference, giving the senior author, year, journal, volume number, and page.

Description of Feed

If the feed can be identified, write in the international feed name in the scientific name area from the list of feed names in the appendix. Fill in the international feed number taken from this list above the aquares on the source form reserved for this purpose. If the international feed name and the international feed number are filled in, the blanks down to the short name do not need to be filled in.

When the international name cannot be identified, describe the sample by using the common name and fill in the other blanks as described below, i.e., class of feed, scientific name, common name, part, process, etc.

Class of feed. Check one of the squares as appropriate.

Scientific name (variety or kind). When this area is not used for the international feedname as outlined above, give the variety or kind, i.e., Zea mays indentata.

Common name for scientific name. Common names are an important part of feed terminology. Many are part of our everyday language. List here all the common name(s) by which the feed is known in your locality.

Part of plant, animal or other product. A list of words or phrases describing the part of the plant, animal or feed product is given in the Glossary. Study these words or phrases carefully. When there is a word or phrase which fits your feed sample, insert it here. These terms are used in the international feed names.

Process undergone before fed to animal. A list of processes which the feed may undergo before it is fed to the animal is given in the Glossary. Study these carefully; if a word or phrase fits the feed, insert it under Processes Undergone Before Fed to Animal. If a word or phrase in the Glossary does not fit the feed, make up a new one and insert it in this space.

Other descriptive terms such as rained on, moldy, frozen, weathered, insect damage, etc., may be added to obtain a more accurate description.

Stage of plant maturity or development or age of animal. Use one of the terms listed in the Glossary. Some forages, especially those in the tropics, bloom intermittently. For these forages, list the length of time in days since the plant started to grow or since previous cuttings.

When the sample is of animal origin, give the stage of development of the animal.

Number of cut. This refers to the number of times the plant is cut and harvested. Fill in first, second, third cut, etc.

Official grade (name and number). Many countries have an "Official" grading system for hays and grains. If your country has such a system, obtain an official grade on your sample and insert it under this item. Some countries have a "Feed Control Service" that describes feeds which are sold. They may specify minimum and maximum guarantees for certain attributes. If feeds in your country carry guarantees, indicate the percentages "less than" or "more than"; for example: wheat, flout by-product, less than 2.5 percent fibre.

Short name. To be filled in at the Centre.

Plant cross. When a plant cross is on the market as a commercial feed, give the plant cross and state "sold on the market". This name will then be added to the name file. However, if the plant cross is not sold on the market, give the plant cross and state "not sold on the market". The plant cross will then be coded by the Centre so the data can be retrieved at a later date if the plant cross becomes a commercial product.

Additives. Give name of additive. These are materials added in small amounts example, sodium hydroxide in treating straw or molasses added to silage.

Weight or additive. Check appropriate square: mg, g, or kg.

Weight per metric ton. Give amount of additive per metric ton of feed.

Season. Record one of the following: dry or wet (rainy).

These reasons apply primarily to the tropics or t0 areas which have long dry and rainy seasons. Note: the stage of maturity takes care of the season in temperate climates so for these climates leave this area blank.

3.2.2 Card 21

Quality of Feed, Soil and Fertilization

Quality designations for feeds. These designations are:

Grade 1 good
Grade 2 fair
Grade 3 poor
Grade 4 inferior.

Degree of purity percent. Give the percent of feed (origin) material present in the sample. Most samples contain impurities. This information helps in establishing a grade.

Foreign material. Record one of the following: mineral contamination, weed seeds, other foreign material.

Soil

Note: each Centre could use the soil classifying system used in the country or area they serve. If such a system is used, record the soil class. At the present time, it is not possible to use an international soil classification system. However, the following soil information may be used when the Centre does not have a system to classify soils.

Soil type. Give one of the following: old surface, volcanic, or alluvial.

Kind of soil. Depending on surface texture, state: sand, loam, or clay.

Soil pH. Give the pH value of the soil.

Water (type). Record one of the following:

rainfall
irrigation (sprinkler)
irrigation (furrow)
irrigation (border flooding)
irrigation (drip).

Irrigation plus rainfall. Give total water in mm.

Fertilization

Nitrogen fertilizer-type. Give one of the following:

nitrogenous fertilizer
anhydrous ammonia, NH₃
ammonium nitrate
urea
calcium ammonium nitrate
calcium nitrate
calcium cyanamide
nitrate of soda
ammonium sulphate, or the name of other nitrogen fertilizer used.

Quantity in kilogramme per hectare. Give kg applied per hectare.

No. of days between last application and harvest. Give number of days.

Quantity in kilogramme per hectare. Give kg applied per hectare.

No. of days between last application and harvest. Give number of days.

Phosphorus fertilizer, type. Give one of the following:

28-30 percent P₂O₅ and 12-15 percent CaCo₃
Novaphos
Rhenania phosphate, CaNaPO₄ + CaSiO₃,
raw phosphate
superphosphate
Thomasphosphate Ca₃P₂O₂ · CaO + CaO · SiO₂
or the name of other phosphorous fertilizer used.

Quantity in kilogramme per hectare. Give kg applied per hectare.

Calcium fertilizer, type. Give one of he following:

quicklime, burned lime
lime, ground, from iron works
calcium carbonate
slaked lime
or the name of other calcium fertilizer used.

Quantity in kilogramme per hectare. Give kg applied per hectare.

Organic manuring, type. Give one of the following:

green manure
guano
semi-liquid manure
horn meal
liquid manure, slurry
sewage sludge
bone meal
compost
garbage
plant residues, plant refuses
peat moss
stable manure, barn manure
or the name of other organic manure used.

Quantity in kilogramme per hectare. Give kg applied per hectare.

Trace element fertilizer, type. Give one of the following:

boron fertilizer
chlorine fertilizer
cobalt fertilizer
iron sulphate
copper sulphate
magnesium fertilizer
manganese fertilize
molybdenum fertilizer
sodium fertilizer
sulphur fertilizer
lime fertilizer
or the type of trace element fertilizer used.

Quantity in kilogramme per hectare. Give kg applied per hectare.

Mixed fertilizer, type. Give one of the following:

P-K fertilizer
N-Mg fertilizer
phosphate - potassium
P-K fertilizer, 15-18 percent, 20-25 K
nitrogen - phosphate
Thomasphosphate - potassium
Nitrophoska grey (11.5% N, 8.5% P₂O₅, 18% K₂O)
Nitrophoska red (13% P₂O₅, 21% K₂O)
12% N, 12% P₂O₅, 20% K₂O)
or the name of other mixed fertilizer used.

Quantity in kilogramme per hectare. Give kg applied per hectare.

3.2.3 Card 22

Storage Structure

This card is used primarily for silage, however, the height when cut may apply to other feeds.

Height when cut. Record height above stubble in centimeters.

Storage place. Record one of the following:

cellar
pit
trench
kiln
granary
case
stack
temporary silo:
upright high stack silo
upright half high stack silo
attached silo
flat silo moveable silo
fence silo
metal or plastic silo
silo made with pressed material (plywood)
sealed upright silo
experimental silo.

Kind of building material. Record one of the following:

concrete
wood
metal
straw
store
soil
plastic
miscellaneous.

Kind of covering or lock. Record one of the following:

concrete cover
plastic sheet
inner race lock
clamp lock
mechanical pressing
sound bag lock
seeger retaining ring
dipping cover.

Number of days stored. Record the number of days stored.

Temperature (°C). Record the temperature to the nearest whole degree.

Air humidity (percent). Record the air humidity to the nearest whole degree.

Light and air conditioning. Record one of the following:

light with air exchange
semi-dark with air exchange
dark with air exchange
air tight with light
air tight and semi-dark
air tight and dark.

3.2.4 Card 30

Digestibility Trial

When a digestibility trial has been conducted on the feed sample, fill in this section of the source form.

Animal kind. The data reported for digestion coefficients, percent rumen digestion (nylon bag), digestible energy, metabolizable energy, nitrogen-equilibrium metabolizable energy, nitrogen-equilibrium metabolizable energy, NE_m, NE_gain, TDN, or other measures made on animals are tied to animal kind; therefore, animal kind must be filled in if these data are reported. Do not put estimated data on the source form. Examples of animal kind are cattle, llama, horse, sheep, swine, etc.

Animal breed. Give the breed name, such as Holstein, Brahman, Nallore, Hampshire. When the animal is a crossbreed, list the male first.

Sex. State whether male, castrate male, female, or spayed female.

Age. Give age of animal in years and months; months and weeks; or in weeks.

Number of animals in treatment. Give number of animals used in the trial for each feed.

Average weight of animals. Record the actual weight expressed in kilogrammes or grammes according to the following schedule:

(kg)

Alpaca
Ass
Camel
Cat
Cattle
Chicken
Deer
Dog
Duck
Fish
Fox
Goat
Goose
Hare
Horse
Llama
Man
Mule
Reindeer
Roe (deer)
Sheep
Swine
Turkey
Water-buffalo
Zebra
Zebu

(g)

Guinea-pig
Hamster
Mink
Mouse
Pigeon
Quail
Rabbit
Rat
Test tube (in vitro)

Record the weight to the nearest 0.1 kilogramme or gramme. When weights are given only to the nearest whole kilogramme or gramme, add a zero (implies accuracy to 0.1 unit) after the decimal point.

Physiological state. Check the appropriate condition in each of the following areas:

non-pregnant, pregnant first 2/3, or pregnant last 1/3;
losing weight, maintaining weight, gaining weight or fattening;
lactating, laying eggs or working;
very thin, thin, thrifty, fat, or very fat.

Percent of test ingredient in ration fed (100.0% dry matter). Calculate and fill in only when feed is not fed alone.

Ad libitum feeding or controlled feeding. Check which method was used.

Feed fed alone or feed not fed alone (digestion by difference). Sometimes it is not possible to feed a single ingredients, such as meat meal(animal, carcass, residue, dry rendered dehydrated ground) to cattle. In this case, the meat meal is fed with some other feed. When water and minerals only are given-with a feed, it is considered to be fed alone. Indicate method used (feed fed alone or feed not fed alone).

Method. Check whether the faeces were measured by the total collection method or by the indicator method.

Length of trial. Record length of the preliminary period and the collection period.

Daily dry matter consumed. Record the average daily dry matter consumed during the collection period according to the schedule given in g or kg (for each animal kind) for average weight of animals outlined above.

Record weights to the nearest 0.01 of a kilogramme or 0.001 of a gramme, as appropriate for the animal. When feed weights are not determined to this accuracy, record zeros in positions to the right of the least significant digit.

3.2.5 Card 40

Chemical and Biological Data

Each datum should represent a single observation; however, if individual data are not available, average values may be used (taken from the published literature).

Check analyses wanted. The squares under this heading are for convenience of the chemist. The squares opposite the attribute are checked for the analyses wanted. At this time, chemical analysis work sheets are made up by entering the laboratory number of source form number in the appropriate chemical analysis work book (Harris, 1970).

Some attributes to be analyzed on the sample not be on the source form. The next step is for the chemist to analyze the sample. The chemical and biological analyses are then copied onto the source form.

Dry matter. Record the as-fed dry matter (attribute identified by number 001 for dry matter) on the source form. A sample may be accepted without an "as fed" dry matter providing the data are reported on a partially dry or dry basis. However, an as fed dry matter is helpful to correct the data to an as fed basis.

Dry matter basis on which analytical data are reported on this form. This area must be filled in for the data to be entered into the system. Check appropriate square and enter one dry matter value opposite 002, 003, or 004 to indicate the dry matter of the data on the form. Note: when the basis of the data is on an as fed basis, attribute 001 and 002 must be filled in using the same value for each.

The following are definitions of as fed, partially dry and dry:

As-fed refers to the feed as it is consumed by the animal; the term as collected used for materials which are not usually fed to the animal, i.e., urine, faeces, etc. If the analyses on a sample are affected by partially drying, the analyses are made on the as fed or as collected sample. Similar terms: air dry, i.e., hay; as received; fresh, green, wet.

Partially dry refers to a sample of 'as fed' or 'as collected' material that has been dried in an oven (usually with forced air) at a temperature usually about 60°C or freeze dried and has been equilibrated with the air. The sample after these processes would usually contain more than 88 percent dry matter (12 percent moisture). Some materials are prepared in this way so they may be sampled, chemically analyzed and stored. This analysis is referred to as "partial dry matter percent of 'as fed' or 'as collected sample". The partially dry sample must be analyzed for dry matter (determined in an oven at 105°C) to correct subsequent chemical analyses of the samples to a 'dry' basis. This analysis is referred to as dry matter percent of partial dry sample . Similar terms: air dry (sometimes air dry is used for as fed).

Dry refers to a sample of material that has been dried at 105°C until all the moisture has been removed. Similar terms: 100 percent dry matter; moisture free. If dry matter (in an oven at 105°C) is determined on an 'as fed' sample it is referred to as "dry matter on as fed sample . If dry matter is determined on a partial dry sample, it is referred to as "dry matter of partial dry sample . It is recommended that analyses be reported on the dry basis (100 percent dry matter or moisture free), and in addition the "as fed dry matter" should be reported (Harris et al., 1969; Harris and Fonnesbeck, 1977).

Analyses of data. Record the analytical data on the source form in the spaces provided. Digestion coefficients such as 106, 104, 84 or 56 are to be recorded using whole numbers only (do not use decimal points). The least significant digit must be recorded in the right most column, and in case of a negative coefficient, the minus sign must be indicated in the column just left of the most significant digit. Positive sighs are assumed and need not be recorded.

Record animal kind for card 30 if biological data such as digestion coefficients, metabolizable energy etc. are filled in.

Other analyses and other digestion coefficients. When analyses are determined by methods other than those indicated under method of analyses, record under "other analyses and other digestion coefficients". Also in the space provided record analyses not shown on the source form (Figures 1). Specify, decimal, unit, kind and method of analysis.

When amino acids are reported on a protein basis (g/16g N) record the name of the amino acid under other analyses and record the unit as (g/l6g N). When a ratio for amino acids is recorded, there must be a protein value (Figure 1).

If fatty acids are recorded as g fatty acids/100g fat, record the fatty acid and the unit as g fatty acids/100g fat. If fatty acids are recorded as g fatty acids/100g fatty acid, record the fatty acid and the unit as g fatty acids per 100g fatty acid. When a ratio of fatty acids is recorded, there must also be a fat value (ether extract).

Record the weight per litre in this area (only applicable for grains and by-product feeds). To obtain this information, fill a litre measure without shaking or packing the feed. Scrape off the excess level with the top of the container and weigh (subtract container weight from total weight).

Supplementary information about feeds. Put any additional information about the feed here. It is helpful to know other factors which may influence the nutritive value of the feed, such as a complete description of the fertilizer used, whether the crop was irrigated or not irrigated, class of plant, crop badly weathered, or otherwise damaged.

4. CALCULATIONS USED IN SUMMARIZATION OF FEED COMPOSITION DATA

The International Network of Feed Information Centres (INFIC) uses the caloric system for, recording energy values, although some propose that the joule be used. Older terms for expressing energy value of feeds such as Total Digestive Nutrient (TDN), Starch Equivalent (SE),-and the Scandinavian Feed Unit system are still in widespread use, but INFIC encourages their substitution by the caloric system.

The raw data must be modified and certain calculations made before they are in their most useful form. It is not possible to obtain experimental values of all feeds, therefore, some values are estimated with equations. Whenever this occurs, these data are identified by an asterisk (*) as shown in the formulae below. These modifications and estimations are performed by using a computer programme that adapts the data to a standard format. The steps in summarizing the data are as follows:

(i) Original Data

Original data are collected on source forms, coded and punched on to computer cards and entered onto a magnetic tape.

(ii) Preferred Unit and Dry Basis

All data are calculated to the preferred unit basis (metric system) and to a dry matter basis (moisture free). Data are exchanged among centres on this basis.

(iii) Means and Coefficient of Variability

All values for each attribute (for each feed) are totaled, means calculated, and where there are four or more values, the coefficient of variability is calculated.

(iv) Nitrogen Free Extract

The mean nitrogen-free extract (NFE) in percent is determined by adding the percentage sums of ash, crude fibre, ether extract and protein.

Nitrogen-free extract is no longer used as an entity to calculate diets, but until sufficient data are available to replace TDN with the calorie system, there is some advantage in having nitrogen-free extract so DE and ME may be calculated from proximate analyses or from TON.

(v) Digestible Energy (DE) Digestible energy for each animal kind is calculated:

(a) from the mean of digestible energy in kcal/g or Mcal/kg

(b) DE in kcal/g = GE(kcal/g) × GE digestion coefficient

(c) from TDN for cattle-and sheep (Crampton et al., 1957; Swift, 1957):
*DE in Meal/kg = % TDN × 0.04409

(d) from TON for horses, equation derived from data (Fonnesbeck et al., 1967 and Fonnesbeck, 1968): *DE in Mcal/kg = 0.0365 × % TDN + 0.172

(e) from TDN for swine (Crampton et al., 1957; Swift, 1957): *DE in kcal/kg = % TDN × 44.09.

(vi) Metabolizable Energy (ME) Metabolizable energy (ME) for each animal kind is calculated:

(a) from the average metabolizable energy in kcal/kg or Mcal/kg

(b) from nitrogen-corrected metabolizable energy (ME) for chickens and turkeys (National Research Council, 1969)

(c) from true metabolizable energy (TME) for chickens (Sibbald, 1977)

(d) from DE for cattle and sheep (Moe and Tyrrell, 1976): ME (Mcal/kg DM) = -0.45 + 1.01 DE (Mcal/kg DM)

Moe and Tyrrell's formula is for dairy cattle, but it is believed it can be applied to sheep until a better formula can be found

(e) from DE for horses as *ME in Mcal/kg = 0.82 DE(Mcal/kg DM)

(f) from DE for swine as (Asplund and Harris, 1969): *ME in kcal/kg = (0.96 - 0.00202 × % crude protein) × DE (kcal/kg DM).

(vii) Net Energy (NE) Net energy (NE) for finishing cattle:

(a) from the average net energy maintenance (NE_m) or for weight gain (NE_gain)

(b) net energy values for some cattle feeds are calculated from equations developed by Garrett (1977):

NE_m (Mcal/kg DM) = 1.115 - 0.8971ME + 0.6507ME² - 0.1028ME³ + 0.005725ME⁴
NE_g (Mcal/kg DM) = 3.178ME - 0.8646ME² + 0.1275ME³ - 0.006787ME⁴ - 3.325

(c) net energy values for lactation (NE₁) are estimated by using the formula of Moe and Tyrrell (1976):

NE₁ (Mcal/kg DM) = -0.12 + 0.0245 TDN (% of DM)

(viii) Total Digestible Nutrients

Total Digestible nutrients (TDN) for each animal kind are calculated:

(a) from average TON

(b) from digestion coefficients as the sum total of the following:

1 × % digestible protein
1 × % digestible crude fibre
1 × %, digestible nitrogen free extract
2.25 × %, digestible ether

(c) from DE for cattle and sheep (Crampton et al., 1957; Swift, 1957):

(d) from DE for horses an equation derived from data in Fonnesbeck et al. (1967) and Fonnesbeck (1968):

* % TDN = 20.35 × DE (Mcal/kg) + 8.90. This formula is only used for class 1 feeds

(e) from ME for cattle and sheep as (Crampton et al., 1957; Swift, 1957):

* % TDN = 27.65 × ME in Mcal/kg

(f) *from regression equations (see Table 9)

(ix) Starch Equivalent

In some areas starch equivalent (SE) is still used to measure energy of feeds. Like TON, it should be replaced by the caloric system.

Starch equivalent, according to Kellner (1905) is calculated on the basis of the digestible nutrients taking into consideration special factors for the single nutrients and correction factors for the raw starch value.

The special factors for single nutrients-vary from one group of feeds to another for protein, ether extract and NFE, but are constant for crude fibre (= 1.0). The mode of correction and the correction factors which have to be used vary for forages and concentrates. For forages the raw starch value is corrected by the crude fibre correction factor, for concentrates by the value number.

Starch equivalents are calculated using codes assigned on the basis of correction factors when the feeds are first described.

The basis of Kellner's system with steers is the amount of fat produced over maintenance by pure nutrients added.

The amount is:

248 g per kg metabolized starch
235 g per kg metabolized protein
474 g per kg roughage fat
526 g per kg grain fat
598 g per kg oil meal fat.

Using the carbohydrate unit as base, the correction factors for the respective fat sources will be: 1.91, 2.12, and 2.41.

Table 9 Regression Equations to Estimate Total Digestible Nutrients ^1/

Animal kind	Feed class	Equation
Cattle	1	* %. TDN = 92.464 - 3.338 (CF) - 6.495 (EE) - 0.762 (NFE) + 1.115 (Pr) + 0.031 (CF)2 - 0.133 (EE)2 + 0.036 (CF) (NFE) + 0.207 (EE) (NFE) + 0.100 (EE) (Pr) - 0.022 (EE)2 (Pr)
	2	* % TDN = -54.572 + 6.769 (CF) - 51.083 (EE) + 1.851 (NFE) - 0.334 (Pr) - 0.049 (CF)2 + 3.384 (EE)2 - 0.086 (CF) (NFE) + 0.0687 (EE) (NFE) + 0.942 (EE) (Pr) - 0.112 (EE)2 (Pr)
	3	* % TDN = -72.943 + 4.675 (CF) - 1.280 (EE) + 1.611 (NFE) + 0.497 (Pr) -0.044 (CF)2 - 0.760 (EE)2 - 0.039 (CF) (NFE) + 0.087 (EE) (NFE) - 0.152 (EE) (Pr) + 0.074 (EE)2 (Pr)
	4	* % TDN = - 202.686 - 1.357 (CF) + 2.638 (EE) + 3.003 (NFE) + 2.347 (Pr) + 0.046 (CF)2 + 0.647 (EE)2 + 0.041 (CF) (NFE) - 0.081 (EE) (NFE) + 0.553 (EE) (Pr) - 0.046 (EE)2 (Pr)
	5	* % TDN = - 133.726 - 0.254 (CF) + 19.593 (EE) + 2.784 (NFE) + 2.315 (Pr) + 0.028 (CF)2 - 0.341 (EE)2 - 0.008 (CF) (NFE) - 0.215 (EE) (NFE) - 0.193 (EE) (Pr) + 0.004 (EE)2 (Pr)
Horses	1	* % TDN = 52.476 + 0.189 (CF) + 3.010 (EE) - 0.723 (NFE) + 1.590 (Pr) - 0.013 (CF)2 + 0.564 (EE)2 + 0.006 (CF) (NFE) + 0.114 (EE) (NFE) - 0.302 (EE) (Pr) - 0.106 (EE)2 (Pr)
Sheep	1	* % TDN = 37.937 - 1.018 (CF) - 4.886 (EE) + 0.173 (NFE) + 1.042 (Pr) + 0.015 (CF)2 - 0.058 (EE)2 + 0.008 (CF) (NFE) + 0.119 (EE) (NFE) + 0.038 (EE) (Pr) + 0.003 (EE)2 (Pr)
	2	* % TDN = - 26.685 + 1.334 (CF) + 6.598 (EE) + 1.423 (NFE) + 0.967 (Pr) - 0.002 (CF)2 - 0.670 (EE)2 - 0.024 (CF) (NFE) - 0.055 (EE) (NFE) - 0.146 (EE) (Pr) + 0.039 (EE)2 (Pr)
	3	* % TDN = - 17.950 - 1.285 (CF) + 15.704 (EE) + 1.009 (NFE) + 2.371 (Pr) + 0.017 (CF)2 - 1.023 (EE)2 + 0.012 (CF) (NFE) - 0.096 (EE) (NFE) - 0.550 (EE) (Pr) + 0.051 (EE)2 (Pr)
	4	* % TDN = 22.822 - 1.440 (CF) - 2.875 (EE) + 0.655 (NFE) + 0.863 (Pr) + 0.020 (CF)2 - 0.078 (EE)2 + 0.018 (CF) (NFE) + 0.045 (EE) (NFE) - 0.085 (EE) (Pr) + 0.020 (EE)2 (Pr)
	5	* %. TDN = - 54.820 + 1.951 (CF) + 0.601 (EE) + 1.602 (BFE) + 1.324 (Pr) - 0.027 (CF)2 + 0.032 (EE)2 - 0.021 (CF) (NFE) - 0.018 (EE) (NFE) + 0.035 (EE) (Pr) - 0.0008 (EE)2 (Pr)
Swine	4	* % TDN = 8.792 - 4.464 (CF) + 4.243 (EE) + 0.866 (BFE) + 0.338 (Pr) + 0.0005 (CF)2 + 0.122 (EE)2 + 0.063 (CF) (NFE) - 0.073 (EE) (NFE) + 0.182 (EE) (Pr) - 0.011 (EE)2 (Pr)

^1/ In the equation CF = Crude fibre; EE = ether extract; NFE = nitrogen free extract;
Pr = Protein; taken from Harris et al. (1972)

The mode of correction and the correcting factors which have to be used vary also from one feed group to another. The mode of correction can be either the use of a crude fibre correction factor or the use of a value number. Further details of this system are available from INFIC Centres.

(x) Digestible Protein

Digestible protein is calculated for each kind of animal by the usual formula:

(a)

(b) or by equations in Table 10 when protein digestion coefficients are not available.*

(xi) Amino Acids and Fatty Acids

If amino acids are reported on a protein basis (g/16g N) they are converted to percent amino acid in dry matter of feed. If fatty acids are reported on a fat basis (g fatty acids/ 100 g fat) or fatty acid basis (g fatty acids/100 g fatty acids) they are converted to a percent fatty acid in dry matter. If it is desired to report amino acids or fatty acids on a ratio basis this information is calculated on the computer as follows:

(xi) Vitamin A Standards

The international standard for vitamin A activity as related to vitamin A and beta-carotene are as follows:

One International Unit (IU) of vitamin A

= the vitamin A activity of 0.300 microgramme of crystalline vitamin A alcohol (retinol) which corresponds to 0.344 microgramme of vitamin A acetate or 0.550 microgramme of vitamin A palmitate.

Beta-carotene is the standard for provitamin A. One IU of vitamin A = 0.6 microgramme of beta-carotene.

One microgramme of beta-carotene = 1.667 IU of vitamin A.

International standards for vitamin A are based on the utilization of vitamin A and beta-carotene by the rat. Because the various species do not convert carotene to vitamin A in the same ratio as rats, it is suggested that the conversion rates in Table 11 be used.

Table 10 - Equations Used to Estimate Digestible Protein (Y) from Protein (X) for Five Animal Kinds and Four Feed Classes ^1/

Animal kind	Feed class	Regression equation
Cattle	1	Y = 0.866 X - 3.06
Cattle	2	Y = 0.850 X - 2.11
Cattle	3	Y = 0.908 X - 3.77
Cattle	4	Y = 0.918 X - 3.98
Goats	1 & 2	Y = 0.933 X - 3.44
Goats	3	Y = 0.908 X - 3.77
Goats	4	Y = 0.916 X - 2.76
Horses	1 & 2	Y = 0.849 X - 2.47
Horses	3	Y = 0.908 X - 3.77
Horses	4	Y = 0.916 X - 2.76
Rabbits	1 & 2	Y = 0.772 X - 1.33
Sheep	1	Y = 0.897 X - 3.43
Sheep	2	Y = 0.932 X - 3.01
Sheep	3	Y =0.908 X - 3.77
Sheep	4	Y = 0.916 X - 2.76

^1/ Knight, et al. (1966)

Table 11 - Conversion of Beta-Carotene to Vitamin A for Different Species ^1/

Species		Conversion of mg of Beta-Carotene to ID Vitamin A	IU of Vitamin A Activity (calculated from carotene), %
		mg IU
Standard		1 = 1,667	100.0
Beef cattle		1 = 400	24.0
Dairy cattle		1 = 400	24.0
Sheep		1 = 400-500	24.0-30.0
Swine		1 = 500	30.0
Horses
	growth	1 = 555	33.3
	pregnancy	1 = 333	20.0
Poultry		1 = 1,667	100.0
Dogs		1 = 833	50.0
Rats		1 = 1,667	100.0
Foxes		1 = 278	16.7
Cat		Carotene not utilized	-
Mink		Carotene not utilized	-
Man		1 = 556	33.3

^1/ Beeson (1965)

5. ENERGY FEEDS

5.1 Chemical Characteristics
5.2 Non-chemical Characteristics of Energy Feeds
5.3 Quality in Energy Feeds

According to the notation in the outline classification, energy feeds are low-protein concentrates. The upper limit for protein is conveniently set at 20 percent, because this figure then includes wheat bran which is otherwise difficult to classify. However, it is the entire seed of the cereals that is the typical energy feed./ If an average is taken of the protein, fat, fibre, TDN, Ca and P figures for the six common grains (barley, corn, milo, oats, rye and wheat), a workable chemical description of an energy feed in terms of those nutrients and proximate principles most useful in determining its proper place in a livestock ration will result. Such data are shown in Table 12.

Table 12 Typical Composition of Cereal Grains

Feed Name	Crude Protein			Ether extract	Carbohydrate
	Total (%)	Dig for swine (%)	Chemical score	(%)	Crude fibre (%)	N-free extract (%)
Barley, grain	11.6	8.2	20	1.9	5.0	68.2
Corn, grain	9.3	7.5	28	4.3	2.0	71.2
Oats, grain	11.8	9.9	464	4.5	11.0	58.5
Rye, grain	11.9	9.6	50	1.6	2.0	71.8
Sorghum, milo, grain	11.0	7.8	-	2.8	2.0	71.6
Wheat grain	12.7	11.7	37	1.7	3.0	70.0
Average	11.4	9.1	-	2.8	4.2	6.8

Feed name	Energy						Minerals
	Cattle			Swine			Calcium (%)	Phosphorus (%)
	DE (kcal/kg)	ME (kcal/kg)	TDN (%)	DE (kcal/kg)	ME (kcal/kg)	TDN (%)
Barley, grain	3257	2671	74	3080	2876	70	00.08	0.42
Corn, grain	3659	2927	81	3569	3351	81	0.02	0.29
Oats, grain	2982	2446	68	2860	2668	65	0.10	0.35
Rye, grain	3336	2735	76	3300	3079	75	0.06	0.34
Sorghum, milo, grain	3139	2475	71	3453	3229	78	0.04	0.29
Wheat, grain	3453	2832	78	3520	3277	80	0.05	0.36
Average	3289	2698	75	3297	3080	75	0.06	0.34

5.1 Chemical Characteristics

5.1.1 Protein

From the above table it will be seen that an energy feed is likely to contain about 12 percent crude protein of which between 75 and 80 percent is digestible. (Throughout this section digestible refers to apparent digestibility unless otherwise stated.)

In practice , one will not go far astray by assuming energy feed protein to be 75 percent digestible. The quality of the protein of energy feeds is uniformly low as measured by any scheme that rates biological value numerically. All feeds of this group show lysine as their first limiting amino acid, which is of importance in the choice of a protein supplement to be used in a balanced ration. It also explains why substitution between energy feeds is not likely to alter appreciably the protein quality of the mixture.

5.1.2 Ash

Energy feeds are low in calcium. In practice, they are often neglected in making calculations for calcium supplementation. The content of phosphorus, on the other hand, is enough that some classes of pigs, and sometimes cattle and sheep also, need no special supplements, but this will depend on the kind and amount of roughage also fed to the herbivorous species.

5.1.3 Carbohydrates

About two thirds of the weight of the seed is likely to be starch, which will usually be about 95 percent digested. Not only is this high concentration of easily digested carbohydrate the distinguishing feature of energy feeds, but variation in this characteristic determines the consequences of substituting among feeds of this category.

5.1.4 Fat

The cereal grains belonging to the energy feeds normally contain from 2 to 5 percent ether extract, but a few by-product feedstuffs contain up to 13 percent fat, as does rice feed, the mill-run by-products of the manufacture of polished rice. Oat groats contain 7 or 8 percent fat, as does corn, hominy feed. The-fat of non-oily seeds is concentrated in the germ, and any processing that removed an appreciable proportion of the protein or carbohydrate, but not of the germ will leave a by-product with higher fat content than the parent seed. A knowledge of the processing involved in the production of a by-product feed is often helpful in understanding the composition of the product. The official definition of feeds may partially define the processing of by-products, as will the international feed names.

The production of starch, on the other hand, involves a wet-milling process. The corn grain, after being softened with warm water and slightly acidified, is partly macerated and then allowed to soak in water in large tanks. The germ, because of its oil content, floats to the top, where it is removed, defatted, and dried into corn germ meal. The residue from the germ separation is reground and sifted to remove the hulls, bran tip cap, and other fibrous material. The gluten and starch are removed from the remaining mass in suspension and later separated centrifugally. The coarse residue made up of hulls, bran, etc.

5.1.5 Crude fibre

The average crude fibre of the energy feeds is about 6 percent but individual feeds vary considerably. The upper limit for concentrates is taken as 18 percent, partly because in Canada - by legal definition - feeds with over 18 percent fibre must be registered as roughages. In particular, the coarse grain (barley and oats) may show wide deviations in fibre from sample to sample, ordinarily because of either an increase in hull or a decrease in the starch filling of the groat. Differences in fibre affect markedly their available energy value and hence their relative feeding value. The most important consequence of substitution between energy feeds is usually traceable to differences in the crude fibre of the products. Fibres of different origin are often quite different nutritionally (see Table 13).

Table 13 Digestibility of Crude Fibre

Crude fibre from;		Class	Coefficient of digestibility (%)
Common name	International feed name 1/
Wheat	Wheat, grain	4	33
Wheat bran	Wheat, bran, dry milled	4	36
Wheat shorts	Wheat, flour by-product, 7 fibre	4	60
Oats	Oats, grain	4	32
Rolled oats	Oats, cereal by-product, ground more than 2 fibre	4	80
Oat clippings	Oats, grain, clippings	1	58
Oat hulls