E/LMS 12605 : Classification of Feeds

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There exist a very large variety of feeds that can be used to feed animals. Anything that is digestible and not poisonous to the animal can be used as a feedstuff.

Animals in fattening units usually receive a complete feed (ready mixed) as this is the best way to ensure an intake of all the necessary elements. The feeds that will be mentioned in this section can be used as ingredients to compile a complete feed mixture that satisfy the requirements of the animal.

Different types of feeds are fed to get a balanced diet that will promote maximum growth in the shortest possible time at the lowest cost.

The most basic classification of feed according to their chemical compositions can be given as:

Roughage and fibre – including hay, silage, pastures and other forages

Energy feeds – including starch-rich, low-protein feeds and protein supplements

Supplements – including minerals, vitamins and non-protein nitrogen (NPN) supplements

Roughage

Roughages should make out at least 40-50% of the total feed in the first two weeks the animal is in the fattening unit. After two weeks it can be reduced to 10-20% but not less than 10%. Types of roughages include but are not limited to:

Lusern hay (Medicago sativa)
Soybean hay and straw (Glycine max)
Barley hay and straw (Hordeum Vulgare)
Oats hay and straw (Avenasativa)
Grass-types hay (Eragrostis)
Different types of Silage (Have relative high energy values)

Dry Roughage - Includes all dry or dried feeds with more than 18% crude fibre on a dry mass (DM) basis.

Pastures and Veld - All feeds that are not dried or processed before feeding.

Silage - Feeds that are processed through controlled fermentation.

Fibre

Beef cattle are ruminants; therefore, they also need some fibre. Straw is a common feed fed in our country. It is high in fibre, but very low in energy and protein and is not a feed. Straw should be used for bedding or left in the field and ploughed down to build soil structure. Alfalfa-grass hay also has fibre but at much lower levels. So, a well-balanced ration of barley and alfalfa-grass hay not only provided most of the protein and all energy needed but also all the fibre needed. Too much fibre limits Dry matter intake and stunts growth.

Following Roughages are Available
Hay from legume plants	Lucerne is the best-known legume hay. It is very palatable and is usually beneficial in nearly all rations. It contains high protein levels in general but is relatively poor in energy. It combines well with feed like maize silage, maize and molasses. There is no restriction on the levels of inclusion. As a result of its high calcium content, it should however be avoided during the dry period in cows that are prone to milk fever. Pea hay is mostly of poorer quality than lucerne hay especially because most of the seeds had been removed. The same principles apply regarding the feeding of it. If hay from peas is stringy, it should preferably be ground to increase intake.
Grain and grass hays	These hays have lower protein and calcium levels than legume hays. The growing stage, during which crops are cut for hay, has a large influence on its spontaneous intake and its nutritional value of it. In lactating cows, the levels of inclusion are usually limited because of their lower quality.
Pasturages	Grazing is normally the cheapest source of roughage for cattle. Factors that limit weight gain from grazings are mainly the energy content and the high moisture content of crops. The protein content of rye grass-clover grazing is usually high. Kikuyu has low levels of calcium. Other pasturages on the other hand have high levels of potassium and should be avoided.
Straw	This comprises the stalks and leaves of crops that remain once the seed had been threshed out. Grain straws are the best-known low-grade roughages. It is low in protein, energy and minerals. Of the most common small grains, oat straw is probably the most valuable, followed by barley and corn straw. Maize straw and grain sorghum straw are just as good as oat hay or even better. Straws should be ground in order to get good intakes. The low nutritional value of straws limits their inclusion levels. Small grain straws should preferably not be used in rations. With the necessary supplementation, straws can be used to a limited extent in the feeding of replacement heifers. In the Western and the Southern Cape small grain straws are often upgraded by treating it in an oven or in a stack with ammonia. That way the energy and protein content, as well as the palatability, are improved considerably. It is not normally necessary to grind ammoniated straw. In the case of feedlot cattle, it should not make out more than 40% of the ration. When ammoniated straw is used, it is important for the levels of phosphorus, magnesium, zinc, cobalt, selenium and copper, as well as vitamin A and E, to be supplemented.
Silage crops	This is the cheapest method of storing roughages. Maize is mainly used for this. Good quality silage can also be made from most grass types and legume plants. Silage has high moisture levels and as a result, it is bulky. The crude protein level in silage is often higher than that of hays. It is excellent feeding for young animals older than 9 months. There is no limit on its inclusion in rations. Mouldy silage often contains fungi with dangerous toxins, and it should therefore not be fed to animals.

Energy

This is the most expensive part of the diet. Energy feeds are included on a basis of 40% when the animal enters the fattening unit and are then increased to levels of about 60-70%. The most important energy feeds are:

Maize (Zea mays)
Grain sorghum (Sorghum vulgare)
Molasses

Energy is provided through the breakdown of carbohydrates, protein and oils/fats within the rumen and small intestine. Starch is the most common form of carbohydrates and is found in cereal grains. Feeding excess protein can be used to provide additional energy for feedlot steers; however, it is less efficient than starch digestion.

Oils/fats are energy-rich forms which provide as much as 2.25 times the energy of starch. Unfortunately, levels exceeding 7% in the ruminant diets can lead to a decrease in rumen efficiency.

Energy Feeds

Feeds with less than 20% protein and less than 18% crude fibre such as cereals (grains), fruit and nuts.

It is important that you have an understanding of the potency of the various ingredients that can be used to formulate feedlot feeds. Commonly when we refer to potency, we refer to the protein content of the different ingredients. There is however a range of factors that can have an influence on the protein content of the concentrates or roughages used in your feedlot blend, so it is important to have the various components tested on a regular basis in order to accurately measure the potency.

The following table contains various concentrates with their relative energy values compared to corn and suggested levels of use in feedlot diets:

Value of various energy sources compared to corn in feeder rations with ration restrictions

Concentrate	Value Compared Ration to Corn	Restriction
Concentrate	(%)	(Maximum %)
Corn	100	100
Animal fat	160-180	5
Barley	88-90	100
Beet pulp, dried	88-95	50
Millet	90-100	50
Milo	85-95	100
Molasses	70	5
Oats	88-94	25
Rye	80-85	20
Wheat	100-105	40
Wheat bran	65-80	10
Wheat middlings	70-85	20

Supplements

Where cattle are on veldt grazing, it is common practice to provide them with supplements. The objective is to add to deficiencies that may exist in the feed available to them and thus prevent losses. It can happen that severe deficiencies exist on a specific farm and farmers should always monitor their livestock to determine the presence of specific problems on their farms. On the other hand, supplements can be used to enhance animal performance. Enhanced animal performance is only advisable when gains provide greater financial returns than the associated input costs.

Summer Supplementation

In many parts of KwaZulu-Natal, shortages of iodine, zinc and magnesium limit the growth of livestock. In addition, on almost all farms in the region, phosphorus and salt should be provided, although in many areas close to the sea, salt inhibits lick intake when added to the licks in even small amounts.

A mature cow requires about 30 g of salt and 10 g of phosphorus per day.

Many commercial summer licks are available, but the most commonly used is to mix dicalcium phosphate or P12 with salt. The salt usually comprises 50% of the lick but must be reduced where lick intakes are too low. Intakes of 170 g per cow per day can be expected.

Winter Supplementation

With winter feeding of beef animals, the objective is to maintain adequate body condition for cows so that they can calve down during the subsequent summer and re-conceive as well. The main deficiency in winter veldt, more specifically in the sourveld, is a protein deficiency. The general recommendation is to provide 200 g of crude protein per adult dry cow per day. This could be achieved by the provision of winter licks or the feeding of oil cakes. Many licks are available, and advisors should be consulted. Whichever lick is used, it must be remembered that enough roughage must be fed with the lick because licks are additives and the bulk of an animal’s diet must be provided by relatively cheaper feed. Some examples follow:

Winter Lick 1:

Feed 2 kg poultry litter per cow per day.

Caution: Livestock being fed poultry litter must be vaccinated for botulism and the litter must be free of maduramycin.

Winter Lick 2, for Sourveld:

Maize meal 20.2%

Salt 46.2%

Feed lime 16.8%

Urea 16.8%

Intake should be 0.4 kg per cow per day.

Caution: This lick contains non-protein nitrogen (urea) and the necessary precautions must be taken, including that livestock must be adapted to the lick and the lick must be kept dry. This lick does not contain phosphorus and is suitable for mature animals, whereas growing animals should still be fed phosphorus.

Winter Lick 3, for Sweetveld:

Maize meal 35.8%

Salt 30.0%

Feed lime 17.1%

Urea 17.1%

Intake should be 0.385 kg per cow per day.

Protein Supplements

Protein feeds are also very expensive and make out 20% of the total feeding cost. Protein is included on a basis of 11-13% in the diet of which not more than 40% must be of NPN and the rest must be natural proteins. Protein sources include, but are not limited to:

Urea (NPN)
Oilseed meal
Fish meal

Protein is necessary for muscle development and appetite. Inadequate protein can lead to a reduction in rumen bug numbers and activity, a reduction in take and slower weight gains. Crude Protein (CP) requirements vary according to the rations energy content and the steer’s age and live weight. Young lightweight calves require higher levels of protein at any given energy intake due to their higher requirement for muscle development.

Urea is a cheap form of non-protein nitrogen that the rumen microbes are able to turn into protein for the steer’s use. Urea can be included in the ration but not to exceed 1%-2% of the ration and must be mixed into the grain evenly. Calves under 100kg of weight should not be fed urea because their rumens are still developing. If urea is used in the ration, it should be introduced slowly over 10 to 14 days and must be evenly mixed into the ration. Urea is converted to crude protein by first being converted to ammonia by the rumen microbes. A sudden increase in ammonia can cause death.

Key ingredients	% CP	NEm	NEg	%ADF	%NDF
Barley	13.5	2.07	1.41	7	19
Wheat	11.3	2.20	1.52	4	14
Corn	10.0	1.94	1.30	3	9
SBOM	49.0	2.07	1.41	10	15
Alfa-G Hay	18.0	1.32	0.75	31	42
Straw	3.6	0.75	0.22	54	85

Energy, Protein and Fibrein Common Feeds

SBOM = Soybean Oil Meal
%CP = Percent Crude Protein
NEm = Net Energy for maintenance
NEg = Net Energy for growth
%ADF = Percent Acid Detergent Fiber
%NDF = Percent Neutral Detergent Fiber

Energy information on the feeds is listed as Magi calories per kilogram. (Note that straw is very low in all important nutrients and too high in fibre)

Mineral Supplements and Vitamins

Steers need a range of minerals to maintain good health. Three are important are calcium, phosphorous and salt. Most cereal-based rations provide enough of the trace mineral needed with the exception of calcium phosphorous and salt. However, alfalfa hay is high in calcium but low in phosphorus and when that is part of the ration, calcium does not need to be fed however phosphorous might need to be added to the ration. So, in the beef feedlot project salt must be provided and phosphorous might need to be added. In the sponsored feedlot project, the hay and grain feed will be tested for mineral content. Calcium, phosphorous, salt and trace minerals will be added to the grain mix to balance the needs not provided by the hay and grain. Lose ground salt available free choice must also be provided in the feedlot. Salt blocks will not provide the salt needed. A steer would have to stand there all day and do nothing but lick salt to get enough sodium.

Vitamins will be added to the grain mix in small amounts if needed, however, it is recommended that the calves be given shots of vitamins A, D, E and B12 when they first come into the feedlot in the neck or ear area. High-quality alfalfa-grass hay will help to correct many mineral and vitamin deficiencies.

Additives

Antibiotics, hormones, vitamins, minerals and growth promoters are usually purchased in a premix which already contains the right proportions and is just mixed into the complete diet.

Forms Of Feed And The Characteristics Of Additive Feed

Different feedstuffs are used to make up a complete diet for a fattening unit animal. The different feedstuffs (ingredients) that can be used are classified as:

Loose Ingredients - These are the types used to make up a complete diet from scratch. Loose ingredients include, but are not limited to Maize, Luzern, molasses, Urea, Salt, Water, Calcium, Vitamins, Minerals, Medicine etc. A combination of some of these ingredients mixed together gives form to a complete diet or feed.

Concentrate - Concentrates can be purchased from animal feed manufacturers. A concentrate usually contains a mix of all the necessary feedstuffs like protein, vitamins, growth promoters, salt, minerals and medicine, while it usually does not contain enough energy feed and roughage. The concentrate is then mixed with maize and roughage to form a complete feed.

The complete feed can take on different types of attributes, determined by the type of processing it went through. The complete feed can be in the form of:

Loose Mix Feed - This is the form when all the ingredients are well mixed together and then fed in that form. This is the way it is done on the farm level and in the big commercial feeding units.

Pellets - A complete feed may be bought from an animal feed manufacturer in the form of pellets. The complete mixed feed is pressed into pellets to make it more compact and to reduce the amount of dust. This form of feed is especially useful for the feeding of sheep. The processing the feed has to go through makes it more expensive than a loose mixed feed.

To ensure the maximum intake of feed by the animal, the animal must find the feed attractive. Feed is of no use if it is not willingly consumed by the animal in large quantities. The more feed the animal consumes the better will the average daily gain (ADG) in weight of the animal be and the faster its weight will increase.

Animals consume feed that is easily digestible better. In the case of cattle and sheep, it helps to add 15-20% water in the feed to reduce the amount of dust that occurs from the milling of the feed. Molasses also help to bind the dust.

Sheep do not eat as willingly as cattle and will pick out certain ingredients in the feed and leave the rest untouched. To reduce this problem, you have to ensure that the feed is uniform and that picking is impossible. If the feed is compressed into pellets the sheep cannot pick out certain parts and the amount of dust in the feed is minimal.

Fattening unit animals, especially sheep, is very picky with what they eat. Even the smallest strange smell or taste in the feed will cause the animal to refuse the feed. It is thus very important to ensure that the ingredients in the feed are fresh and of good quality. Feed that is rancid or starting to rot has a strange smell to it and will not be eaten by the animals. Certain types of fungi that develop on wet feed are poisonous and can cause the death of an animal. Other feeds with a strong smell are some of the protein sources. Although there is nothing wrong with the fishmeal that is being used, the smell may be too strong and the animal will refuse to eat it.

Animals take time to adapt to a new kind of feed and will not eat it willingly from the start. This is often seen with feeds that have a strong taste, such as silage. When an animal is not used to silage, a small amount should be added at first so that the animal can get used to it. The amount of silage can then be slowly increased with time.

E/LMS 12605 Livestock Production Manage a Feedlot

Classification of Feeds