CLASSIFICATION OF FEEDSTUFFS

Introduction

Various classification systems are employed to differentiate feedstuffs, each according to a certain purpose.

Classification of feedstuffs divided by origin into three categories:
1. Plant origin Roughage and concentrates
2. Animal origin All products have a high energy content and often a high protein content
They are considered concentrates, except for poultry manure, as it has a high CF contents
3. Chemical Used in feeding when CP in ration is (too) low

Classification of feedstuffs is divided by CF% into two main categories:
1. Roughage With a CF% in the DM higher than 18%
usually vegetative plant parts.
2. Concentrates With a CF% in the DM lower than 18%
ripe seeds/grains or products derived from these

Artificially dried roughage is considered an intermediate between roughage and concentrates. Classification is divided by digestibility percentage into four groups:
Digestibility percentage:
over 70% = good digestibility
60 – 70% = moderate digestibility
40 – 60% = low digestibility
under 40% = very poor digestibility
Within the classification, suitability of feedstuffs for feeding can be categorized according various qualities: DM, feed value, structure, maximum intake, tenability, preservation, labour at feeding and storage provision.

4.1 Classification of Feedstuffs by Origin

Feedstuffs can be divided into plant and animal origin. The latter is less important in animal nutrition.
4.1.1 Feedstuffs of Plant Origin

Feedstuffs classified according origin and composition can be divided into three groups, the majority categorised as roughage.
1.Farm products
2.By-products from agricultural industries
3.Artificial dried fodders

4.1.1.1 Roughage From the Farm
 With high moisture content, fresh products like grass, tubers, roots, silage
 With moderate moisture content, like wilted silage;
 With low moisture content, like hay, straw, stover;
 Miscellaneous, like fruits, pulp.
4.1.1.2 Roughage By-products From Agriculture Industries
 From sugar industries, like pulp, bagasse
 From breweries, like brewers and distillers grains
 Fruit juice/packing industries, like fruit pulps
4.1.1.3 Artificial Dried Fodders, Like Grass and Lucern Meal-pellets

As far as known this way of producing feedstuffs is not often practised in Poland. In The Netherlands artificially drying of grass is especially done in the western parts of that country. The dried pellets are used for e.g. horse breeding.

4.1.2 Products of Animal Origin

These products can be divided into four main groups, most of them categorized as concentrate:
1. Milk and milk by-products (fresh or dried)
2. Products from meat and carcass-industry, e.g. meatmeal, bonemeal, blood meal and feather meal
3. Products from the fish industry like fish meal and shrimp meal
4. Manure of poultry & pigs can be used in the nutrition of ruminants (Their CF content is too high to be classified as concentrates!)
4.1.3 Products From the Biochemical Industry
– Urea and biuret (NPN sources)
4.2 Roughage

Roughage can be divided into seven main groups:

1.Grasses (pasture)
2.Legumes
3.Fodder crops
4.Agricultural by-products
5.Conserved fodders
6.Industrial roughage
7.Miscellaneous feedstuffs

4.2.1 Grasses (Pasture)

Generally, grasses and its products are the main supplier of roughage in most countries with an advanced dairy-farming system. Pasture (grasses) provides a basis for dairy-production. They are abundantly available and with their good quality (usually) the cheapest source of food for cattle.

Unfortunately, the quality of grasses in development countries can be rather of poor quality. The availability may be limited due to land pressure (first priority is to provide staple food for human nutrition) and/or high production costs.

The poor quality is mainly due to:
– Type of grass (varieties, species). Tropical grasses and natural grasses in temperate climates have often a lower protein content and lower NFE (N-free extract, e.g. starch, sugars), while the CF contents is (much) higher than in well managed special selected temperate grasses.

– Maturity is usually reached earlier and flowering may be continuous, also due to climatic and soil factors.

– Quality of grass is affected by management factors, such as:
· Fertilizer input. Low or non N input results in lower CP contents and lower quantities of product.
· Stage ad method of harvesting. Late harvesting (over-mature) provides more bulk but the product will be of poor quality (CF).

– Method of conservation. Usually, warm and humid climates provide a rather poor environment for conservation (hay making, silage making), while similar factors contribute to losses during storage (mould due to moisture).
All in all, the nett result often is a rather poor quality and yield. Grasses and its conserved products do have often a much lower digestibility and feeding value
A low digestibility and feeding value, together with limited availability of grass (in general roughage) complicates making a balances ration for high yielding dairy cattle. In other words: to judge the proper amounts and quality of the supplement concentrates required is more difficult! Low digestibility and feeding value affects the DM intake in a negative way, which results in a more than proportional lower intake of nutrients! The limited amount of nutrients obtained from poor quality roughage should be balanced by towering amounts of usually expensive high quality concentrates. This leads to an increased cost-price of milk, as feeding is the main factor in the total cost-price. Sometimes, feeding costs are up to 60% of the total cost-price per kg milk.

A low digestibility and feeding value often leads to sub-optimal feeding levels and strategies of the potentially high yielding dairy cattle, causing a poor production, low fertility, high incidence of diseases, and disappointed farmers and managers. Availability of good quality concentrates is often limited (or expensive) and strong competition may exist with the monogastric animal production systems (pigs & poultry) and/or export (foreign currency, policy priorities). The expensive (imported) dairy cattle, however, never get a real chance to express their genetic potential for high milk production, but under the above described conditions, the blame should not be put on the cow!

However, developing countries do not always produce sufficient milk to meet the relatively low, but probably rising demand for milk. Only policy decision can solve the following dilemma:
– To moderate production levels from available food resources at reasonable prices. Milk production is a by-product from the agricultural system and is related to the reality of food prices, food quality and milk prices.

– To allow a high cost-price to realize high milk production levels to express the cows’ full genetic potential.
Grasses can be used by grazing or zero-grazing (mowing, cutting and feeding in the corrals, yards, barn or shed: the so-called “cut and carry” system) or can be fed after conservation (hay, silage). Every type of utilization results in losses:
– Grazing
Losses of 25-30% as a result of trampling, urine/dung patches and refusal.

– Zero-grazing
Selective intake may require 10-35% extra feeding to allow for refusal. If the product is chopped (<5 cm), no selective intake can take place. In this case, the average quality is lower resulting in lower DMI and the need for more and better quality concentrates (balancing the ration). - Conservation Losses up to 30% DM in the silage. Losses of nutrients can be even higher (DCP up to 60-70%) due to refusal, soil contamination, side losses in the pit and risk of quality. In hay making there are losses due to weather conditions, leaf losses, storage and refusal. Conclusion It can be said that animal production on grass depends on: - Herbage availability · land · yield - Herbage quality - Herbage intake (related to a = b) - Losses during conservation and/or feeding 4.2.2 Legumes The feeding value of legumes (lucerne, alfa alfa, clovers) varies less when compared to grasses. Protein and mineral contents are often higher, whereas the CF content is lower compared with grasses. Legumes have a high calcium, but a low phosphorus content. Some legumes (clover, lucerne) are able to produce large amounts of high quality fodder under intensive management conditions. Legumes differ a.o. from grasses as their growing points are higher above the ground. Legumes do not allow close cutting (or grazing). In order to obtain high yields irrigation may be necessary. Especially to sustain yields during the dry season. Legumes can be conserved as hay, but leaf losses may be very high. They are less suitable for silage making. The inclusion of some fresh legumes in a diet can be very beneficial for a high yielding dairy cow. 4.2.3 Fodder Crops The most common fodder crops are: roots, beets, carrots, cassava, turnips, swedes, mangolds, tubers (sweet potatoes + vines, potatoes), fodder grains (maize, sorghum, oats, rye) and Brassica species (kale, cabbages, rape). The main advantage of these fodder crops is, that they are capable of producing high yields per/ha, often during periods when other roughage (grass) are in short supply. Frequently they are produced on irrigated land and can be fed fresh or conserved (maize silage), while some products can be relatively easy stored (tubers, roots). Roots, tubers and Brassica species have a low DM% (10-20%) and are relatively rich in energy, supplying nutrients like starches and sugars. Their CF content is low which results in a high digestibility (and palatability). Their protein content is generally low, as well as their mineral/vitamin contents with the exception of carrots, which are rich in vitamin A. Fresh/green fodder crops provide a welcome component in a diet, especially where dried roughage and concentrates are prevailing. Care should be taken with the laxative effect these fodder crops generally have, which may cause diarrhoea (introduce gradually) and may depress the fibre digestibility of other components of the ration. Fodder grains can give high yields: relatively energy rich roughage per unit land. The feeding value depends largely on the quantity and maturity of the seeds included. Sometimes, seeds are harvested for human consumption. This reduces the feeding value of the remaining plant. The protein content is relatively low. Maize is an excellent product for silage making, sorghum can provide several cuts of fresh material (irrigation and cutting at immature stage). Sorghum should not be grazed during the first 3-4 weeks after cutting. Sorghum may contain a rather high amount of prussic-acid in the young stage, causing poisoning (death). 4.2.4 Agricultural By-products Only a part of agricultural products can be utilized by man himself. The amount of by- products for feeding farm animals can be considerable. There is a considerable variation in quantities and qualities of by-products between crops, influenced by species, varieties, climate, season, region and stage at harvest. The most important parts of roughage are the aerial parts (stems, leaves). These can be utilized fresh or dry, cut or grazed, in the field or in the stable/barn. The most common agricultural by-products are: - Straw of legumes, like lupin, with a rather high nutritive value (if properly handled and stored after harvesting). - Cereal grains give straw, stubble, stovers, and chaff as by-products. On average, most cereals yield equal amounts of grain and straw per ha. The quality of straw is very variable, but in general quite low. Generally P content is low and the Ca not easily absorbed, while the very high Silicium (Si) content depresses digestibility. - Sugar beet tops and residues can be an important by-product from agricultural production. The energy content could balance the hay silage feeding (with high content of protein). Often, these residues can be obtained from sugar factories. Include costs for transport when considering sugar beet residues (it has a high percentage of water [85 %], therefore costs per kg dry matter should be calculated beforehand). Summarizing, most agricultural by-products (roughage) have a rather low feeding value, which implies that they need supplementation with concentrates to enable high milk production. 4.2.5 Conserved Roughage Roughage can be conserved into hay or silage. Losses during the conservation process and storage can be 30-50% of the DM, due to continued respiration, leaching by rain, mechanical handling and self-heating. The losses depend on the climate and the success and speed of the conservation process. Generally, losses of energy and DCP are even higher, up to 75%, leaving a conserved product with a low quality compared to the original product. Before fodder conservation is practised, the real feasibility of conservation should be determined, as well as the extra costs for equipment. Modern conservation methods (wilting, quick harvesting and proper sealing) can reduce losses in silage making considerably (15-20% DM). The course book on Grassland Management and Fodder Production elaborates on this subject. 4.2.6 Industrial Roughage By-products from several agricultural industries can be used as roughage for ruminants. Their disadvantages are an often high water content, which affects keeping quality and makes transport more difficult, while the feeding value varies frequently. For those reasons, their use is generally limited to farms in the vicinity of the industrial plants. 4.2.7 Miscellaneous Feedstuffs Chicken manure or litter is quite a valuable "roughage". It contains excrements of poultry, which consists of undigested parts of the feed and the metabolic products with a high NPN content, wasted poultry feed and bedding material. Its feeding value varies, but on the average it has an energy content of 760 FUM and 20-25% DCP in the DM. 4.3 Concentrates Concentrates are mainly derived from the following sources: 1.Cereal grains 2.Pulsus 3.Other seeds & parts 4.By-products from agricultural industries:  Oil industries, like cakes  Milling industries, like bran  Sugar/alcohol/fruit industries, like citrus pulp, beet pulp, brewers grain 5. Animal products 6. Industrial feedstuffs 4.3.1 Cereal Grains They have a DM content of 85-90% and only contain small quantities of CF. Fat content is usually low (1,5-5%) and protein is of moderate quality. Mineral content is not high. DCP varies from 5% (sorghum) to 10% (wheat). Their main function is to provide energy. Usually, there is a strong competition for cereal grains for human needs and the feeding of monogastric animals (pigs & poultry) and the price may be high. 4.3.2 Pulses The main difference with cereal grains is their higher protein content, from 15-30% DCP. In some cases they also contain large amounts of fats. CF content will be decreased considerably if the pulses are dehulled. 4.3.3 Other Seeds & Parts Other seeds, e.g. sunflower seeds and cotton seeds are used as feedstuffs. When dehulled and/or decorticated they have a high energy (fat) content. 4.3.4 By-products From Agricultural Industries From several agricultural industries, by-products become available as feedstuffs for animals. The main by-products are divided into 6 groups: 1. Residues from oil and fat industries (cakes, meal); 2. By-products from milling industries, e.g. bran, pollard, polishing, etc. Corncob meal is specially made for animals. It has a low feeding value; 3. By-products from starch industries, e.g. gluten & cassava/potato residues; 4. By-products from sugar industries, e.g. beet pulp (dried) and molasses. Molasses can be used in rations, e.g. included in concentrates. It facilitates pelleting. In many countries it is a relatively cheap source of energy and can be used to improve taste. Molasses are also used as an fermentation agent in silage making of grasses; 5. By-products of the fruit industries like citrus pulp, pineapple pulp etc.; 6. Miscellaneous products, like bean curd residue 4.3.5 Animal Products Animal products are mainly: 1. Milk and its by-products 2. Slaughter house by-products 3. Fish products 4.3.6 Industrial Feedstuffs Sources of NPN like urea and biuret.