Potential feed resources and

their characteristics

By

Adugna Tolera

Categories of feeds Roughages or forages

High fiber content (>18%

CF or >35% NDF

Low energy content per

unit weight

Low digestibility

Dry roughages: hay,

straw, stover, bagasse

Wet roughages– green

forages, silage, banana,

plantain and enset

leaves, cane tops,

horticultural by-products

Concentrates

High in energy and/or protein

Low in fiber (<18% CF or

<35 NDF)

High energy-low protein

(<20% CP) e.g. cereal grain,

roots & tubers, fruits,

molasses

High protein-low energy

(>20% CP) e.g. oilseed

meals, brewers’ grain

Intermediate protein and

energy content e.g. wheat

bran

Forages and roughages

High fiber, low energy and variable protein

content

Variable nutritive value and digestibility

because of variations in species, variety,

harvesting stage (maturity) and storage

condition

Necessary to maintain normal rumen function

Required by lactating cows to maintain

normal milk fat content

Limited use in swine and beef finishing

rations 3

4

Ingredients for Concentrates

Energy Protein Energy &

Protein

Cereal grains

- Maize

- Sorghum

- Barley

- Wheat etc.

Molasses

Roots &

tubers

Oilseed cakes

–Noug cake

–Cottonseed

–Sesame

–Peanut

–Sunflower

–Linseed

–Soybean

meal

Poultry litter

Brewers grain

• Wheat bran

• Wheat short

• Wheat

middling

• Rice bran

• Whole

cottonseed

Concentrate mixtures may

contain any or all of

Energy feeds

Protein supplements

Mineral supplements – limestone, calcium

carbonate, steamed bone meal

Vitamin supplement – ensiled yeast,

carotene, fish oil etc.

Feed additives ? – antioxidants, probiotics,

enzymes, emulsifying agents, buffers etc.

5

High energy concentrates

Primarily added to increase energy density of

the ration

High in energy and low in fiber content

Protein content is low compared to oilseed

meals and protein quality is variable or low

Low Ca but fair P content

Low vit D, vit A (except yellow maize),

riboflavin, vit B12, panthotenic acid, fair vit E

6

Protein supplements

Contain >20% CP

Critical for young, rapidly growing animals and high

producing dairy cattle

Much more expensive than energy supplements =>

optimum use without wastage is a must!

Ruminants – rumen degradable protein for microbes

and microbial protein and undegradable protein for

the host. Protein quality is important for high

producing animals (microbial protein is not adequate)

Non-ruminants – indispensable amino acids and N

for synthesis of dispensable amino acids (consider

the limiting amino acids) 7

Potential feed resources

Natural pastures – grasslands, bushes and

shrubs (browses)

Crop residues

Cereal straws and stovers

Grain legume haulms

Agro-industrial by-products

Milling by-products – cereal & legume brans and

middlings

Oilseed cakes & meals – cottonseed, noug, linseed,

groundnut, sunflower, sesame, rapeseed cake, soybean meal

Sugar factory by-products – molasses, bagasse, cane

tops

Brewery and distillery by-products – including from

home brewing and distilling

8

Potential feed resources (cont…)

Grain and grain screenings Screenings – barley, wheat, bean, lentils

Whole cottonseed

Cultivated forages and pastures

Conserved forages

Horticultural by-products and wastes

Other feeds derived from cropping systems Thinning, leaf stripping, topping

Enset, banana and plantain leaves and sweet potato vines

Other feeds Poultry litter, Cactus, Prosopis and Acacia pods etc.

9

Natural pastures

Traditionally - major

source of feed

Availability decreasing

from time to time

Decreased productivity

due to heavy use and

other factors (prolonged

and excessive use)

Increased dependence

on supplementary feeds

=> more demand for

concentrates 10

Challenges: Land use change (shrinkage of grazing land due

to expansion of cropping)

Grazing restricted to road sides

11

Natural pastures –

Challenges (cont…)

Encroachment of

invasive species

Restricted livestock

mobility

12

Seasonal fluctuation in availability and quality of natural pastures

13

Natural pastures –

Challenges (cont…)

Recurrent droughts

Weakening of customary institutions

Lack of sustained investment in rangeland improvement

•

14

Make >50% of biomass of crops Have become increasingly

important sources of animal feed

Contribute about 50% of feed supply

Low nutritive value and wide variability

Seasonal availability Bulky to transport over long

distance Limited use of technologies for

improving quality

Crop residues

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Genetic factors (species, variety)

Stage of maturity at harvest

Harvesting and handling losses

Plant morphological components

Duration and degree of weathering after harvest and before residue collection

Climatic conditions More than one year old stack of

wheat straw

Nutritive value of crop

residues is affected by

Varietal selection

Harvesting at the right stage of maturity

Proper handling and storage

Treatment

physical,

chemical and

Biological

Mechanisms of enhancing crop residue use as roughage source

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Crop

residue

CP % NDF% ME (MJ/kg

DM)

Barley 3.3 71.6 6.0

Wheat 2.7 75.0 5.8

Maize 4.8 77.0 6.3

Tef 4.7 71.7

Cereal crop

residues –

relatively low

nutrient content

and high fibre

content, low

digestibility and

low voluntary

intake

Cereal crop residues

Crop residue CP % NDF% ME (MJ/kg

DM)

Chick-pea 5.8 65.4 6.9

Lathyrus 9.2 53.9 7.6

Lentils 8.5 55.9 7.5

Haricot bean 6.8 56.1 7.7

Field pea 6.5 54.8 7.7

Lupins 5.6 58.8 7.7

Legume crop

residues – of

better quality

higher protein

lower fiber

higher

digestibility

Legume crop residues

Cultivated forage crops

Grasses

Elephant (Napier) grass

Rhodes grass

Guinea grass

Oats (highlands)

etc.

Herbaceous legumes

Stylosanthes spp.

Desmodiums (D. intortum & D. uncinatum)

Vetch

Lablab

Cowpea

Alfalfa

Clovers

etc.

•Fodder trees

• Leucaena

• Sesbania

• Calliandra

• Pigeon pea

• Tagasaste

(highlands)

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Forage Types Legumes

Nitrogen fixers

Bacterial system associated w/roots

Assimilate N from the atmosphere

yields (3-4 cuttings)

protein (8-20% CP)

Ca and Mg

Vitamin A

Leaf:stem

Palatable

Forage Types Grasses - General

Long, blade-like leaf

> cell wall content (vs legumes)

Low to Moderate CP, dependent upon maturity

Young, growing plants: 8 - 14% CP

Mature, dormant plants: 2 - 6% CP

Moderate TDN (35-55%), dependent upon maturity

Moderate in Ca, but low in Phos

Can require year round Phos supplementation for many

species

Potential for commercial

production of cultivated

forages for sale as

• High quality green feed

• High quality conserved forage (hay or silage)

• Leaf meal as protein supplement in compound feeds

• Forage seeds for other forage producers

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Characteristics of Common Roughages

Compared to concentrates:

Major component - CELLULOSE

Higher in fiber content; > 20% CF

Bulky - low nutrient density, fewer nutrients

consumed per unit volume

Nutrients made available through microbial

digestion in rumen or cecum

Compared to concentrates:

better sources of fat-soluble vitamins

A -- synthesized from the carotene

D -- prevalent in sun-cured forages

E, K -- abundant among green forages

Greater variability: nutrients & acceptability

stage of maturity when harvested

different harvest & storage procedures

Characteristics of Common Roughages

Forage Quality Factors

Plant anatomy and morphology

Leaf:stem - positive association

Leaves higher in protein and DMD, lower in

fiber than stems

With forage maturity, then leaf:stem (more

stems)

Increase in fiber and lignification, lower

digestibility

Forage Quality Factors

Visually Assess for:

Color - Green with no evidence of mold

Leaf:stem (80% of nutrients in leaf)

Maturity - seed heads, stems, moisture %

Weeds and trash

Moisture content

Measures of Forage Quality NDF - Neutral-detergent fiber

negatively correlated with DMI

ADF - Acid-detergent fiber

lignified cellulose -- undigestible

negatively correlated with digestibility

Protein Content (DM basis):

Excellent = > 13% CP

Medium = 7 - 12% CP

Poor = < 6% CP

Forage Intake

In ruminants - controlled by physical fill

Rate of digestion

Rate of passage

ForageQuality

Expected DMI(% of BW)

Low 1.50

Medium 2.00

High 2.50

Crude Fiber and Protein Relationships

% CP

Crop

Residue

Poor Grass

Hay

Good Grass

Hay

Legume

Hay

Human Food

By-products Grains

Forage

Conc. 10

20

30

40

50

%

CF

5 10 15 20

Adapted from Moore, 1996 Pro

tein

Su

pp

l

Feed value as CF &/or CP

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Conserved forage

Grass hay

Variable quality

CP may vary 3-12%

depending on

Grass species (botanical

composition)

Stage of maturity

Harvesting, drying and

storage conditions

Weather condition

Moisture content

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Hay

Mechanical harvest

Optimize quality & quantity DM

Dehydrated green forage: < 15% moisture

Purpose:

Preserve quality forage for use during period of

inadequate poor nutrient availability

Weathering or maturity of forage

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37

ለድርቆሽ የሚታጨድ ሣር

ሳሩ በትክክለኛ የእድገት ደረጃ ላይ ሲደርስና ጥሩ የአየር ፀባይ ሲኖር ድርቆሽ

የማዘጋጀት ሥራ በሣር ማጨድ ይጀመራል.

38

The grass cannot be baled

immediately after being mown, as

the moisture content is too high.

These neat rows of grass will be

turned in order that the sun dries

the grass.

ለድርቆሽ የታጨደ ሣር

Hay

Critical:

Moisture

Palatability

Mold, Dust, Stems

Weeds & foreign matter

Nutritive value

Protein

Maturity

Leaf:stem

40

41

ከፍተኛ ጠራት ያለዉ ድርቆሽ ማከማቻ መጋዘን

More mechanisation is used to stack the top quality hay into the barn.

This preserves the hay and ensures that the quality is retained ready

for animals that will feed on it.

Common Losses in Haymaking

Shattering leaves

up to 8% loss for grass hays (5% normal)

up to 40% loss for legume hays (20% normal)

Heat damage

25-30% moisture promotes mold growth in hay

high moisture produces heat

dry hay -- normal maximum temp = 84o F

> 120o F, nutrient destruction & binding

> 160o F, danger of spontaneous combustion

Common Losses in Haymaking

Bleaching

color loss due caused by the sunlight

reduces carotene or Vitamin A activity

Leaching due to rainfall

Nutrient content of orchardgrass hay

harvested at optimum stage or 16 days

later

Nutrient analysis

(DM basis)

Harvest date

May 4

(optimum)

May 20 (16 days

later)

Crude protein (%) 13.3 7.0

ADF (%) 37.0 46.3

NDF (%) 67.1 75.1

NEL (MCal/lb) 0.53 0.39

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% Dry matter loss

0

10

20

30

40

50

60

70

0 20 40 60

% Moisture at time of storage

% D

ry m

att

er

loss

Spoilage loss in bales made from alfalfa-grass hay at

different moisture levels

desirable conditions for

making hay

Maintain leaves

Dry rapidly to 15-20% moisture level

Maintain green colour

Harvest at first bloom or heading

(anthesis) stage

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Color – greenish color

Leafiness – high proportion of leaves indicates well managed and preserved hay

Maturity – Good quality hay is made from forage crops harvested before or at the beginning of flowering of the plants

Dry rapidly to 15-20% moisture level

Odor – desirable odor

Foreign materials – free from undesirable weeds and foreign materials

Mold & insect pests – free from these

Criteria for assessment of hay quality

Silage - Cereal Grains/Forages

Product of acid fermentation of green forage

crops that have been compressed and stored

under anaerobic conditions.

Objective: Preservation on high quality

forage for later use.

Used by dairies and beef feedyards

(+) Preserves nutritive value of the crop

(+) Palatable, nutritious feed source

Agro-industrial byproducts

Oilseed cakes, milling by-products,

molasses, brewery and distillery by-

products etc.

Relatively high quality feed

Important sources of nutrients (protein and/or

energy) for market oriented livestock production

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Agro-industrial byproducts (Cont…..)

Localized availability and distribution

Supply could not satisfy demand

Factories operate below capacity

Very variable quality – depends on processing & handling

Unpredictable price increase

Increase in price of raw materials

Competition from export market (for raw materials)

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By-products of oil extraction from oilseeds

Important protein supplements

Could be rich in energy depending upon amount of residual fat content

Low in Ca but high in P

Nutritive value variable and depends on

Species of oil crop

Processing methods

Storage and handling

Oil seed cakes

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Component

(%)

Decorticated Undecorticated

Press Solvent Press Solvent

Ether extract 7.6 1.9 8.5 1.6

Crude protein 44.5 51.1 25.0 26.6

NDF 23.5 21.1 48.9 55.2

Lignin 4.6 4.8 10.7 11.0

IVDMD 77.8 78.6 56.7 53.2

Chemical composition and IVDMD of cottonseed cake as influenced by extraction methods

Component

(%)

Tella

atella

Areqe

atella

Brewers

dried grain

Molasses

DM 13.2 14 93.3 71.5

OM 96.6 96.8 96.3 83.5

CP 21.1 21 26.1 2.95

EE 7.8 - 3.9 3.36

NDF 53.2 41.1 55.5

Lignin 10.3 - 4.7

ME (MJ/kg0 9.7 8.4

Atella, brewers grain & molasses

The way forward

Map the availability and temporal and spatial distribution of potential feed resources

Exploit complementarities between food and feed production

Develop mechanisms for preserving, storage and transport of feed from seasonally surplus producing areas

Clearly understand the availability, potentials and limitations of the different feeds

Make effective use of available feed resources Avoid wastage of agricultural and agro-industrial by-

products

Use balanced feed to increase efficiency

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Questions and exercises

Major feed resources?

Roughages?

Wet roughages

Dry roughages

Concentrates?

Protein sources

Energy sources

Supplements?

Mineral

Vitamins

Protein/amino acids

Others

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