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Grain Quality for Feeding Livestock Peter Oriko Kenya Bixa Ltd

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Grain Quality for Feeding Livestock

Peter Oriko

Kenya Bixa Ltd

What does Grain Quality MEAN?

• Grain Trade– Test weight– Level of foreign

material– Color

– Fines & broken kernels– Moisture

• Animal feeding– Level of energy– Level of protein, lysine– Availability of

nutrients

Grain Quality Factors

Let’s look at some of them from each point of view

Foreign Material

• To the Food Manufacturer, Importer-Exporter, or elsewhere in the grain trade:– Very important that corn be all corn

• To livestock:– Depends on what the foreign material is.

Foreign material

• If a truck previously carried a load of rock, foreign material might be a very bad thing.

Foreign Material

• If a truck carrying corn had previously carried wheat, then the foreign material present to feed to livestock might not be such a bad thing.

Sometimes there is a relationship between foreign material and test

weight.

Effects of TEST WEIGHT

• Test Weight is important because of the way we sell corn, by volume (bushel)– but we weigh it to determine that value

• We do not want to buy a light test-weight bushel because we will get less corn.

• But … If we have 100 lbs of corn, does it matter what the volume (test weight is)?

Effect of Test Weight on Composition of Dry Matter (NRC)

Test Weight, lb/bu(%) 46 49 52 54 56

Crude Fiber 2.4 2.4 2.4 2.4 2.3Ether Extract 4.4 4.4 4.5 4.6 4.6NFE 81.3 81.2 81.4 81.1 81.4Crude Protein 10.4 10.5 10.3 10.5 10.2DE, Kcal/lb 1846 1808 1865 1848 1848

Effect of Corn Test Weight on Composition, JAS 29:977

Corn test wt (lb/bu)Nutrient, % 35.2 46.1 57.8

Crude protein 11.7 10.5 11.0Ether extract 2.9 3.1 4.7Crude Fiber 3.5 2.7 2.2Ash 2.0 1.8 1.4NFE 79.9 81.9 80.7Gross Energy,Kcal/lb

2018 2013 2036

Effect of Test Weight on Digestibility of Corn by Swine

(NRC - Corn, dent, grain gr 1-5 US)

Test Weight, lb/bu(%) 46 49 52 54 56

Crude Fiber 35 41 47Ether Extract 67 72 70NFE 92 94 93Crude Protein 76 81 80TDN 92.1 90.2 93.1 92.2 92.2

Comparisons for Swine of Corn by Test Weight and Foreign Material

(NRC - Corn, Grain, Canadian)

Test Wt, lbs/bu: 56 54 52 50 57Foreignmaterial,%:

2 3 5 7 12

Digestibility coefficient

Crude fiber 47 47 47 47 47Protein 80 80 80 80 80Energy, Kcal/Kg 4071 4071 4064 4063 4069TDN, % 92.3 92.3 92.2 92.2 92.3

Effect of Test Weight on Chick Performance

Test Weight DietaryProtein,

21-daywt gain

Feed/gain

Grain Ground %55 55 20 383 1.6749 52 20 350 1.7242 48 20 372 1.6636 41 20 337 1.76

Effect of Test Weight on Chick Performance

Test Weight DietaryProtein,

21-daywt gain

Feed/gain

Grain Ground %55 55 15 274 1.9742 48 15 267 1.9936 41 15 266 1.97

Broken Kernels

• For livestock, we grind the grain anyway!

• But:– Broken kernels more susceptibility to:

• insect damage• mold growth• moisture accumulation

– So Storage Quality Decreased

Conclusion - Effect of Test Weight on Animal Performance

• ALMOST NONE!

• If they can eat enough feed to meet their energy needs.

Conclusion - Effect of Foreign Material on Animal Performance

• Depends on the foreign material

• There may be other considerations, however– Storage quality– Insect susceptibility

– Drying characteristics– Transportation & storage costs

Cost Considerations

• Example: $2.80/56 lb. = $0.05/lb

• If corn weighs 50 lb/bu instead of 56, then its equivalent price is $2.50 (because $2.50/50 = 0.05).– If priced lower it may be a good value

(depending on those other factors: storage, transportation, etc.)

High Moisture Corn

• Some studies have shown higher digestibility of diets fed wet vs. dry

• Wet diets spoil more readily

• Most advantage is probably from limiting feed wastage

• Performance differences are seldom shown

Ensiled High Moisture Corn vs. Dry Corn for Swine

1956 1958 1958 1960 1960 1961

ADG 103 105 100 103 98 98

F/G 108 104 111 105 101 107

Performance compared to dry corn.

Dry Corn = 100

Conclusions: H.M. vs Dry Corn

• High Moisture can be = to dry corn

• Not generally better for swine

• Use therefore depends on other factors

• See PIH 73 for further conclusions

Factors influencing choice of high moisture corn

• Availability of fuel for drying

• Equipment to dry or ensile

• Harvest time requirements (speed, etc.)

• Equipment or labor to feed every day

• Costs - all considered of each system

• Compatibility with present program

• Flexibility of the program

A Word on Palatibility

• Given a choice pigs will display their preferences

• Within reason, without a choice pigs will eat about the same amount of feed

Ingredient Quality (Qualitative)

• Physical characteristics (analyst’s skills): Color, Texture, Odor and Taste, Particle size (screen analysis), shape, evidence of wetting, Adulteration, damage and deterioration, bulk density storage, pests, faecal material, hairs etc, spot chemical tests.,

Ingredient Quality (Quantitative)

• Chemical analysis: Moisture, CP, CF, EE, NFE, ash, Acid insoluble ash (silica or sand), salts, free fatty acids, biogenic amins urea, and NPN, amino acids.

Quantitative factors• Anti-nutritionalfactor:Extrinsic

(contaminants):mycotoxins,weeds, insecticide, herbicides, fungicides

• Intrinsic:allergins,lectins, phytoestrogens, glucosinolates (rapeseed),saponins, tannins, ricin, sinapine, gossypol, (cotton seed cake), lipoxygenase, trypsin inhibitor, urea.

• Decomposition and rancidity test: acid value, peroxide value, etc.

• Protein quality: protein solubility or dispersibility, Nitrogen solubility, mailard reaction product, dye binding, pepsin digestibility, amino acid digestibility.

Quality evaluation of grains

• The feeds are usually subject to following three types of tests

• Physical

• Chemical

• Biological

Physical evaluation of grains

• Colour : Any change in the colour of the feed ingredients gives an indication of the maturity of the grain, storage conditions, presence of toxins, contamination due to sand, possible use of insecticides/fungicides which gives dull and dusty appearance.

• •

• Size : Size of the grains govern its energy value due to the proportional decrease/ increase in seed and its coat. Smaller the grain lower will be the ME value.

• Homogeneity: The presence of contaminants like other grains, husks broken grains, weed seeds, infested seeds.

• Smell: Smell is the next best indicator• Taste: Each ingredient has a different taste, any

change in the taste like bitterness in the grains, soya, sunflower oil meal and groundnut cake indicates the presence of mycotoxins.

• Touch: Feeling the raw material will indicate the dryness and moisture content and clumpy ness.

• Sound: Dry grains on pouring down or biting will produce sound of spilling coins.

Chemical Evaluation• An analytical laboratory for the precise

estimation of nutrient contents and contaminants is of utmost importance.

• Analyse the feeds for proximate principles. This indicates possible constraints on usage due to the presence of excessive content of crude fiber, fat or total ash. Low CP and high CF of oil seed meals is indicative of adulteration with fibrous material.

• The high CF alone is indicative of adulteration with urea and or some inferior quality oil seed meals like mahua, castor or karanja cake.

• The amount of acid insoluble ash is a good guide to the amount of sand or other dirt which may be present. The fish meals are usually adulterated with sand during drying process.

• Maximum permissible aflatoxin levels by different agencies

• Food/Feed Maximum level

Feeds for broilers 400 ppbFeeds for layers 900 ppbFeeds for breeding stock 300 ppb

USA Dairy/Breeding animals

100ppb

Finishing Swine 200 ppb

BIS Poultry 20 ppb

New Delhi

Chicks 150 ppb

Microscopic Evaluation• Feed microscopy is commonly used for

confirming the adulteration and identifying the adulterants ( AOAC, 1970). Feed ingredients, adulterants and contaminants must be studied under low and high magnification for distinguishing features whether coarsely or finely ground. At physical characteristics such as shape, color, and particle size, softness, hardness, and texture of the feeds are examined at low magnification of 8x to 50x.

• It is useful method to identify impurities/contaminants and evaluating the quality of feed ingredients. It also serves as a useful method for identifying missing ingredients in finished feed.

Chemical Evaluation

• Cereals are characterized by relatively low protein and high carbohydrate contents contained in kernel. The germ is rich in proteins, fats, sugars and minerals whereas the endo-sperm is low in protein, fat and ash contents.

contd

• The various chemical changes that occur during storage are due to increased activity of endogenous and exogenous enzymes which are respon-sible for quantitative and qualitative changes in carbohydrates, proteins and fats of the cereals in addition to colour, flavour and texture

Carbohydrates:• In Coastal Kenya, the temperature and relative

humidity varried greatly ( Temp: 6-45 C ; R.H: 22-100%) during storage which causes biochemical and physical changes in grains such as bursting and gelatinisation of starch and depending upon the moisture content. Amylases hydrolyse the starch into dextrose and maltose and significantly increase the content of reducing sugars during storage.

Contd

• Storage of wheat above 12 % moisture increased sucrose, glucose,fructose and rafinose contents. The storage of cereals at high moisture content also produces sour odour due to the production of alcohols and acetic acid.

Proteins

• The high temperature and production of chemicals in grains during storage denature the proteins and make them less dispersable in water, deteriorates the gluten quality and increase the free amino acids contents.