Animal nutrition,feed additives most important., Lecture notes of Nutrition

Download Animal nutrition,feed additives most important. and more Lecture notes Nutrition in PDF only on Docsity!

Feed Additives

• What are Feed Additives?
• Feed additive is an non drug ingredient or combination of ingredients

added to the basic feed mix or parts thereof to fulfil the specific

need. Usually used in microquantities and requires careful handling and

mixing.

• A dose of a few mg/kg is added
• Types of Feed AdditivesFeed additives are broadly classified into
• A) Nutrient Feed Additives (suppliments) e.g., amino acids, minerals and

vitamins

• B) Non-nutrient Feed Additives : e.g. antibiotics, arsenic and copper

supplements, hormones, beta agonists, immunomodulators, coccidiostats,

enzymes, probiotics, yeast culture and acidifiers, antioxidants, sequestrants,

mycotoxin binders, anticaking agents, humectants, feed preservatives,

flavouring agents, colouring agents, pellet binders, dietary buffers, methane

inhibitors, roughage substitutes, propionate promoters, defaunating agents,

ketosis and bloat controlling agents, surfactants, sweetening agents,

tranquilizers, emulsifiers and stablilizers, bile acid, methyl donors,

sweeteners, etc.

Advantages of use of Feed Additives

• 1. Increase feed quality and feed palatability: Emulsifiers,

pelleting agents are used to meet the demands of feed

manufacturers while antioxidants, fungistatic agents and

fermentation inhibitors ensure proper shelf life of feed.

• 2. Improve animal performance: increases growth FCR and

reduce stress.

• 3. Improve the final product: Addition of antioxidants to diets

produce grades of meat in which the fat does rot rancidify or does

so more slowly. The use of additives such as enzymes also makes

end products more homogenous and of better quality.

• 4. Economise the cost of animal protein: mainly of antibiotics

animal feed contribute to increased production of animal Feeding

antibiotics and other additives lower the cost of meat, milk

and egg production.

 Antibiotic feed additives:

• Antibiotics are a group of soluble organic substances produced from

microorganisms, which in small concentration have the capacity of

inhibiting the growth of other microorganisms and even of

destroying them.

• The antibiotic feed additives are of two types:
• Ionophore antibiotics and non-ionophore antibiotics.
• A) Non-ionophore antibiotics: e.g. Chlortetracycline, oxytetracycline, zinc

bacitracin, virginiamycin, flavomycin, bambermycin, avoparcin, tylosin, etc.

• Mechanism of action:
• 1. Affects enzyme systems : such as some oxidative phosphorylation

reactions, increased intestinal alkaline phosphatase level. Which is

required in the transport of nutrients across the intestinal wall.

• 1. Nutrient-sparing effect : results in, stimulation of good microorganisms

in GIT which favour nutrient synthesis. E.G. Vitamins, amino acids also it

causes, reduce competition for nutrient , gut thinning , lower vitamin

d requirement

• 1. Increase the rumen propionate and decrease the acetate

concentration

• 1. Decrease methane production. Monensin kills

methanogens, while not disturbing propionate-producing bacteria

making utilization more efficient.

• 1. depress the activity of some rumen enzymes like proteases,

deaminases and urease which protects proteins from

rumen and increase utilization.

• 1. Monensin and lasalocid inhibit biohydrogenation resulting

in unsaturated fatty acids are deposited in the body tissues.

• 1. Lower calcium and potassium concentrations.
• 1. Decrease passage rate and this is associated with an

increased amount of organic matter fermented in the

rumen. effective ME value of the diet may be increased by

approximately 10%.

Sulfa Drugs:

During earlier days 5% flowers of sulfur was added to the

feed to control coccidiosis in poultry.

Arsenicals

1. 3-nitro-4-hydroxy phenylarsonic acid (3-nitro) 5%

1. P-amino phenylarsonic acid (arsanilic acid)

Arsenicals improve growth of broilers and such birds have

bright red combs and wattles. Capillaries are enlarged and

engorged through the dilator effect of arsenic.

Copper supplements: These are routinely added to pig

grower diets asgrowth promoters. Copper is believed to be an

effective growth promotant with a mode of action at the

intestinal level due to its bactericidal properties.

Characteristics of a Good Probiotic

1. The culture should exert a positive effect on the host. It

should be gram positive, acid resistant, bile resistant

and contain a minimum 30 x 10

9

CFU (colony forming unit)

per gram.

1. The culture should possess high survival rate and

multiply faster in the digestive tract. It should be strain

specific.

1. microorganisms should be Non-pathogenic nor toxic to

the host.

1. The adhesive capability of microorganisms must be firm

and faster.

1. Be durable enough to withstand the duress of

commercial manufacturing, processing and distribution so

that the product can be delivered alive to the intestine.

Prebiotics : are non digestible feed ingredients for host

that beneficially affect the host by selectively stimulating

the growth and or activity of one or limited number of

bacteria in the colon that can improve the host health.

Act as feed for probiotic microrganism

E.g Galactooligosaccharide (GOS)

Fructooligosaccharide (FOS)

Synbiotic : is a combination of Probiotic and Prebiotic

Feed Enzyme Additives: they act as biocatalysts to assist

the digestion process and support utilization of nutrients that

otherwise go unused. Mostly used in pig and poultry diet.

Acidifiers

Organic acids usually are added only as preservatives, but they

do positively influence performance when included at higher

quantities. Liquid acidifiers are

1. Formic acid 6-8 kg/ton and

1. Propionic acid 8-10 kg per ton.

Advantages

1. improved consistency of feed ,
2. reducing E. coli and Salmonella populations.
3. They include mould inhibition droppings,
4. resulting in fewer dirty eggs,
5. better calcium absorption and egg shell quality.
6. Organic Acids as Alternative Hydrogen Sink

Mycotoxin binders : Mycotoxins are diverse group of

chemicals that are harmful to animals and humans and have

the greatest impact on human and animal health.

The three major mycotoxin producing fungi are Aspergillus,

Fusarium and Penicillium and the toxins are aflatoxins,

zearalenone, trichothecenes , fumonisins, ochratoxin A,

Mycotoxin binding agents include activated charcoal, yeast

cell wall(MOS) products , synthetic zeolites and mined

mineral clays such as aluminosilicates like Hydrated

sodium calcium aluminosilicate (HSCAS) , sodium

bentonite

 Hormones

• These are broadly of two types.
• 1. Anabolic hormones: e.g. Somatotropin, Thyroxine,

Androgens Somatotropin. stimulates growth of endochondrial

bones and epiphysis of long bones while in protein metabolism

it aids nitrogen retention and overall protein synthesis.

• 2. Catabolic hormones: e.g. Oestrogens, Glucocorticoids

Oestrogens inhibit skeletal growth , inhibit protein synthesis

in extrahepatic tissues.

 Saccharomyces cerevisiae yeast cell wall (YCW): is

composed of complex polymers of ẞ-(1-3/(1,6) glucan,

mannan-oligosaccharide (MOS) and chitin.

• MOS is able to play important roles in binding mycotoxins

and improving the micro-environment of the animal

digestive tract

Flavouring Agents :

Flavours are used to improve palatability and thus food appeal.

Palatability and feed conversion ratio are interdependent.

Types of flavours are spices and sweeteners. Taste and odour

are important properties of a food or feed by which they are

recognized and enjoyed.

E.g Capsicum, red pepper, MSG, fennel, fenugreek seed,

ginger

Food colours: They make the food more attractive and

pleasing. e.g. acid fuchsine, amaranth, brilliant blue.

brilliant black, eosin, indigo carmine, sudan red,

azolutin, erythrosine, ẞ-carotene , canxanthin, bixin

(obtained from annatto seed), crocation (saffron), beetroot red,

chlorophyll, anthocyanins.

Pigments: lutein (xanthophyll), cryptoxanthin, zeaxanthin,

• Pellet Binders : improved pellet quality, more control over the

additions of fat and moisture, greater pelleting efficiency,

improved press capacity and die life, lower power consumption,

lower production costs, less fines returns and feed rejections and

less dust in the mill.

• E.g Calcium lignosulphonate, sodium lignosulphonate are

byproducts from wood pulp manufacture. 4% added fat. The

others are molasses 5-10%, calcium aluminates 0.6-1%, and

guar meal 2.5-5%.

• Buffers: Feeding high grain (low fibre) diets to meet the energy

requirements of high yielding (over 35 kg milk/day) cows to

minimize the energy crisis during early lactation leads to changes in

rumen pH and rumen fermentation pattern.

• Buffers are used to correct these changes. e.g. sodium

bicarbonate 200 g/cow/day or 1.5% of grain ration, sodium

sesquicarbonate, magnesium oxide, calcium carbonate,

sodium bentonite. Salt level of the ration may be reduced to half

normal.