ANN 111: Principles of Animal Nutrition and Feed Technology (2+1)

ADDITIVES THAT AFFECT THE HEALTH STATUS OF LIVESTOCK

• Antibloat compounds:
  • Surfactants such as poloxalene is used as a preventive for pasture bloat,several other products have been shown to be highly effective to prevent bloat are also available in the market.
• Antifungal additives:
  • Mould inhibitors are added to feed liable to be contaminated with various types of fungi such as Aspergillus flavus, Penicillium cyclopium etc.
  • Before adding commercial inhibitors all feedstuff should be dried below 10 percent moisture. Propionic, acetic acid and sodium propionate are added in high moisture grain to inhibit mould growth.
  • Antifungals such as Nystatin and copper sulphate preparations are also in use to concentrate feeds to prevent moulds.
• Anticoccidials:
  • Various brands of anticocidials are now available in the country to prevent the growth of coccidia which are protozoa and live inside the cells of the intestinal lining of livestock.
• Antihelmintics:
  • Under some practical feeding conditions anthelmintics have also been used. The compounds act by reducing parasitic infections.

Anticaking agents

• Anticaking agents are anhydrous substance that can pick up moisture without themselves becoming wet. They are added to dry mixes to prevent the particles clumping together and so keep the product free flowing.
• They are either anhydrous salts or substance that hold water by surface adhesion yet themselves remain free flowing:
  • Salt or long chain fatty acids.
  • Calcium phosphate
  • Potassium and sodium ferryocyanide
  • Magnesium oxide
  • Salts silicic acid – Al, Mg, Ca, Salt.
• Sodium aluminium silicate
• Sodium calcium aluminium silicate
• Calcium aluminium silicate

Humectants

• These are substance which are required to keep the product moist, as for example, bread and cakes.
• Anticaking agents immobilise moisture that was picked up. Humectants are not of much use in poultry feed.

Firming and crisping agents

• These are substances that preserve the texture or vegetable tissues and by maintaining the water pressure inside them, keep them turgid.
• It prevents a loss of water from the tissues.

Sequestrants

• Certain metals – copper, iron can act as pro-oxidant catalytic and there fore need to the immobilised. Sequestrants are compounds added to do this.
• These compounds should have affinity to metal ions and should prevent the metal in becoming engaged in oxidative action. Most effective sequestrants Ethylene diamine tetraacetic acid (EDTA).
• Calcium salt of EDTA works satisfactorily as a sequestrant without interferring with trace mineral metabolism.

Sweeteners

• It is common constitution of food but yet used as additive. Eg. Sugar
• Some are poorly digestible, may cause digestive upsets.
• Saccharin – extensively used during World War I. It is a compound without any calorific value.
• Additives such as humectants, firming and crisping agents, sweeteners, emulsifiers, stabilisers, acid, buffers are not commonly used in poultry feeds.