1. Feed Additives Dr. Özge SIZMAZ University of Ankara Faculty of Veterinary Medicine Department of Animal Nutrition and Nutritional Diseases, Ankara, Turkey
Ankara Üniversitesi Veteriner Fakültesi Hayvan Besleme ve Beslenme Hastalıkları

2. Organic Acids
Carboxylic compounds that are found in animal and plants naturally.
For example:
Formic acid
Acetic acid
Propionic acid
Butyric acid
Fumaric acid
Citric acid

3. Organic Acids
Some OA can be used as an alternative for antibiotics like formic and propionic acid. Especially they have a direct effect on E. Coli and other pathogen microorganisms.

4. Organic Acids They shows their effects by different way:
By lowering pH
By increasing the enzyme activity
By being used as an energy sources
By reducing the form of biogenic amins
By increasing the microvillus of intestine by affecting the mucosal morphology

5. Organic Acids
6. By preventing the loses of energy in ruminants by decreasing the methane emmision
7. By preventing the ruminal acidosis by preventing the sudden decreasing of pH

6. Organic Acids
1. By lowering pH: OA reduce the pH and inhibit the generation of microbial growing.
When pH decrease, lactic acid bacteria increase, so the microbial colonization is affected.

7. Organic Acids
2. By increasing the enzyme activity: OA increase the proteolytic activity by reducing the gastric pH.
- Also stimulate the pancreatic secretion
-so they contribute to digestion and absorbation

8. Organic Acids
3. By being used as an energy sources: propionic a., butyric a., lactic a. Which are the big mollecules have an energy value and are used as an energy sources by metobolizing in the body. So they can not effect the microorganism. For this purpose it must be protected- by pass

9. Organic Acids
However the small mollecules like formic acid has no energy value. So it can be absorbed from the intestine and wasted fastly. Therefore it can be affected on enteropathogens by passing the intestine where the pathogens colonized.

10. Organic Acids
4. By reducing the form of biogenic amins: the addition of some OA to the feeds that are rich in protein reduce the biogenic amins like putrecin, cadaverin..

11. Organic Acids
5. By increasing the microvillus of intestine by affecting the mucosal morphology: Therefore OA improve the absorbation of nutrients

12. Organic Acids
6. By preventing the loses of energy in ruminants by decreasing the methane production: Fumaric and malic acid increase the DM digestibility and the ratio of propionate. Then it can reduce the methane production.

13. Organic Acids
7. By preventing the ruminal acidosis by preventing the sudden decreasing of pH: Especially malic and fumaric acid increase the usage of lactic acid by Selonomanas ruminantium and CO2 production.

14. Organic Acids
OA are used in feeds as a free acids or their salts and in forms of liquid and dry.
Blend OA are better, because of their synergetic effect and economical function.