Organic acids as potential alternatives to antibiotic growth promoters for pigs

In the context of phasing-out antibiotics for growth promotion and prophylactics against enteric diseases in pigs within the EU, a particular interest is now paid to the antimicrobial potency of various carboxylic acids, and of short chain fatty acids (SCFA), in particular. Their addition generally lowers the pH and buffering capacity of the diet, increases gastrointestinal acidity, proteolysis and nutrient digestibility, promotes beneficial bacteria at the expense of pathogens and modulates numerous physiological processes after absorption. Four major benefits can be expected: • improved health and resistance to disease; • faster growth; • increased efficiency of diet utilisation; • better carcass quality. Also, secondary effects may be achieved with supplemental SCFA, i.e., less volatilised ammonia (“acidic rains”) and pollutants (N and P). This paper outlines some physicochemical features and mode of action of SCFA and their salts, which are commonly available for pig producers. Also, some nutritional, bacteriological and physiological responses to graded doses and sources of SCFA during post-weaning, growing-finishing and reproductive cycles of pigs are examined