The Use of Organic Acids in Swine Nutrition, with Special Focus on Dietary Potassium Diformate

With costs of pig production under mounting pressure, the nutrition of pigs is of increasing interest, as this is critical to their subsequent performance through to market. Sustaining growth rate and optimising feed efficiency at this time are key requirements for economic success.

The application of organic acids and their salts to diets for pigs has been studied extensively. They have proved especially effective in maintaining growth performance since the ban on antibiotic growth promoters (AGP) came into effect in Europe in 2006. Numerous trials have demonstrated their mode and magnitude of action and established effective doses for piglets, fattening pigs and sows. A multifactorial analysis (holo-analysis) demonstrates that using acids in pig diets (tested in almost 38,000 pigs world-wide – data include 484 published data-sets covering 658 trials with 158 different acids, acid salts and admixtures) improves the productivity parameters of greatest importance to economic success. All acidifiers in general had a positive effect on feed intake (+1.21%), on weight gain (+5.48%) and feed conversion (-3.69%) – always compared to a negative control. 

The use of formic acid and its double potassium salt in particular have been the subject of intense investigation, with the result that we now know its dose-dependent effect on growth performance and feed conversion in pigs under a range of different environmental conditions and feed formulations. Its main mode of action is its antimicrobial effect, which makes it comparable with AGP’s; but organic acids also reduce pH in the stomach, which optimises conditions for pepsin activity; and increase the digestibility of nitrogen, phosphorus and a number of minerals. This is not only beneficial in sparing nutrients for growth, but it also prevents nutrient losses that might otherwise contribute to environmental pollution. Again, the holo-analysis confirmed the effects of dietary potassium diformate (KDF) in pigs. The model shows that dietary KDF leads to beneficial effects on feed intake (+3.52%), weight gain (+8.67%) and feed conversion ratio (-4.20%). 

With a growth-promoting effect comparable to antibiotic growth promoters, switching from AGP to organic acids, and especially KDF, can be achieved without detriment to profitability.