Scientific Opinion on the safety and efficacy of formic acid, ammonium formate and sodium formate as feed hygiene agents for all animal species

Efficacy of sodium formate as a technological feed additive (hygiene condition enhancer) for all animal species

In 2015, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) issued an opinion on the safety and efficacy of formic acid, ammonium formate and sodium formate as feed hygiene agents for all animal species. In this opinion, two forms of the additive sodium formate, a solid form (specified to contain ≥ 98% sodium formate (w/w)) and a liquid form (specified to contain a minimum of 15% sodium formate, a maximum of 75% free formic acid and a maximum of 25% water), were assessed. Sodium formate was considered safe for all animal species at a maximum concentration of 10,000 mg formic acid equivalents/kg complete feed (with the exception of pigs, for which a maximum concentration of 12,000 mg formic acid equivalents/kg complete feed was considered safe). Sodium formate was also considered safe for the consumer and the environment. The Panel also concluded that sodium formate is corrosive. The Panel also concluded that ‘for sodium formate, limited data are available to demonstrate their effects in feed’. In the current opinion, additional data to demonstrate the efficacy of sodium formate liquid as a hygiene condition enhancer in feed for all animal species were assessed. The Panel concluded that sodium formate liquid has the potential to be efficacious as hygiene condition enhancer in feedingstuffs for all animal species at the proposed use level.

Porcine intestinal yeast species, Kazachstania slooffiae, a new potential protein source with favourable amino acid composition for animals

There is little information about Kazachstania slooffiae which dominates among other yeasts in the pigs' intestine. Therefore, the aims of this study were to characterise the yeast cell contents and to investigate which nitrogen sources, organic acids and alcohols may be utilised or produced by this species. The results showed that, K. slooffiae could use urea, ammonium sulphate, peptides and single amino acids and produce thereby ethanol and formic acid. However, this yeast did not metabolise amino acids, lactic, butyric, propionic and acetic acids as sole carbon source. Using a global metabolite profiling approach employing gas chromatography and high-resolution liquid chromatography mass spectrometry, was found that the amount of peptides and dehydroascorbic acid considerably increased in the fermentation residues after yeast cultivation. It is noteworthy that the cells of K. slooffiae had higher contents of nitrogen and total amino acids (especially lysine) than the cells of nutritional yeast (Saccharomyces cerevisiae). This study indicates that due to potential production of peptides and formic acid in the intestinal tract, K. slooffiae might have an impact on the gut health. Moreover, from a nutritional standpoint, the cells of this yeast can be a good source of protein with useful amino acid composition for animal.