Scientific Opinion on the safety and efficacy of Formi™ LHS (potassium diformate) as a feed additive for sows

Following a request from the European Commission, the European Food Safety Authority (EFSA) was asked to deliver a scientific opinion on the safety and efficacy of Formi™ LHS when used as a zootechnical additive in sows. This product has been authorised for use in piglets, pigs for fattening and sows. The applicant is now seeking re-evaluation of this additive for use in sows. Formi™ LHS is a feed additive consisting of potassium diformate intended to be used in sows at a proposed dose range of 8000 - 12000 mg/kg of complete feedingstuffs. A tolerance study made with sows and including Formi™ LHS at doses up to 5% showed no adverse effects. Consequently, the FEEDAP Panel concludes that Formi™ LHS is safe for use in sows at a maximum dose of 1.2%, with a margin of safety of approximately four. Although Formi™ LHS has a potential antimicrobial effect in the gastrointestinal tract, the nature of the product makes selection for bacteria resistant to clinically relevant antibiotics unlikely. There was no evidence of genotoxicity of Formi™ LHS. The acute oral toxicity was low, and no adverse subchronic effects at the tested dose levels were detected in laboratory animal studies. In chronic studies, the NOAEL was 50 mg/kg body weight/day for forestomach irritation in rats. In addition, data from residues studies in pigs indicate that no increase in the intake of formate is expected from consumption of animal tissues when Formi™ LHS is used. The FEEDAP Panel concludes that the use of Formi™ LHS as a feed additive in sows under the proposed conditions of use is safe for the consumer. Formi™ LHS is an eye irritant. No other effects requiring specific user protection measures were identified. The FEEDAP Panel concludes that use of Formi™ LHS would not pose a risk for the environment. The results from three of four studies show that supplementing sows’ diets with Formi™ LHS has some effects directly on sows (increase in feed intake in two studies) or indirectly on litter’s performance (increase in daily litter weight gain in two studies and an increase in weaning weight in another study). The data support a potential for efficacy at the highest proposed level (1.2%) over the period from one week before farrowing until weaning of piglets. The efficacy of the product at the lowest proposed dose (0.8%) is not demonstrated. No negative effects on meat quality would be expected from the use of Formi™ LHS in sows’ feed at the proposed dose range.