The European Food Safety Authority has recently published safety and efficacy opinions on a silage inoculant, urea, chelated zinc, phytogenic feed additive, 6-phytase enzyme, flavours and phosphate retention in dogs.
The European Commission frequently requests the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) to provide a scientific opinion on the safety for the target animals, consumer, user and for the environment and on the efficacy of several products.
Recently the following products have been reviewed and judged:
The strain of Lactobacillus brevis is intended for use as a technological additive to improve the ensiling process at a proposed dose of 1x108 to 1x109 CFU/kg fresh material.
The bacterial species L. brevis is considered by EFSA to be suitable for the Qualified Presumption of Safety approach. Therefore, the strain does not require any specific demonstration of safety other than confirming the absence of any determinants of resistance to antibiotics of human and veterinary clinical significance.
Provided laboratory results showed that the additive has the potential to improve the production of silage from forages by increasing acetic acid production resulting in an extended aerobic stability of the treated silage.
Urea in ruminants
Urea supplementation to feed for ruminants provides non-protein nitrogen for microbial protein synthesis in the rumen and thus in part replaces other dietary protein sources.
Urea supplementation of feed for ruminants at doses up to 1% of complete feed DM (corresponding to 0.3 g/kg bw/day) is considered safe when given to animals with a well adapted ruminal microbiota and fed diets rich in easily digestible carbohydrates.
Urea is considered to be non irritant to skin and eyes and its topical use suggests that it is not a dermal sensitiser. The risk of exposure by inhalation would be low. Based on the metabolic fate of urea in ruminants, the use of urea in ruminant nutrition does not raise any concern for consumers’ safety.
Zinc from zinc chelate of amino acids hydrate would not exert additional or different adverse effects in target species than those observed for zinc from authorised inorganic sources.
Consequently it is concluded that the zinc chelate of amino acids hydrate is a safe source of zinc for all animal species, considering the maximum authorised contents for total zinc in feedingstuffs.
However, in order to draw a final conclusion, some further refinement to the assessment of zinc-based feed additives in livestock needs to be considered (drainage and run-off of zinc to surface water), for which additional data would be required.
Zinc chelate of amino acids hydrate is recognised as an efficacious source of zinc in meeting animal requirements.
Crina Poultry Plus (CPP) is a feed additive consisting on seven active substances: benzoic acid (83 %), thymol (1.9 %), eugenol (1 %), benzylsalicylate (0.3 %), piperine (0.1 %), isoamylsalicylate (0.1 %) and trans-anethole (0.1 %).
It is intended to be used as a zootechnical additive in complete feed for chickens for fattening (300-450 mg CPP/kg feed) to favourably affect their performance.
The FEEDAP Panel could not draw any final conclusion on the safety for the consumer of CPP used as feed additive in chickens for fattening. In the absence of data on the environmental fate of piperine, isoamylsalicylate and benzylsalicylate, or the additive itself, the safety for the environment could not be assessed.
FEEDAP said that there is insufficient evidence that CPP at the recommended dose can improve the zootechnical performance of chickens. The sensory properties of the meat from chickens fed CPP are not affected.
6-phytase enzyme for minor poultry species
Phyzyme XP is a feed additive that contains 6-phytase, produced by a genetically modified strain of Schizosaccharomyces pombe (ATCC 5233) and is authorised for use in feed for chickens and turkeys for fattening, laying hens, ducks, piglets, pigs for fattening and sows.
The applicant requested for an extension of use of the additive to all minor poultry species. Safety for chickens and turkeys for fattening and for laying hens was previously established at 750, 1000 and 1500 U/kg feed, respectively. Given the margin of safety established for the major poultry species, a maximum dose of 1000 U/kg feed was considered safe for all minor poultry species.
Since the mode of action of phytases can be reasonably assumed to be the same in all avian species the minimum effective dose authorised for fattening birds (250 U/kg feed) and for laying birds (150 U/kg feed) was considered efficacious for minor poultry species.
Food flavours for feed
The flavour compounds 3-propylidenephthalide, 3-butylidenephthalide and 3,4-dihydrocoumarin belong to chemical group 11, defined as ‘alicyclic and aromatic lactones’. All three additives are currently authorised for use as flavours in food.
The FEEDAP Panel was unable to perform an assessment of 3-butylidenephtalide because of the absence of data on the purity of the compound.
The proposed use of 1 to 5 mg 3,4-dihydrocoumarin/kg complete feed was considered safe for all animal species with a margin of safety in the range from 5 to 18 fold.
For 3-propylidenephthalide, the maximum safe level in feed would allow a use level of 1 mg/kg complete feed for all species with a margin of safety ranging from 1 to 2.5.
Safe concentrations should be appropriately reduced if used in water for drinking.
Since 3-propylidenephthalide and 3,4-dihydrocoumarin are used in food as flavourings, and their function in feed is essentially the same as that in food no further demonstration of efficacy was considered necessary.
Restricting phosphate uptake in dogs
Llanthanum carbonate octahydrate (Lantharenol) is a feed additive currently authorised for use in cats. The producer also asked an opinion for use in dog food.
Lantharenol is intended to be used in the feed of adult dogs (1500 – 7500 mg/kg complete feed) to restrict the intestinal absorption of phosphorus. Restricting phosphorus uptake may act to prevent/reduce chronic renal malfunction in ageing animals. The proposed duration of administration is continuous throughout the adult life of the dog.
Based on the data presented, FEEDAP concluded that Lantharenol has the potential to reduce the phosphorus bioavailability in adult dogs at the lowest recommended dose (1500 mg/kg complete feed). The Panel was not in a position to comment on whether the changes to phosphorus absorption following the addition of Lantharenol to the diet of dogs will have any long-term effects on renal function.