Opinion of the Scientific Panel on Additives and Products or Substances used in Animal Feed on a request from the Commission on the safety and efficacy of the product Farmatan for rabbits and piglets

Farmatan is intended to be used as a feed additive for growth promotion in rabbits up to 8 weeks of age at a level of 3-5 g kg-1 and in piglets up to 10 weeks of age at 3 g kg-1 complete feed. Farmatan contains as active substances 55 % hydrolysable tannins extracted from sweet chestnut wood. Tannins are commonly found in feedstuffs of plant origin. The Commission asked the European Food Safety Authority to issue an opinion on the safety and efficacy of the product Farmatan based on tannin, for rabbits and piglets, evaluating the data provided by the dossier. The efficacy of Farmatan as growth promoter in rabbits was not demonstrated. The dose range recommended for rabbits (3-5 g kg-1 feed) was not confirmed either. In four additional experiments feed supplementation with Farmatan was already started in feeding lactating animals, for which the use of Farmatan is not claimed. In piglets, the efficacy of Farmatan (3 g kg-1) was statistically demonstrated in two experiments (including 4 trials) of the four submitted. However these experiments were carried out with a small number of animals or under poor husbandry conditions (high mortality due to massive diarrhoea). In summary, insufficient evidence of the efficacy of Farmatan in piglets is demonstrated under normal farming conditions. The only positive effects were seen in animals suffering from enteropathy, and were predominantly expressed in a lower mortality and/or less severe signs of diarrhoea. The latter would result also in higher body weight gains which were seen mainly in piglets. Farmatan apparently has no adverse effect on sensory properties of rabbit or pork meat. FEEDAP Panel concludes that the tolerance of Farmatan in rabbits and piglets is not satisfactorily demonstrated. In rabbits, pathology indicated signs of severe inflammation of the stomach and the gut mucosal wall after Farmatan exposure to 50 g kg-1 and even at the recommended dose. In both animal species a tendency for spleen hyperplasia could be seen. The findings in rabbits and piglets suggest also that Farmatan has a potential to promote excessive iron absorption. FEEDAP Panel concludes that at present interactions of Farmatan with protein based feed additives (enzymes, microorganisms) can not be excluded. Dietary additions of Farmatan at 2 and 4 g kg-1 feed did not interact with phytase concerning mineral utilisation in pigs. However, 8.2 g Farmatan showed a tendency for reducing phosphorus and calcium digestibility. All three Farmatan levels significantly depressed nitrogen digestibility in phytase supplemented diets. Despite the fact that tannins are recognised to have antimicrobial properties, no studies on the effects of Farmatan on the gut flora of each target species were presented. Although the data on the metabolism of hydrolysable tannins is scarce, it would appear that higher molecular weight fragments are probably not absorbed to any detectable extent and that only free or released gallic and ellagic acids are available for uptake. It is not possible to conclude on the extent to which the products of hydrolysable tannins are deposited in animal tissues, however, this is likely to be low and not to detectably alter normal human exposure. Although tannins naturally occuring in animal feed can be considered safe for the consumer, the product Farmatan can not be fully assessed because of incomplete characterisation and the lack of relevant toxicity data. In case of negative results with the mutagenicity test battery, one 90 day toxicity study in rodents with the product Farmatan is considered sufficient, provided the study takes into account the already established adverse effects seen in target animals. The low dusting property of Farmatan allows the conclusion that the respiratory risk would be small. Other data to assess worker safety were not provided. However, considering the structure of the tannins, the level of exposure from this use, and their occurrence, they are unlikely to represent a risk for skin irritation or sensitization. In view of the FEEDAP Panel the use of Farmatan in rabbit and piglet feeding would not pose an added risk to the environment