Opinion of the Scientific Panel on additives and products or substances used in animal feed [FEEDAP] on the safety of Zeolite (sodium aluminosilicate, synthetic) for the reduction of risk of milk fever in dairy cows
Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed was asked to issue an opinion on the safety of Zeolite (sodium aluminosilicate, synthetic) when used to reduce the risk of milk fever in dairy cows. In its former opinion on Zeolite, the FEEDAP Panel stated that Zeolite has the potential to reduce the risk of milk fever. Recent data confirm this conclusion, particularly for older cows with three or more calvings. Zeolite gradually prevents the decrease in serum calcium occurring after calving. Although only 500 g day-1 Zeolite was shown to significantly reduce milk fever incidence, a dose range of 250 to 500 g day-1 (approximately 25 to 50 g kg-1 complete feed) may be realistic under field conditions. The use of doses higher than 500 g of Zeolite leads to a dramatic depression of feed intake. Even the effective dose reduces feed intake and induces hypophosphataemia; however, these effects are considered transient. Zeolite may reduce serum Mg but this is without physiological significance. Serum levels of copper and zinc as well as milk yield and composition are not affected by Zeolite treatment. The FEEDAP Panel concludes that (i) the observed side effects after a two-week treatment with Zeolite do not have long lasting consequences on health of dry cows, that (ii) aluminum from Zeolite does not lead to any safety concern for the dairy cow provided that the appropriate use level and duration are followed, and that (iii) Zeolite treatment of the dry cow does not result in adverse effect in calves. Milk aluminum concentration was not affected by the use of Zeolite, but serum aluminum significantly increased. The FEEDAP Panel concludes that, considering the range of aluminum found in commercial milk samples, treatment of dry cows with Zeolite will not measurably increase consumer exposure to aluminum. The FEEDAP Panel considers that the use of Zeolite to reduce the risk of milk fever does not pose a risk for the environment. The FEEDAP Panel eventually gives some recommendations for the new entry on the use of Zeolite to reduce the risk of milk fever and on how this could be consequently introduced in the existing legislation on feedingstuffs for particular nutritional purposes.