Abstract: The invention relates to growth-promoter fodders or feed additives, comprising as active ingredient 0.002 to 98% by weight of prenylamine or a salt thereof, suitable for feeding purposes, in admixture with 99.988 to 2% by weight of an inert fodder carrier and optionally with further feed additives.The growth promoting fodders and feed additives of the present invention provide high weight gain, good fodder utilization and do not cause resistance or cross-resistance.

Abstract: The invention relates to an improved process for the production of practically non-hygroscopic, easily grindable copper(II) sulfate monohydrate which is stable even in finely ground state and can be applied as trace element additive in animal fodders, by neutralizing the free sulfuric acid content of copper(II) sulfate pentahydrate with sodium, potassium or ammonium hydroxide, carbonate or hydrocarbonate (further on: alkaline agent) and removing four moles of its crystal water content by drying at 80.degree. to 150.degree. C. for at least 30 minutes. The improvement according to the invention consists in that copper(II) sulfate pentahydrate, melted in its own crystal water, is treated with 3 to 20% by weight, preferably 5 to 8% by weight, of an alkaline agent calculated as sodium carbonate for the weight of the copper(II) sulfate pentahydrate, over the stoichiometric amount required to neutralize the free sulfuric acid content.