The invention relates to a method for the non-therapeutic treatment of animals selected from the group consisting of poultry, pigs and fish. The treatment comprises orally administering at least one ß-alanine compound to the animals in an amount of between 2 and 55 mmol/kg dry weight of said feed for the treatment of poultry and fish and between 2 and 25 mmol/kg dry weight of said feed for the treatment of pigs. These amounts of the ß-alanine compound are used for reducing the conversion ratio or for increasing the bodyweight gain of the animals. The ß-alanine compound is in particular ß-alanine. In prior art methods higher amounts were used resulting also in a reduction of the feed conversion ratio but this to the detriment of the bodyweight gain.本發明係關於一種對於選自包含家禽、豬及魚之群組中之動物的非治療性處理之方法。該處理包含口服投予動物至少一種β-丙胺酸化合物,對於家禽與魚之處理,投予量係介於2與55mmol/kg所述飼料乾燥重之間,以及對於豬之處理,投予量係介於2與25mmol/kg所述飼料乾燥重之間。這些β-丙胺酸化合物的量係用於降低轉換率或增加動物之體重增重。該β-丙胺酸化合物特別地係指β-丙胺酸。在先前技術之方法中,使用較高量亦會造成飼料轉換率的降低,但是這會不利於體重增重。