Abstract: The invention includes a process wherein a solid, substantially non-polymerized alkyl aldehyde mono urea is produced if methanol or ethanol is used as the solvent for each of urea and an aldehyde in a reaction carried out under basic conditions. The process is useful in connection with making the following novel compounds: isobutyraldehyde mono urea, isovaleraldehyde mono urea, 2-methyl butyraldehyde mono urea and valeraldehyde mono urea. The compounds are useful as feed supplements for ruminants as they produce microbial attack-inducing acids and slowly release ammonia in the rumen.