The head of a German zoo and three of his staff were convicted of cruelty Thursday in the city of Magdeburg for killing three newborn tiger cubs which no zoo wanted to keep, DPA reported.
As part of a programme to protect the world stock of Siberian tigers, the zoo mated two adults, only to discover later that the male was not purebred and that the offspring would be hybrids.
German pro-animal campaigners were upset and called in police.
A court in Magdeburg, west of Berlin, put the director of the zoo, a vet and two senior keepers on probation, meaning a fine will be due if they commit any crime in the next two years. Judges said pedigree was not an acceptable reason to kill an animal.
The "mongrels" were put down with an injection as soon as the female gave birth in May 2008.
The prosecution triggered controversy, with the World Zoo Federation in Berne, Switzerland saying it was normal to cull surplus animals. German hunters have said they also routinely cull mixed- breed animals in the wild.
A pro-animal organisation, Animal Public, called the zoo "morally reprehensible." Germany has enshrined animal protection as a fundamental purpose of the state in its constitution.