EN
Cases of canibalism in sheep during lambing-period on one farm were observed. From a total of 526 sheep births of Berrichon and Polish Merino breed ewes, cases of mutilation or biting off tails by mothers were noted on the average in 14.5% lambs. In two sheep-coops, the percentage of mutilated lambs was 40 and 80%. Aggressive behaviour of sheep in relation to lambs concerned both mothers as well as other sheep. The relationship between cases of canibalism and the concentration of animals in sheep-coops, feeding, environmental temperature and the learning of negative behaviour was discussed.