The breed is believed to be a causal factor in the
tail-biting syndrome. Sambraus (1985) proposed
that tail biting first became a problem when the
more sensitive, agile and heavy baconer replaced
the old phlegmatic lard hog. Petersen (1994) has
suggested that a breed effect is a plausible explanation
for the lack of tail biting among Swedish
Landrace pigs reared in semi-natural environments.
This is in contrast to Newberry and Wood-
Gush (1988) who observed tail biting among the
Large White breed. Floppy-eared pigs especially,
such as Landrace, are suspected to be eager tail
biters (Fraser & Broom, 1990). Additionally, Penny
and Hill (1974) discovered that floppy-eared pigs
were more frequently tail bitten than prick-eared
animals. However, Lund and Simonsen (2000) did
not find any significant difference in frequency of
tail biting in their preliminary study on Danish
Landrace and Duroc pigs, but tail biting occurred
hardly at all in this study, although they found significantly
higher levels of aggression among Danish
Landrace than Duroc. Hereditary nervousness, in
combination with an unfavourable environment,
has also been mentioned as increasing the motivation
to bite pen-mates’ tails (Van Putten, 1970).