Behavioral Genetics in Pigs and Relations to Welfare - Genetics and the Behavior of Domestic Animals - page 422

Selection against fear of humans could be relevant, but it is probably
more important to choose the caretakers carefully.
Maternal behavior is crucial for piglet production, but it may be more
efficient (and much easier) to select for piglet survival and growth,
including both direct and maternal effects. Even so, further studies on
genetic and environmental effects on sow and piglet behavior are impor-
tant in order to better understand the biological background of piglet
survival.

It is still too early to use the group model in the genetic evaluation of
growth rate. We need more knowledge about pigs' behavior in groups
and consequences of selection for social effects before using the group
model on a large scale. In the meantime, the consequences of a direct
selection against aggressiveness in young pigs ought

to be further

investigated.

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