Knowledge of what normal species-appropriate behaviour looks like is the essential foundation for recognising welfare problems and designing welfare-positive environments.
Knowing what normal looks like is the prerequisite for recognising what abnormal means. A stockperson who has never seen a pig engaged in extended rooting does not recognise a barren system's failure to provide this opportunity. A dairy farmer who has normalised 20% lameness prevalence does not recognise it as a welfare failure. The scientific descriptions of species-appropriate behaviour provide the baseline against which farm welfare can be honestly assessed — not against legal minimums or industry averages, but against the behavioural ecology of each species. This baseline reveals the welfare deficit in most intensive systems clearly and specifically.