PST treatment and leg disorders in growing swine: a welfare hazard?

PST treatment of growing pigs causes major improvements in growth performance. The rapid growth however is an important factor in relation to leg weakness including osteochondrosis which is of significant importance for both economy and animal welfare. Modern pigs are indirectly selected for high levels of growth hormone which is significant for growth performance. Accordingly it has been shown that injection of PST in growing pigs has a negative effect on bone physiology and leg health. It therefore is resonable to predict, that an increase in growth performance in modern pigs by means of PST injections will increase the frequency and severity of leg disorders and thereby decrease welfare of growing pigs.