Oxytocin injections can be used to supplement the effects of naturally occurring oxytocin. Avoid improper use by observing these guidelines: belly and tail are generally noted to some degree before delivery begins. The sow’s respiration or breathing rate may increase from a normal 25 to 30 breaths per minute to as high as 80 breaths per minute five to six hours before the initiation of farrowing. The rate then begins to fall and may approach normal rates by the time farrowing begins.