Metabolic and production responses to different porcine somatotropin injection regimes in pigs

Abstract

Thirty-two female crossbred pigs (initial weight 75 kg) were used in this experiment to investigate the effect of differing porcine somatotropin (pST) regimes on growth performance. Pigs were kept in individual pens and fed ad libitum a wheat-based diet formulated to contain 14.4 MJ DE/kg and 180 g ideal protein/kg. Treatments were daily injection with saline (Sal), daily injection with pST (5 mg) (D), bi-daily injection with pST (10 mg) (2D), and injection with pST (12 mg) every Monday, Wednesday, and Friday (MWF). On the days that pigs were not receiving pST they were injected with saline (0.5 mL). All pST regimes caused a reduction (P < 0.001) in feed intake and feed conversion ratio (FCR..