Effect of carazolol on parturition performance of sows and piglet growth during the peripartum period

Perinatal intervention for sows holds immense significance in maintaining sows' health and ensuring optimal reproductive performance. However, because of the influence of various factors, during parturition, sows often suffer stress, affecting both the sows and the piglets. Carazolol is an adrenergic receptor blocker, but little research has reported on the effects of its administration at different injection sites on sows' farrowing performance and piglet growth. Therefore, this study investigated the effects of carazolol administration at different injection sites on both sows' farrowing performance and piglets' growth characteristics. The results indicated that, in comparison with the gilts, both the sow muscular injection group and the primiparous vulvar injection group exhibited significantly shorter average intervals between piglet births, shorter farrowing durations, quicker expulsion of the final placenta, and a shorter weaning-to-estrus interval (p < 0.05). The incidence of postpartum diseases was notably decreased (p < 0.05). The estrus rate within 7 d post-weaning was significantly elevated in both the muscular and vulvar injection group (p < 0.05). Furthermore, the serum cortisol and haptoglobin concentrations in sows, as well as the lactic acid concentrations in the umbilical cord blood of piglets, were notably lower in both the muscular and the vulvar injection groups (p < 0.05). Among multiparous sows, the vulvar injection group exhibited a tendency for shorter average intervals between piglet births, a decreased farrowing duration, and faster expulsion of the final placenta. In conclusion, injecting 0.02 mL/kg of carazolol after birth in gilts can effectively improve farrowing performance. Compared with injections in the muscle, injections in the vulva demonstrated a more significant effect.