Pulsatile administration of gonadotropin releasing hormone (Gn-RH) to lactating sows using a portable automatic pump ("Zyklomat").

The object of this investigation was to study the feasibility of using a “Zyklomat roller peristaltic pump” for pulsatile administration of gonadotropin releasing hormone (Gn-RH) in primiparous lactating sows. Four primiparous sows were used. The pump catheter was inserted into a jugular vein on day 8 or day 22 of lactation. The pump delivered a 1 min Gn-RH pulse of 10 μg every 89 min for 7 days. The pump worked without any complication or detrimental effect on the sows throughout the experimental period. Two sows showed standing oestrus during lactation and one of them ovulated. It can be concluded that the “Zyklomat” pump can be used for pulsatile infusion of Gn-RH in lactating sows.