Postovulatory effect of repeated intravenous administration of ACTH on thecontractile activity of the oviduct, ova transport and endocrine status ofrecently ovulated and unrestrained sows

The effect of repeated intravenous administration of ACTH (Synacthen(R) dep ot) on the contractile activity of the oviduct, ova transport and endocrine status was studied in 11 Swedish crossbred (Landrace x Yorkshire) multipar ous sows. In the second estrus after weaning, the ACTH group (Group A, n=6) sows were administered 0.01mg/kg body weight of ACTH every 6 h commencing 4 to 8 h after ovulation, whereas the control group (Group C, n=5) sows wer e administered saline solution. Immediately after standing estrus, a Millar (R) pressure transducer was placed about 3 cm into the isthmus via a laparo tomy. Blood samples for hormonal analyses and pressure recordings of the ov iduct were collected from all sows until slaughter. After slaughter, the ge nital tract opposite to the side with the transducer was retrieved, and 3 e qual isthmic segments and the first third of the uterine horn portion adjac ent to the UTJ were flushed separately for ova recovery. Cortisol levels we re significantly (<0.05) elevated after ACTH administration. Progesterone a nd PGF(2<alpha>) metabolite levels were significantly (P<0.05) elevated onl y after the first ACTH administration. No significant differences (P<0.05) were seen in the mean pressure and frequencies of phasic pressure fluctuati ons either before or after every ACTH administration between Groups A and C . No significant difference (P>0.05) was seen in the proportion of ova reco vered in the different segments between Groups A and C.