Effects of post-ovulatory food deprivation on the hormonal profiles, activity of the oviduct and ova transport in sows

The objective of the present study was to investigate the effect of post-ov ulatory food deprivation on the hormonal profiles and consequently on the a ctivity of the oviduct and ova transport in sows. Sows were randomly alloca ted to the control (C-group, n = 6) or fasted (F-group, n = 5) group. The F -group sows were fasted for four meals starting with the morning meal after detection of ovulation in the second oestrus after weaning. Ovulation was checked by transrectal ultrasonography. Blood was collected for the analyse s of progesterone, oestradiol-17 beta, prostaglandin F-2 alpha metabolite, insulin, free fatty acids and triglycerides. Oviductal isthmic motility was monitored on Polyview(TM) before and after ovulation until the time of sla ughter. After slaughter, the isthmus opposite the side with transducer was divided into three equal segments and flushed separately and a third of the uterine horn part from the utero-tubal-junction (UTJ) was also flushed, A high proportion of ova in the F-group was found in the first and second par ts of the isthmus. In the C-group, a high proportion of ova was found in th e third part of the isthmus and the uterus. The mean isthmic pressure in th e C-group decreased significantly (P < 0.05) during the period immediately after ovulation while in the F-group mean pressure remained unchanged. The frequency of phasic pressure fluctuations were significantly (P < 0.05) hig her in the F- than in the C-group 13 to 24 h after ovulation, No significan t differences in progesterone concentrations were seen between the two grou ps of sows. Prostaglandin metabolite levels were significantly (P < 0.05) h igher in the F-group than in the C-group. Oestradiol-17 beta levels signifi cantly (p < 0.05) decreased earlier in the F- than in the C group. Serum in sulin levels were significantly (p = 0.05) lower in the F- than in the C-gr oup while free fatty acids were significantly(p < 0.01) higher in the F- th an in the C-group. Then were no significant differences in the serum levels of triglycerides between the F- and the C-group. Therefore, it can be conc luded in the present study that food deprivation is associated with changes in the hormonal profiles, activity of the oviduct and a delay of ova trans port in sows. (C) 2000 Elsevier Science B.V. All rights reserved.