Effects of post-ovulatory food deprivation on the hormonal profiles, activity of the oviduct and ova transport in sows.
MWANZA, A.: ENGLUND, P.: KINDAHL, H.: LUNDEHEIM, N.. EINARSSON, S. Animal Reproduction Science (2000) 59, 185-199. Department of Obstetrics and Gynaecology, Centre for Reproductive Biology, Swedish University of Agricultural Sciences. Box 7039. SE-750 07 Uppsala. Sweden. The objective of present study was to investigate the effect of post-ovulatory food deprivation on the hormonal profiles and consequently on activity in the oviduct and ova transport in sows. Sows were randomly allocated to the control (C-group, n=6) or fasted (F-group, n=5) group. The F-group sows were fasted for 4 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 analyses of progesterone, oestradiol-17b, PG metabolite, insulin, free fatty acids and triglycerides. Oviductal isthmic motility was monitored on Polyview before and after ovulation until the time of slaughter. After slaughter, the isthmus opposite the side with transducer was divided into 3 equal segments and flushed separately and a third of the uterine horn part from the utero-tubal-juction (UTJ) was also flushed. There was a high proportion of ova in the F-group in the first and second parts of isthmus. In the C-group, a high proportion of ova was found in the third part of isthmus and the uterus. The mean isthmic pressure in the C-group decreased (p<0.05) during the period immediately after ovulation while in the F-group mean pressure remanded unchanged. The frequency of phasic pressure fluctuations were higher (p<0.05) in the F-than in the C-group 13-24 h after ovulation. No significant differences in progesterone concentrations were seen between the 2 groups of sows. PG metabolite levels were higher (p<0.05) in the F-group than in the C-group. Oestradiol-17b levels decreased (p<0.05) earlier in the F-than in the C-group. Serum insulin levels were lower (p=0.05) in the F-group than in the C-group. There were no significant differences in the serum levels of triglycerides between the F-and the C-group. It is concluded that food deprivation is associated with changes in the hormonal profiles, activity of the oviduct and a delay of ova transport in sows. Copyright CAB International
