Impact of postovulatory food deprivation on the ova transport, hormonal profiles and metabolic changes in sows

The effect of food deprivation on ova transport, hormonal profiles and meta bolic changes was studied in 20 crossbred multiparous sows during their sec ond oestrus after weaning. To determine the time of ovulation, transrectal ultrasonographic examination was performed. The sows were divided into 2 gr oups, one control group (C-group), which was fed according to Swedish stand ards, and one experimental group (E-group). The E-group sows were deprived of food from the first morning meal after ovulation until slaughter. Blood samples were collected every second hour from about 12 h before expected ov ulation in the second oestrus after weaning until slaughter and were analys ed fbr progesterone, prostaglandin F-2 alpha-metabolite, insulin, glucose, free fatty acids and triglycerides. All sows were slaughtered approximately 48 h after ovulation and the genital tract was recovered. The isthmic part of the oviduct was divided into 3 equally long segments and flushed separa tely with phosphate buffered saline (PBS). Uterine horns were also flushed with PBS. A significantly greater number of ova were found in the first and second part of the isthmus in the E-group (p = 0.05) while in the C-group most of the ova were found in the third part of the isthmus or the uterus ( p = 0.01). The level of prostaglandin F-2 alpha-metabolite was significantl y higher in the E-group compared with the C-group. The concentration of pro gesterone increased in both groups after ovulation hut there were no signif icant differences between the groups. The other blood parameters showed tha t the food-deprived sows were in a catabolic state. The 48 h period of fast ing results, directly or indirectly in an delayed ova transport, which may be due to a delayed relaxation in the smooth circular muscle layer of the i sthmus.