Transport of fertilised and unfertilised ova in sows

Transport of fertilised and unfertilised ova was studied in 22 crossbred (Landrace×Yorkshire) multiparous sows. Sows in the inseminated group (I-group, n=11) were inseminated once with 100 ml of BTS extended semen from two fertile boars with a total of 10×109 spermatozoa during the second oestrus after weaning between 18 and 8 h prior to estimated time of ovulation, as estimated from the first oestrus after weaning. All the sows were slaughtered between 36 and 48 h after ovulation in the second oestrus after weaning by stunning and bleeding. After slaughter, the reproductive tract was immediately recovered, the isthmus was divided into three equal segments, and the number of ova was determined in each segment and in the upper third of the uterine horn from the UTJ. There were no significant differences (P>0.05) either in the intervals from ovulation to slaughter (42.3±6.2 h versus 43.2±5.4 h) or in the numbers of corpora lutea (CL) (18.2±5.5 versus 15.9±3.5) between the non-inseminated (N-group) and the inseminated groups (I-group), respectively. Ova recovery rate was 92.5% in the N-group and 82.9% in the I-group (P>0.05). In the I-group, ova had passed 2.2±0.3 segments whereas in the N-group, ova had passed 2.6±0.3 segments (P=0.38). It can be concluded that there is no difference in the transportation of either fertilised or unfertilised ova in the reproductive tract of pigs.