Influence of insemination conditions on early pregnancy in pigs, with emphasis on embryonic diversity
1992
Soede, N.M.
In pig husbandry, reproductive performance (litter size, pregnancy rate) after either artificial insemination or natural mating is considered to be similar. However, under experimental conditions, boar stimulation around insemination has been found to influence reproductive performance. For the present study, it was hypothesized that boar stimuli around insemination affect reproductive parameters during early pregnancy. Effects on embryonic diversity were emphasized because of its suggested relationship with embryonic mortality. In the first part of the present study it was found that insemination conditions affect parameters such as the duration of oestrus, accessory sperm count of the embryos and embryonic diversity, presumably through an influence on sperm transport and the process of ovulation. The effects were partly dependent on the social conditions of the gilts. In the second part of the study, attention was given to the process of ovulation. The duration of ovulation was of interest because of its suggested relationship with embryonic diversity. Transrectal ultrasonography was developed to study the onset and duration of ovulation in individual animals. Embryonic diversity did not appear to be related to the duration of ovulation, but was related with the accessory sperm count, suggesting a relation between the duration of fertilization and embryonic mortality.
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