A short walk around the barn might improve the future fertility of Yorkshire gilts. According to research presented by Samantha Kaminski, a graduate student at North Dakota State University, swine fetuses showed significant ovarian development after their mothers exercised.
Kaminski and fellow researchers already knew that uterine blood flow could affect blood flow to the ovaries of developing fetuses. To further study the relationship between uterine blood flow and ovary development, Kaminski and fellow researchers designed an experiment to increase blood flow through exercise.
The team selected 15 female pigs and bred them to a boar. They then exercised the pregnant sows between days 40 and 105 of gestation. For exercise, the sows were walked for 30 minutes a day, three times a week. The researchers used this exercise regimen with two generations of pigs.
With the first generation, Kaminski and fellow researchers studied ovaries from neonate piglets, adolescent piglets and gilts at six months of age. They looked at ovarian weight, cell proliferation and types of developing cells to compare how exercise might affect ovarian development.
They found that the effects of exercise seemed to decrease as the female pigs grew. In an analysis of heavier weight neonates, Kaminski saw more cell proliferation in the group from the exercised sows.
The adolescent pigs showed no differences in ovarian weight or overall cell proliferation. Kaminski did find a difference in the types of cells in the ovaries between treatment groups. The pigs from exercised sows had a greater proliferation of cells in the antral healthy follicles. The proliferation of antral healthy follicles has been used in previous studies as an indicator of healthy ooyctes and follicles.