Sparing effects of intrauterine treatment with prostaglandin E2 on luteal function in cycling gilts

Twelve crossbred gilts, 8 to 9 months of age, were used to study the effects of prostaglandin E2 (PGE2) on luteal function during the estrous cycle. Intrauterine and jugular vein catheters were surgically placed before day 7 of the treatment estrous cycle and gilts were randomly assigned to 1 of 3 treatment groups. Groups I and II received constant intrauterine infusion of vehicle (6.0 ml/24 hr) or PGE2 (2400 micrograms/day; 6.0 ml/24 hr) respectively; while group III was given intrauterine infusions of 400 micrograms PGE2 every 4 hr. All infusions were initiated on day 7 and continued until estrus or through day 23. Jugular blood samples were collected twice daily from days 7 to 30 for progesterone analysis. Intrauterine infusion of PGE2 at the dose and frequencies given in this study delayed the decline in jugular plasma progesterone and resulted in prolongation of the estrous cycle length. The results of this study have shown that PGE2 at the dosage and frequency of administration used was capable of extending corpus luteum function.