Effect of Intrauterine Infusion of Equine Fresh Platelets-Rich Plasma (PRP) or Lyophilized PRP (L-GF(equina)) on Ovarian Activity and Pregnancy Rate in Repeat Breeder Purebred Arabian Mares

SIMPLE SUMMARY: Persistent endometritis is one of the major causes of infertility in mares and results in endometrium degeneration, namely, endometrosis. Platelets-rich plasma (PRP) is an emerging therapeutic application in tissue regeneration because of its high concentration of growth factors with a high mitogenic and anti-inflammatory potential, but reduced preservation time. L-GF(equina) is a freeze-dried, stabilized, platelet-rich plasma product (PP) that can be stored at 2 to 8 °C for several months. It can be easily used after reconstitution with sterile saline or water, eliminating the need for repeated blood product collection and special equipment. The intrauterine infusion of equine platelet-rich plasma or L-GF(equina) can be used indistinctly in repeat breeder mares, shortening the estrous cycle, with no significant effect on the follicular diameter, as well as increasing pregnancy rate in Arabian purebred mares. ABSTRACT: This study was designed to examine the effect of the intrauterine infusion of platelet-rich plasma (PRP) or equine lyophilized growth factor (L-GF(equina)) on the follicular growth, endometrial thickness, estrus cycle length, and pregnancy rate in purebred Arabian mares. A total of 73 purebred Arabian mares who experienced repeat breeding for three successive cycles were randomly divided into the following three groups: control group, without treatment; second Group (PRP group), in which mares were intrauterine infused with 20 mL of fresh PRP on the second day after the end of physic estrus phase; and the third group (L-GF(equina) Group), consisting of mares that were intrauterine infused with 20 mL of reconstituted lyophilized horse platelets growth factors (L-GF(equina)) on the second day after the estrus phase. The results showed no significant difference between control and treated groups in the diameter of the preovulatory follicles during the post treatment cycle. The endometrium thickness increased significantly in the L-GF(equina) and PRP groups ahead of the non-treated group. Intrauterine L-GF(equina) or PRP administration shortened the estrus cycle length. A higher pregnancy rate was recorded in the L-GF(equina) and PRP treated mares. In conclusion, the intrauterine infusion of L-GF(equina) or PRP increased the endometrial thickness and pregnancy rate and could be used to improve fertility in Arabian purebred mares who experienced from repeat breeding.