Date of this Version
Roth, K. 2021. Effect of Medroxyprogesterone Acetate (a Progestin) on Spermatogenesis in Farmed Male Reindeer. Undergraduate Honors Thesis. University of Nebraska-Lincoln.
Male reindeer express aggressive behaviors when in breeding season, or rut causing damage to property, injury to female reindeer and to other male reindeer, and handlers. The breeding season also has a negative effect on the body condition of male reindeer. Rut decreases body reserves, food intake, and tissue maintenance in male reindeer. This causes survival rates during rut to decrease. Because reindeer are farmed, methods to reduce injury and enhance sustainability of reindeer producers is necessary. Progestins, such as Medroxyprogesterone Acetate (MPA), have been used in short term doses to prevent male reindeer aggression with minimal effects on male fertility. However, no long-term effects of progestins on testis characteristics have been determine. Thus, we hypothesized that long-term administration of Depo-Provera (a progestin; also known as MPA) to male reindeer during the reindeer breeding season, would reduce male aggressive behavior and not affect ability of males to maintain spermatogenesis and fertility. Eight reindeer were utilized in one year, four treated with MPA, and four maintained as controls. Two MPA and two Controls were harvested after one month of treatment while the other two MPA and control reindeer were harvested after exposure to females at two months after treatment. At each collection, testes were weighed, measured, fixed and sections were used to determine immature and mature sperm and density of sperm per tubule per testis area. No differences were detected in overall body or testis weight. However, right testis length was reduced in MPA-September treatment compared to controls and MPA-August. After harem induction percentage of tubules with mature sperm were reduced in September Control and MPA when compare to August. However, sperm density was reduced in MPA-September reindeer compared to Control-September and MPA-August suggesting length of MPA treatment reduced spermatogenesis. Therefore, while long-term exposure to MPA reduces male aggressive behavior, it appears to have detrimental effects on spermatogenesis when given long-term. Thus, MPA long-term treatment would not be feasible for reindeer producers because of its negative effects on spermatogenesis and reduction of male fertility.