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RESEARCH INTERESTS SUMMARY: Sperm Physiology/Improved AI Efficiency in Cattle RESEARCH SUMMARY: The broad goal of our research program is to improve reproductive performance in cattle which have been artificially inseminated. Our research has dealt with spermatozoal physiology and the fate of spermatozoa in the cow reproductive tract following artificial insemination. After our finding that greater than 60 percent of spermatozoa are lost to the exterior within 12 hours after artificial insemination of the cow, we have focused efforts on describing the influence of site of insemination upon sperm retention and fertility. Also, we are investigating whether the addition of myometrial stimulants (oxytocin, angiotensin II, phenylephrine, and ergonovine) to the seminal extender might improve sperm retention in the cow. The goal is to determine if the stimulants can: a) cause a change in uterine motility; b) improve sperm retention and; c) improve fertility. Our most recent efforts have been the development of a subcutaneous implantable device (SQID) for continuous estrous detection in cattle.
REPRESENTATIVE PUBLICATIONS: Johnson M.S., P.L. Senger, C. H. Allen, D.D. Hancock, B.M. Alexander, and R.G. Sasser (1995). Fertility of Bull Semen Packaged in .25- and .5 Milliliter French Straws. J. Dairy Sci. 73:1914-1919. Alexander B.M., R. Guardia, M.S. Johnson, W.L. Van de Graff, R.G. Sasser, and P.L. Senger (1995). Embryonic Loss From 30 to 60 Days Past Breedings and the Effect of Rectal Palpation on Pregnancy. Therio. 43:551. Budworth, P.R., P.L. Senger, M.D. Griswold, and E.M. Donaldson (1994). Relationship of plasma steroids to germ cell development and the presence of protamine mRNA in rainbow trout during the induction of spermatogenesis with partially purified salmon gonadotropin. J. Fish Biol. 44:983-995. Senger, P.L. (1993). Site of Semen Deposition and Its Effect of Fertility and Sperm Retention: Areview. Reprod. Fertil. Dev. 5:659-663. Butt, B.M., P.L. Senger, and P.R. Widders (1991). Neutrophil migration into the bovine uterine lumen following intrauterine inoculation with killed Haemophilus somnus. J. Reprod. & Fertil. 93:341-345. |
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