The Tiger Project has been a long-term program of the Reproductive Sciences Department that has focuses on all aspects of assisted reproductive technology including artificial insemination, semen freezing, in vitro embryo production (including fertilization by intracytoplasmic sperm injection), freezing and transfer, and the production of tiger-specific hormones for stimulating and synchronizing ovarian activity in tigers.

In-Vitro Embryo Production and Cryopreservation in Siberian Tigers

Studies have been conducted to test the effectiveness of pig (porcine) gonadotropins for repeatedly stimulating ovarian activity (follicle growth for oocyte or egg collection) in tigers. The porcine hormones are the most similar product commercially available. Sperm and in vitro produced tiger embryo procedures have been successful, however, pregnancy rates have been less than satisfactory using the porcine hormones to synchronize ovarian cycles. The success of the treatments are being examined by measuring reproductive hormone metabolites in the feces of the tigers.

Determining the Efficacy of a GnRH Implant for Performing Assisted Reproductive Techniques in Tigers

A continuation of previous laparoscopic assisted reproduction studies in tigers. In this case we want to laparoscope the tigers when they are in natural heats, artificially inseminate them and implant a synthetic hormone implant (deslorelin) to induce ovulation.

Sequencing Tiger-Specific Gonadotropins (specifically LH)

For use in ovarian stimulation and synchronization for cat embryo transfer. This project is a collaboration with the University of Nebraska Medical Center's Eppley Institute. Sequencing of the DNA section coding for tiger FSH and LH has been completed and transfection of cat kidney and Chinese hamster ovary cell lines is accomplished. Current efforts focus on propagation and testing of various cell line strains to find the most productive ones. The product will be collected in culture medium and concentrated by lyophilization will be tested for bioactivity in domestic cats.

Development of Novel and More Effective Techniques for Freezing (Vitrifying) Cat Embryos as a Model for Exotic Felids

Traditional methods for cryopreserving (freezing) embryos from livestock or humans can work with domestic cat embryos, but do not necessarily work for exotic felids such as tigers. A more recent technique, called vitrification, was found to be most effective for freezing cleavage stage embryos from in-vitro produced tiger embryos with an approximately 50% survival rate post-thawing.

Non-Invasive Diagnosis of Pregnancy and Reproductive Disorders in a Variety of Species by Measuring Fecal Reproductive Hormone Metabolites

To diagnose pregnancy or determine if there is a reproductive disorder in a non-domesticated animal, multiple samples are required over an extended time period.  For that reason, blood sampling is not an option because this would require chemical immobilization, unless the animal has been trained to allow voluntary blood sampling.  Techniques have been developed to measure the metabolites of reproductive hormones in urine or feces, and this has proved to be an invaluable procedure to:

• Determine seasonality for male/female introductions
• Diagnose pregnancy and forecast parturition
• Evaluate the effectiveness of assisted reproduction protocols such as exogenous hormone delivery and artificial inseminations
• Evaluate fertility/infertility of individual animals.  These procedures assist in improving reproductive success and the well-being of animals in managed breeding programs.

Monitoring of Stress in Captive Female Okapi

Using urinary and fecal hormone analyses: This is a collaboration with Dr. Cynthia Bennett of the Dallas Zoo. The results may be useful for improving husbandry of captive okapi.

Development of Optimal Methods for Cryopreserving Sperm in a Variety of Species

An ongoing project conducted opportunistically upon the death of an animal or with semen collected during a routine medical examination.  It is important to note that, as with tigers, wild or domestic animal counterparts do not always serve as model species for determining what treatment regimen should be used for freezing sperm.  Each species often requires refinement or modifications of existing protocols to be optimal for cryobanking semen.

Embryo Production by In-Vitro Oocyte Maturation, Fertilization and Culture and In-Vitro-Derived Embryo Cryopreservation in Domestic Cattle

These procedures are used as quality controls for the CCR In Vitro Fertilization Laboratory as well as for training of new students and personnel in the proper handling and processing of mammalian oocytes and the in-vitro production of embryos.  Since unfertilized oocytes can not be frozen in practically all species, it is necessary to produce embryos by in vitro fertilization since these generally can survive freezing and thawing.

Cryopreservation and Culture of Ovarian Tissue

In light of the fact that unfertilized oocytes can not be cryopreserved very successfully in any species, researchers have demonstrated in humans and laboratory animals that ovarian tissue may be a more effective means of salvaging gametes from females after ovariectomy or death.  The tissues are frozen then thawed and cultured until the ovarian follicles grow to a point that oocytes can be recovered and fertilized to produce viable embryos.  These same procedures are being tested by the staff and students of the CCR Reproductive Sciences Department on model species such as domestic cats and cows, with the intention of eventually applying effective methods to their endangered species counterparts.  Below is an electron micrograph of a domestic cat ovarian follicle containing a maturing oocyte.

Omaha's Henry Doorly Zoo and Aquarium's CCR Genome Resource Bank

Currently, over 20,000 individual samples of sperm and embryos from over 40 species are in liquid nitrogen storage and monitored by a state-of-the-art computerized system.

Vogler, B.R., Blevins, B.A., Goeritz, F., Hildebrant, T.B., and Dehnhard, M. (2009). Gonadal activity in male and female captive fossas (Cryptoprocta ferox) during the mating season. Reproduction in Domestic Animals 44:98-102.

Blevins, B.A., Armstrong, D.L. and Loskutoff, N.M. (2009) Tiger (Panthera tigris) ovarian stimulation: the effect of timing on exogenous hormone delivery. Reproduction, Fertility and Development 21(1):153.

Mattson, K.J., DeVries, A.T., Krebs, J. and Loskutoff, N.M. (2009) Cryopreservation of corn snake, Elaphe gutatta, semen.  Reproduction, Fertility and Development 21(1):161.

Pedersen, M.J., Watson, C.A., Blevins, B.A. and Loskutoff, N.M. (2009) Domestic cat (Felis catus) embryo cryopreservation: slow-cooling versus vitrification. Reproduction, Fertility and Development 21(1):163.

Aaltonen, J.T., Mattson, K.M. and Loskutoff, N.M. (2009) The effect of a novel recombinant protease treatment on bovine sperm fertilizing capacity and embryo development in vitro. Reproduction, Fertility and Development 21(1):104.

Blevins, B.A., de la Rey, M. and Loskutoff, N.M. (2008) Effect of density gradient centrifugation with trypsin on the fertilizing capability of bovine sperm in vivo. Reproduction, Fertility and Development (accepted; in press).

Mattson, K.J., Devlin, B.R. and Loskutoff, N.M. (2008) Comparison of a recombinant \ trypsin with the porcine pancreatic extract on sperm used for the in vitro production of bovine embryos. Theriogenology (accepted; in press).

Nascimento, J.M., Shi, L.Z., Meyers, S., Gagneux, P., Loskutoff, N.M., Botvinick, E.L. and Berns, M.W. (2008) The use of optical tweezers to study sperm competition and motility in primates. Journal of the Royal Society Interface 5:297-302.

Aaltonen, J.T., Bedows, E., Estes, K.A.,. Butnev, V.Y., Bousfield, F. and Loskutoff, N.M. (2008) Production of recombinant LH for use in tiger (Tigris altaica) assisted reproduction: a preliminary report. Reproduction, Fertilty and Development 20(1):159.

Blevins, B.A., de la Rey, M. and Loskutoff, N.M. (2008) Effect of density gradient centriguation with trypsin on the fertilizing capability of bovine sperm. Reproduction, Fertilty and Development 20(1):84.

Mattson, K.J., Devlin, B.R. and Loskutoff, N.M. (2008) Comparison of a recombinant trypsin versus the pig pancreatic extract on in vitro-produced bovine embryos. Reproduction, Fertilty and Development 20(1):184.

Mattson, K.J., DeVries, A., McGuire, S.M., Krebs, J., Louis, E.E. and Loskutoff, N.M. (2007) Successful artificial insemination in the corn snake, Elaphe gutatta, using fresh and cooled semen. Zoo Biology 26(5):363-370.

Blevins, B., Steenson, S. and Loskutoff, N.M. (2007) Effects of different trypsin sources and concentrations on the viability of bovine sperm pre- and post-cryopreservation. Reproduction, Fertility and Development 19(1):121.

Mattson, J.K., DeVries, A.T., McGuire, S.M., Krebs, J., Louis, E.E. and Loskutoff, N.M. (2007) Successful artificial insemination in the corn snake, Elaphe gutatta, using fresh and cooled semen. Reproduction, Fertility and Development 19(1):240.

Chatfield, J., Zhang, L., Ramey, J., Bowsher, T., Loskutoff, N.M. and O?Neill, K. (2006) Resolution of a prolactinoma in a western lowland gorilla (Gorilla gorilla gorilla). Journal of Zoo and Wildlife Medicine 37(4):565-566.

Spindler, R.E., Crichton, E., Agca, Y., Loskutoff, N.M., Critser, J., Gardner, D.K. and Wildt, D.E. (2006) Improved felid embryo development by group culture is modified but not lost with heterospecific companions. Theriogenology 66:82-92.

Loskutoff, N.M. (2006). Proceedings of the Third International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Companion Animals, Non-Domestic and Endangered Species,. Henry Doorly Zoo, Omaha, NE, USA, 22 pages.

Graham, L.H., Byers, A.P., Armstrong, D.L., Loskutoff, N.M., Swanson, W.F., Wildt, D.E. and Brown, J.L. (2005) Natural and gonadotropin-induced ovarian activity in tigers (Panthera tigris) assessed by fecal endocrine analysis. General and Comparative Endocrinology 147:362-370.

Skidmore, J.A., Loskutoff, N.M and Billah, M. (2005) Developmental competence in vitro and in vivo of vitrified, hatched blastocysts from the dromedary camel (Camelus dromedarius). Reproduction, Fertility and Development 17:523-527.

Loskutoff, N.M., Huyser, C., Singh, R., Morfeld, K.A., Walker, D.L., Thornhill, A.R., Smith, M., Morris, L. and Webber, L. (2005) Removing HIV-1 and hepatitis C virus from semen: an improved method for washing sperm using a trypsinized silica particle suspension and a novel tube insert. Fertility and Sterility 84:1001-1010.

Huyser, C., Loskutoff, N.M., Singh, R. and Webber, L. (2005) O-212. Quantification of HIV-1 RNA in washed sperm samples. 21st Annual Meeting of the European Society of Human Reproduction and Embryology. Human Reproduction 20 (Suppl. 1): i79

Loskutoff, N.M., Huyser, C., Singh, R., Morfeld, K.A., Walker, D.L., Thornhill, A.R., Smith, M., Morris, L. and Webber, L. (2005) A novel and effective procedure for removing HIV and hepatitis B and C viruses from spiked human semen. Reproduction, Fertility and Development 17 (1,2): 185.

Morfeld, K.A., White, B., Mills, G., Krisher, R., Mellencamp, M.A. and Loskutoff, N.M. (2005) A novel sperm processing method for eliminating porcine reproductive and respiratory syndrome virus (PRRSv) from boar semen and its effects on embryo development in vitro and in vivo. Reproduction, Fertility and Development 17 (1,2): 186.

De la Rey, M., Morfeld, K.A., Treadwell, R. and Loskutoff, N.M. (2005) The effect of a novel semen disinfection treatment on the viability and fertilizing capacity in vivo of bovine spermatozoa. Reproduction, Fertility and Development 17 (1,2): 184.

Skidmore, J.A., Loskutoff, N.M and Billah, M. (2004) Developmental competence in vitro and in vivo of cryopreserved, hatched blastocysts from the dromedary camel (Camelus dromedarius). Reproduction, Fertility and Development 16:605-609.

Donoghue, A.M., Blore, P.J., Cole, K., Loskutoff, N.M. and Donoghue, D.J. (2004) Detection of Campylobacter or Salmonella in turkey semen and the ability of poultry semen extenders to reduce their concentrations. Poultry Science 83:1728-1733.

Loskutoff, N.M., Huyser, C., Singh, R., Morfeld, K.A., Walker, D., Thornhill, A.R., Smith, M., Morris, L., Webber, L. (2004) A novel and effective procedure for removing HIV-1 RNA from human semen. In: International Congress Series; Special Issue: Research Papers in Fertility and Reproductive Medicine. Proceedings of the 18th World Congress on Fertility and Sterility (IFFS 2004). Eds: Daya S., Pierson R. & Gunby J.; 1271C, pp. 200-204.

Huyser, C., Loskutoff, N.M., Singh, R. And Lindeque, K. (2004) A novel antibiotic cocktail for eliminating bacteria in human semen. In: International Congress Series; Special Issue: Research Papers in Fertility and Reproductive Medicine. Proceedings of the 18th World Congress on Fertility and Sterility (IFFS 2004). Eds:
Daya S., Pierson R. & Gunby J.; 1271C, pp. 205-209.

Loskutoff, N.M., Bowsher, T.R., Chatfield, J.A., Stones, G.A., Ramey, J.W., Zhang, L., Putman, M., Boland, C., Wharton, D. and Gardner, D.K. (2004) Ovarian stimulation, ultrasound-guided oocyte retrieval, ICSI and blastocyst production using sequential media in the western lowland gorilla (Gorilla gorilla gorilla). Reproduction, Fertility and Development 16:225.

Armstrong, D.L., Crichton, E.G., Dankof, S.M., Schwalbach, L.M.J., Gardner, D.K. and Loskutoff, N.M. (2004) Ovarian stimulation, laparoscopic oocyte retrieval, IVF and blastocyst production using sequential media in the African lion (Panthera leo). Reproduction, Fertility and Development 16:221.

Loskutoff, N.M., Singh, R., Huyser, C., Morfeld, K.A., Walker, D., Thornhill, A.R., Smith, M., Morris, L. and Webber, L. (2004) A novel and effective procedure for removing HIV from human semen. Proceedings of the International Federation of Fertility Societies, International Congress Series 1266, Montreal, Quebec, Canada
(20-25 May 2004).

Huyser, C., Loskutoff, N.M., Singh, R. And Lindeque, K. (2004) A novel antibiotic cocktail for eliminating bacteria in human semen. Proceedings of the International Federation of Fertility Societies, International Congress Series 1266, Montreal, Quebec, Canada (23-28 May 2004).

Loskutoff, N.M. (2003) Research programs
connecting African zoos and wildlife. Proceedings of the American Zoo and Aquarium Association (AZA) annual conference, Columbus, OH (7-11 September 2003).

Loskutoff, N.M. (2003) The South African Center for Conservation and Research. Proceedings of the African Zoo and Aquarium Association (PAAZAB) annual conference, Oudtshoorn, Klein Karoo, South Africa (3-6 June 2003)

Mastromonaco, G.F., Crawshaw, G., Loskutoff, N.M. and King, W.A. (2003) Cytogenetic screening of a family of gaur (Bos gaurus). Proceedings of the 13th North American Colloquium on Animal Cytogenetics and Gene Mapping, Louisville,
KY (13-17 July 2003).

Loskutoff, N.M., Morfeld, K. and Crichton, E.G. (2003) Trypsin activity after prolonged refrigerated storage. Theriogenology 59:384.

Crichton, E.G., Obringer, A., Lund, A., Kirshner, E., Pryor, W. and Loskutoff, N.M. (2003) Monitoring reproductive activity in the Tasmanian devil (Sarcophilus harrisii). Theriogenology 59:389.

Morfeld, K., Skidmore, J.A., Billah, A.M. and Loskutoff, N.M. (2003) Effect of various cryoprotectants and methods for the short- and long-term preservation of sperm from the dromedary camel (Camelus dromedarius). Theriogenology 59:400.

Kubisch, H.M., Rasmussen, T.A. and Loskutoff, N.M. (2003). Interferon-tau secretion by hybrid cattle x bison blastocysts and blastocyst outgrowths. Theriogenology 59:483.

Loskutoff, N.M. (2003) Role of embryo technologies in genetic management of conservation of wildlife. In: Reproductive Sciences and Integrated Conservation. W.V. Holt, A.R. Pickard, J.C. Rodger & D.E. Wildt (Eds.). Cambridge University Press, Cambridge, UK.

Loskutoff, N.M., Holt, W.V. and Bartels, P. (2003) Editors: Conservation Breeding Specialist Group (SSC/IUCN). Biomaterial Transport and Disease Risk: Workbook Development. CBSG, Apple Valley, MN.

Crichton, E.G., Bedows, E., Miller-Lindhom, A.K., Baldwin, D.M., Armstrong, D.L., Graham, L.H., Ford, J., Gjorret, J.O., Hyttel, P., Pope, C.E., Vajta, G. and Loskutoff, N.M. (2003) The efficacy of porcine gonadotropins for repeated stimulation of ovarian activity for oocyte retrieval and in vitro embryo production and cryopreservation in Siberian tigers (Panthera tigris altaica). Biology of Reproduction 68: 105-113.

Gjorret, J.O., Crichton, E.G., Loskutoff, N.M., Armstrong, D.L. and Hyttel, P. (2002) Oocyte maturation, fertilization and early embryonic development in vitro in the Siberian tiger (Panthera tigris altaica). Molecular Reproduction and Development 63:79-88.

Loskutoff, N.M. (2002). Proceedings of the Second International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife. Henry Doorly Zoo, Omaha, NE, USA, 322 pages.

Spindler, R.E., Gardner, D.K., Loskutoff, N.M., Critser, J. and Wildt, D.E. (2002) Beneficial impact of heterospecific companion embryo culture in the cat appears to be species dependent. Theriogenology 57:524.

Edens, M.S.D, Galik, P.K., Riddell, K.P., Givens, M.D., Stringfellow, D.A. and Loskutoff, N.M. (2002) Bovine herpesvirus-1 associated with single, trypsin-treated embryos is not infective for uterine tubal cells. Theriogenology 57:570.

Stander-Breedt, H., Schwalbach, L.M., Greylig, J. and Loskutoff, N.M. (2002). Effect of different cryodiluents and thawing methods on the motility and heterologous fertilizing capacity of African lion (Pathera leo) spermatozoa. Proceedings of the 9th International Symposium on Spermatology, Cape Town, South Africa (6-12 October 2002).

Motlomelo, K.C., Schwalbach, L.M., Greylig, J. and Loskutoff, N.M. (2002). A novel sperm cryopreservation method for the South African cheetah (Acinonyx jubatus). Proceedings of the 9th International Symposium on Spermatology, Cape Town, South Africa (6-12 October 2002).

Loskutoff, N.M. and Goodrowe, K. (2002). the AZA Reproductive Sciences Advisory Group and the IETS Parent Committee on Companion Animals, non-domestic and endangered species: novel resources for zoo and wildlife veterinarians. Proceedings of the American Association of Zoo Veterinarians annual conference, Milwaukee, WI.

Othen, L., Jarsky, T., French, J., Crichton, E., Loskutoff, N. and Bennett, C. (2002) Correlating ethological and physiological parameters as indicators of well-being in okapi (Okapia johnstoni) ACTH challenge, patterns of excretion, and impact of
introductions. Proceedings of the 2nd International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife. Henry Doorly Zoo, Omaha, NE, USA., pp. 73-79.

O?Brien, J.K., Crichton, E.G., Evans, K.M., Schenk, J.L., Stojanov, T., Evans, G., Maxwell, W.M.C. and Loskutoff, N.M. (2002) Sex ratio modification using sperm sorting and assisted reproductive technology ? a population management strategy. Proceedings of the 2nd International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife. Henry Doorly Zoo, Omaha, NE, USA., pp. 224-231.

Loskutoff, N.M. (2001) Giving nature a helping hand. American Zoo and Aquarium Association Communiqu?, February issue.

Bowsher, T.R. and Loskutoff, N.M. (2001) Assisted reproductive technologies in the great apes. Proceedings of the 1st International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife. Henry
Doorly Zoo, Omaha, NE, USA, pp. 152-156.

Loskutoff, N.M. (2000) Assisted reproductive technology using sex-sorted sperm: an alternative strategy for the Gorilla SSP. Proceedings of the Bachelor Gorilla Workshop, Disney?s Animal Kingdom, Orlando, FL, USA.

Janesch, L., Rohr, J., Volenec, D., Grobler, D., Puffer, A., Prokupek, A.K., Armstrong, D.L., Dankoff, S., Curro, T., Simmons, H., Crichton, E.G., Hamilton, J., Rasmussen, L., Zimmermann, D., Lomneth, R., Wood, R., Wood, D. and Loskutoff, N.M. (2001) Post-thaw viability of wild cattle (Bos gaurus) and buffalo (Syncerus caffer) sperm cryopreserved using a novel, non-animal protein cryodiluent. Theriogenology 55:387.

Morfeld, K., Henton, M.M., Grobler, D., Bengis, R., Puffer, A., Armstrong, D.L., Dankoff, S., de la Rey, M., de la Rey, R., Hansen, H., Strick, J., Rasmussen, L., York, D., Zimmermann, D., de Klerk, L.M., van Dyk, D.S., Crichton, E.G., Popescu, A., Stringfellow, D. and Loskutoff, N.M. (2001). Elimination of Brucella abortus from infected domestic (Bos taurus) and wild (Bos gaurus) cattle and buffalo (Syncerus caffer) semen without compromising sperm viability. Theriogenology 55:393..

Puffer, A., de la Rey, R., de la Rey, M., Hansen, H., Grobler, D., Hofmeyr, M., Malan, J.H., Armstrong, D.L., Dankoff, S., Rasmussen, L., York, D., Zimmermann, D. and Loskutoff, N.M. (2001) Choice of chemicals used in immobilization protocols can significantly affect semen quality in ejaculates collected from free-ranging African buffalo (Syncerus caffer). Theriogenology 55:398.

Givens, M.D., Galik, P.K., Riddell, K.P., Stringfellow, D.A., Brock, K.V., Bishop, M.D., Eilertsen, K.J. and N.M. Loskutoff (2001) Reverse transcription nested polymerase chain reaction (RT-nPCR) to detect bovine viral diarrhea virus (BVDV) associated with in vitro-derived bovine embryos and co-cultured cells. Theriogenology 55:378.

Loskutoff, N.M. (2001). Proceedings of the First International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife. Henry Doorly Zoo, Omaha, NE, USA, 226 pages.

Hammer, C.J., Tyler, H.D., Loskutoff, N.M., Armstrong, D.L., Funk, D.J., Lindsey, B.K. and Simmons, L.G. (2001) Compromised development of calves (Bos gaurus) derived from in vitro-generated embryos and transferred interspecifically into domestic cattle (Bos taurus). Theriogenology 55:1447-1455.

Solti, L., Crichton, E.G., Loskutoff, N.M. and Cseh, S. (2000) Economical and ecological importance of indigenous livestock and the application of assisted reproduction to their preservation. Theriogenology 53:149-162.

Loskutoff, N.M. and Stroud, B. (2000) Editors: Proceedings of the 26th Annual Conference of the International Embryo Transfer Society. Theriogenology 53, No. 1 , pp. 1-535.

Loskutoff, N.M., Amstrong, D.L., Ohlrichs, C.L., Johnson, D.L., Funk, D.J., VanRoekel, P.V., Molina, J.A., Lindsey, B.R., Looney, C.R., Bellow, S.M., Hammer, C.J., Tyler, H.D. and Simmons, L.G. (2000) Transvaginal ultrasound-guided oocyte retrieval and the developmental competence of in vitro-produced embryo in vitro and in vivo in the gaur (Bos gaurus). Theriogenology 53:337.

Crichton, E.G., Armstrong, D.L., Vajta, G. and Loskutoff, N.M. (2000) Developmental competence in vitro of embryos produced from Siberian tigers (Panthera tigris altaica) cryopreserved by controlled rate freezing versus vitrification. Theriogenology 53: 328.

Morato, R.G., Crichton, E.G., Paz, R.C.R., Zuge, R.M., Moura, C.A., Nunes, A.L.V., Teixeira, R.H., Porto, L., Priscila, M.A.B.V., Guimaraes, S.H.R., Correa, S.H.R., Barnabe, R.C., Armstrong, D.L. and Loskutoff, N.M. (2000) Ovarian stimulation and successful in vitro fertilization in the jaguar (Panthera onca). Theriogenology 53:339.

Gjorret, J.O., Crichton, E.G., Armstrong, D.L., Loskutoff, N.M. and Hyttel, P. (2000) Oocyte maturation, fertilization and early embryonic development in vitro in the Siberian tiger (Panthera tigris altaica). Theriogenology 53:334.

Skidmore, J.A., Billah, M. and Loskutoff, N.M. (2000) Developmental competence of cryopreserved blastocysts collected from dromedary camels. Fertility 2000: Proceedings of the Joint Conference of the UK Fertility Societies, Edinburgh, UK.

Crichton, E.G., Armstrong, D.L., Graham, L.H., Bedows, E., Miller, A., Gjorret, J.O., Hyttel, P. and Loskutoff, N.M. (2000) The efficacy of porcine gonadotrophins for repeated stimulation of ovarian activity for in vitro embryo production in Siberian tigers (Panthera tigris altaica). Fertility 2000: Proceedings of the Joint Conference
of the UK Fertility Societies.

Finnegan, J.M., Loskutoff, N.M. and Brown, C.S. (1999) Cost effective method to Transport manually collected gorilla semen for long term storage. Proceedings of the American Association of Zoo Veterinarians, Columbus, Ohio.

Loskutoff, N.M. (1999) Interspecies embryo transfer ? a feasible strategy for safeguarding endangered species? Proceedings of the American Association of Zoo Veterinarians, Columbus, Ohio.

Loskutoff, N.M. (1999) How to preserve your own gametes at home (practical and generalized procedures for genome resource banking). Proceedings of the Association of Zoo Veterinary Technicians, Indianapolis, Indiana.

Loskutoff, N.M. (1999) The advantages and disadvantages of assisted reproductive technology (ART) for propagating exotic felids. Proceedings of the Pan African Association of Zoos and Botanical Gardens, Cape Town, South Africa.

Pope C, Schmid R, Mikota S, Dresser B, Pirie G, Lamb K, Godke R, Aguilar R, Loskutoff N. In vitro production of tiger (Panthera tigris) embryos after daily gonadotropin treatment and off-site laparoscopic oocyte retrieval. (1999) Proc. 7th Int. Conf. Breeding Endangered Species in Captivity, Cincinnati, Ohio, 1999; 244.

Skidmore, J.A. and Loskutoff, N.M. (1999) Developmental competence in vitro and in vivo of cryopreserved expanding blastocysts from the dromedary camel (Camelus dromedarius). Theriogenology 51:293.

Kurz, S.G., Healy, M.R., Loskutoff, N.M., Brown, C.S., Crichton, E.G., Barnes, A.M., Finnegan, J.M., Volenec, D. and DeJonge, C.J. (1999) In-vitro maturation and intracytoplasmic sperm injection of western lowland gorilla oocytes. Theriogenology 51:361.

Finnegan, J.M., Warnes, C.A., Belifore, M., Crichton, E.G., Volenec, D. and Loskutoff, N.M. (1999) Heterologous fertilizing capacity of cryopreserved sable antelope (Hippotragus niger) and scimitar-horned oryx (Oryx dammah) sperm using fresh and salt-stored bovine oocytes. Theriogenology 51:284.

Nelson, K.L., Crichton, E.G., Doty, L., Volenec, D., Finnegan, J.M., Morato, R.G., Pope, C.E., Dresser, B.L., Armstrong, D.L. and Loskutoff, N.M. (1999) Heterologous and homologous fertilizing capacity of cryopreserved felid sperm: a model for endangered species. Theriogenology 51:290.

Pope, C.E. and Loskutoff, N.M. (1999) Embryo transfer and semen technology from cattle applied to nondomestic artiodactylids. In: Zoo and Wild Animal Medicine: Current Therapy, 4th Edition. M.E. Fowler and R.E. Miller (Eds.), W.B. Saunders Co., Philadelpia pp. 597-604.

Loskutoff, N.M. (1998) Biology, technology and strategy of genetic resource banking in conservation programs for wildlife. In: Gametes: Development and Function, A. Lauria et al. (Eds.), Serono Symposia, Rome, Italy, pp. 275-286.

Brown, C.S. and Loskutoff, N.M. (1998) A training program for noninvasive semen collection in captive western lowland gorillas (Gorilla gorilla gorilla). Zoo Biology 17:143-151.

MacLean, R.A., Swanson, H., Hancock, J., O?Brien, E., Williams, K.R. and Loskutoff, N.M. (1998) Comparison of three techniques for separating motile sperm in cryopreserved Bos gaurus semen. Theriogenology 49:263.

Loskutoff, N.M. (1998) Assisted reproduction in western lowland gorillas. Proceedings
of the Pan African Association of Zoos and Botanical Gardens annual conference, Bloemfontein, Free State, South Africa.

Kurz, S.G., Barnes, A.M., Healy, M.R., Brown, C.S., Loskutoff, N.M., Armstrong, D.L., Ramey, J.W. and DeJonge, C.J. (1998) Comparative characteristics of semen collected by electroejaculation vs. Manual stimulation in the western lowland gorilla. Proceedings of the 8th International Congress on Spermatology, Montreal, Quebec, Canada.
O?Brien, E.S., Hoffman, S., Schawang, T., Suedmeyer, W.K., Easton, E., Schmitt, D. and Loskutoff, N.M. (1998) An update on studies to improve the short- and long-term storage of elephant semen. Proceedings of the 3rd International Elephant Research Symposium, Springfield, MO, USA.

Loskutoff, N.M. (1997) Okapi reproduction. Proceedings of the Okapi Metapopulation Workshop, White Oak Conservation Center, Yulee, FL, USA.

O?Brien, E., McCullough, K., Jefferies, E., Williams, K. and Loskutoff, N. (1997) Effect of different cryoprotectants on the short- and long-term storage of semen from the African elephant (Loxodonta africana). Proceedings of the 2nd International Elephant Research Symposium, Pittsburgh, PA, USA.

Watson R., Lanterna J., Garcia A., Cooper C., Tomsett G. and Loskutoff N.M. (1997) Freezing resistances of epididymal sperm from waterbuck, greater kudu and warthog using glycerol, ethanediol or DMSO. Theriogenology 47:411.

Rush E.M., Jewell M., Cooper C., Garcia A., Tomsett G. and Loskutoff N.M. (1997) Effect of cryoprotectant and thawing method for cryopreserving epididymal sperm from impala (Aepyceros melampus) for IVF. Theriogenology 47:406.

Schmid R., Lanterna J., Garcia A., Tomsett G. and Loskutoff N.M. (1997) A comparison of standard bovine and equine cryodiluents for cryopreserving epididymal sperm from greater kudu (Tragelaphus strepsiceros). Theriogenology 47:407.

Winger Q., Damiani P. and Loskutoff N.M. (1997) The application of standard bovine protocols for the maturation and fertilization of blesbok (Damaliscus dorcas phillipsi) oocytes using epididymal sperm cryopreserved in DMSO or glycerol. Theriogenology 47:412.

Pope, C.E., Dresser B.L., Chin N.W., Liu J.H, Loskutoff N.M., Behnke E.J., Brown C., McRae M.A., Sinoway C.E., Campbell M.K., Cameron K.N., Owens O.M., Johnson C.A., Evans R.R. and Cedars M.I. (1997). Birth of a western lowland gorilla (Gorilla gorilla gorilla) following in vitro fertilization and embryo transfer. American Journal of Primatology 41:247-260.

Meintjes, M., Bezuidenhout, C., Bartels, P., Visser, D.S., Meintjes, J., Loskutoff, N.M., Le, R., Fourie, F., Barry, D.M. and Godke, R.A. (1997). In vitro fertilization of in vitro matured oocytes recovered from free-ranging Burchell's (Equus burchelli) and Hartmann's (Equus zebra hartmannae) zebra. Journal of Zoo & Wildlife Medicine 28:251-259.

Loskutoff, N.M., Simmons, H.A., Goulding, M., Thompson, G., De Jong, T. and Simmons, L.G. (1996) Species and individual variations in cryoprotectant toxicities and freezing resistances of epididymal sperm from African antelope. Animal Reproduction Science 42:527-535.

Kurz, S.G., Barnes, A.M., Ramey, J.W., Brown, C., Loskutoff, N.M., Simmons, L.G., Armstrong, D.L. and De Jonge, C.J. (1996) Semen characteristics of a western lowland gorilla determined by manual and computer-assisted motion analysis. Biology of Reproduction 54, Suppl. 1: 301.

Dresser, B., Pope, E., Chin, N., Liu, J., Loskutoff, N.M., Behnke, E., Brown, C., McRae, M., Sinoway, C., Campbell, M., Cameron, K., Evans, R., Owens, O., Johnson, C. and Cedars, M. (1996) Successful in vitro fertilization, embryo transfer and pregnancy in a western lowland gorilla. Theriogenology 45:248.

Loskutoff N.M. (1996) Reproductive biotechnology for the conservation and genetic management of wildlife. Embryo Transfer Newsletter, International Embryo Transfer Society Vol. 14, No. 4, pp. 23-26.

Buice, R., Maloy, D., Raath, C. and Loskutoff, N.M. (1995) Effects of various cryoprotectants on epididymal sperm from the African elephant (Loxodonta africana). Proceedings of the Association of Zoo Veterinary Technicians, Baltimore, Maryland.

Armstrong, D.L., Looney, C.R., Lindsey, B.R., Gonseth, C.L., Johnson, D.L., Williams, K.R., Simmons, L.G. and Loskutoff, N.M. (1995) Transvaginal egg retrieval and in-vitro embryo production in gaur (Bos gaurus) with establishment of interspecies pregnancy. Theriogenology 43:162.

Shaw, D.G., Kidson, A., van Schalkwyk, J.O., Bartels, P., Loskutoff, N.M., Bezuidenhout, C., Barry D.M. and Lishman, A.W. (1995) In-vitro production of African buffalo (Syncerus caffer) embryos derived from follicular oocytes and epididymal sperm. Theriogenology 43:322.

Kidson, A., Loskutoff, N.M., Raath, C., Wood, C.A., Williams, K.R., van Schalkwyk, J.O., Dyche, W.K., Barry, D.M. and Bartels, P. (1995) Age- and parity- dependent differences in ovarian activity and oocyte maturity in the African elephant (Loxodonta africana). Theriogenology 43:246.

Meintjes, M., Bartels P., Bezuidenhout, C., Visser, D.S., Meintjes, J., Loskutoff, N.M., Fourie, F. le R., Barry, D.M. and Godke, R.A. (1995) In-vitro fertilization of in-vitro matured oocytes recovered from free-ranging zebra in South Africa. Theriogenology 43:279.

Fordyce-Boyer, R., Sanger, T., Loskutoff, N.M., Kumamoto, A., Johnston, L. and Armstrong, D. (1995) Comparative cytogenetic study of the roan and sable antelope, Hippotragus equinus and Hippotragus niger. Applied Cytogenetics 21:189-191.

Loskutoff, N.M., Bartels, P., Meintjes, M., Godke, R.A. and Schiewe, M.C. (1995) Assisted reproductive technologies in nondomestic ungulates: a model approach to preserving and managing genetic diversity. Theriogenology 43:3-12.

Schiewe, M.C., Loskutoff, N.M., Durrant, B.S., Johnston, L.A., Armstrong, D.L. and Simmons, L.G. (1994) Gaur sperm cryopreservation trial: analysis of packaging type and rapid freezing method for potential field application. Theriogenology 41:291.

Loskutoff, N.M. and Bartels, P. (1994) Assisted reproductive technology for the preservation and management of genetic diversity in wildlife species. Proceedings of the 11th LatinAmerican Congress on Genetics, Puerto Vallarta, Mexico, 25-30 September 1994.

Dr. Monica Stoops,
Director of Reproductive Sciences

Dr. Jason Herrick,
Vice President of Conservation and Animal Health

Dr. Jessye Wojtusik,
Lead Scientist

Dr. Shelley Sandmaier,
Postdoctoral Fellow, Reproductive Sciences

Jonathan T. Aaltonen, M.H.S.
Reproductive Sciences Lab Supervisor

Linnie Krause,
Endocrine Lab Technician