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Determine the effects of locoweed (swainsonine) on reproductive performance, specifically early embryonic growth and development in sheep. Develop recommendations to better manage breeding animals on locoweed ranges.
In vivo fertilized ovine embryos and in vitro fertilized bovine embryos will be collected and cultured in the presence of swainsonine (loco toxin) at different concentrations in the culture media. Embryos will be examined and scored for cleavage rate and development and subsequently transferred to normal ewes or heifers to monitor normal growth and development. Subsequently, mature western white face ewes (donors) will be divided into treatment groups and gavaged locoweed at dosages of 1mg/kg per day per ewe for 7, 14, 21, and 28 days. Each ewe will be superovulated using hormone treatments, bred to Suffolk rams and embryos collected 5 days after breeding. Embryos will be collected, examined, scored, and subsequently transferred into normal synchronized ewes (recipients). Secondly, embryos will be collected from normal superovulated ews (donors) and transferred into recipient ewes treated with the same dosages of locoweed as above for 7, 14, 21, and 28 days. This study is intended to determine if locoweed-induced embryonic loss results from the toxic effects of locoweed directly.