Yucca Baccata Seed Recovery Following Ruminal and Post Ruminal Digestion in Beef Cattle

TitleYucca Baccata Seed Recovery Following Ruminal and Post Ruminal Digestion in Beef Cattle
Publication TypeConference Paper
Year of Publication2005
AuthorsSmith F, Fredrickson E.L., Bezanilla G., Endress B
Conference NameSociety for the Advancement of Chicanos and Native Americans in Science
ARIS Log Number183676
AbstractIn the desert southwest, Yucca is a plant whose usefulness has served peoples of the past and present. In the past Yucca has served indigenous peoples by providing soap, food, and fiber. More recently, it serves as a source for forage, often when forage is least available, and has become a symbol of the American Southwest. Despite its importance, remarkably little is know about the ecology of Yucca. Of primary ecological importance is the birth of a new generation of plants via dispersal and establishment as seed becomes independent of the parent plant. One hypothesis asserts that plants such as Yucca evolved during the Pleistocene, or earlier, evolving for dispersal by Pleistocene megafauna by passage through the animal’s digestive tract. To our knowledge, this hypothesis has not been tested for Yucca. To test this hypothesis we ruminally dosed four-beef cows with 1,000 Yucca baccata seeds. Each cow was then equipped with fecal collection bags for total recovery of all feces and seeds contained therein. Feces was then weighed and all seeds removed by sieving the feces through a 2-mm sieve. Approximately, 10% of all seeds dosed were recovered intact from the feces within 48 hours post-dosing. For periods greater than 48 hours, primarily seed fragments were recovered. If subsequent tests find that intact seeds are germinable then we can conclude that cattle and other large ruminants act as dispersal agents of Yucca; substantiating their role as architects of southwestern desert environments.