If you think of valuable products that come out of a meatpacking plant, the contents of a cow's rumen probably don't come to mind. But Lindley Reilly thinks differently. She thinks rumen extracts could yield a low-cost source of protein for livestock and also help solve a vexing environmental problem.
Reilly, who graduated in May from the University of Wisconsin-Madison with a degree in dairy science, made her case in a 3,000-word review of scientific literature that earned her the Regional Young Scientist award for North America — a contest entered by 1,100 undergraduates. As the winner, she received $1,000 and an all-expense-paid trip to Alltech's 25th Annual Animal Health and Nutrition Symposium to compete against three other regional winners.
Reilly suggested that bacteria in a cow's rumen could provide a protein source for monogastrics. She noted that there is enough of the essential amino acid lysine in the rumen of a normal steer to meet the required daily intake of 3.5 pigs, and calculated that the cattle on U.S. feedlots could supply enough lysine for more than 100,000 pigs.
Turning rumen contents into a lysine-rich feed byproduct, she said, could both reduce feed costs and address concerns about nonpoint source pollution related to the practice of overfeeding protein. Livestock producers often overfeed protein in order to meet dietary requirements for "limiting" amino acids, those present in relatively small amounts. Overfeeding protein increases the nitrogen content of livestock manure, which in turn increases the risk of pollution through nitrogen in runoff and is associated with larger of ammonia emissions to the atmosphere.
"The best solution to reduce environmental risk of excess manure nitrogen from livestock operations is to formulate diets with protein sources that contain amino acids balanced in the exact proportions to meet animal needs based on production and health status," Reilly concluded.
Reilly prepared for the contest with guidance from dairy scientist, Michel Wattiaux, who teaches a course in ruminant nutrition. With Wattiaux's guidance, Reilly looked for a topic with a global perspective that involved multiple species.
"I felt it was important to combine the dairy, livestock and swine industries," Reilly remarked. "We need to work together."
Wattiaux was confident that Reilly would excel in the contest. "Early in the semester, she distinguished herself as a student who thought critically – with a researcher's perspective," he said. "Lindley worked very independently and did an excellent job creating a compelling story."
Reilly also traces her success in the contest to a dairy science seminar taught by dairy scientist Ric Grummer, which required her to summarize research and present data.
As a mentor and professor, Wattiaux strives to get students excited about lifelong learning. "It's very gratifying to work with students such as Lindley, who, given the opportunity, can get so engaged in gaining understanding and new ideas on their own."