#20

Screening Oak Taxa for Suitability for Producing Acorns as an Animal Feed Crop

Shawn Overstreet, Independent Scholar, UC Davis

Thomas Gradziel, Department of Plant Sciences, University of California, Davis

Substituting perennial carbon-sequestering oak trees for a portion of the annual cereal grains grown for animal feed is a way to help California meet its 2030 goals of curbing greenhouse gas emissions. Feeding studies indicate that oak acorns can be substituted for 25% of the grain in animal feed rations for most livestock species, with the ideal acorn being low in fat and tannins, and high in protein.

Acorns from sixty-three oak taxa were collected from across the United States in the fall of 2015 for a chemical analysis of their nutritional composition. Additionally, the oak taxa were screened for their climatic adaptability based on the number of USDA hardiness zones in which they would grow successfully. Four taxa were identified as having a high potential to be an animal feed crop. Acorns of Quercus macrocarpa, Q. lyrata, and Q. suber all met the requirements for an ideal acorn animal feed, and the climatic adaptation and growth requirements of these three taxa compliment each other. If acorn oil extraction prior to use as animal feed is considered as an option, Q. emoryi (35.9% fat) would also have a high potential as an animal feed crop.

These encouraging results suggest that all 21+ taxa of native California oaks should also be screened.  Understanding the suitability of our locally-adapted oak species for use as an animal feed crop could help inform management of both natural oak woodlands and marginal croplands suitable for acorn orchards.