Developing Selenium-Enriched Animal Feed and Biofuel From Canola Planted for Managing Se-Laden Drainage Waters in the Westside of Central California

We studied the reuse of selenium (Se)-laden effluent for producing canola (Brassica napus) and subsequent bioproducts in central California. Canola was irrigated with poor quality waters [electrical conductivity (EC) of approximate to 5 dS m-1 sulfate-salinity, 5 mg B L-1, and 0.25 mg Se L-1]. Typical seed yields were 2.2 metric tons ha-1. Seeds were processed for their oil, and transesterified to produce ASTM-quality biodiesel (BD) blends. The resulting Se-enriched seed cake meal (containing 2 mg Se kg-1 DM) was used in a dairy feed trial. Seventy-two Jersey and Holstein cows, 36 respectively, were fed Se-enriched canola meal as 6.2% of their daily feed ration for five weeks. Blood and milk samples were collected weekly and analyzed for total Se. This study showed that Se-enriched canola meal did not significantly increase total blood Se content in either cow breed. Milk Se concentrations did, however, significantly increase to safe levels of 59 g Se L-1 and 52 g Se L-1 in Jersey and Holstein cows, respectively. The production of BD 20 biofuels and Se-enriched feed meal from canola irrigated with poor quality waters may help sustain similar phytomanagement strategies under Se-rich conditions.