Submitted to: Journal of Animal and Feed Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 2000
Publication Date: N/A
Interpretive Summary: The Water Management Research Laboratory has proposed that plants which accumulate Se could be cultivated, harvested, and removed as Se-enriched plant material, resulting in lower Se concentrations in Se-rich soils. Selenium, while not required by plants, is an essential trace element for normal nutrition and health of animals. Selenium accumulation by lambs fed canola (used for phytoremediation of Se) was evaluated in central California. Lambs were fed 'Se-contianing canola' or 'low Se-containing canola' for 64 days. Urine and fece samples were collected weekly and analyzed later for Se. After animals were killed, the following tissues were analyzed for Se: heart, liver, kidney, spleen, muscle, toe-nail, and blood. Selenium concentrations were greater in all tested tissues from sheep fed 'Se-containing canola'. Our results show that canola used for the phytoremediation of Se may be used as a source of supplemental Se to lambs and increase Se concentrations in selected animal tissues.
Technical Abstract: The Water Management Research Laboratory have suggested that harvested plant material used for phytoremediation of Se, e.g., canola (Brassica napus) may be mixed with other animal feedstuffs and fed to animals in Se-deficient areas. This study was conducted to evaluate the excretion of Se in urine and feces and evaluate the accumulation of Se into different tissues, including blood, of lambs. Treatments consisted of feeding lambs 'Se-enriched canola' up to 5 mg Se kg/DM) and 'control canola' (<0.1 mg Se kg/DM). A weekly feces and urine sample was collected and analyzed for Se. After 64 days the feeding study was terminated. The following samples were collected at necropsy: blood, heart, liver, kidney, spleen, longissimus muscle, and toe nail. Se concentrations increased over time in urine and fecal samples, while Se concentrations were significantly greater in all tested tissues from sheep fed 'Se-enriched canola', Se concentrations were greatest in kidney and lowest in longissimus muscle and toe nail. Strict monitoring of Se concentrations in proposed forage material is essential before considering this method of plant disposal in Se-deficient regions.