Selenium Biofortification in Triticale (x Triticosecale Wittmack) Under Mediterranean Conditions: Effects on Forage Yield and Quality Parameters

Abstract Selenium (Se) biofortification in triticale (x Triticosecale Wittmack) was evaluated under Mediterranean conditions to address livestock Se deficiency. Different foliar application of sodium selenate dose (0, 10, 20, and 30 g Se ha − 1 ) were assessed on triticale forage yield, quality, and nutrient accumulation over two growing seasons (2017/18 and 2018/19) in Badajoz, Spain. Selenium application significantly increased forage yield by 14% compared to the control, but had varying effects on nutrient content and removal, with 20 g Se ha − 1 producing the highest Mg and Zn accumulation. Forage Se content increased proportionally with application rates (2–4 times higher than control), meeting livestock’s recommended intake of 0.05–0.10 mg Se kg − 1 . However, the highest dose (30 g Se ha − 1 ) had some negative effects on forage quality, such as increased acid detergent fiber and decreased organic matter digestibility. This suggests that the intermediate application of 20 g Se ha − 1 may be an optimal application rate that balances increased Se content with overall forage quality.