A Low Concentration of a Sustainably Obtained Blueberry Extract Improves the Post‐Thawing Motility of Cryopreserved Bull Spermatozoa

Natural extracts could improve sperm storage and artificial insemination (AI). This study, for the first time, evaluates the suitability of a blueberry extract (Vaccinium corymbosum), obtained from pomace using a sustainable methodology, as a supplement for bull semen extenders. Cryopreserved semen doses from eight bulls were combined in 9 pools (3 bulls/pool), supplemented with 0%, 1%, 5%, or 10% extract and incubated up to 5 h at 38°C. Motility was assessed hourly using OpenCASA, and the effects of treatment and time were evaluated using linear mixed-effects models. Motility was significantly better preserved with 1% extract (total and progressive motility, linear velocity and linearities, with lower BCF and fractal dimension, related to hyperactivation). The effect of 5% was overall positive but lower than 1%, whereas 10% showed a mostly negative effect. This natural extract could safely supplement bull semen extenders by at least 5% and even help improve sperm motility. Therefore, its use as a supplement in bull semen extenders offers an opportunity to enhance assisted reproductive techniques in cattle using a sustainable approach.