Selenium fertilizer use on beef cow/calf farms: Effects on calves from birth to weaning

A randomized clinical trial of selenium fertilizer was conducted on 30 beef cow/calf farms on Prince Edward Island, a selenium deficient area of Canada. Selenium-enriched superphosphate fertilizer was top-dressed on all pasture and forage crops on 14 farms in the spring of 1989 and 15 farms in the spring of 1990. The other farms served as controls and received no fertilizer. Calving data including birth weights were collected for all calvings that occurred during the spring of 1990. Pasture and forage samples were collected for selenium analysis in the summer of 1989. Blood samples were obtained for serum selenium determination from a random sample of approximately 20 weaning age calves on each farm. Two hundred day adjusted weaning weights were collected for calves on all study farms. Blood samples were obtained from approximately 20 nursing calves and their dams in the spring of 1990 following winter feeding of home grown forages. Information on calf management and selenium supplementation practices was collected by a personal interview questionnaire in 1989. (Abstract shortened by UMI.).