Selenium and vitamin E: Reproductive disorders in dairy cows

Abstract

Selenium and vitamin E deficiency leads to reproductive disorders in dairy cows: placental retention, ovarian cysts, metritis, reduced percentage of conception, abortions, birthing of poorly vital calves. Placental retention is a post partal disorder of multifactorial etiology which has harmful effects on reproduction and the feasibility of milk production. The administration of selenium and vitamin E reduces the incidence of placental retention, which suggests that oxidative stress is responsible for the occurrence of this disorder. The occurrence of ovarian cysts has as its consequence a disorder in the oestral cycle. Vitamin E prevents oxidative damage of lipid membranes by preventing the forming of destructive hydroperoxides, acting in synergy with selenium. These nutrients protect cell membranes and lipid organelles, inhibit and destroy endogenous peroxides, and in that way protect the integrity of the membranes and reduce oxidative stress.