Selenium status of 12 herds of Indiana dairy cattle

Abstract

Ten of twelve herds of dairy cattle in Indiana that were surveyed were determined to have adequate selenium (Se) status (serum Se concentration >0.040 μg/ml); two herds had marginal Se status (serum Se concentration between 0.020-0.040 μg/ml). In 6 herds where Se supplementation was not given, mean serum Se concentration in lactating cows was 0.051 μg/ml (n=25) and in dry cows was 0.043 μg/ml (n=5). In 6 herds giving Se supplementation, mean serum Se concentration in lactating and dry cows were 0.071 μg/ml (n=26) and 0.049μg/ml ((n=14), respectively. Serum Se concentration had significant positive correlation to Se content of concentrate mixture but not to Se content of hay or corn silage. Two herds that were given no Se supplementation and had adequate Se status reported a high frequency (>20%) of placental retention but the incidence decreased to normal rates over the following year; one herd used no Se supplementation during this decline and a controlled field study of selenium-vitamin E prepartum injection in the other herd had similar decline in frequency of placental retention in cows either with or without selenium-vitamin E supplementation.