Selenium and Mammary Resistance to Infectious Disease
DOI:
https://doi.org/10.21423/aabppro19887030Keywords:
Selenium, mastitis trial, mammary resistance, Vitamin EAbstract
We designed an experimental mastitis trial to study, under more controlled conditions, the effect of Se on mammary resistance to disease. We divided twenty Holstein heifers into two groups of ten. One group was maintained on a Se deficient (Se-) diet with 0.04ppm Se on a total ration basis. The other group was fed a selenium adequate (Se+) diet that contained 0.14ppm Se. We fed both groups identical rations, except the Se+ group received an additional 2 mg of Se per head per day. All other nutrients, including Vitamin E, were fed at or above NRC recommended levels. We challenged the heifers at about 14 weeks post-partum with 30 colony forming units (cfu) of Escherichia coli in one quarter. Quarters selected for challenge had SCC <250,000 cells / ml and no prior infections.