APPLYING fertiliser containing the trace element, selenium to grazing pasture could boost milk yields by 9% in deficient areas, according to research conducted by fertiliser manufacturer Hydro.
The main source of selenium for dairy cows is concentrate feeds, but maintaining intake can be a problem with grazing animals when concentrates are cut, says Hydros Rosie Carne.
"Vets report increased levels of selenium deficiency since slag became unavailable in the late 1980s. Our research shows selenium and sodium deficiency in grass can lead to fertility problems, increased mastitis and reduced overall performance in dairy cows." *