5 September 1997

Grazed grass under study

MAKING better use of grass by dairy cows in mid to late season is the aim of new research just started at the Scottish Agricultural College at Auchincruive, Ayr.

Leading the project is Jan McBride who says by mid-season, undergrazing can lead to 40% of pasture being rejected if early season conditions have not allowed efficient control.

"Even under intensive grazing, rejected areas can be as high as 20% by mid season due to dung pats," she says.

"What we are going to do over the next few years is to see how we can manipulate the sward in mid to late season by stocking density. We will look at the effect on the grazing animals, the time spent grazing, and intake a day and then relate that back to milk yield and composition.

Sward death, stem to leaf percentages, height of sward, frequency of defoliation and how all that ties in with herd fertility will also be studied.

"We will be looking at cows calving from January to June and studying them in mid-lactation. Concentrates will be fed at 3kg a day and we will see the effects of forcing animals to eat pasture they would reject if there was understocking.n