Selecting grass varieties on yield as well as quality differences and factors such as extended grazing could result in an extra two litres a day from each dairy cow.
Speaking at the Dairy Event and Livestock Show, British Seed Houses‘ Paul Billings said looking at yield was only part of the story.
“The difference between the best quality and poorest quality on the NIAB Recommended List is stark. The top to bottom differential on grazing D-Value on the NIAB lists is five points.”
Specifically, intermediate perennial ryegrass AberStar is the highest yielding on the NIAB recommended List and offers a 1.1t DM/ha advantage over the lowest yielding variety on the list.
“Using the Kingshay cost of production for grazed grass figure of £79/t DM, this gives a financial benefit of £87/ha,” said Mr Billings.
One unit of D-value can improve animal performance by 5% and, with AberStar five points ahead on the NIAB List with a D-Value of 79.2 compared to the lowest at 74.2, this again has significant financial consequences.
“Within the list the difference between the best and worse performer could be as much as 25%,” added Mr Billings.
Research at DARD in Northern Ireland equates one unit of D-Value to 0.2kg/cow/day of dry matter intake and 0.4kg/cow/day of milk yield – that’s 2 litres/cow/day extra from the best listed variety instead of the worse listed variety.