High levels of WSC in grass lifts yields
High levels of WSC in grass lifts yields
GRASS varieties which maintain high levels of water soluble carbohydrates through the grazing season could lead to increased cow intakes and milk yields.
Thats the conclusion from early results of an MDC, MAFF and Germinal Holdings funded study. This shows improvements in animal performance using a high WSC variety, AberDove, compared with AberElan – the top NIAB recommended variety for simulated grazing yield.
At the conference, Dai Hides of the Institute of Grassland and Environmental Research, Aber-ystwyth, explained that in the trial grass was zero-grazed by dairy cows in three four-week periods between March and August.
Cows fed AberDove ate 1.7kg more grass dry matter a day and produced 2.7kg more milk a day than those fed AberElan. In trials, AberDove was also more digestable.
"Cows fed AberDove also excreted less nitrogen and used more in the milk, reducing losses of valuable protein. If we can combine high protein with high energy, as in increased WSC varieties we can make the rumen more efficient."
In the past, grasses with high WSC have had poor disease resistance. But AberDove is a late flowering diploid ryegrass with high WSC and disease resistance and is in official UK trials.
But benefiting from these and other new varieties requires reseeding more often than is common on farms. A grass variety has a life of only 10 years, he added.
"New varieties are available as quickly for grass as they are for cereals. But to benefit, producers must have a realistic reseeding policy. We have to give grass the crop status it deserves."
Modern varieties with imp-roved digestibility and WSC levels producing more dry matter through a longer growing season are becoming available, he added.