Monoculture swards might boost yields
Monoculture swards might boost yields
OFFERING sheep and cattle grass and clover separately rather than in a mixed sward could boost intakes and milk yield, according to recent research.
Speaking at the BGS conference, IGER North Wyke researcher Mark Rutter explained how offering sheep and cattle a choice between grass or clover influenced their grazing behaviour.
"Dairy cattle and sheep were offered adjacent monocultures of grass and clover compared with a mixed perennial ryegrass/clover sward containing 30-40% clover.
"Animals offered grass and clover separately included 70% of clover in their diets. Ewe intakes were 0.8kg dry matter a day higher on this system than on a mixed sward, which could lead to faster lamb growth.
"Milk yield from dairy cows on the grass and clover monocultures increased by an average of 3.5kg a day," he said.
Dr Rutter believes that the explanation for why intakes increase in the monoculture system is because sheep and cattle waste less time searching for clover, their preferred herbage.
But sheep and cattle do not live on clover alone, and their choice is also influenced by time of day, said Dr Rutter. "Both sheep and cattle show a stronger preference for clover in the morning, but increase grass intake towards evening.
"Animals tend not to graze much at night due to predator risk. As grass passes more slowly through the gut than clover – making it less likely that they will need to graze in the night – this could explain why they prefer grass towards evening."
This knowledge about grazing preferences could be used to develop new grazing systems, designed to maximise intake, he said.
"Adjacent monocultures are tricky to set up and manage in a commercial situation. A way round this would be to have paddocks containing either grass or clover in a rotational grazing system." *
Milk yield from dairy cows offered grass and clover monocultures rose by 3.5kg a day, according to Mark Rutters research.