“Grass remains the most cost-effective and sustainable feedstuff for ruminant livestock,” says the company’s Mhairi Dawson, “and the UK is blessed with the perfect climate to grow it in abundance.
“Now’s the time of year to consider whether your swards are capable of providing sufficient forage for coming season – not just dry matter, but also its energy content – for that to be the case”.
Reseeding might be the only way for some growers to take advantage of such strategies, because some swards may be falling far short of their true capacity.
“From talking to farmers around the country, I know reseeding is viewed with caution. But when looking beyond the initial cost and see its value as an investment on which to make a return, it’s then that the figures become quite persuasive.”
Consider new grass varieties
While new varieties of grass rarely receive the same attention and consideration as those for cereals, similar advances in genetics – yield, disease resistance, drought resistance, winter hardiness – are being made all the time. “To give you some idea, Barenbrug has had 46 new grass varieties in the Recommended Lists over the last 30 years.
“So, if your sward is more than about 8 years old – and many will be – consider this: whatever variety or mixture you planted, there will now be a better one; and anyway, it’s likely to contain no more than half of the original sown species. The rest will be unproductive weed species, like annual meadow-grass.”
It’s on this basis that the three main reasons to reseed become evident: better dry matter yield (DM), better metabolisable energy (ME), and better nitrogen-use efficiency.
Using standard industry figures, Barenbrug calculates that an older or damaged sward, comprising 50% sown species, has a yield potential of 7t DM/ha. A new sward, it says, could yield up to 15.5t DM/ha which, with DM typically valued at £140/t, offers an extra £1,190/ha.
“Each extra tonne of DM can provide approximately 11,000 MJ of energy,” explains Mhairi, “which is enough – at 5.2MJ per litre – to produce nearly 2,000 litres of milk, about 234kg of lamb or beef.
“If grass is your primary forage, that extra milk, lamb or beef has been produced without the cost bought-in feed.
“What’s more, because sown species are bred to make better use of nitrogen, you won’t be wasting expensive big-bag nitrogen on inefficient weed grasses such as annual meadow-grass.
“AMG is just 17% efficient in using applied nitrogen,” reveals Mhairi, “while ryegrass swards are 100% efficient in nitrogen use. With N prices as they are, that alone must be one of the most convincing reasons not to struggle on with old, tired swards.”