Reseeding still pays despite price rise
Despite the increase in the cost of grass seed – up to 50 percent for some cultivars – reseeding remains an excellent investment, according to Barenbrug agricultural product manager David Long.
"Old and worn out leys lose out in several ways as they are significantly lower yielding – up to 40 percent less productive than a new ley in its first year," he says. "Couple this loss in production with the lower feed value of the weed grasses in the ley and producing highly digestible silage or maintaining top-quality grazing becomes far more difficult. A worn out ley can also waste money as the weed grasses that fill worn out leys are much less effective at utilising nitrogen. A sward made up of 50 percent weed grasses wastes 30 percent of nitrogen applied – that could be a lot of money.
"Also, weed grasses tend to be shallow rooted so, in times of drought stress, they are the first thing in the sward to either die or contract back, causing additional loss of production. It really is a case of good quality grass makes money, while poor quality grass costs money – and that’s true even with the high costs of the grass seed."
Results from a study conducted at AFBI Hillsborough in Northern Ireland underline the savings livestock farmers can make on another input that’s seen its price rise significantly over recent times – concentrate feed.
The study looked at the advantages of producing quality silage and the savings that could be made in purchased compound feed. The research shows that 500kg continental steers offered high-quality silage – D-value 70, ME 11.2 MJ/kg DM – supplemented with 1.5kg concentrate per head per day are predicted to gain 1kg/day during the finishing period.
To obtain a similar level of performance from an average-quality silage with a D-value 65, ME 10.4 MJ/kg DM, or low quality silage with a D-value 60, ME 8.8 MJ/kg DM, an additional 2.3 or 4.9kg concentrates/day respectively would be required.
Over a five-month finishing period this would be equal to an additional 0.36 and 0.76 tonne of concentrate per head, and would increase concentrate input by £87 and £182 per head, for the average and low-quality silage respectively, relative to high-quality silage.
The importance of sward quality also affects sheep performance; work from New Zealand shows a straight-line relationship between grass quality and live-weight gain. A 30kg lamb grazing 9 ME grass, with dead and stemmy material, will gain no weight, compared to the same lamb on 11 ME grass, a short, dense leafy sward, who will achieve live-weight gains of 200 gm/day. For high weight gains, lambs need a diet with an ME higher than 11. This means green, leafy pastures, with low levels of dead matter or stem, and preferably high levels of clover.
The importance of white clover in the sward cannot be ignored; trials have shown a 30 percent increase in lamb output from grazing a sward with a high white clover content compared to a similar sward receiving high levels of nitrogen.
David concludes: "The dairy cow is also severely affected by loss in grass quality with a fall in yield due to worn out pastures reducing milk output by up to 50 percent. To get the best out of your grassland, keep the grass young and in good condition; and, especially if it has been damaged by the recent drought conditions, consider re-seeding with a more drought-tolerant mixture that includes drought-tolerant species like tall fescue, cocksfoot and Timothy."
