“We found a wide range in results,” says Limagrain’s John Spence. “This highlighted the range of feed quality possible, even in samples taken from farmers’ ‘best’ fields and cut at the right time.”
ME scores ranged by as much as 1.2 MJ/kg, with digestible fibre (dNDF), sugar and protein levels all differing by more than 6%. “Trial work has shown that each 1% increase in DNDF can result in an increase in milk production of 0.25l per cow per day, so a 6% variation in DNDF across grass Samples, represents 1.5litres per cow per day.”
And the results also demonstrated the importance of looking at more than one constituent of the feed value. “As we would expect, samples with high sugar content had the lowest protein levels and vice versa – high protein grasses had low sugar levels,” he adds. “The sample analysed with the highest sugar content actually had the lowest ME of all, showing us that just looking at one constituent isn’t a good way to judge feed quality.”
“We used the results to draw attention to the importance of considering all aspects of grassland production – soil, cultivation and seed mixture,” adds Mr Spence “And the importance of considering the nutritional qualities of the seed mixture, as well as its agronomic values. Seed mixtures with poor feed value can be expensive.
“The aim is to grow high energy grass. A significant proportion of this energy comes from the fibre. The higher proportion of digestible neutral detergent fibre (DNDF) in the grass varieties used in the LGAN mixtures and the inclusion of more palatable tetraploid varieties, that cows prefer over diploid grass varieties, helps to boost the grass’ feed value and boost intakes.
Limagrain, OPICO and Sustainable Soil Management offered free soil advice, 10 acres of premium grass seed mixture and the seeding work for the fresh grass sample that tests highest for metabolizable energy (ME) at this year’s Grassland and Muck Event.
This top prize, valued at £1500, will go to the sample with the highest ME across the two-day event.
“Our winning sample had a more balanced nutritional profile with good protein and sugar levels but, most importantly, the highest DNDF figure resulting in an excellent ME of 14.9 MJ/kg.”