Farmers are being advised to take advantage of lower neutral detergent fibre (NDF) levels being reported in this year’s silage analysis by ensuring rumen throughput is maximised to encourage greater milk output.
“This year’s silages are promising, with good dry matter (DM), energy and protein levels, but lower NDF levels are being reported,” says Bronwen Pihlwret, nutritional advisor at Quality Liquid Feeds.
However, she explains that farmers can use this to their advantage. “Lower NDF levels present an opportunity to maximise dry matter intakes (DMI) as a lower level of structural fibre and increased intake potential will allow rumen throughput to be increased. This results in a rise in the cow’s potential to eat more home produced forage.”
“This has been seen already this autumn, with clamps of first cut silage fed out through the summer dwindling fast.” Bronwen adds that to maximise this effect, microbial efficiency needs to be optimised.
“Research has proven that by replacing some starch with sucrose in the ration, it will help increase NDF digestibility (NDFD) and allows better utilisation of RDP in the grass silage.
“This leads to a more efficient rumen environment, which will undoubtedly encourage rumen throughput and provide an efficient source of fermentable energy for rumen microbes so they’re working to their optimum to fully utilise the nutritional components of the ration,” says Bronwen.
When the cows shown in figure 1 were fed a source of sucrose, the diets were found to have an NDFD percentage of 66.1 percent, which was 5.2 percent more than cows fed starch diets.
“Further studies have also suggested that an increase in NDFD is also proven to increase milk yield,” explains Bronwen.
“Incorporating a sugar level of 5 to 7 percent of the DMI in the form of a molasses based liquid feed, from QLF’s ‘simply sugar’ range, into rations will not only improve NDFD, but will also increase the palatability of the ration and reduce sorting,” says Bronwen.
She adds that with milk prices rising, there’s a real opportunity for farmers to increase margins, especially if they’re able to fully utilise the availability of home-grown forage.
Figure 1: Graph to show effect of Starch and Sucrose on NDF Digestibility in Continuous Culture