Grass growth averaged 30.5kg DM/ha/day for the week ending 23rd April, which is an increase of 6.3kg DM/ha/day on the previous week. Due to lower average rainfall this year, the grass growth rate is still behind the 6-year and 2020 averages, which were around 47kg DM/ha/day. Growth rates are expected to continue to be behind previous averages as the weather remains mostly dry and settled.
Milk Yield from Grazing (MYFG)
Potential MYFG has seen large variations across GB this week, with M-1.8 litres/day in the East and M+9.5 litres/day in Wales and the West. Unfortunately, Trouw received no samples from the North East and Yorkshire. Across the samples submitted, average MYFG of M+6.0 litres/day, has fallen below the 6 year and 2020 averages of M+10litres/day and M+7.45litres/day respectively. This decrease in MYFG can be attributed to a fall in potential dry matter intake, totalling 1.1kg/day lower than last week’s average of 9.6kg/day. The average dry matter value of samples submitted this week are drier than those submitted during the same period last year, which was expected given the dry conditions experienced across the country recently.
With slow grass growth and forecasts expected to remain dry it is important to review feeding strategies and ensure optimal grass covers are maintained. This will help to minimise a further reduction in grazing quality and subsequent negative consequences on animal performance:
• Good grassland management through the monitoring of sward heights to achieve target entry and residual covers, as well as managing rotation lengths and stocking densities.
• The high sugar, low fibre profile of spring grass results in fast rumen fermentation and passage, increasing the risk of acidosis and low butterfat. Strategic buffer feeding should be considered, for example offering high levels of digestible fibre and readily fermentable starch.
• Continue to implement strategies to reduce the risk of butterfat depression, such as the inclusion of stable live yeasts cultures yeasts or the addition of rumen buffers.
Pre-Cut NDF Tracker 2021
There has been an increase in pre-cut sample submissions this week indicating that farmers are thinking about cutting and silage making. The national average NDF this week is 32.7% DM, which is below the optimum level of 38-40% NDF for cutting. However, samples show large variations of 21.6 to 40.9% DM NDF, indicating that on individual farms some are closer to optimal cutting levels than others. Samples submitted from the North of the country are already at a higher NDF level than those further South.
Sugar levels are very good, averaging >15% DM, and free nitrate levels are low averaging 300mg/kg (fresh weight), however crude protein is also low averaging 18% DM. Care should be taken after the dry weather, when there is a period of rainfall to monitor free nitrate levels (<2500mg/kg before cutting), their uptake into the plant and to ensure these have been converted to crude protein.