Applying a sodium fertiliser to summer grass can help with this issue. Sodium increases the grass sugar content, making it more palatable to grazing cattle.
Sweetgrass®, a high-nitrogen fertiliser with added sodium produced by Goulding Fertilisers, is designed to increase grass palatability compared to CAN or other high-nitrogen compounds at this part of the growing season.
An independent research trial, conducted by the National University of Ireland in Athy last year, looked at whether Sweetgrass® fertiliser increased the sugar content of grass, improving its palatability compared to a standard compound fertiliser.
Results showed that Goulding Sweetgrass® fertiliser:Increased sodium content by 56%, giving higher palatability and intake.Increased sugar content by 21%, providing optimum fermentation and preservation.
While sodium in the fertiliser does not necessarily increase grass growth, a minimum level in the diet is essential for livestock health and performance. This is because animals require sodium for saliva production, which neutralises acids formed by bacteria in the rumen. If the sodium level is low, the animal replaces sodium with potassium, which leads to a reduction of magnesium in the blood. This can lead to disorders and production losses including loss of appetite and reduced DMI, reduced milk yield, an increased somatic cell count and an increased risk of hypomagnesaemia (grass staggers).
Increasing the levels of sodium in silage improves mineral balances such as the potassium to sodium ratio. The NUI trial showed Sweetgrass® reduced the K:Na ratio by 33%, reducing the risk of mid-season hypomagnesaemia.
Improving palatability is particularly beneficial when grass becomes less digestible or following slurry application which can ‘sour’ pastures. When the sward tastes better, cows increase their bite rate and the length of grazing time, improving grass utilisation.
Sweetgrass® contains 23% nitrogen, 2% sulphur, 5% sodium and 1.2% magnesium. Goulding also produces Sweet SustaiN, containing 35% nitrogen, 5% sulphur and 5% sodium. Sweet SustaiN is an NBPT-protected nitrogen fertiliser containing Agrotain®, with added sulphur and sodium.