A full understanding of forage quality is essential if nutritional requirements of dairy herds are to be met.
Silage expert at Volac Peter Smith says this can be achieved through regular silage sampling.
Mr Smith says: "While initial silage quality samples should have been collected once fermentation had been completed six weeks after harvest, monthly quality tests should also be taken once feeding begins.
“Ideally, producers will also be sampling silage for dry matter (DM) content each week to ensure accurate ration formulation.
“But if that is not practical, it is essential to conduct DM tests at least every fortnight, especially in periods of wet weather.”
Dr Richard Kirkland at Volac Wilmar Feed Ingredients reiterated this, saying that balancing a winter ration should begin with silage analysis to fully understand the quality of basal forage.
Dr Kirkland says: “This is needed to enable appropriate supplementation for key macro nutrients, including fibre and protein, and to meet requirements for total metabolisable energy (ME).”
“With an increasing trend in the dairy industry to adopt multi-cut silage systems, further attention to detail is needed to balance these high-energy, low-fibre forages.”
“Short-regrowth pasture silages are more rapidly fermentable in the rumen and can pass through the digestive system more quickly.”
With inappropriate supplementation, Dr Kirkland said lower fibre levels can compromise rumen pH.
“While high fibre ingredients such as straw are an effective buffer to slow down flow of feed through the digestive system, they also fill the rumen with low feed quality bulk that can compromise energy intake and milk protein.”
“Overloading the diet with high starch supplements to make up for the energy deficit should be avoided as it will lead to the accumulation of acid in the rumen, further increasing the risk of acidosis.
"Instead, choose a rumen-protected fat supplement.”
Dr Kirkland explains that the typical dairy cow needs 15 to 20 per cent of its ME to come from fat, and suggests this could be equivalent to more than 6 per cent of ration DM for high yielding cows.
He says: “It is important to note that fat supplements are more than just a dense energy source, as individual
fatty acids impact cow performance by partitioning nutrients to different aspects of performance.
“Therefore, fat supplements should be selected based on the fatty acid make-up and depending on the stage of lactation, individual farm challenges and requirements to maximise returns from specific milk contracts.
“While targeting the specific fatty acid requirements is not feasible in a year-round calving system, a multi-purpose fat supplement is the most effective way to meet nutritional needs of the entire herd at different stages of lactation."