Ahead of the winter months, farmers need to ensure that they have their silage tested.
With second-cut silage secured on a lot of dairy farms, some farmers will not be opting for another cut, but all farmers need to make sure they know what quality the silage in the yard is.
If the silage that is in the yard turns out to be of poor quality, farmers either need to eye up making another cut of quality silage themselves, making more surplus bales, or buy in quality silage.
However, a decision like this needs to be made in the next couple of days, as a silage analysis along with a fodder budget will give each farmer an idea how much silage is in the yard and how much extra is needed.
According to the National Fodder Survey, 90% of farms expect to have sufficient feed in place for the winter ahead, but approximately 5% of farms expect to face fodder deficits of 20% or greater.
Of the farmers who were surveyed, it was highlighted that only 30% of those surveyed intend to analyse their silage quality.
This is far too low, considering that this feed is what will dictate performance, condition, and health throughout the winter months and can considerably reduce the need for extra costs through substituting poor silage for meal or bought-in feed.
Earlier turn-out to grass, favourable grazing conditions, and good grass growth rates throughout the summer months this year have put farmers in a better position in terms of fodder supplies when compared to the last couple of years.
Getting silage tested
The biggest variation in silage test results and particularly silage dry matter digestibility (DMD) stems from the date the crop was cut – which has to be at the back of every farmers’ mind as second cut approaches.
Realistically, farmers are only going to need dry cow silage for about 10-12 weeks of the winter. The remaining weeks and into the spring are going to require a higher quality silage for milking cows.
Milking cows are going to need at least a 74% DMD silage for the few weeks they may be housed, as well as for the shoulders of the year when they are getting buffer fed or they need extra silage to support grazing during poor growth.
Conducting a silage test is a simple and cheap, and will give you very valuable information on this year’s feed along with good guidance on what to improve for the next cut of silage.
The DMD of your silage for dry cows should be between 68-70% and over 74% for milking cows and young stock. The DMD of silage is the key determinant of the overall feed value.
When it comes to the UFL of your silage – which is an indicator of energy, as the higher the UFL, the more feed energy for milk solids – dry cow silage should be between 0.72-0.75UFL/kg. and milking cow silage from 0.83-0.88 UFL/kg.
The crude protein of silage can be impacted by the DMD of the silage and the timing and quantity of nitrogen applications. It should be over 12% for dry cow silage and over 14% for milking cow silage.
The PDIE – which is the digestible protein in the small intestine – should be 75g/kg for dry cows and over 80g/kg for milking cows. This is determined by the UFL and crude protein levels in the silage.
The intake value of the silage should be between 90-95g/kg LW (live weight)0.75 for dry cow silage and over 105g/kg LW0.75 for milking cow silage.
The potassium (K) content should be less than 2.2% for dry cows, as high K silage fed from two weeks pre-calving creates a milk fever risk. For milking cows, if the K content is over 2.4%, there should be no issue.
Preservation metrics
The pH of your silage should be between 4.0-4.2 and up to 4.4 for drier crops. If the pH is too high, it indicates poor preservation and if it is too low, intakes may be affected.
High ammonia also indicates poor preservation and reduces intake, so it should be less than 8% nitrogen.
Higher values of lactic acid indicate a stable and palatable silage, as ideally it should be between 8-10% of lactic acid DM while high ash indicates soil contamination and should be less than 8% DM.
Testing silage needs to be done on every farm, and especially when cows are going to be milking off this silage, as dietary decisions to ensure maximum milk production need to be conducted based off silage quality.
Having good quality silage will allow farmers to produce milk from mainly silage, which will reduce winter feed costs and increase profitability during the housed period.
Grass silage is the basis of most winter milk systems and good animal performance is largely down to the adequate intake of quality silage.
