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The Silage Dilemma - Bulk or Quality

The Silage Dilemma -  Bulk or Quality

Aidan Murray, Teagasc Beef Specialist discusses bulking up the silage crop and warns of the negative impacts such as reduced overall digestibility and therefore feed value. Lower quality means extra feed costs. Aidan has advice on deciding on cutting date and on getting good preservation

After swallowing the bitter pill of have to fork out for very expensive fertiliser most of you will have spread it on your silage ground at this stage. So now it is a matter of waiting to allow the plant to use up the nutrients and have the fingers crossed that we get good growth. It is important to point out though even with expensive fertiliser grass is our cheapest feed source for cattle so we will get return on our investment and particularly at this time of year when response to fertiliser is greatest.

Over the coming days and weeks if the weather conditions come right and we can get a contractor you will have to make the decision as to whether to cut or not. It is very tempting for many to let crops bulk up and cut as much as you can. Some crops may be let grow out by up to 8 weeks. You may have one of the reasons below for letting a crop bulk up by delaying cutting but as the table below shows it is not all positive.

The biggest impacts of delayed cutting will be to reduce overall digestibility and therefore feed value. This is an important consideration depending on what you intend to over winter. Stock such as weanlings, finishing cattle and autumn calving cows should ideally have access to high quality (70%+DMD) silage otherwise costly meal supplementation will be needed. At predicted meal costs of €450-€500/t every kilo of meal saved will be significant. The example below shows that feeding a weanling a 62%DMD Silage versus 72%DMD will mean an extra 1.5kg concentrate which over a 5 month winter will equate to an extra €100 per weanling. You can double that figure for a finishing animal.

Store cattle and dry spring calving suckler cows only require 66-68%DMD silage so it can be left to grow out that bit longer.

The table below shows the causes of changes in digestibility, what will have the biggest impact on silage quality and their effect on dropping %DMD. A standing crop of grass left for an extra week will see digestibility drop by 2-3% whereas a heavy crop that has lodged will deteriorate by 7-9% units. So a delay in getting a contractor, poor weather and a lodged crop can see a rapid deterioration in quality over a relatively short period of time.

All these points need to be considered as to when you decide to cut. It is always worth bearing in mind though, that good quality silage gives you much more flexibility. Let quality slip and you are into extra feed costs straightaway something that is not appealing going into this winter.

In advance of cutting give yourself the best chance of a good preservation.

  • Ideally cut in good weather conditions when sugars are over 3%
  • If sugars are between 2-3% consider a 24 hour wilt to increase dry matter
  • If sugars are less than 2% then unless you are going to use an additive you may have to delay cutting
  • Ask your adviser to test sugar & nitrate levels pre harvest

In summary, silage will be expensive to make this year and the decision to go for bulk or quality will be determined by the stock you intend to keep this coming winter. High quality silage will always give you feeding options and can reduce you feed costs overall. With poorer quality silage your hands are tied before the winter even starts.

 The Teagasc Beef Specialists issue an article on a topic of interest to Suckler and Beef farmers every Wednesday here on Teagasc Daily.  Find more on Teagasc Beef here  Teagasc provides a Local Advisory and Education service to farmers. Find your local Teagasc office here