Farm Ireland

Wednesday 21 March 2018

Beef: A clean pit face reduces the risk of mouldy silage

Eight Friesian bullocks with an average weight of 446kgs made €780 each last week at Corrin Mart, Fermoy, Co Cork. Photo: O'Gorman Photography
Eight Friesian bullocks with an average weight of 446kgs made €780 each last week at Corrin Mart, Fermoy, Co Cork. Photo: O'Gorman Photography

Gerry Giggins

As I checked my old diary for a misplaced telephone number I was reminded that this time two years ago I was in northwest France, as part of the IFA delegation sourcing hay at the peak of the fodder crisis.

I don't wish to remind farmers of that bleak period but as I travel throughout the country it is great to see silage stocks now replenished on most farms. On many farms there are large excesses of pit and bale silage. Barring any unnatural weather patterns, this silage will be stored until feeding next winter.

However, as I have written before, 2014 wasn't a vintage year for silage quality, with disappointing results for dry matter, energy levels, preservation and mineral content. Unlike a fine wine or whiskey, this silage won't improve in storage between now and its consumption date.

With the grazing season now in full swing, any cattle that remain indoors are on finishing diets that include little or no grass silage.

So many silage clamps are now temporarily redundant, but this silage is still a highly valuable feed and every effort should be made to preserve and retain it in its best form for feeding next season.

Given the risks that are present for forage deterioration, it is important that the pit face is cleaned prior to closing, ideally using a sheer grab. This will remove the loose material that is highly susceptible to secondary fermentation and leads to mould formation.

It is these moulds that have the potential to create huge problems in the silage clamp, which can multiply over the summer and subsequently at feeding stage.

While not being the easiest of tasks, especially without a sheer grab, and being well down the list of priority jobs at this time of year, cleaning the face of the pit will prevent tonnes of feed from wasting. If the silage has a fairly average drymatter of 25pc, there is less need to pull plastic over the pit face. Simply cutting the face clean and leaving it exposed will suffice until first cut silage is put up against it.

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However, the case for maize and wholecrop silage is very different. Obviously, they are much more susceptible to bird attack and mould due to their higher dry matter and grain content.

Pulling down the cover and ensuring it is well weighed down is of absolute necessity in this scenario.


Ongoing analysis of forages in Ireland indicate that mycotoxins are present in a large number of cases.

These mycotoxins are produced by fungi during the storage period of the forage. Fungi such as fusarium and penicillium produce mycotoxins that will hamper the natural bacterial activity within the rumen.

The rate of their multiplication within a silage clamp is influenced by the moisture content and the temperature of the feed. Dry forages, exposed to higher summer temperatures will rapidly produce moulds.

I regularly see with fungi in profusion across the exposed face, and wonder if it is really possible to fully remove all of this highly toxic contamination prior to feeding.

Unfortunately, not all moulds are visible. The perception that only feeds showing visible evidence of mould growth contain harmful mycotoxins is incorrect.

Mycotoxin contamination of forage can predispose livestock to sub-clinical or chronic ill effects. Early signs of animals affected by mycotoxicosis are poor rumen function, reduced feed intakes, low feed conversion efficiency, diarrhoea and higher incidences of respiratory diseases.

In extreme cases, drying and peeling of the skin is visible, increased lameness, swelling of the testicles on bulls and tail mecrosis can be wittnessed. The most effective way of dealing with the mycotoxin issue is to eliminate the mould formation and minimise the feeding of affected forages.

In the event of the above symptoms being verified as being the result of mycotoxin contamination, an effective mycotoxin binder should be fed. These binders are designed to absorb the vast majority of the harmful toxins and allow them to pass through the digestive system of the animal without any of the adverse side effects.

Gerry Giggins is an independent feed and animal nutritionist based in Louth


Indo Farming