Preservatives help avoid hazardous moulds
Analysis of preservative treated and untreated straw bales have highlighted the potentially high levels of harmful moulds that can occur in bales and how this can be easily avoided.
Mould and yeast are both present in hay and straw, and when found at high levels are indicative of crop quality deterioration. Increased levels are evident through bales heating up, especially if harvested damp, with an increase in dust and matting of the wads. Less visible will be the rise in micro-toxin fungal spores, which potentially will be liberally spread when the bale is shaken up or put through a bale spreader, so posing a health hazard for both humans and livestock.
The micro-toxins present in a dusty or mouldy bale can be a major challenge to the respiratory system and the cause of illness. In humans the most common association would be 'farmer's lung', and again in livestock the spores will result in respiratory illness, loss of performance and potentially can lead to abortion.
The analysis compared the use of Baler's Choice preservative on oat straw baled at between 16% to 24% moisture last autumn. Baler's Choice uses a buffered, near-neutral form of propionic acid, plus citric acid to retain colour and freshness.
Similar results have also been found in trials conducted at the University of Wisconsin into the effectiveness of Baler's Choice when used on hay. Here the crop was harvested at 22% moisture content and the mould levels in the treated and untreated bales were then monitored over a storage period of up to 120 days after baling. As the table below shows, in untreated bales, mould counts rose considerably to around 2,250,000 cfu's/gram, whilst those in the bales treated with propionic acid remained at the same virtually insignificant levels.
"Whilst not a replicated trial, the oat straw analysis is interesting. If Baler's Choice allows crops to be baled at higher moisture contents then this will buy flexibility at harvest and be a useful tool for the farmer," says Dr Martin Yeates, Technical Manager at the Kingshay Farming Trust. "Crops will deteriorate when harvested in less than ideal conditions, so there is a benefit if this product enables you to confidently store bedding or forage bales that will not deteriorate and become matted and dusty."
"It has long been accepted that propionic acid is by far the most effective preservative for hay and hayleage, and these trials confirm that. The reduction of mould and dust is important if forage or bedding quality is to be maintained, especially where the bales are being used as a source of long fibre in a cow's diet, or being fed to horses which can develop hypersensitivity if fed dusty bales," comments Richard Snell of the Profitable Farming Company.