Mycotoxin testing might be worth considering for farmers looking to increase milk production, lower cell counts and improve empty rates.
Jason Bake, from Crossmaglen near Coffs Harbour, NSW, has seen a dramatic improvement in all three of these areas since identifying and dealing with a mycotoxin issue on his 90-hectare farm.
Mycotoxins are caused by moulds in feed, which both decrease digestibility and often cause production and health issues. These issues range from minor illness to major impacts that greatly reduce milk production, or cause reproductive failure, abortion, or even death in cows.
Mr Bake, who grows corn for silage and grain in the humid conditions of the NSW north coast, was aware that mycotoxins were an issue, but did not realise how much effect they were having on his 400 crossbred cows."We had a bit of an issue and were working closely with Dr Bruce Hamilton from Ruminant Nutrition Australia," he said.
"We were looking at our production figures and we knew there was something not right. We did a test for mycotoxins and a couple of the strains were at very high levels.
"We already used a mycotoxin binder in the feed, which wasn't doing the job for us, so we did a bit of testing and changed to our present binder. Once we started using it, within three weeks we had an increase of three litres per cow per day of milk and our somatic cell count average dropped from 230,000 back to 180,000. Our empty rate was up to about 18 per cent and after a season with the binder in, it dropped back to about 12pc."
Mould risk can be identified in feed through visible moulds and musty smells. If mould can be seen or smelt, farmers should avoid purchasing it if they can. Mould isn't always visible but there can still be fungal impacts.
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White moulds are dangerous - not just coloured moulds and fungi. There are a few types of fungi that usually produce white-coloured mould and also produce dangerous toxins. This includes fusarium fungi, which is the most common fungi of forages in southern Australia. The white mould it produces can have toxins detrimental to cow health, production and reproduction.
For Mr Bake, identifying potential mycotoxin risks and finding the correct binder was well worth the effort. "If you open your silage bunker or round bale and there is white mould on it, that is a form of mycotoxin," he said. You need to test your feed, find out if you have it, what the concentration is and what the strain is. Then you can deal with it.
"We feed mycotoxin binder and have seen great results from it. It actually attracts the mycotoxin to it, it binds it to the product and it passes through the cow without it affecting digestion."
Correct harvesting also plays a big part in reducing mycotoxin risk, with Mr Bake careful about the process from paddock to feeding. These include cutting pastures early, compacting forage as densely as possible, sealing quickly to exclude air and repairing any holes in the stack. "Ensuring it is harvested at the right time and you have the right compaction is important," he said.
"We bag it all in a big sausage-style bag rather than put it in a bunker. It means we have a smaller face and you can work it back quicker so you don't get the mould starting to grow on the face."
Mould and fungi a risk when using alternative feeds Seasons with low growth can see a range of less common feed ingredients being used. These include older hay, alternative co-product feeds, and a high volume of failed cereal and canola crops.
If using these less common feed ingredients, it is important to understand potential risks and upsides for the herd.
Alternative crop hays such as canola hay are often cut and on the ground for longer than normal hay sources. This time 'down' increases the chances of microbial action within the plant mass.
The thicker stem means it hard to dry down and may have a higher moisture level than pasture or cereal hay. This can also apply to failed cereal crops cut for hay, with moisture still in nodes. Microbial load plus moisture carries a higher risk of becoming mouldy in storage.
It is hard to keep oxygen out of silage made from mature crops, so there is a higher risk of spoilage. Incorrectly stored hay, silage or other high moisture feeds bring a similar risk of mould spoilage as microbial action takes places. This is the early stages of a composting process, which is a significant negative.
These moulds can produce toxins called mycotoxins, which both decrease the digestibility of feed and often cause production and health issues. These range from minor illness to major impacts that greatly reduce milk production, or cause reproductive failure, abortion, or even death in cows.
If concerned about the level of mould in feed, getting a mould and fungi count is a sensible first option to check the risk.
In the case of production or reproduction issues, other common causes should be considered and ruled out before attributing issues to mycotoxins.
These may include reduced dry matter intake due to basic feed availability or feed quality.
It may also include seasonal impacts such as heat.
For more information see the Dairy Australia mycotoxin factsheet at www.dairyaustralia/feedshortage.