Wet harvest raises fears of feed contamination

Farmers should be alert to contaminated feed this winter, with mould and mycotoxins brought about by the wet harvest possibly putting production and fertility at risk. And with this year’s weather already conducive to fusarium mycotoxin development in growing cereals, the HGCA says farmers should be extra cautious.

Beef and sheep

Inadequate storage and drying may see more penicillin in stored grain, particularly where there are damp hot-spots, says beef consultant David Hendy.

“Damp wheat is going to be a problem this year,” he says. “Moulds thrive in moist conditions, so be careful with crops of a dry matter of 17-18%.

“Also, when you see shrivelled grain with a slight pinkness to it, this is a good indication that it may be contaminated with fusarium.

“Farmers have a number of options when presented with mouldy grain. For beef and sheep, shrivelled grain possibly containing fusarium and even mouldy grain could be diluted in the ration, adding contaminated grain at a rate of 25% with clean grain.”

But Mr Hendy stresses that even diluting the ration may still have an effect on palatability – reducing feed intake and ultimately affecting production.

“When you have a high proportion of mouldy grain, the other option may be to grade out contaminated grain or treat with caustic soda or propionic acid,” he adds. “When you have a lot of mouldy grains, the latter two treatments may be relatively cost-effective, costing about £20/t for treatment with propionic acid.”

Pigs and dairy

But for pigs and dairy cattle, giving feed that is mouldy or contains mycotoxins could have more detrimental effects, says pig technologist and Farmers Weekly Livestock Adviser of the Year Mark Hawe.

“Feeding mouldy feed or feeds containing mycotoxins will inevitably affect production, reducing feed intake, growth and possibly reproduction,” he warns. “If it has to be fed, this should be to finishing pigs only.”

And with about one-third of the pig industry home-mixing, Mr Hawe says producers should be on the look-out for darker, clumped, mouldy cereal which may be contaminated. “If you have clumping or grain bridging in the bin, this would suggest damp grain and a possible problem. Producers should be cautious this year and it’s important to be wary of quality.”

The Dairy Group‘s Chris Savery says that when there is a noted reduction in performance, a process of elimination is needed to find the source of the problem.

“Particularly with farms feeding TMR, the operator must be selective and prepared to reject. The risk would be far greater when you feed something that is contaminated either with a mould and possibly a mycotoxin. And feeding something that isn’t palatable will ultimately result in a fall in milk production and then fertility.”

He advises: “Knowing how bad your grain is is important. Propionic acid and caustic soda won’t get rid of the problem, but can help preserve cereals. You can get a degree of moulding without mycotoxins. However, when you suspect mycotoxins, then specific mycotoxin inhibitors can be added, targeted to reduce mycotoxin risk.

“It is difficult to know when to use the inhibitors, but when stock aren’t performing and all other possibilities have been eliminated and your grain or silage is showing signs of moulds, then an inhibitor may be worth using.”