It goes without saying that this year some pretty ropey silages have been made. The constant wet weather and lack of sunshine have given us all some difficulties. But how has the silage analysis been affected and how do you stop it affecting productivity?
Silage pH of less than 3.6 indicates that it is very acidic which can result in lower intakes by cows, try to improve palatability by mixing with drier silages or chopped straw and by not over mixing. You could also consider using a buffer to reduce acid levels. Also, wet silages will need dry ingredients added to them to get the DM up to 45%, also avoid moist feeds where silage DM is low.
We have seen some silages with high levels of soil contamination, indicated by ash contents over 10%. Again, effects on palatability may occur, but the greatest threat could come from mycotoxins. This coupled with a wet season means mycotoxin problems will be on the horizon for some farmers. If your cows are not quite performing at the levels you’d like, have a word with us about mycotoxin binders.
We are also seeing some high potential acid load (PAL) figures, and although NDF levels look OK, this may not be structural fibre. High PAL and poor NDF figures will result in poor rumen stability and increased risk of acidosis. Farmers will need to monitor dung and cow health for signs of acidosis. While diets should be formulated to try to maximize rumen stability, sometimes with the feeds available on-farm this isn’t possible, some rations will benefit from buffers such as sodium bicarb. Also some silages have struggled for energy and so will need complementing with high energy cakes and blends.
There have also been analyses where oil levels are over 6%. If oil is too high in the rumen, the bugs can’t work so well and may reduce their contribution of microbial protein to metabolizable protein total. Effects will be seen on milk fat content too. When looking at ingredients to complement these silages avoid oily feeds such as brewers’ grains etc.
Even in the clamp we think silages will continue to change in some cases. Where ammonia-N levels are greater than 15% and pH is over 4.5, the silage can be considered unstable. Unstable fermentations will lead to clamps and consequently TMRs heating, resulting in cows rejecting feed offered to them. Heating silage also leads to nutrient losses; around 50% of sugar may be lost. In a year where sugar levels are low to start with, this isn’t good. Speak to me or your local rep to mitigate these problems.

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