Grass silage mineral analysis highlights major problems
Noel has several grass silage mineral analysis back for this year’s crop. He tells me that they do not make for pretty reading.
Many silages are very wet, have a high pH, and ammonia nitrogen readings are excessive. Some silages are coming back with good DMD results, but wet silages with high ammonia nitrogens are not palatable.
Getting livestock to eat this material in sufficient amounts will prove to be a challenge on many farms.
These silages will also require very careful management in the pit.
High ammonia nitrogen, with a high pH, will cause silage to go off at the pit face very soon after it is exposed to the air.
The high ammonia nitrogen levels are due to nitrogen fertiliser applied to the grass not being fully utilised before harvesting.
Obviously this is due to poor growing conditions. However, it also has a little to do with some farmers still putting out excessive nitrogen on silage ground.
If you couple excess nitrogen with poor growth it will lead to high ammonia nitrogens and poor preservation.
Pit management in these circumstances will be crucial. Getting across the pit face quickly will be essential to reduce spoilage.
A shear grab will be the best way to keep pits neat and tidy and reduce the surface area. Those used to taking silage out of a pit with a loader bucket may need to go back to the grab, in order to avoid huge silage waste this season.
Another thing that is popping up in silage analysis is a high ash content.
This indicates that a significant amount of clay has been brought into pits.
Clay will carry moulds and bacteria which will have supressed preservation.
Some silage results so far are showing in excess of 10% ash.
Wet silages are very difficult to manage in any year, and this year may pose an even bigger problem if they have not preserved well.
Getting all stock types to eat enough will prove difficult, therefore making sure the silage is clean and not gone off before feeding will be essential.
Poorly preserved silages have in general turned up, with poor mineral content. This will be more of a problem in 2012, because poor growth conditions have resulted in less than optimum nutrient uptake from soils. This will invariably result in more mineral deficiencies in stock, if deficits are not dealt with correctly.
This coming season, more than ever, it will be critical to use the correct vitamin and mineral premix for livestock.
Years with good quality silage are much more forgiving in herds, with regard to metabolic disorders caused by mineral imbalances.
The last thing a beef or dairy farmer wants is a lot of held cleanings or milk fevers caused by silage for which the mineral profile is poor.
It is best to avoid this eventuality by matching your silage with an appropriate mineral for each class of stock on your farm.
nMany farmers over the last few years have begun using a mineral bolus as part of their supplementation programme. They work really well where deficiencies are identified on the farm, and the bolus includes the mineral in low supply.
Many suckler farmers I speak to find calving goes much better after cows got a dry cow bolus.
However, a bolus should be used in conjunction with a complete mineral pack for stock, and not as the sole mineral supplement.
Macro minerals, such as magnesium, sodium, phosphorous and calcium, are not included in high enough levels in a bolus to supply an animal’s entire requirement.
Formulating the correct mineral
In my conversation with Noel Lynch from Inform Nutrition last week, he mentioned that they are currently testing silages for minerals to help them formulate the correct mineral premixes to balance 2012 silage.
Noel said that animal health issues and poor animal performance can be avoided by feeding a suitable balanced mineral supplement in conjunction with a well-balanced diet.
Testing and correctly balancing silage for minerals this year could be the best money you will spend.
