Testing, testing - silage analysis
Silage analysis has been part of farming in the UK over 40 years but are you making the most of it and getting useful and accurate information? The pretty charts are all very interesting but if you rely on forage the data contained in a your silage analysis is the key to unlocking the financial success of your business.
So how can you get the most out of your silage analysis and use this to your advantage?
The information in the analysis is the topic for another piece in this series but in this section we examine
· when to sample
· where to sample
· where to get the analysis carried out.
So starting in at the wrong end, who are you going to get to do the analysis?
For most livestock farmers, silage analysis will be offered for “free” by a feed compounder or supplier. As we all know there is no such thing as a free lunch but the cost of running the testing lab is shared by all the customers of the compounder. So it’s unlikely your feed costs will be any lower if you don’t use the testing service; but would you be better using an independent analysis?
That all depends on the lab standards and what you are going to be doing with the results. In general most laboratories now use the Near Infra Red analysis method (NIR) as this gives much quicker, cheaper results than the older “wet technique” of chemical analysis. The NIR system is very similar to those used on board harvesters such as John Deere’s Harvest Lab. The technology is really accurate… but, & there is always a but, this system needs to be constantly re-calibrated against “wet” analysis results. If this is not done regularly then the resulting analysis is not wrong, it’s just not completely accurate. So, to try and explain this in a bit more detail, let’s imagine a range of samples from different clamps. In a non-calibrated lab, the good silage analysis will still show better figures than the poor silage but it’s the absolute figures that are not accurate. You therefore cannot be completely sure of the absolute energy and protein levels in the silage. These results can also not be compared with results from other labs. The solution – to use a lab that regularly recalibrates with data from other labs in the area. In the UK this will be done in any lab that is part of the Forage Analysis Assurance Group (FAAG). Results from FAAG labs can be compared with any other so if the lab shows the energy is 0.5MJ/kg higher in your report, then you are sure this figure is accurate. This matters if you (or the feed rep) is trying to formulate a ration accurately.
It’s hard to look a gift horse in the mouth, but if your “free” test is carried out in a lab that is not part of the FAAG, then it might be worth getting a comparative test done. The testing costs are less than you might imagine, and the potential feed cost savings are huge.
So we know who is going to do the analysis, we now need to know how to collect the sample. There is a really handy video on the FAAG site that explains the “W” sample technique to collect silage from the face of the clamp. Basically the aim is to get a really good sample of all the silage you will be feeding. Don’t try and just take the “good bits”. If you are feeding all the silage then you need to sample all the silage. This is particularly important for AD operators. Livestock are selective about what goes into their tummies, but everything in the bucket goes in to the digester so take a sample from all the forage that’s fed. The samples then need to be thoroughly mixed and divided up into a suitable sized batch, generally about 500g. Pack the sample in to a plastic zip tie bag and squeeze out as much air as possible. Double bagging is a good idea to avoid any potential spoiling in the air. Once the bags are sealed & labelled they need to get to the lab ASAP. You can use the post or a courier but I prefer to deliver them straight away to the lab door. Obviously this isn’t always possible but it’s a good practice to avoid any delays.
So what about on farm analysis?
There are portable NIR kits that can do the analysis on site but there are questions around the accuracy of the results due to the calibrations. To be truly accurate, NIR machines need to be re-calibrated against wet chemical analysis several times a week. I would still recommend a FAAG lab to get consistent accurate results.
Now we just need to decide when to analyse the silage.
Traditional farmers would get the silage analysis results in early autumn so they could get the ration formulated before they started feeding the silage. And many still work to this timetable but many farmers have recognised that this one snapshot is not an accurate depiction of the silage picture. Working with the nutritionist it makes sense to sample the silage regularly and tweak the mix to meet the required ration profile. It’s also important to sample the silage as close to the cows’ mouth as possible. Losses in the feed value will be occurring as soon as the silage is open to the air - whilst in the clamp, in the diet feeder and sitting in the trough. Again this is particularly important to AD operators where the silage can sit in the feed system for many hours before going into the digester tank. The losses in January will also be much less than those in July so if your are using silage all year round then you need to keep up the testing regime all year too. This is the only way to get an accurate picture of what you are actually feeding.
Finally you can – and I suggest you really should - use testing to identify where the losses are occurring in the silage system. This is a big subject but in essence you need to sample and analyse the standing crop, use on harvester NIR, then FAAG testing two weeks after ensiling and at feed out. Using this information it’s possible to identify where the losses are occurring and where improvements can be made. This is the proof of all the “puddings” that are the other topics in this series. By using the data you can quantify the savings that you can make by paying attention to the details.
If you need further information or help on testing your silage, or for any of the other aspects of silage making covered in this series – contact Jeremy Nash @ jeremynash1@btinternet.com