Some Useful Tips on How to Sample for a Feedtest
Using the services of a feed test laboratory should give you useful information regarding the value of your feed. This can help you to make critical farm decisions such as feed purchases and budgets.
If you decide to use a feed analysis service it is important that you send an accurate feed sample to the laboratory. The sample must truly represent the average composition of the batch of feed you wish to test. A ‘batch’ of feed could be hay or silage that has been taken from the same cutting, or species, or paddock, or the same pit or bunker.
It should not be too difficult to get a representative sample. You don’t need any fancy equipment. You can borrow a core sampling device from a DPI Dairy Extension Officer. If you do a lot of sampling you may wish to invest in your own corer. You can make one yourself relatively easily. One farmer from Gippsland made a corer from a length of 38 millimetres diameter steel tube. It is about 500 millimetres long and has a tapered end which needs to be sharpened with a metal file every now and then. A simple hand brace is used to drive the corer into a bale of hay or silage; it is also possible to get corers fitted with a hexagonal shaft that fits into the drill chuck on a cordless drill.
When sampling hay, randomly select around 10 bales of hay from the batch, and take a single core from each bale. A good idea is to take the core at a right angle to the bale surface. It is also very important to ensure that the corer does not get too hot.
If you are sampling wrapped silage, you will also need to use a corer device. The corer will easily break through the silage wrap, and you simply take a core through the bale. As with the hay, you would take around 10 samples, enough to fill the sample bag. Afterward, you simply seal the opening of the hole with a large piece of silage repair tape. Be sure to make certain you have sealed the tape well.
When sampling pit silage you would ideally take random handfuls of silage from across the area of the pit or bunker. As this may be difficult, do your best to take as many random samples from its entirety as possible. You need to take your sample from a fresh ‘face’, which means that the area you are sampling from has been freshly exposed. Do not take a sample from an area that has been exposed to the air for any length of time.
With any feed sample, it is important that you place the sample in the appropriate ‘press-seal’ plastic bag. You need to remove as much air from the bag as you can before sealing it. Put your samples in an esky to keep them cool while you organise for the parcel to be sent to the laboratory. Be sure to label your samples correctly and fill out the required forms. Feedtest kits are available at your local DPI office.
You need to get your sample to the laboratory as soon as you can. The ideal time to take a sample would be at the beginning of the week and send the sample off as soon as possible. Allow up to a week (approximately) to receive your feed test results. If you send a sample at the end of the week there is a risk that it will end up spending the weekend in a mail storage centre and your sample could be spoiled. However, if you can only take feed samples at the end of a week, you can store the samples in a refrigerator over the weekend to avoid spoilage and then send them first thing the following Monday.
Do:
- Ensure a representative sample
- Remove air from sample bag
- Keep samples cool
- Sample and send at the beginning of the week
- Label samples accurately
Don’t:
- Expose samples to heat
- Send samples at the end of the week
