Testing hay for annual ryegrass toxicity (ARGT) risk

Page last updated: Tuesday, 5 March 2024 - 12:17pm

Hay, silage, pasture, and feeds that contains annual ryegrass may cause annual ryegrass toxicity (ARGT). Samples can be tested for ARGT risk by the DPIRD Diagnostic and Laboratory Services team (DDLS). The test is highly sensitive and provides a risk rating for potential toxicity. See below for sampling and submission information.

Vendor declarations

When buying hay, it is recommended that you ask for a vendor declaration before purchase. Also, ask if ARGT testing has been done. Suitable declarations are available from the Australian Fodder Industry Association and Meat and Livestock Australia.

Note: The information below does not apply to certification testing of hay for export overseas or interstate or for ARGT testing of grain, pasture or animal samples.

How to sample for ARGT testing

Sampling for ARGT testing should be undertaken at any one of the following production stages: 

  1. bales in the paddock
  2. bales in storage
  3. Windrows - prior to baling 
  4. processed feed, grains

Please contact DDLS for sampling instructions for processed feed or grain sampling.

Selecting bales to sample in the paddock

Sampling bales in the paddock for ARGT testing can be done in a few ways, however the key is to sample the greater of 12 bales or 15% of the total number of bales.

Common methods for selecting bales are:

  • Samples taken from all bales on the perimeter of the paddock, then taken from bales that fall within the lines of a ‘W’ or ‘M’ pattern across the rest of the paddock OR
  • Samples taken from each bale that is produced by every 7th lap of the baler and bales from the perimeter lap OR
  • Starting from the first bale produced in the paddock, every ‘x’ bale is sampled, following the path of the baler to ensure that the greater of 12 bales or at least 15% of all bales are sampled.


A sub-sample can be made from up to 10 bales, to make up a total of 1kg for testing. For example, if there are 10 bales, collect approximately 100g hay from each bale to make up 1kg. However, it is advisable that samples from perimeter and non-perimeter bales are tested separately.

Label all samples and composite sub-samples clearly so that they can be readily traced back to their original lot.

Sampling bales in the shed

Bales that have been placed into storage should be sampled from a minimum of 20% of the total number of bales for testing.

How to sample:

The preferred method is to use a hay bale corer. Australian suppliers of hay bale corers can be found online.

  • Square bales - Take a core sample(s) from one or both ends of the bale at right angles to the direction of the stems  
  • Round bales - Take a core sample(s) through the netting to the centre of the bale.


Alternatively, ‘grab’ samples can be taken from the bale, ensuring that you get a representative sample. Reach as far into each end of bale/stack/row as possible to take a grab sample.

The sample MUST weigh more than 100g per bale sample and be as dry as possible. 'Green' samples do not necessarily reflect the true levels of ARGT. After drying off of the pasture there is the possibility that the ARGT levels may increase.

Sample Submission

Put hay sample/s into a clean plastic bag and sealed in such a way as to retain seed head/fines in the bag during transport and avoid cross-contamination of other samples. Label the sample with your name and, if multiple samples are submitted, label with a meaningful identifier such as 'Bales 1 to 10 - Paddock 1'.

Submit the bagged hay sample to:


DPIRD Diagnostics and Laboratory Services
DDLS Interim Laboratories, Building 102
Department of Primary Industries and Regional Development
3 Baron-Hay Court, South Perth WA 6151

Email: DDLS@dpird.wa.gov.au

  • All samples must have a completed ARGT testing submission form when the samples are dropped off. Please ensure that you fill out the property identification code (PIC) box on the submission form.

DDLS animal disease investigation submission form

Time to results

  • Testing takes a minimum of 24 hours.
  • During peak season, DDLS aims to report results on the following working day, for submissions received by 3pm Monday to Thursday (Friday submissions will be reported on Tuesday.)
  • During off season, samples are held and testing is generally conducted once a week.

Cost of testing

The cost of conducting testing for a 1kg hay sample (from up to 10 hay bales) for ARGT risk is $49.00 per sample (GST inclusive) plus a $17.50 (GST inclusive) handling fee per submission. (Note: prices are subject to change at end of financial year.)

More information

Contact DDLS South Perth on +61 (0)8 9368 3353.