Assessing pasture quantity and quality for sheep

Determining pasture quantity

It is important to regularly monitor the amount of feed you have available in your paddock for your sheep. An easy way to do this is to use pasture photo-standards which give you a rough idea how much pasture (in kilograms/hectare) you have based on a visual comparison.

Find out more about pasture photo-standards and corresponding yields for many areas in Queensland on the Future Beef website.

Determining pasture quality

To determine if your sheep need supplementary feeding and what kind of supplements they may need, you should firstly determine the quality of the pasture they are consuming. The most comprehensive way to do this is to conduct a Near Infrared Reflectance Spectroscopy (NIRS) test (below); however, you can also use the following table as a rough guide.

Energy and digestibility in green and dry pasture

  Green pasture Dry pasture
Energy 10-12 MJ ME/kg DM 7-9 MJ ME/kg DM
Digestibility 70-80% 50-65%

A useful resource to compare species is the pasture picker tool.

Conducting a Near Infrared Reflectance Spectroscopy (NIRS) test

A NIRS test can help you work out if any supplementation is needed. Although NIRS testing is designed for cattle, there is currently no other option available for sheep.

The NIRS test analyses faecal samples to determine the quality of the pasture. It can be used to estimate the:

  • amount of crude protein in the diet
  • percentage of feed that is absorbed by the animal
  • nitrogen concentration
  • amount of plant material (non-grass) in the diet
  • growth rate, based on a 300kg medium frame steer.

Collecting and submitting samples for NIRS testing

It is recommended that you collect fresh dung samples to avoid contamination from soil or other external elements.

When submitting your samples you should include information about the land systems, pastures species, rainfall, and animal class and stage of production for the paddock where the samples were taken.

Find out more about NIRS testing, including how to get your samples analysed.

Using results of the NIRS test

The results from the NIRS test can determine if supplementation is needed and what nutrients may need to be supplemented.

By repeating the NIRS test regularly a nutritional strategy can be established and monitored over time, ensuring both short and long-term nutritional requirements of the sheep are being met.