Fasting Sheep Before Shearing

American Sheep Industry
(Previously published in the Sheep Industry News: February 2022)

Whatever your thoughts on fasting sheep, there’s no doubt your shearer will thank you for keeping the flock off feed and water before shearing. More importantly, your sheep will thank you, too. While there are various views on fasting, the benefits to sheep and shearer are significant, and backed by research.

The ASI Code of Practice for the Preparation of Wool Clips and even ASI’s Sheep Production Handbook don’t go into much detail about why fasting is important, but both call for sheep to be penned anywhere from 4-12 hours before shearing. And both recommend keeping sheep off feed and water while penned before shearing.

So, why is it important? First and foremost, for the health and safety of both the sheep and the shearer. If the gut of the sheep is full, it can add significant weight to the sheep, placing additional downward pressure on the sheep’s organs when in the shearing position causing discomfort and stress to the sheep. In turn, this often causes the sheep to not only be uncomfortable, but to kick and struggle more, leading to even more stress to the sheep.

Also, if sheep urinate or defecate on the shearing floor, there is an increase risk of the sheep slipping when it stands up from being shorn. A slippery shearing surface is also a significant hazard for the shearer.

The goal of fasting is for sheep to urinate, defecate, and empty their digestive tracks before entering the shearing facilities. The minimum and maximum times off feed an water will depend on the sheep’s stage of production (see table below). The minimum fasting times ensure that the gut is emptied, while the maximum times ensure the health and welfare of the sheep.

It’s important to note that sheep should not exceed the maximum time off feed and water, which can happen on long (or multiple) shearing days. Keep in mind that if all sheep are penned at the same time, the last sheep sheared will have fasted for longer than those shorn first.

A secondary reason for fasting is to improve the quality of the wool clip. Eliminating the possibility of sheep urinating or defecating on the shearing floor means a cleaner surface for harvesting wool. And clean wool generally translates to a better, more valuable slip.

“A year is spent growing the product, while only a few minutes are required to harvest it. It is in this brief harvest period that quality is often adversely affected,” according to ASI’s Code of Practice for the Preparations of Wool Clips.

For more information, visit Worksafe – Fasting of sheep prior to shearing guide.

Minimum Number of Hours W/O Feed Maximum Number of Hours W/O Feed Minimum Number of Hours W/O Water Maximum Number of Hours W/O Water
Mature Sheep (Ewes and Rams)
Non-pregnant, non-lactating 20 32 12 24
Early – mid gestation 18 30 12 24
Late preganacy and lactation 12 24 8 20
Non-pregnant, non-lactating 18 30 12 24
Pregnancy and lactation 12 24 8 20
Pre-weaning 6 24 6 20
Weaned 12 24 8 20

Special considerations:

  • Mature Sheep (Ewes and Rams) – Exceeding these maximums may induce metabolic problems and/or clinical diseases. Where practical, unweaned lambs should remain with their mothers until ewes enter the woolshed.
  • Yearlings – Use special care when handling pregnant yearlings. Exceeding these maximums may induce metabolic problems and/or precipitate clinical diseases. Where practical, unweaned lambs should remain with theirs mothers until the yearlings enter the woolshed.
  • Lambs – Exceeding these maximums may precipitate clinical diseases.