Using Snow for Wintering Sheep

An essential nutrient for a healthy and productive flock is water. Watering grazing sheep after freeze-up can mean walking the sheep to heated waterers in corrals or daily water-hauling to field tanks.
Is snow an option as a water source for wintering ewes?
Studies here in Alberta (Degen, Young, 1981), in Ontario (Wand, Richardson, 2009) and in the United States (Butcher, 1966) showed that dry ewes and ewes in early pregnancy experienced no problems with eating snow as a water source when compared to ewes supplied with water. Normally sheep whether in winter pens or out grazing consume small amounts of snow throughout the daylight hours. Studies on ewes that were provided with water all winter and those that only consumed snow through the maintenance period showed similar milk yields and lamb growth rates. The heat produced by digestion and the activity of grazing/feeding melts the snow eaten and brings the snow-water up to body temperature.

Unfortunately snow is anything but dependable in many parts of Alberta.
Adding to consistent supply issues is the normal Alberta temperature fluctuations and wind-drifting that result in ice or crusted snow. Ewes like soft, powdery, clean snow and have difficulty getting enough fluids when snow is iced or crusted. Also when there is little new snow or when there are a number of sheep in an area the snow becomes compacted as well as contaminated. Cows tend to have a brief adjustment period of 3–5 days while they adapt to not having liquid water. Sheep are able to rapidly shift from water to snow as a liquid source with no signs of abnormal behaviour, such as bleating. Ewes experienced in using snow for water help reduce the learning time, and stress, of inexperienced animals.

To successfully use snow as a winter water source:

Use for healthy, mature ewes in a body condition score of 3 to 3.5 in the maintenance or early pregnancy stage. Ewes should have adequate fleece length.
To maintain adequate feed intake for pregnancy and lactation be sure to supply water to ewe lambs, second lambers, highly productive ewes, old ewes and to all ewes in late pregnancy.
Provide shelter from wind and extreme temperatures to reduce the energy expended in keeping warm and melting snow.
Snow needs to be clean, soft, fluffy and/or wet. Snow with hard granular ice particles in it can result in lower intake and decreased feed consumption.
Crusted snow can be broken by driving over it to expose softer snow. Walking or digging through crusted snow can result in leg abrasions that impair walking to feed and fresh snow.
Check animals daily. Monitor body condition. Have a ‘plan b’. If animals are restless, reduce their feed intake, or spend all day foraging – there’s a problem somewhere. Make changes before ewes begin to lose weight.

References
Butcher, J.E. February 1970. Is snow adequate and economical as water source for sheep? National Wool Grower.
Butcher, J.E. 1966. Snow as the only source of water for sheep. J. Anim. Sci. 26:590 (Abstract)
Degen, A.A., and Young, B.A. 1981. Response of lactating ewes to snow as a source of water. CD J. Anim. Sci. 61: 73–79

This document is maintained by Amrit Matharu.
This information published to the web on January 31, 2017.