Cold cows kept warm by science
When it's cold and wet and people look at the cows they think that's terrible, but they are quite resilient. Jim Webster Animal welfare scientist
Dairy cows exposed to chilling rain, hail and snow will be better off as a result of research to help them get through wintry weather on farms.
Images of cows wading in winter mud and enduring freezing elements draws a sharp response from city people.
However, Agresearch scientists say a wealth of research is providing a greater understanding of how livestock cope and what can be done to help manage them through icy spells.
Agresearch animal welfare science team leader Jim Webster said it was understandable that people, and especially those unfamiliar with rural life, might see animals out in a paddock in tough conditions and be concerned for their welfare. ‘‘When it’s cold and wet and people look at the cows they think that’s terrible, but they are quite resilient and are big animals and if they have full stomachs they are generating heat.’’ He said research carried out over more than 10 years into dairy cows told scientists that they could generally cope well in cold weather, as long as they were in good condition, healthy and well fed. ’’While extreme cold can result in stress on the animals, they are able to adjust with physiological adaptations such as thickening of their skin and coats, and drawing on their fat reserves.
‘‘Cows are typically more affected by heat than by cold as lactation and rumination generate heat which can protect against cold, but can cause overheating in warm conditions.’’ He said the wellbeing of cows was probably threatened more by rain and wind as they wanted a dry and soft place to lie down. ‘‘We know that daily periods of lying down are important for cows, and if they don’t lie down enough, this negatively affects their health and productivity.’’
The guidelines are that cows prefer to lie down eight hours a day. Farmers should provide shelter where practical, as cows will naturally seek it out in rainy and windy conditions. Providing extra feed could assist cows with their energy and heat generation so they could digest it before bad weather set in as they tended to reduce their food intake during wet and cold weather.
Dairynz’s animal husbandry and welfare specialist Helen Thoday said farmers should ensure cows had access to shelter during cold weather. ‘‘It’s good practice when cows are grazing winter crops to fence them front and back, allowing them to access only a narrow strip of fodder at any one time. This helps to protect the soil and prevent them from stamping over and spoiling fodder. However, when the weather turns nasty we recommend farmers drop the back fence so their cows can move to shelter.’’