Managing dairy cows in winter

The dairy cattle breeds found in South Africa today, originated in Western Europe and the British Isles, where winter conditions are much colder than in South Africa.

- Dr Carel Muller

Their dense coat, thick skin, subcutaneous fat layers, large muscles, and digestive system which generates internal heat, ensure that these cows are well insulated.

But despite their resistance to cold, there are still some aspects that require more careful dairy cow management during winter.

Rainfall regions in South Africa

The Western Cape has a typical Mediterranean climate. Summers are hot and dry, and winters are cool to cold, with rain from May to September. Although winter temperatures are not very low – around 8 to 18°C – rain and wind can cause a drop in temperature.

Local research showed that the milk production of cows in open camps is only affected by hard, continuous rain – for example 20mm/day over four days. Shorter rainfall periods had little to no effect on milk production. Cows’ response to rain and cold varied and not all cows experienced a drop in milk production on rainy days compared to non-rainy days. Similar results were recorded in Australia.

In the summer rainfall regions, rain has a cooling effect and is not seen as too problematic. Keep in mind that rain rarely falls continuously, and cows can usually maintain their feed intake. It is only when cows ingest less feed that milk production is impaired.

How cold is cold?

In the interior of the country extreme night temperatures (lower than 3°C) occur from May to August. Average minimum temperatures in Bloemfontein are -0,2°C in June and -0,5°C in July, with a maximum temperature of around 17°C. These low minimum temperatures are still higher than the lowest thermoneutral temperature of -5°C for dairy cows.