Milk deliveries dropped back considerably in the week ending 15th August, most likely as a result of the extreme heat, AHDB reports.
GB daily milk deliveries averaged 32.21 million litres, which was down 1.7 per cent on the previous week. While milk production would be expected to decline seasonally at this time of year, AHDB says the drop is considerably larger than expected.
Most parts of England and Wales saw temperatures of more than 30 degrees between 7-9th August. According to the Met Office, the 7th was the warmest August day since 2003, with a maximum temperature of 36.4 degrees recorded at Heathrow Airport. These warmer temperatures continued until the Wednesday (12th August) for many areas of the UK.
The upper thermal comfort zone of a cow is around 25oC. When air temperatures exceed this upper limit, the cow must re-direct energy in order to thermo-regulate, AHDB points out.
Furthermore, cows will tend to reduce their dry matter intake in warmer weather, in order to reduce heat production from rumination. This would normally be expected to lead to a reduction in milk yields.