We have had a high pressure system over England and some beautiful sunny weather – at least in the South. Temperatures have risen during the day resulting in some short term heat stress – this will alter cow behaviour, lying times and maybe water intake. However as temperatures fall away at night to 10-14’C the daily average THI has not risen that high giving the cows have ample opportunity to shed themselves of the acquired heat load before the next day starts. The outlier is the herd in E Devon where we are monitoring a fresh cow shed with deep bedding. As is often the case this shed gets used for any cow who cannot join the grazing herd and is easily over-crowded. The high yielding fresh cows have a high heat output which overloads the shed and results in heat stress and we would predict noticeable milk yield losses.
The start of the week generally had the higher THI scores but as this hot spell continues night time temperatures are rising and we will see more heat load in the coming week.
