As I write this post it feels that the recent heat wave has eased – but the forthcoming forecast is not much cooler. Given this is June we can be certain this will not be the last heat wave. Generally last weekend was the hottest part of the week with heat loads easing as the week went on. Most farms were in the top of the ‘moderate’ heat stress category or up into the ‘High’ band with predicted milk losses averaging 2.2 l/cow/day across all the farms. All regions suffered heat stress last week with a clear geographical pattern of being more severe in the South and inland.
The daily average index figures shown here hide a very big daily range. Temperatures in the full sun can be over 38’C from 11:00am through to 4:00pm on a typical sunny afternoon. These are very hot and unpleasant conditions to be out in the full sun especially for a milking cow with a high rate of work (metabolic load). Shade provision is a first step but natural shade is not available in many grazing paddocks. Where buffers are being offered then feeding this under shade in the middle of the day will provide some relief.