The September heat wave continued through the past week and were highest in the Sunday, Monday and Tuesday before dipping a little on Wednesday but building again at the end of the week. The southern monitor farms were in mild heat stress throughout the past week but it was cooler in N Ireland and Scotland where heat stress abated from Monday onwards.
Cows have suffered a prolonged heat wave and we will feel the repercussions for several months to come. Milk yields and quality will have been depressed and fertility, as seen by reduced oestrus signs or reduced conception rates can be expected. Reduced feed intakes may cause metabolic diseases in fresh calvers and excessive standing and ‘huddling’ can lead to more lameness problems in a few month’s time. American workers consider the milk yield/quality losses are about half the total losses. If yields dropped 3 litres you may have lost £1.00 of milk income but may yet suffer a further £1.00 loss from the other factors mentioned. If this has happened on a 400 cow unit with 7 days of heat stress the total would be £5600 from this heat wave alone.
