We have seen several monitor farms install fans over the summer to good effect. The picture shows a bank of four fans installed over the cubicles in the ‘Highs’ shed. These fans are non-ducted so ideally need angling down slightly so that the plume of moving air hits the ground just below the next fan. This way any air flow that bounces off the cows, cubicles etc. is redirected back in amongst the cows. Many similar pictures from USA show simple fans with minimal or no grid over the fan blades. Over a season close grids will block up with dust and efficiency can drop by a third. A careful local risk assessment may enable you to take the grids off. These fans should run whenever heat stress is affecting behaviour (excessive standing and clustering, panting etc) and should be run for long enough each day for the cows to shed any acquired heat load overnight.
Next season the farmer plans to put more fans in the collecting yard along with a spray/misting system. Thes systems require good control systems to work at their best. The aim is to blow dry air over wet cows to maximise heat loss through evaporation. Blowing damp air does not achieve this. Any system needs to pull (warm) dry air in from outside and blow it on to the cows at speed. Generally the ‘soakers’ need not be on all of the time so can be on a time clock or placed at the start of the collecting yard.
