HEAT STRESS IN THE NEW ENGLAND….SERIOUSLY???

We are based in Armidale – and it would have to be pretty fair to say the town is not renowned for high temperatures. When it comes to livestock and temperature the focus is definitely on the impact of cold conditions in winter rather than worrying about a few hot days in summer.

So with this in mind it has been very interesting to look at the Optiweigh records for this part of the world over the past week or so - and find a very definite pattern of weight loss. With lots of people having stock ready for sale to feedlots any unexpected change in weight gain trends over those last few weeks prior to delivery will have a pretty big impact on the $ received.

As we have seen over the past few years there are lots of factors that can contribute to unexpected weight loss – feed quality, water quality and animal health just to name a few.

But there is no consistent theme around any of those in this case. There is plenty of feed about (and no sudden change in quality), animal health is up to scratch and plenty of good quality water. So it is no wonder that people are surprised that animals have been losing weight.

Introducing heat stress:

Dairy farmers in the northern hemisphere have been concerned about heat stress for years. The Temperature – Humidity Index (THI) is an index value that is an easy way to assess the risk of heat stress:

·???????? Below 68 = No Stress (Optimum performance)

·???????? 68-71 = Light Stress (Seeking shade, increased respiratory rate)

·???????? 72-79 = Moderate Stress (Reduced feed intake, increased body temperature)

·???????? 80-89 = Severe Stress (Significant decreased intake and production)

·???????? 90 + = Very Severe Stress

·???????? 100 and above = Deadly

Heat Stress at Armidale?

We had a look at the numbers for Armidale for January 2025 and found some pretty high numbers – certainly enough to expect weight loss according to the research.

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?Looking through some of the local Optiweigh units we found the following examples of ADG numbers over the past 2 weeks:

·???????? -0.8 kg / day

·???????? -0.7 kg / day

·???????? -0.1 kg / day

·???????? -0.3 kg / day

·???????? -0.6 kg / day

They were not all this bad – with a few around zero and some others slightly positive – but universally not the types of gains we would have expected to see given that it is summer and there is plenty of feed and water.

While this is not a comprehensive study and there could be other contributing factors one thing is certainly clear: by continuously monitoring the weight of the cattle we are learning more and more about the drivers of weight gain. This knowledge is going to be a key tool for increasing productivity and profitability in the future.

If you’d like to know more or talk to one of our team about Optiweigh and the advantages it could offer on your farm contact us here