Even cattle get hot under the collar
The summer may have cooled a little now, but the extremely high temperatures we’ve seen this year could be a thing of the future. It is therefore important to recognise that it’s not only us that get hot under the collar.
Heat stress in cattle is a serious issue; cows are officially stressed when confronted with waves of extended heat periods as temperatures soar up above 28°C and into the 30s and over.
Heat plays a key role in cattle behaviour related to lameness. In hot conditions, cows tend to accumulate heat while lying and cool down when they stand. Rest time can drop by four hours per day during a six-day heat wave, elevating the risk of lameness.
It also directly affects feed intake (feed intake begins to decline at air temperatures of 25-26°C in lactating cows and reduces more rapidly above 30°C) which reduces growth rate, milk yield, reproductive performance, and even leads to death in extreme cases. Dairy breeds are typically more sensitive to heat stress than meat breeds, and higher producing animals are more susceptible as they generate more metabolic heat.
Heat stress suppresses the immune and endocrine system, enhancing susceptibility of an animal to various diseases.
Monitoring lameness is critical during periods of high temperatures and humidity. You need to look for cows with reduced feed intakes as well as slight limping in one rear foot. Also, monitor the colour of the hair line at the foot and the claw. If it is white or a nice flesh colour, the cows’ metabolism is working well. However, if the hair line is slightly swollen and pink, then that animal is probably in an acidotic state.
If you have white-line lesions a hoof trimmer should inspect the feet and block any animals.
Blocking the healthy claw is the best practice. Cows with blocks can walk right away with reduced pain and typically heal approximately 50 to 60 per cent faster than non-blocked cattle.
Nick Challenor is owner of ND Challenor Professional Livestock Services
