We can’t deny it; Our world is warming, even Scotland, weather records are being broken and it's having a direct effect on our livestock.

Carbon footprints for our industry are being measured and scrutinised but ultimately, driving business’ to be more efficient. Animal health and welfare are fundamental to our farm's sustainability. This summer we are definitely seeing the direct effects of record temperatures and lack of rain on our livestock.

Heat stress

More and more of our dairy cows are housed through the summer months, consistent diets and comfortable accommodation mean cows can be happy and achieve level production. We have some excellent dairy farms with superb housing. Unfortunately, Scottish livestock housing hasn't always been designed for our increasingly warm weather. Heat stress is definitely becoming more common. Our sheds are still being designed to keep the Scottish weather out rather than keep our livestock cool.

Heat stress is a combination of temperature and humidity, even temperatures of 20’c and high humidity start to effect cattle. We’ve definitely seen a drop in pregnancy rates in some of our dairy herds and an increase in mastitis cases and their severity. Reduced dry matter intakes and crowding also cause reduction in yields and increase the risk of injury.

Dairy cows water requirements are significant, needing over 100litres water per day, much of this is drunk within the three hours after milking. This puts pressure on farm water supplies, water trough space and refill rates. With low rainfall recently, water tables have dropped, springs are running low and boreholes struggling to supply at peak demand. Restricted access to water results in lower dry matter intakes, lower milk yields and immunity.

Shed design and modifications can have a dramatic effect on reducing the effects of heat stress. It's not rocket science; hot moist air rises and is desperate to leave through the ridge of a roof. If we let that air escape, it naturally draws in cooler air to replace it. Far more moisture leaves a shed through an open ridge than enters through precipitation.

Air inlets are also crucial to allow the 'stack effect’ to work efficiently. Simple design and modifications can easily be implemented to allow a shed to ventilate efficiently. Opening ridges and sides will have the biggest effect on airflow but fans and active ventilation systems should also be considered to reduce heat stress. Water trough space of at least 10cm per cow is an easy calculation with water flow rates to ensure troughs never run dry. AHDB have an excellent advice for shed design, stocking density and ventilation. https://ahdb.org.uk/knowledge-library

Heat stress is costly, effects fertility, increases mastitis and ultimately higher involuntary culls.

We’ve recently seen an increase in summer mastitis in dairy heifers and autumn calving beef cows. Even maiden heifers are at risk, with symptoms from mild to severe, it is a frustrating disease. Even mild disease can result in damage or loss of the effected quarter but in more severe cases, animals can have massive inflammatory and toxic response, with systemic signs which can unfortunately lead to the death of the animal.

Two very common bacteria are often associated with this type of mastitis. They are found on the teat skin of even healthy animals. But increased risk of infection occurs if teat ends are damaged or inflamed, often by the presence of biting flies. Prevention is always key to disease management but often impossible to totally eradicate. Grazing at risk cattle in low risk fields, those with less trees and flies can help. Regular fly treatment will also reduce the risk, but ensure you use a licensed product at the correct dose and frequency.

Early detection and treatment are also key to saving cows and quarters. If you have an affected animal, speak to you vet to ensure they receive appropriate treatment. The bacteria involved are easy to kill but they can produce a massive inflammatory and pain response, so anti-inflammatories and stripping quarters are important if possible.

‘Iceberg’ diseases

For the most part, sheep have had a good summer, plenty of grass early on. Lambs have had good liveweight gain and low parasite burdens. However, if ewes are lean or dying at this time of year we may be dealing with an 'Iceberg’ disease.

Clinical signs in a small number of sheep may actually be an indicator of something much more significant at a flock level. Common Iceburg diseases include OPA, Johnes, MV and CLA. These are easy to diagnose with input from your vet. Post-mortem examinations of dead or lean ewes will provide essential information but blood sampling a proportion of affected animals will also give you valuable information.

Controlling these diseases, diagnosis is fundamental, then a tailored flock approach to the control involving your vet. Bio-security, vaccination, blood sampling and lung scanning will result in a healthier and more profitable flock.

* If you have a burning question you would like to ask Charles Marwood, please email patsy.hunter@thescottishfarmer.co.uk