Monitoring heat stress risk via a smartphone application: this is the goal of the systemic approach developed by Techna feed experts to mitigate heat stress risks in dairy cows during severe episodes of heat and humidity.
The temperature-humidity index for measuring heat stress in cattle
The steady rise in temperatures on the planet, combined with sometimes heavier rainfall, can put animals in an awkward position. This is particularly the case of heat stress in cattle. This phenomenon is the result of a combination of temperature & humidity which disturbs the comfort and metabolism of animals such as dairy cows.
Cows’ zone of thermal neutrality ranges from 5 to 15°C. Beyond these limits, milk production can be affected. The Temperature Hygrometry Index (ITH) is a first-line indicator for measuring the impact of heat stress on dairy cows. It allows one to compare the impacts of various weather conditions on animals: dry and hot climate, moderate but humid climate...
However, the ITH does not take into account air speed nor duration of exposure. The most productive breeds (Holstein), animals at the beginning of lactation and the most productive animals generally are the most sensitive to heat stress.
What are the risks of heat stress in dairy cows?
Heat stress results in faster respiration and heart rate and reductions in nutrient absorption and in blood flow available in the udder. Reduction in feed consumption, combined with feed sorting due to a preference for fine particles, results in increased risk of acidosis and energy deficit for cows. This deficit is even more worrying if it occurs at the beginning of lactation. The first consequence is a drop in milk production. The animals undergo inflammatory issues that impact their metabolism (lower blood levels of antioxidants), and are exposed to risks of increased somatic cell count. Reproductive parameters, primarily AI success rate, are also affected during periods of heat stress.
How can a smartphone application help reduce the high cost of heat stress?
Animals under heat stress seek to release their extra body heat: they stand up instead of lying down in order to allow more of their body surface area to disperse heat into the air. Prolonged periods in a standing position reduces the cow’s comfort, makes her feel more exhausted and reduces production. This also worsens stance/posture issues with well-known consequences on estrus expression.
Milk production, use of milking robots, and ingestion are also impacted... All in all, the cost of heat stress revolves around 400 € / animal / year. More than half of this is due to decreases in milk production.
How can these be reduced? In some cases, a smartphone app can help determine the risk of heat stress by taking ambient temperature and humidity into account, along with herd management and milk production level.
This tool provides a glimpse of potential production losses. By providing updates on the phone screen regarding the intensity of observed signs of heat stress, the app can help to establish a proper nutritional strategy depending on the herd status.
6 ways to mitigate the risks of heat stress on dairy cows
It is important to favor cows’ ingestion (distribution strategy, addition of water to the diet) and to provide water in substantial quantities.
It is also useful to increase air circulation without producing air currents and giving way to an excessively humid environment (use misting sparsely). Also adjust the management of feeding plans via Automatic feeding systems and robots.
On the nutritional level, the important thing is feed concentration in terms of both energy and protein. Bypass profiles are recommended in order to limit the production of extra rumen heat. TECHNA trials have shown that fat supplementation allowed cows to better withstand heat stress phases during breeding trials.
It is necessary to closely monitor fiber quality to limit feed sorting while favoring the mechanism of action of the digestive process.
Heat stress disrupts the mineral balance in feed. It is advised to enrich the cow’s diet via buffer substances (bicarbonate). It is recommended to increase provisions of salt and potassium to compensate for sweat losses.
6- Vitamins, yeasts, trace elements
Live yeasts may be beneficial. Vitamins A, E and C are also important, as are vitamins from the B group (energetic metabolism) and trace elements CU, Zn and SE.
Techna feed experts have set up a structured and original approach to identify heat stress issues and deal with them by various means. The Dairy Cool approach consists of three stages:
- Reminder of the adjustments that must be made in rearing contexts in cases of heat stress
- Design of an innovative additive solution based on vegetal extracts aiming to reduce oxidative stress and to stimulate dry matter intake and water.
- Use of a smartphone app, PROFITAB.
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