The International Dairy Federation (IDF) is acting to help world's dairy farmers to cope with heat stress

Summer heat stress is currently one of the biggest causes of economic losses to the global dairy industry, especially in the hot regions of the world.

The International Dairy Federation (IDF) decided to deal with the problem and established recently an expert's committee to examine the issue and recommend ways to deal with it at the global level.

After being recommended by the Israeli Dairy Board to participate in this committee, I found myself serving in a central role in managing this scientific team, which includes representatives from New Zealand, India, Israel, Italy, Germany, Denmark, Sweden, Brazil and USA. We also have two students from Iran and Pakistan, who are conducting research, through scholarships provided by VES fan manufacturing company.

The scientific team of experts meets virtually once a month and has held 17 meetings to date. A “division of responsibilities” was made between the team members, where each one contributes in his field of expertise. Some of the members dealing with characterizing the climatic conditions and the expected worsening of them in the coming years. Others, deal with the effect of heat load on the performance of the cows, a third group gathers all the existing knowledge regarding the various methods that exist today in the world to mitigate heat load from the cows, while adapting each method to the climate conditions and the production method in the different regions of the world. The fourth group, consists of two teams of economists, one from the IFCN organization in Germany and the other from the University of Florida in the USA. These researchers try to quantify the extent of the losses caused by heat load to the industry’s economy and to the environment. They will also calculate the extent of the economic benefit to the industry from the optimal implementation of the heat mitigation measures in the various countries, today and in a time frame of 30 and 50 years to come. We believe that presenting the economic benefits to milk producers, wherever they are, can contribute to encouraging them to invest in the installation of the equipment needed to mitigate heat stress in the farms, the dairy industry, to help subsidize the aforementioned investments. Governmental bodies too, are interested in the economic side, as well as in the environmental aspect, within the framework of which the emission of greenhouse gases into the atmosphere may be reduced.

To date, the work of characterizing the climatic conditions in different regions of the world in terms of days per year with heat load conditions above the threshold for dairy cows has been completed, this for today's situation and the forecast for the years 2050 and 2100. The characterization of the scope of the financial loss and damage to the environment due to the heat load was completed too, and these two topics were presented, as part of a conference on which I will report later.

The team’s goals, as defined by the IDF organization, are as follows:

- Share light on the global situation regarding the effect of heat stress on the performance and welfare of cows and buffaloes, and the effect on the environment.

- Characterize the actual climate conditions (in terms of time per year above the THI threshold), and to estimate the expected changes in the future, under different IPCC scenarios.

- Quantify actual economic losses and negative impact on the environment, in farms located in different regions (based on time of year with THI above the threshold).

- Quantify the expected future economic losses and negative impact on the environment in different regions and IPCC scenarios.

- Collect all relevant literature dealing with heat mitigation measures used in different climates and their effect on improving cow performance.

- Assess the cost effectiveness of implementing measures to reduce heat, adapted to the farm area and the production system.

- Bring the knowledge to dairy farmers in different parts of the world.

- Give farmers the instructions on how to properly install and operate their heat mitigation measures.

- Give farmers the instructions on how to evaluate the effectiveness of their heat mitigation measures.

As part of the effort to bring the issue closer to the public’s attention, the IDF management decided to hold a special symposium on the issue, as part of the organization’s annual summit, held this year in Chicago, USA. The symposium was held on October 18 and for about two hours, four short lectures were given (three of them by scientific team members), and a concluding discussion was held on the subject.

First lecture was given by Dr. Andrea Vitali from Italy entitled: “The current and future risk of heat stress for dairy cattle herds in different regions of the world”. In the study, the climate conditions in the different regions of the world were characterized in terms of days per year when THI heat load conditions exceed the threshold values for dairy cattle. He later presented a forecast for the worsening of the situation in accordance with the change forecasts of the IPCC organization, which depend on humanity’s ability to cope with the emission of greenhouse gases into the atmosphere. In the conclusion of his lecture, Dr. Vitali points out the connection between this ability, global warming and the aggravation of the problem in terms of the global dairy industry. In scenarios of great global warming, most of the world’s cow population may be in heat stress conditions on an increasing number of days during the year.

Second lecture was given by Dr. Torsten Hemme from Germany, founder and chairman of the IFCN organization, who dealt with the quantification of the production and economic losses caused by the heat load to the global dairy industry and the environment, and the expectation of an increase in these losses and negative impacts in the future. The results of the research presented by Dr. Hemme indicated, on the scale of milk production, loss of 50 billion liters at the global level in 2020, which is expected to rise to 90 billion liters in 2050, when assuming moderate global warming. In the scope of the financial losses, this is expected to increase from 13 billion dollars per year in 2020, to 30 billion dollars in 2050. At the same time, an increase in the release of Co2 into the atmosphere is also expected until 2050 in the amount of 105 million tons each year, beyond the current situation. The conclusion reached by Dr. Hemme at the end of his lecture is that the global dairy industry must continue to invest in developing tools to cope with the heat load, which can indeed be seen within the framework of our committee’s work.

Third lecture was given by Dr. Mario Mondaca, from the VES fans manufacturing company.

The lecture dealt with the means available to milk producers to deal with heat load. Among the measures mentioned are, providing shade, wetting and forced ventilating the cows.

According to him, the most effective means is the providing shade plus a combination of wetting and forced ventilation. According to Dr. Mondaca, in order to ventilate the resting area (without wetting), a wind speed of 0.5 - 1.0 meters per second is required, while in cooling the cows by combining wetting and forced ventilation, a wind speed of 2.0 - 3.0 meters per second is required. The cooling sites to combine wetting and forced ventilation are the “waiting yard”, in the entrance to the milking parlor and the “feeding line”. Providing shade plus a combination of wetting and forced ventilation before and between milking session was found to be the most effective and profitable heat mitigation treatment.

Fourth lecture was given by Dr. Chanchal Waghela from the Indian National Dairy Board organization (NDDB), and dealt with the characteristics of the dairy industry in India (the largest milk producer in the world), and the possibilities of dealing with heat load in “small holders” dairy farms, with mainly crossbreeds of European with local cattle, and in Buffalo for milk. From Dr. Waghela’s lecture, we learned that the conditions of heat stress throughout India cause a production loss of 22 liters per year in cows from the local breeds (Bos Indicus), 104 liters in crossbred cows, and about 450 liters per year in cows from the European breeds. Providing shade and cooling crossbred cows and buffalo can increase annual production by almost 10%. Providing shade and forced ventilation may increase annual profitability per cow by $17 per cow, providing shade and wetting will increase profitability by $48, and when providing shade plus a combination of wetting and forced ventilation, profitability will increase by $67. In all the three cases, the return on investment is expected to be less than 6 months.

In conclusion - heat load has recently become more important due to global warming and the increase in the yield of cows, which means the production of more metabolic heat that they must lose to the environment. Hence the need to deal with heat load has become a factor of great importance in almost all regions of the world, including temperate regions that until recently were not encountered this need.

We in the IDF scientific committee intend to complete the work and submit a first draft to the IDF organization - towards the middle of 2024.