Project launched on early warning system and heat stress monitoring for dairy cattle

At the Austral Agricultural Experimental Station (EEAA) of the Austral University of Chile, the project “Early warning system and heat stress monitoring for dairy cattle in Chile” was officially launched, awarded by the Austral University of Chile and supported by the Foundation for Agricultural Innovation (FIA).

The proposal contemplates the creation of an early warning and monitoring system that allows producers to know, at least 5 days in advance, the risk of heat stress for dairy cattle, enough time for them to take preventive measures and minimize its impact. .

In this line, the launching ceremony of the project was held, which was attended by representatives of the executing institutions, associates and regional, academic unions and on behalf of the Faculty of Agricultural and Food Sciences of the UACh, attended the Prodean, Dr. Carolina Lizana.

On the occasion, Dr. Rodrigo Arias, presented the objectives of the project, highlighting that this arises as a result of the increase in heat waves that have been evidenced in the country as observed in the meteorological data of Chile, being the most extreme the one that occurred in Curicó in 2017, with a duration of 16 continuous days.

In addition, he pointed out that when he carried out the first heat stress risk assessment in Chile, 12 years ago, the risk was limited only to the central zone of the country. Currently, this has changed substantially both due to the effect of climate change, as well as due to the greater productive potential of the animals. For this reason, he stressed that the central idea of ​​the project is for the producer to have validated local information as an input for decision-making regarding this issue.

Dr. Arias also made a presentation in which he addressed the main aspects of heat stress in dairy cattle from a welfare point of view, as well as from a productive point of view and the economic impact it causes in other countries. Highlighting the results of the research that he and his team have carried out in Chile on this subject, from 2008 to date.

On the other hand, the Regional Representative of FIA, Patricio Cantos, emphasized that “the project will be able to avoid significant economic losses for the productive sector. This is because anticipation of heat stress in dairy cattle is essential to prevent bovines from reducing feed consumption, with lower feed conversion, decreased animal health and welfare problems, as well as reproductive activity with fertility problems, lengthening of the interpartum period, and a decrease in rumination, among other consequences”.

MSc Agronomist Reinaldo Pinto P., hired to carry out the project, presented some of the partial results of the survey (available to answer at: https://questionpro.com/t/AWIy1ZuKy6) that is being applied to find out the perception of the producers regarding the subject of heat stress, corresponding to the first stage of execution of the project.

In this context, the majority of producers consider that the issue of heat stress is relevant and express their interest in having a practical and simple tool to learn about the risk of heat stress in their herds and thus be able to implement control measures. mitigation. On the other hand, they also expressed their interest in training on this subject, especially on how to nutritionally manage cows under these conditions.

What is the real impact in Chile?

On the other hand, partial results were presented regarding the potential economic impact caused by heat stress in each dairy macrozone of the country. For this, the team collected data from 19 meteorological stations of the different dairy macrozones for the last 5 years, with this information three thermal comfort indices were estimated, namely, temperature and humidity index (THI), THI adjusted for wind speed and solar radiation (THIaj) and the comprehensive climate index (CCI).

The values ​​of these indices were estimated both hourly and the daily average. With this information, and based on the methodology proposed by St-Pierre et al., (2003), an estimate of the economic impact was made based on the number of hours that the animals suffered stress for the period November-March of the last 5 years, establishing the threshold values ​​for THI and THIaj at 65 and at 25 for CCI.

The results analyzed so far indicate that there is a great variation in economic losses associated with heat stress, fluctuating between approximately $10,000 to $165,000 on average per cow per season for the November-March period of the last 5 years. Observing a high variability depending on the dairy macrozone and the year under evaluation. In other words, the reductions in milk production on average fluctuate between 0.2 to 3.1 L/cow/day for the evaluated period.