We all know from decades of study that a gap in the comfort of animals negatively impacts their production. When we focus on dairy animals, a big number of farmers and many professionals from this field are dedicating their time to mitigate animals’ stress regarding comfort and thereby optimize production.
- A big area from Brazil is under a tropical climate, so heat stress is a huge challenge here. So, there are three main pillars that we should consider when we think on that:
- Decrease in milk production and in the daily weight gain from youngstock. Cows and heifers shift more energy to decrease their body temperature, energy that could be used to produce more milk or be used on their growth;
- In any stress situation there is an increase of Cortisol, a hormone which is extremely immunosuppressive. As a result, stressed animals are less able to prevent and combat metabolic and infectious diseases (metritis, retained placenta, mastitis, etc.);
- Low values in reproductive rates. Cows in a stressful situation not only express less heat, reduce its pregnancy chance, but also have higher pregnancy losses. As a result, there is an increase in the calving interval and a decrease in the number of lactating cows (which are the ones that generate most of the income on a farm).
In the graph below, from a herd located in Minas Gerais state, we clearly can see how the conception rate oscillate during hottest and coldest months of the year.
In this case, the conception rate fluctuated from 7,7% in February 2019 to 64,3% in July from the same year. The cows were saying that they were suffering from heat stress!
There are many things we can do to offer them a better comfort, of course with different investment levels, but that brings us up a good return (with better KPI’s results and as consequence better economic outcome as well).
From simpler ways, like planting trees in pastures and resting areas for cows to simple shelters (as a temporary solution until shadows from the trees occur), up to the biggest investments but with greater results, such as sprinkling and ventilation in the trough line, cooling of cows in the pre-milking room, and even total confinement (free stall or compost bedded pack barn).
The professionalization of the sector is already an important factor in selecting who will or will not remain in the business. Monitoring results within a farm is essential to know where and how to make the best decisions, and as consequence achieve the goal, which is to make dairy farming an increasingly attractive activity economically.
André Navarro Lobato