The severity of heat stress issues on dairy cows will continue to increases as we experience warmer summer temperatures. Fortunately, a system that includes fans, misters, and an intuitive controller that is continuously monitoring the conditions in your barn, relieving the effects of heat stress on your cows' health, production, and reproduction can be a reality.
Feed intake begins to decline at air temperatures of 25–26°C in lactating cows. The reduction of dry matter intake for heat-stressed cows is about 10 to 15% compared to cooled cows.
Cows under heat stress also have elevated respiration and sweating rates. For high-producing cows, the respiratory rate starts rising above 50–60 breaths/min at temperatures higher than 25°C.
Studies show a heat-induced decline in milk yield can reach 14% during early lactation and 35% during mid-lactation.
Reproduction is effected by high temperatures because it reduces the expression of estrous behaviour, modifies follicular growth, and inhibits embryonic development severely affecting conception rates. As a result of the effects of heat stress, the dairy industry experiences significant reproduction losses every year, in both Canda and the United States.
Evaporative cooling systems, like CowkühlerZ, use the energy from the air to evaporate water. The evaporation of water into warm air reduces the air temperature cooling the cow.
Fine misting nozzles mounted in front of variable speed fans disperse very fine droplets of water into an extremely focused, fast-moving stream of air. As mist droplets are emitted, they are immediately spread into the fan’s air stream where they soon evaporate. The second set of nozzles mounted halfway between these powerful 25" fans inject mist droplets into the still powerful air stream after the mist from the first set of nozzles has fallen. This provides animals cooled air over their bodies in the stall, where we want them to spend at least 14 hours a day.
Air movement is an important factor in the relief of heat stress, as it affects both convective and evaporative heat losses. Fans force air over the cow’s body, causing evaporative cooling to take place on its surface. A fine mist, controlled by an intuitive monitor runs as needed depending on the THI.
Research has proven that sprinkler and fan cooling can result in lower body temperatures (0.3–1.1 °C) and respiration rates (7–55 breaths min−1) and improved dry matter intake (0.9–3.0 kg∙day−1) and milk yield (1.0–4.1 kg∙day−1∙cow−1).
The available information unmistakably shows that heat stress negatively impacts cow performance, resulting in important economic losses for the dairy industry.
A combination of fans (to increase convective heat loss) and misters (to promote evaporative cooling) has been shown to be the most effective way to cool dairy cows other than using air conditioning. In fact, the addition of CowKühlerZ inside existing buildings to recirculate the air can successfully reduce heat stress, decreased body temperatures and respiration rate, and enhanced milk production.
If you would like to receive more information about the CowKühlerZ cooling system fill in the contact form below and we will be happy to contact you.