What climatic factor can impact livestock health the most?

Extreme temperatures can significantly impact livestock health as they directly affect the animals' physiological processes. High temperatures can lead to heat stress, which impairs feed intake, reduces milk production, and affects overall growth rates. Animals may become dehydrated in such conditions if proper hydration is not managed. Conversely, extremely cold temperatures can lead to hypothermia, frostbite, and increased energy demands for maintaining body temperature, which can detrimentally affect feed consumption and overall health.

While humidity levels, wind speed, and rainfall can also influence livestock health, their effects are often secondary to the immediate stresses caused by extreme temperatures. For instance, high humidity can exacerbate heat stress, but it is the high temperature that is predominantly responsible for the animals' distress. Wind speed can affect cooling but does not have the same direct and immediate impact as extreme temperatures. Rainfall influences different aspects of livestock management, such as pasture conditions, but does not directly threaten livestock health in the same immediate way. Therefore, extreme temperatures stand out as the climatic factor that has the most significant and direct impact on livestock health.