Everyone knows that weather can have a major impact on calf health and well-being. To promote optimum performance as seasons change, calves require different management, nutrition and housing to help them thrive through the cold.
Because calves have a higher surface-area-to-bodyweight ratio than older animals, they become cold-stressed at fairly moderate temperatures. As temperatures drop below 60 degrees F, calves have to expend their internal energy reserves to simply maintain their core body temperature of 102 degrees F. In fact, for every degree the temperature drops below a calf’s lower critical temperature, the amount of energy needed for maintenance increases by 1 percent.
The correlation between temperature decreases and calf stress may occur at warmer temperatures than some think.
If calves don’t receive the energy they need to maintain their body temperature, resources are diverted from growth. When energy is diverted from growth, calves will not gain weight and they become more susceptible to diseases like pneumonia and scours; calves could also die. Financial losses may also begin to mount from treatment costs and poor growth which delays age at first calving and impacts future milk production.
Cold calves impact future production
Recent work conducted at Cornell University sheds light on the long-term implications cold stress has on calves. For the two farms studied, calves born during the winter produced, on average, 1,226 pounds less milk during their first lactation than calves born during the summer. Researchers believed the observations were related to energy intake, but unable to rule out the impact of photoperiod or differences in colostrum status of calves explaining some of the milk response difference.
These additional calculations show that calves born during the colder months produced 1,173 pounds less milk than calves born in thermoneutral conditions. Within the Cornell herd, positive correlations with first, second and third lactation milk yields were observed for megacalories of energy consumed above the maintenance requirements.
If you weren’t focused on protecting their calves from cold stress before, this new research should spur renewed interest.
Defend against the cold with nutrition
“Energy is the limiting factor to calf performance during times of cold stress, so it’s highly recommended that producers implement a feeding program that supports increased energy demand,” says Tom Earleywine, director of nutritional services at Land O’Lakes Animal Milk Products. “The first line of defense against the cold is nutrition. All of the bedding and blankets in the world can’t save a starving calf.”