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. Looking at areas of improvement today can help calves transition through temperature changes. To best determine a cold weather calf management strategy with your dairy clients, you must first understand when calf performance drops. The correlation between temperature decreases and calf stress may occur at warmer temperatures than some think.
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°F, calves have to expend their internal energy reserves to simply maintain their core body temperature of 102°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%.1
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.2 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 above maintenance, but unable to rule out the impact of photoperiod or differences in colostrum status of calves explaining some of the milk response difference, researchers further correlated the data to temperature at birth.
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 your dairy clients weren’t focused on protecting their calves from cold stress before, this new research should spur renewed focus.
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, PhD, 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.” New seasonal formulations of milk replacer and calf starter have been developed to deliver optimal combinations of protein, energy and technologies to help during times of cold stress. The lactose in these products is designed to provide immediate energy and fat helps to build an energy reserve for the calf. Oxidation of this reserve when calves experience cold stress can be the difference between calves that thrive and ones that do not, explains Earleywine.
Regardless of the milk replacer selected, at a minimum calves should be receiving two gallons of liquid nutrition each day. In addition to meeting calves’ increased energy requirements in the winter, eight university trials show that increased intake during the first eight weeks of life resulted in improved milk production during the first lactation. If calves are fed a ‘maintenance diet’ of 1 gallon of liquid nutrition daily, they will fall behind on weight gain and be susceptible to disease.
“The long-term benefits of feeding a higher plane of nutrition are well documented and this is something dairy producers should consider year-round, not just to help calves thrive in cold weather,” adds Earleywine.
A third feeding of milk replacer can also be incorporated into the feeding program. “Incorporating a third feeding of milk replacer, preferably late in the evening, provides the extra energy young calves need,” he says.
Trials conducted at the USDA Forage Research Center by Don Sockett, DVM, PhD, with the Wisconsin Veterinary Diagnostic Laboratory, explored the benefits of feeding three times versus traditional feedings of two times daily.5 Calves were fed the same amount of milk replacer during a 24-hour period; the only difference was the number of meals – two vs. three.
Research results show that for every six calves fed three times a day, one additional heifer entered lactation. Calves fed three times per day also averaged 1,136 pounds more of milk and calved 16 days earlier which was approaching a statistical difference.
Regardless of the feeding strategy chosen, calves need more energy during the winter months. As the seasons change and temperatures dip don’t let your clients overlook calf nutrition programs.
For more information, visit www.lolmilkreplacer.com.
Winter calf care reminders
In addition to nutrition, there are a number of management steps that can be taken to help protect calves this winter:
• Feed calves three quarts of high quality (>50 mg/ml of IgG) colostrum within one hour of birth via nipple bottle, or four quarts administered by esophageal feeder within one hour of birth. A high-quality USDA approved colostrum replacement fed to provide at least 150 grams of IgG will also do the job efficiently and effectively.
• Provide milk or milk replacer as close to the calf’s body temperature (102°F) as possible. Anything below that temperature and calves have to use energy to warm the milk to their body temperature.
• Provide warm water frequently throughout the day.
• Bed often enough that bedding stays dry. Deep bedding will allow calves to nest in the bedding to stay warm.
• Implement calf jackets to provide additional protection to calves.