In many parts of the country the heat has subsided, replaced with crisp fall air. “We aren’t yet in the cold weather mindset, but if you’re finding yourself putting on an extra layer of clothes, chances are your calves are already experiencing cold stress.” This according to Ed Denton, a calf and heifer specialist with Purina Animal Nutrition located in New York.
Calves under three weeks of age can begin feeling cold stress much earlier than most people think. Denton notes that even at ambient temperatures of 60 degrees F and below, cold stress can hinder calf growth and performance. Cold stress can continue to affect calves over three weeks of age as ambient temperatures dip to 40 degrees F and below.
Denton offers some tips to help keep calves growing and thriving until temperatures begin to heat back up.
Use calf jackets
Calf jackets are a simple and effective tool to help calves conserve heat. Denton recommends using calf jackets on newborn calves and to continue using until they outgrow them. When using calf jackets, calf raisers should review their sanitation practices, as it is important to properly wash calf jackets between uses.
Maintain dry and deep straw beds
A deep straw bed can help calves’ ability to nest and conserve heat. Calf pens and hutches should always be clean and dry, notes Denton. A quick way to test whether or not bedding is dry is the knee test. If you put your knee down and it stays dry, your bedding is dry enough. If not, it is time to re-bed.
Denton uses a 1 to 3 bedding scorecard to evaluate whether or not bedding packs are deep enough based on how much of the calf’s legs are showing when they are lying down. If no legs are showing (optimal), the bedding score would be a 3; if half of their legs are showing (acceptable), the score would be a 2; if all of the legs are showing (unacceptable), the bedding score would be a 1. A score of 1 indicates that it is time to add bedding to the pack.
Offer consistent nutrition, formulated for cooler weather
Feeding calves a higher plane of nutrition, formulated for the season is particularly important as temperatures begin to drop. Denton recommends feeding calves 2.5 pounds of calf milk replacer powder per day to ensure that calves are receiving enough energy.
Providing the correct balance of fat and carbohydrates is key to achieving optimal energy intake, says Denton. A common misconception amongst calf raisers is that increasing fat alone in the calf diet during cooler weather will make up for a calf’s increased energy demands. Denton notes that a 50 percent increase in calf milk replacer powder can yield a 50 percent increase in energy. Alternatively, a 100 percent increase in fat alone in the calf diet may only yield a 12 percent increase in energy (NRC 2001).
Denton also stresses the importance of limiting the time that calves are not receiving nutrition. A three times per day feeding program (eight hour increments) allows for more balanced energy intake and availability.
Denton advises calf raisers to introduce calf starter ad libitum to calves at 2 to 3 days of age and increase feeding rate as appetite increases. In cool weather, a calf starter formulated to stimulate appetite and provide optimal energy availability can help support calf weight gains and structural growth in spite of cold weather.
Offer plenty of fresh, warm water
During heat stress periods, providing calves with extra water is a no-brainer. But calf raisers often underestimate the level of dehydration associated with the lower relative humidity and dry air brought on by colder weather, says Denton. He recommends feeding calves warm water between 101 to 102 degrees F. Water temperature becomes increasingly important in cold weather. Cold water forces calves to use extra energy to heat the water up to their core body temperature post-consumption.
Provide a draft-free environment
In warm weather, drafts can keep calves cool, but when the air cools, cold air drafts promote body heat loss. Body heat loss requires calves to allocate more energy towards body temperature maintenance and thus limits energy available for growth. A simple way to check for drafts is with your bare hand. If you feel more than slight air movement, a draft could be present.
Cold weather doesn’t only affect young calves, says Denton. Calf raisers need to address post-weaning calf management, especially in cooler weather. To help cut down on the added stress of weaning, post-weaned calves should be grouped in small, even groups for up to three weeks post-weaning. To help promote intake post-weaning, Denton recommends that calves be fed the same calf starter, all the way up to 12 weeks, where they can then be fed a grower feed as they transition to a diet higher in fiber.
Maintaining optimal calf growth and health can be a delicate balance. Cold weather adds stress for both the calf and the producer. Taking a proactive stance in keeping calves’ energy levels up, stress levels down and facilities up to par can help your calves avoid winter growth slumps so that they can keep growing and gaining and enter the lactating herd sooner.