When Old Man Winter moves in, he brings with him harsher conditions that leave newborn calves fighting harder for survival compared to their herd mates born in more temperate seasons.
“We have seen a lot of problems with calves that are born during the winter and somehow are not housed as well,” said Dr. Carla Maris Machodo Bittar, associate professor at the University of Sao Paulo, Brazile. Whether it’s due to their being born wet in cold conditions, wind, or simply needing more energy to maintain their core body temperature, Bittar said winter-born calves have more demands on their resources.
On a recent episode of the Dairy Nutrition Blackbelt podcast, Bittar shared the results of a study in which colostrum feeding volume was increased incrementally, then the impacts of a cold challenge were measured.
Thirty male Holstein calves were divided into 3 feeding groups, with colostrum delivered at 10, 15, and 20% of bodyweight (BW). In all groups, the feedings were divided, with the first dose administered by 2 hours of age, and the second 6 hours later.
At 24 hours of age, calves were placed in a walk-in cooler set at 10°C (50°F) for 150 minutes. Skin and rectal temperature, heart and respiratory rates, and shivering were measured every 15 minutes. Blood samples were taken every 30 minutes. Afterward, all calves were raised on a consistent nutrition program and housed in identical conditions, including ambient temperature.
Feed intake, fecal scores, and rectal temperature were recorded daily until 56 days of age. Blood samples, bodyweight, and body measurements were taken weekly. Findings included:
- During the cold challenge, prescapular temperature and total serum protein were greater for calves fed colostrum at 15% or 20% of BW.
- Leukocytes increased preweaning, presenting higher values for calves fed colostrum at 20% of BW.
- Shivering incidence during the cold challenge was lowest for the calves fed colostrum at 20% BW, followed linearly by the 15% group and then the 10% group, which demonstrated the greatest amount of shivering.
- There was no difference among treatments for heart rate during the cold challenge, but respiratory rate was highest among calves fed the lowest amount of colostrum (10%).
- Feeding higher volumes of colostrum resulted in no difference in performance during the rest of preweaned phase.
- The calves fed the highest amount of colostrum (20% of BW) showed increased immune response – measured via serum total proteins and immunoglobulins -- during the preweaned phase.
“We may have the opportunity to increase colostrum feeding from the current recommendation of 15% of bodyweight to 20%,” Bittar observed.
Podcast host Bill Weis asked Bittar whether she thought to boost in colostrum dose could be beneficial to immunity even under thermoneutral conditions.
“Yes, for sure,” she stated. “We have data showing that the more immunoglobulins, nutrients, and bioactive compounds that are present in colostrum are consumed and absorbed, the better the health and performance of the calves.
Bittar’s full study, published in the journal Animals, can be accessed here.
