Earlier this fall, temperature dropped to -28 degrees Celsius (or colder). In some parts of the province, the temperature was up to 5 degrees Celsius. This impacts how much cattle can eat and resulting weight gain or loss.
Ingested feed is digested. Heat is produced during the process. The heat is used to keep the animal warm. Mature cattle that are dry, protected from the wind and in good condition can withstand temperatures down to -20 degrees Celsius. This is the lower critical temperature. Smaller animals are not able to withstand the cold temperatures and need more care. No matter what type of animal is fed, when it is below the lower critical temperature, extra energy is required.
As it gets colder, cattle consume more feed. This helps produce more heat to withstand the cold down to the lower critical temperature. When cows are in colder conditions; feeding an extra two pounds of grain per head per day for every 10 degrees Celsius temperature drop below -20 degrees Celsius is needed to produce extra heat. If no extra grain is provided, cows will mobilize fat off their backs to produce energy for heat production. A cow at a body condition score of 2.5 versus 3.0 cannot withstand as much cold and requires more grain supplementation.
A warming trend also creates feeding concerns. Cows will eat the higher grain rations when offered. The extra heat produced causes the animals to become stressed and feed intake drops. Lower intakes can continue for up to a week.
To prevent the drop in feed intake, watch the weather forecast. Reduce the amount of grain fed two to three days prior to the moderating trend to prevent over production of heat. Expect a drop in total feed intake. By the time temperatures stabilize, animals should be back on the regular ration.
For more information on feeding cattle with the variations in temperatures, call Barry at 403-741-6032 or bjyaremcio@gmail.com.