The polar vortex had major implications for livestock producers last week, but the after-effects should not be ignored, particularly when it comes to bull management in the cowherd. While the number of bulls in the operation is generally not large, they have a major role when it comes to the production of the herd for the year.
During the winter, bulls are not typically kept with the herd, so they don’t receive the same benefits as they would from the herd environment. They tend to be more solitary instead of huddling up, so they don’t receive the same benefits of sharing body heat like cows do. Bulls typically survive cold weather when given proper nutrition, dry, warm bedding and an escape from the wind; but they are at risk for reduced fertility due to frigid temperatures.
Cold weather and wind chill put bulls at risk for infertility going into the breeding season. Tissue damage to the scrotum from frostbite causes scabbing, blisters and swelling. Where there is dead skin, heat from inflammation damages sperm production and storage capacity of the bull’s reproductive tract and bulls could experience decreased fertility or even infertility for a couple of months.
It’s important for cattlemen to visually inspect their bulls following extreme cold weather. Determine whether tissue damage is present, looking for scabbing and blisters. Next, schedule a breeding soundness exam with your local veterinarian. The breeding soundness exam is a uniform method of assessing a bull’s likelihood of establishing pregnancy in an appropriate number of open, healthy and cycling cows and heifers in a defined breeding season. A breeding soundness exam involves four components: general physical exam, scrotal circumference, sperm motility and sperm morphology. This should be performed regardless of weather conditions and should be performed 4-6 weeks prior to turn-out. Due to this year’s increased risk of injury, producers should not be delay so that necessary adjustments can be made if needed.
Bulls can recover from frostbite, but the process takes 61 days. Bulls that don’t pass a breeding soundness exam can be retested if they received some injury. Testing early gives producers adequate time to purchase a replacement if animals don’t pass. If a breeding soundness exam has not been a practice in your operation, it certainly should be this year.
For more information about agriculture, contact the Cowley County Extension Office at 221-5450 or 441-4565.