By Russ Daly
A previous SDSU Extension article
looked at lingering health effects in calves that survive the persistent cold and periodic blizzards that commonly punctuate a Northern Plains winter and spring. Poor immunity, respiratory disease, and scours cases with longer incubation periods were some of the issues discussed.
What about cows and bulls? While mortality directly due to harsh winter weather is much more likely in calves rather than adult cattle, these older animals can be affected too – and some of those effects might linger into the days of better weather and warmer temperatures.
Nutrition and Reproductive Health
The most obvious problem cows and bulls face during a harsh winter is the failure to maintain body condition – unless aggressively addressed through adjustments in nutrition. Severe and persistent cold presses these animals’ systems into burning more dietary energy for body maintenance. In the worst cases, these calories get burned in favor of the survival of the developing fetus and maintaining the animal’s body temperature – at the expense of fat cover and “luxuries” such as milk production. Another one of these luxuries is reproduction – the ability to cycle and establish and maintain a pregnancy. Producers should work with their nutrition information sources to formulate a plan to minimize this lingering effect on reproduction.
Bulls are subject to these same challenges during the winter, but their reproductive capacity can be affected in a different way. Frost damage to the scrotum and testicles can cause abnormal or reduced sperm production. Since the sperm production cycle takes a good couple of months from start to finish, these effects could linger at least that long in affected bulls. Producers should ensure each bull to be used during the breeding season passes a complete breeding soundness examination by a veterinarian. Testicular damage can occur when there is no apparent external damage to the scrotum, so simple visual appraisal doesn’t cut it.
Environment and Mobility
Other lingering effects of the winter and spring may come from muddy conditions they experience late in the season. For example, udder problems in the form of mastitis are more apt to occur when muddy conditions allow bacteria more consistent access to the teat canal. When mastitis becomes chronic, these effects can linger throughout lactation and could adversely affect calf performance. Producers should remember to evaluate udders after calves are weaned; this information should be used in culling decisions.
Movement on and through ice, snow, and mud can put strain on an animal’s feet and legs. Sprains, strains, and dislocations can affect an animal later on if they do not heal in a timely fashion or remain chronic. These can affect a cow’s (and even more importantly, a bull’s) ability to travel on pasture.
In a similar manner, cattle standing in persistent mud can be prone to foot rot. If these cases go untreated or evade detection, the infection can extend into one of the coffin joints (last joint at the level of the hoof) and wall off into an abscess that creates long-term lameness.
The Bottom Line
Some effects of a harsh winter and spring are hard to avoid. In many of those cases, nutrition or treatment interventions can resolve these issues. In others, an awareness of these lingering problems can help inform culling decisions following weaning.