by A.J. Tarpoff, DVM, MS; extension veterinarian
Early weaning of calves during a drought can have many benefits to the cow herd such as improved body condition of the cows, improved rebreeding rates, increased forage availability, and possibly improved calf performance. However, increased management is essential for the young calves, and several factors should be considered before this decision is made.
The most successful early wean programs begin with a healthy calf prior to weaning. Calf age plays a crucial role on when to early wean. Animal health procedures conducted prior to weaning will help ensure calf health through the transition of weaning. In a recent nationwide survey of practicing veterinarians, the largest number of respondents (38%) recommended the earliest age to wean calves is 90-120 days of age (Fike et.al.). Consulting with your local veterinarian to help establish a health protocol to help boost calf health, while reducing stress will be extremely beneficial in an early wean situation.
Understanding the calf’s immune function during this time is also important. Calves are born with a fully functional immune system, but they have yet to mount a response to any pathogen. The intake of colostrum shortly after birth helps fill the gap and provide passive immunity of immune cells and antibodies that act as the natural immune function early in life. Until 2 to 4 months of age, maternal antibodies are the key players in the calf’s immune protection. This plays a role in how the young calves will respond to immune challenges such as vaccines. When these maternal antibodies start to decrease, it is a prime time to initiate a vaccine protocol to help boost the active immune protection of the calf. While every calf may not fully respond to vaccines at this age, vaccination primes the immune system for a booster later in life. Vaccines to consider would be a multi-strained respiratory vaccine (modified-live), and a clostridial (7-way or more).
Multiple stressors and decreased health go hand in hand. Painful procedures such as castration, dehorning, and branding should be conducted well before the day of weaning. Handling calves prior to weaning is important and gives opportunity to include many “preconditioning” type practices to help ensure calf health.
Initial vaccination and management procedures such as castration should be conducted 2-3 weeks prior to weaning. During this period of time, control of other stressors such as external parasites and internal parasite can be initiated. External parasites of concern are mostly flies during the summer months. Internal parasite control should target gastrointestinal nematodes (worms) as well as coccidiosis during this stressful time.
To further increase calf comfort, developing a plan to control heat stress and minimize dust can be very helpful in ensuring overall health, performance, and welfare of these calves.