With the fall run of calves knocking at the door, it pays to keep in mind management associated with a decreased incidence of mycoplasma (non-responsive pneumonia and arthritis). As Kansas State University researchers noted in the mycoplasma survey they conducted among stockers and backgrounders in 2001, "As mycoplasma appears to be an opportunist occurring most frequently during times of stress or when a calf's immune system is weakened, management programs should focus on procedures that can get calves started in the right direction."
- Watch your cattle buying practices. Are you going to buy large numbers of cattle and find cattle free of mycoplasma? Probably not. The organism is too wide spread. As a simple recommendation, know your order buyer. Cattle represented as cheap and "too good to be true" probably aren't in the long run. Buying stale, stressed calves increases the likelihood of having cattle that respond poorly to treatment. A significant finding from the survey was cattle-buying practices do increase the risk of having cattle with non-responsive pneumonia and arthritis.
Yes, there's a difference between lightweight and heavyweight cattle. Lightweight cattle are at greater risk, but you obviously still must buy what fits your program and pocketbook. Minimizing the number of states you buy cattle from or at least sourcing cattle from a single order-buying facility, regardless of the state or region of origin, appears to help in reducing loads of affected cattle. This appears particularly important for cattle brought in during winter months.
- Buy what you can handle. It takes a pretty good workday for one or two people to feed, check pens for sick calves, and pull and treat those calves. Add into the mix days when you process a load or two, and it's not hard to see why everything begins to stack up.
Cattle should be fed and observed for sickness first thing in the morning. Watching how calves rise and come to the bunk goes a long way in picking up sick animals. Waiting until later in the day is a problem, particularly if there's a wide difference in temperature from morning to afternoon, since most calves will have increased respiratory rates that can mask signs of early pneumonia.
Additionally, cattle appear to better handle the stress of handling for treatment and processing earlier in the day than later in the afternoon or evening (Breazile, 1988). Leaving sick calves for treatment until everything else is done prolongs the time from when a calf actually gets sick and when the drugs begin to work. Because mycoplasma is an opportunist, extensive lung damage resulting from delayed or ineffective treatment of common pneumonia-causing organisms may increase the likelihood of mycoplasma invading the lungs.
- Vaccinate for common respiratory pathogens. Again, mycoplasma is an opportunist. Doing all you can to minimize common respiratory viruses such as infectious bovine rhinotracheitis (IBR), BVD, Parainfluenza 3 (PI3) and bovine respiratory syncytial virus (BRSV) from occurring will decrease the likelihood of damage to the respiratory tract and debilitation.
As clinical cases of BVD have been associated with increased risk to mycoplasma infection, a BVD vaccine component should be used in the receiving program. Based on survey results, whether a modified-live or killed BVD vaccine was used, no particular vaccine program appeared to have an advantage over another.
Based on the survey results, Pasteurella vaccines are currently being used in a large number of stocker operations. There was no statistical difference in the number of operations with affected loads of cattle using this type of vaccine and those that don't.
- Minimize contact between arriving cattle and sick pen cattle. Large numbers of mycoplasma organisms are shed from nasal secretions of sick calves. Exposing new cattle to the unnecessary risk of contact with the organism should be avoided. Utilize separate sick pens and receiving or holding pens. Clean and disinfect hospital pen waterers daily.
Moreover, water fountains are a source of infection for calves that are sick from other causes besides mycoplasma and for incoming cattle being exposed to the organism through these and common handling facilities. Since the organism can stay viable in water for extended periods of time, drain, clean, sanitize and rinse waterers daily. Disinfectant solutions of peracetic acid and iodophores have been shown to be effective against mycoplasma ((Pfutzner and Sachse, 1996). These products are commercially available in the U.S. Hypochlorides tend to be ineffective because of the prolonged contact time needed to kill the organism.