A few simple steps can help cattle producers become more effective in battling respiratory disease in their herd, get full value of any vaccine they purchase and possibly increase their operational profit in the process.
According to Oklahoma State University, studies show that bovine respiratory disease — also known as shipping fever or pneumonia — may cost the U.S. cattle industry more than $2 billion annually. Management techniques can offset much of this cost, Oklahoma State said, noting that having a good vaccination program can maintain the health of a calf all the way through the production system.
“A vaccine can cost more than $3 per head, and if not stored properly, the vaccine can be rendered ineffective,” said Bob LeValley, Oklahoma Beef Quality Assurance coordinator with Oklahoma State University’s Division of Agricultural Sciences & Natural Resources.
Biological products should be stored under refrigeration at 35-45°F unless the nature of the product makes storing at a different temperature advisable. If vaccines are not stored within this temperature range, efficacy to the calf can and will be reduced, LeValley said.
“Killed vaccines are especially susceptible to freezing temperatures,” LeValley said. “Freezing a killed vaccine will alter its delivery system. In turn, this negatively affects the immune response to the antigen in the vaccine.”
He also pointed to a 2013 study that showed modified live virus (MLV) vaccines are more stable but can be inactivated if they are repeatedly cycled above or below the required temperature range. Also, once activated by mixing, the effective life of an MLV vaccine will be reduced to a few hours, and it needs to be maintained at the 35-45°F range.
“This can be accomplished by only mixing the doses a producer will use at the time and using a cooler to maintain the proper temperature range while working cattle,” LeValley said.
He also noted that researchers from the University of Arkansas and Idaho analyzed the consistency of temperatures for different types, ages and locations of refrigerators over a 48-hour period. They found that only between 26.7% and 34.0% of refrigerators were within the acceptable temperature limit 95% of the time.
Refrigerator location also can affect temperature. A 2009 study found that refrigerators located in barns were colder (35.6°F) than those in mud rooms (41.72°F) and kitchens (40.82°F).
Temperature within a 24-hour period also can be highly variable for individual refrigerators, LeValley said, noting that the same 2009 study demonstrated that some refrigerators may take up to eight hours to cool down to the 45°F level required, or equally problematic, the temperature may drop below freezing; temperatures were found to range from 28.4°F to 44.6°F.
“Producers need to be aware of these variations so they are able to adjust refrigerator temperature as needed,” LeValley said. “Thermostats also can be variable from unit to unit, so keeping a thermometer inside works well to monitor and make adjustments as needed.”
Simple indoor/outdoor thermometers work well to achieve this goal. The outdoor unit can be placed in the refrigerator, while the LCD display can be hung with a magnet on the door. This allows the refrigerator temperature to be monitored without opening the door. In addition, many models will record the high and low temperatures in a 24-hour period.
How a producer handles vaccine outside of the refrigerator also is important, LeValley said. Coolers can be easily modified for syringes and are important in maintaining vaccine efficiency when chute-side. Inserts can be made through the cooler by using PVC pipe and work well to keep syringes cool and out of the light while in use.
“Either ice or freezer packs can be used as a coolant to maintain temperature for several hours, depending on outside ambient temperature,” LeValley said. “Make sure enough coolant is used to maintain temperature while working cattle. Extra ice may be needed if working cattle all day or during warm days. Remember, it may take up to an hour for the cooler to reach the needed 45° mark, so producers need to plan ahead prior to processing cattle."
Detailed instruction on the construction of a chute-side vaccine cooler is available online at http://facts.okstate.edu in the Oklahoma State Cooperative Extension fact sheet ANSI-3300, “Chute Side Vaccine Cooler.”