Stress and the immune system are not friends.
That’s why an understanding of major swine stress factors is key during the vaccination process, said Alejandro Ramirez from the College of Veterinary Medicine at Iowa State University.
Ramirez, along with Chris Chase, professor of veterinary medicine at South Dakota State University, spoke about vaccinology during a July webinar hosted by National Hog Farmer.
“Trying to minimize that stress as much as we can at time of vaccination will help us ensure that that vaccine response will be better. And then we’ll have better protection in our herd health,” said Ramirez.
While vaccines play a critical role in boosting immunity, they are only one-third of the formula for building herd immunity against insults.
“Like a three-legged stool, one leg is biosecurity, one leg is monitoring what’s going on in the herd and a third leg is vaccination,” said Chase.
“Vaccines are great, but they’re one of the tools that we need to use in conjunction with the things we do every day in raising pigs to make sure we maximize that health of that pig.”
It’s important to understand disease problems in the herd and have a vaccine protocol in place so animals have a chance to develop immunity.
The trick is to do that while also minimizing any animal stress caused by day to day operations on the farm, said Chase.
The impact of environmental stress on the animals’ immune systems, combined with vaccination, can affect overall herd health.
Some stressors involve operational flow, which includes transportation, feed changes, temperature and labour.
Mixing pigs into a new social order during weaning is also a major stressor, as is heat stress.
“We do a pretty good job of managing the cold end of it, but heat is much more of a bigger issue in terms of immune system,” Ramirez said.
“The immune system has kind of a breaker that it uses called heat shock proteins and trying to avoid that breaker being turned down too much is important.”
If a hot day is imminent, vaccination should be carried out in the morning when temperatures are likely to be cooler, added Chase.
Optimum feed and water intake are also important to good vaccination response. Transportation and labour will also have an effect.
“If we’re looking at transportation of pigs and we’re going to vaccinate them, let’s say coming right off the truck and they haven’t had any feed intake for a while, or they’re dehydrated, these things compound themselves and the ability of those pigs to respond to the vaccines (is) certainly going to be less,” said Chase.
Producers need two different vaccination protocols for sows: one for diseases that might impact the sow and another for stimulating its immune system so protection can be passed in the colostrum.
“When we vaccinate we’re trying to stimulate at the right time, in other words right before breeding to make sure we have the most protection at the time we need it,” said Ramirez.
However, protecting and preventing piglets from scours, E. coli and other coronaviruses and rotaviruses requires stimulation before sows farrow. It takes the immune system about 10 days to two weeks to respond.
Traditionally, producers vaccinate about five weeks before farrowing, followed by a booster two weeks later. The intervals give the sow’s immune system time to produce as many antibodies as possible in colostrum.
“If they go ahead and farrow two days post vaccination, there’s not enough time for that sow to have produced that immune response to maximize that immunity,” Ramirez said.
“Timing and the selection of the right vaccine at the right time is going to be critical to make sure that we maximize the opportunity for the vaccine to give us the maximum protection we can achieve.
Chase encouraged producers to consider all factors at play and then develop a vaccination plan in consultation with a veterinarian.