Nanotechnology – it’s a word most people became familiar with while watching science fiction movies, but it’s become a modern reality. But what exactly is it? And how can it help push the pork industry forward into a new future? That’s precisely what the Prairie Swine Centre wanted to discover with a recent research project.
But first, what is nanotechnology? Nano basically means small… really, really small. A nanometer is one millionth of a millimetre. To illustrate just how small, consider that a normal, healthy fingernail is just one millimetre thick. Nanotechnology is all about harnessing the power of individual atoms and molecules at a very small scale to make a really big difference. For example, the nanoparticles, (which are between one and 100 nanometres in size) of zinc oxide are used in transparent sunscreens to block out the damaging rays of the sun.
So, what does all that have to do with raising pigs? As it turns out, potentially quite a bit.
“We wanted to see if we could control the growth and transmission of disease-causing microorganisms in swine barns through the use of nanotechnology,” said Dr. Bernardo Predicala, engineering research scientist at the Prairie Swine Centre, and the project’s lead.
Disease spread during swine production is usually controlled through two distinct methods – biosecurity and sanitation. Biosecurity involves protocol, policies and procedures that reduce the risk of initial contamination and subsequent spread of a pathogen within an operation. This can include acts such as showering in and out, Danish entries, and ensuring staff, guests and visitors don’t pose a health risk to the herd.
Battling disease on the sanitation front means treating the environment to reduce the level of possible pathogens that could make animals or people sick. This can include the proper cleaning and drying of barns and trucks, and applying the correct disinfectants in the correct volumes to reduce the risk of illness. In other words, biosecurity is about preventing infectious agents from entering the barn, and sanitation is about controlling and reducing infectious agents that may already be present in the barn.
While biosecurity and sanitation efforts are always improving and evolving, so are the pathogens they seek to contain. The industry has changed too, and sometimes, with greater efficiency comes greater risk.
“The swine industry has shifted toward production systems where more animals are raised in larger confinement facilities. These changes have increased efficiency, productivity and profitability, but it’s also increased the risk and prevalence of animal diseases,” said Predicala.
That’s why scientists are constantly looking for new ways to manage and mitigate health risks. Not only is a healthier herd better for productivity and profitability, but it’s much better for the pig – and animal welfare is an increasing priority to the public and to producers alike.
“Nanoparticles are known to have antimicrobial properties,” said Predicala. “They’ve been used in drinking water purification, as well as in air filtration systems in hospitals to provide a clean environment for patients, especially during surgery.”
Predicala, along with Prairie Swine Centre engineering grad student Alvin Alvarado, wanted to investigate how nanoparticles could supplement the safeguards already provided by biosecurity and sanitation measures. But that’s not all – the research could also determine whether the novel nanotechnology application could also help manage gas emissions – an inevitable byproduct of swine production.
“If proven effective, with a single treatment application, we could simultaneously address concerns with hazardous gas emissions as well as the spread of disease – both which greatly affect the profitability and sustainability of livestock operations,” explained Predicala.
Predicala and Alvarado designed a research project to be conducted right on site at the Prairie Swine Centre. But first, the effectiveness of a variety of commercially available nanoparticles in controlling the growth of certain pathogens had to be selected. In order to do that, laboratory scale experiments were conducted at the University of Saskatchewan to determine which nanoparticle would be most effective. The results showed that zinc oxide (ZnO) was the clear winner.
The next step was bringing the ZnO to the Prairie Swine Centre facility to assess whether the nanoparticles could really pack the punch the researchers were looking for. Two identical chambers, each 4.2m x 3.6m x 2.7m, were used to conduct the first portion of the research. Each chamber was fully instrumented and had identical environmental conditions, and each housed a pen of the same size. The chambers were operated with a negative pressure ventilation system.
Next, a filter was installed into each of the chambers’ ventilation air recirculation systems – one loaded with nanoparticles and the other without. The trials were 15 days long, and the scientists monitored microbial loads both in the air and on surfaces, as well as greenhouse gases, manure characteristics and pig performance.
To measure whether the nanoparticles could help with sanitation duty, two levels of ZnO nanoparticles were sprayed on concrete surfaces and compared to the control, which was treated with the standard chemical treatment ordinarily applied.
The results from both wings of the experiment were encouraging.
“Partial filtration of the air in the chamber with the ZnO nanoparticles did achieve a reduction in bioaerosol levels in both the human and the animal-occupied zones,” said Predicala, adding it was important to note that the nanoparticles didn’t appear to negatively affect any other measured aspects of swine production. “There was no significant impact on carbon dioxide and methane emissions, manure characteristics, or pig productivity.”
The ZnO particles were shown to be effective in controlling the growth of certain commonly encountered pathogens such as Salmonella and S. suis. Also, the filtration system could be improved thus further reducing bioaerosol pathogens with better air capture, forcing more air to pass through the treated filter.
The sanitation experiment showed that the nanoparticles can indeed make a big difference by inhibiting the growth of microorganisms and in fact, could be a better option than conventional disinfectants. Of course, new technologies not only have to work, they have to be reasonably priced in order for any potential implementation to make sense. In that regard, the sanitation nanotechnology was ahead of the filter application.
“Cost analysis indicated that filtration treatment with ZnO nanoparticles in a 100-head grow-to-finish room during the pig-rearing period would amount to about 3.3 per cent of the estimated production cost for the grow-finish stage,” explained Predicala. “However, the use of the nanoparticle solution during sanitation was only about 12 cents higher than the use of conventional disinfectant.”
Predicala and Alvarado recommend pilot-scale testing in other parts of the barn such as the nursery, breeding, gestation, and farrowing areas to further determine the feasibility of both the sanitation and the filter nanoparticle applications.
“It would also be useful to conduct trials at higher recirculation rates, which would likely have a better impact on reducing bioaerosol levels,” said Alvarado.   •
— Submitted By Ken Engle
Prairie Swine Centre