Did Germany’s Friedrich-Loeffler-Institut botch experiments with pigs and COVID-19?

Was there a better way to infect pigs with THE COVID-19 virus? Do pigs, with ACE2 receptors, get infected with THE COVID-19 virus in some other way?

"Germany’s Friedrich-Loeffler-Institut (FLI) started infection studies with SARS-CoV-2 in pigs, chickens, fruit bats, and ferrets several weeks ago. The animals were inoculated nasally with SARS-CoV-2 to mimic the natural route of infection in humans via the nasopharyngeal route."

http://www.farmbusiness.co.uk/news/german-study-shows-pigs-and-poultry-are-not-susceptible-to-covid-19.html