One of the top causes of antibiotic resistance is the use of the medicines in livestock. Many factory farms feed animals antibiotics to prevent disease and promote growth. Yet, despite countless warnings that the practice fuels drug-resistant superbugs, it continues to be a serious problem. Thankfully, establishments such as McDonald’s claims to finally be taking more action against widespread antibiotic use.
In recent years, the poultry industry has made some progress in reducing unnecessary antibiotic use. In 2015, McDonald’s announced a plan to prohibit its chicken farmers from using antibiotics considered important to human health, and many other food chains soon followed, including Wendy’s., as well as KFC. 
In December, McDonald’s took its efforts to reduce the use of medically-important antibiotics in livestock to the next level when the company announced plans to reduce the use of antibiotics in cows that are part of the fast-food company’s global beef supply.
Bruce Feinberg, a senior director at McDonald’s Corp., who oversees global quality systems for protein and dairy products, called the plan “probably the most ambitious project that McDonald’s has ever taken on.”
McDonald’s said it will measure antibiotic use in its top 10 beef markets, including the U.S., Brazil, and New Zealand. The company will then set targets for reduction by the end of 2020. It will start reporting its progress in meeting those targets in 2022.  
Environmentalists are more than happy to see McDonald’s taking action against the overuse of antibiotics in farm animals. 
In a statement, Lena Brook, interim director of food and agriculture at the Natural Resources Defense Council (NRDC), wrote:
“McDonald’s is the first major burger chain to announce a comprehensive antibiotic use reduction policy for all beef sold by its restaurants – and the largest, by far.”
According to the NRDC, some 40% of medically-important antibiotics sold in the livestock sector in the U.S. are used in the beef industry. By comparison, just 6% goes to the poultry industry. That, the NRDC says, is why “addressing overuse in beef production is critical to combat drug resistance.”
It’s tougher to remove medically-important antibiotics from livestock than it is to remove them from poultry because cattle live longer than chickens and have more chances to fall ill. 
Bob Smith, an Oklahoma-based cattle veterinarian for Veterinary Research and Consulting Services, explained that cattle farmers face unique challenges in reducing antibiotic use while also keeping their animals healthy, as there are few good alternatives to the medicines.
“We will need those medically important antibiotics in meat production for a long, long time. We want to use those wisely.”
But someone has to get the ball rolling, and it might as well be a monstrosity of a company like McDonald’s.
Keith Kenny, McDonald’s global vice president for sustainability, said in a statement: 
“McDonald’s believes antibiotic-resistance is a critical public health issue and we take seriously our unique position to use our scale for good to continue to address this challenge.”
In October, McDonald’s received a failing grade in the Chain Action Report. Produced by the Center for Food Safety (CFS), Consumer Reports (CR), Food Animal Concerns Trust (FACT), U.S. PIRG Education Fund (USPEF), Friends of the Earth (FOE), and NRDC. The report rated the top 25 fast-food chains’ antibiotic policies.
USPEF, who has been pressuring McDonald’s to phase routine antibiotic use out of its meat supply for more than 3 years, applauded the fast-food chain’s commitment.
Matthew Wellington, the consumer group’s antibiotics program director, remarked:
“The Golden Arches just raised the bar for responsible antibiotic use in meat production. McDonald’s new commitment is a promising step forward that will help preserve antibiotics for the future and that’s something we should all be happy about.”
As the biggest beef buyer to pledge to reduce antibiotic use in cattle, McDonald’s could set a new benchmark for livestock producers and other fast-food chains alike. 
David Wallinga, a senior health adviser for the NRDC, said:
“McDonald’s iconic position and the fact that they’re the largest single global purchaser of beef make it hugely important.”
While McDonald’s is in no way a healthy place to eat, the chain has been making strides in recent years to make their food a bit less … er, toxic? In addition to banning antibiotics in its chicken supply, the company said in 2014 that it would not be sourcing genetically modified (GM) Simplot potatoes, which are engineered to brown slower and bruise less easily than non-GMO potatoes.
Then, in 2015, McDonald’s said it would replace the high-fructose corn syrup in their hamburger buns with regular sugar, and ditch preservatives in its McNuggets, pork sausage patties, omelet-style eggs, and scrambled eggs.
 USA Today