Chances are you haven't considered the tail of the cow that made the milk that goes into your Nestle Crunch bar or the cheese in your (Nestle-made) Lean Cuisine frozen dinner.

But as animal welfare groups report, many dairy cows have their tails partially amputated, or docked, to help keep their udders clean. Not only is docking painful, but it also pretty much disables the cow's personal fly switch, making it more susceptible to fly attacks.

On Thursday, Nestle, the world's largest food company, announced that it's requiring all of its suppliers to eliminate tail docking as part of a new commitment to improving the welfare of the farm animals in its supply chain. It will also mandate that its 7,300 suppliers of dairy, meat, poultry and egg products end all kinds of other common farming practices — like cage systems for chickens, gestation crates for pigs and dehorning cows.

But it's not just animal welfare groups that have been speaking up about the practices, which scientists largely agree cause suffering in the animals. The well-being of food animals is also increasingly important to consumers, as the company acknowledged.

"We know that our consumers care about the welfare of farm animals, and we, as a company, are committed to ensuring the highest possible levels of farm animal welfare across our global supply chain," said Benjamin Ware, the company's manager of responsible sourcing, in a statement.

In the past year, several other major food companies have indicated that animal welfare is a new priority. Smithfield, the world's largest hog and pork buyer, said in January that it would extend the contracts of its suppliers who got rid of gestation crates — narrow stalls used to confine pregnant sows — by 2022.

But Nestle's new commitment is unique in a few ways. For one, it's the largest food company in the world, with $101 billion in sales in 2013. Delivering its milk, chocolate, eggs and meat to a growing consumer base involves a highly complex supply chain of farms with varying standards around the world.

Secondly, Nestle is partnering with World Animal Protection, an animal welfare NGO, which it says helped draft the new policy. The company says that makes it the first major food company to form an international partnership with an animal welfare NGO.

Nestle is also hiring the auditing firm SGS to check on its suppliers to ensure they make the changes. World Animal Protection will help verify that process.

Nestle's move is "the latest, and one of the biggest, in a series of actions by major food retailers, moving them away from an industrial-type production system that is callous and unforgiving toward animals," wrote Wayne Pacelle, president of the Humane Society of the United States, on his blog.

How many suppliers will have to change their ways? Nestle doesn't yet know.

First, it says, it will have to monitor the farms it buys from to figure out exactly what their animal welfare practices are and if they're bad actors. With that baseline, it will come up with a program to eliminate the crates and cages as well as enforce "responsible use of antibiotics."

But unlike recent commitments from Smithfield and Tyson, Nestle is not giving its suppliers a deadline for upgrading their animal operations. So it's unclear how quickly the changes will happen.

Other animal welfare groups who were in discussions with the company leading up to the announcement say they're optimistic the policy will yield real changes for the animals throughout Nestle's supply chain.

"Nestle's new industry-leading policy will reduce the suffering of millions of animals each year and hopefully inspire other food providers to implement and enforce similar animal welfare requirements," said Nathan Runkle, president of Mercy for Animals, in a statement.

