It hasn't said how that translates into percentage of sows it houses on farms.
It converted another 10 per cent of its farms last year and intends to have them all converted by next year.
It has also told its contract suppliers they need to be converted by 2022 and is offering “guidance and expertise”.
The Humane Society of the United States pressured retailers and pork packers to ban sow gestation crates and Smithfield fell in line, along with most others across North America.
“At Smithfield Foods, we are committed to keeping animals safe, comfortable and healthy," said Ken Sullivan, Smithfield Foods president and chief executive officer.
"As the world's largest pork producer, we have a responsibility to be a leader in animal care, and we view our conversion of the pregnant sow housing system as a key component of our dedication to this goal."
There continues to be sharply-divided opinion about the housing systems HSUS pressures farmers to adopt, including a ban on caging egg-laying hens.
Sows that are housed in gestation stalls can have their diets carefully controlled to meet their needs and they are protected from bullying that can cause injuries and loss of t their feed to the bullies.
Hens that are housed on open floors with perches available suffer more infections and diseases from walking in poop and parasites and break wings when they have accidents trying to fly to perches.
Researchers and farmers have made strides in improving welfare for sows housed together in pens and hens cooped in aviaries.