The Humane Society has released undercover video which it says show workers kicking and tossing piglets at a Wyoming factory farm.At a Denver news conference Tuesday, Humane Society officials condemned the cruelty captured in videos taken in April at Wyoming Premium Farms, a pig factory farm in Wheatland, Wyo., owned by Denver-based Itoham America, Inc.A word of caution, this undercover video is graphic and you may choose not to click the link to view it.The Humane Society's national president called on Tyson Foods to stop "buying pork from this hellhole for pigs."The group said the video shows farm workers swinging sick piglets in circles by their hind legs, striking mother pigs with their fists and repeatedly and forcefully kicking mother pigs as they resisted leaving their young."In one case, a mother pig with a broken back leg endured a very heavy worker sitting and bouncing on top of her hindquarters as the pig screamed in pain," the Humane Society said in a statement."I am sickened and outraged by what Ive seen, and any right-thinking person will have the same reaction," said Wayne Pacelle, president and CEO of the Humane Society of the United States. "The shocking abuse at this facility shows why so many Americans are calling for reforms in the pork industry. It is also deeply disconcerting that Tyson and other companies are buying pork from this hellhole for pigs, and I hope those corporate relationships end tomorrow."The Humane Society said it met with the Platte County Sheriffs Office to present investigation evidence and urged the office to pursue filing criminal charges if warranted.The group also condemned the farm's practice of confining pregnant sows in two-foot-wide gestation crates, which virtually immobilize pigs for almost their entire lives and cause health problems including infections, sores and mental stress."It is also time for Tyson to join so many other major food industry companies and make a commitment to ending the confinement of sows in gestation crates," Pacelle said. These crates immobilize animals for their entire lives, and its no longer acceptable to the American public.The group noted that major fast-food outlets, including McDonald's, Wendy's and Burger King, have publicly committed to getting gestation crates out of their supply chains. Smithfield Foods, the world's largest pork producer, and Hormel have announced they will be 100 percent gestation crate-free for company-owned operations within five years and Cargill is already 50 percent gestation crate-free.Colorado and seven other states as well as the European Union have passed laws to phase out gestation crates.