A new Mercy For Animals investigation used a hidden camera in Willet Dairy Farm (biggest dairy farm in New York)-
"Cows with bloody open wounds, prolapsed uterus's, pus-filled infections, and swollen joints.
-Sick/Injured cows left to suffer for weeks before dying or being killed
-Workers hitting, kicking, punching, and electric-shocking cows and calves
-Calves having their horns burned off without painkillers, as a worker shoved his fingers into the calves' eyes to restrain them.
-Newborn calves forcibly dragged away from their mothers by their legs, causing emotional distress to both mother and calf
-Cows living in overcrowded sheds on manure-coated concrete flooring."
Videos can be found at http://dairy.mercyforanimals.org/