Dairy cows feed through a fence at an Idaho farm, in this 2009 file photo. Idaho's Gov. C.L. "Butch" Otter enacted a bill Friday that criminalizes the act of secretly filming animal abuse at farms. Charlie Litchfield/AP hide caption

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Charlie Litchfield/AP

Cows wait to be milked at a California dairy farm. Justin Sullivan/Getty Images hide caption

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Justin Sullivan/Getty Images