BOSTON, Feb 16 (Reuters) - Activist investment firm Jana Partners made big portfolio changes at the end of 2020, buying a stake in life sciences company Laboratory Corp of America Holdings and exiting long-owned stocks including Callaway Golf Co and HD Supply Holdings which was sold to Home Depot. Jana Partners bought 811,661 shares in Laboratory Corp of America Holdings, known as Labcorp, making it one of the firm’s five largest investments, according to a regulatory filing made on Tuesday. Jana, founded by Barry Rosenstein, has a history of pushing for change in the healthcare space and also owns a stake in Encompass Health Corp. A spokesman for the firm declined to comment on how it may proceed with its Labcorp investment. Jana also added new stakes in materials company W. R. Grace & Co. and communications company Tegna, which last year beat back an activist investor’s efforts to elect directors to the regional TV station operator’s board. The filing shows Jana also increased its holdings in consumer staples company TreeHouse Foods Inc during the fourth quarter of 2020. Last week Jana nominated three directors to TreeHouse’s board and is pushing management to consider a possible sale. Jana has experience in pushing for consolidation in the consumer space, having lobbied for the sale of Pinnacle Foods and for changes at Whole Foods Market Inc. before it was sold to Amazon.com Inc.