According to reliable sources, the ABC News "Nightline" segment on the dairy industry that was to have aired last week will now air Tuesday, Jan. 26.

The in-depth feature by investigative journalist Brian Ross will focus on “where your milk comes from.”

Apparently, the piece will feature undercover video of tail-docking and other "abusive" practices. Portions may appear on ABC World News in addition to Nightline.

This story was posted on the Nightline Web site Tuesday afternoon.

ABC News producers have reportedly showed up at a couple of dairy farms unannounced to ask about videos that were allegedly taken there by animal-rights groups. ABC also planned to film somatic cell testing in a laboratory and/or conduct its own testing of retail milk samples for somatic cell counts, according to an advisory from Dairy Management, Inc., which manages the national dairy checkoff program.

Dairy Management Inc. and other members of the dairy industry have served as resources to ABC News over the last few months in the hopes of encouraging a more factual report. 

The air date is subject to change due to breaking news.