The expression can be traced back to horse racing in the 1700s when goats were used to settle the horses. A young goat. An idiom is a turn of phrase that doesn't make sense when literally translated.
Description: GTF file is a General Feature Format File. The Gene transfer format (GTF) is a file format used to hold information about gene structure. It is a tab-delimited text format based on the general feature format (GFF), but contains some additional conventions specific to gene information.
Media Descriptor File (MDF) is a proprietary disc image file format developed for Alcohol 120%, an optical disc authoring program. Daemon Tools, MagicISO, and PowerDVD can also read the MDF format. A disc image is a computer file replica of the computer files and file system of an optical disc. Unlike an ISO image, a Media Descriptor File can contain multiple layers (as used in dual-layer recording) and multiple optical disc tracks. Like the IMG file format, a Media Descriptor File is a raw image of an optical disc.