Possible Clues:

• Stock of jeans, in a manner of speaking
• Dog or horse's family tree
• High-class sports science qualification? I came fourth
• Exercises, like dance, almost in line
• Line of greed with pie
• Lineage of purebred animal
• Stock exercises needed by girl with almost excessive appetite
• Well-bred girl with endless gluttony should join gym
• Indication of purity
• What a mongrel doesn't have