Functional roles for both sterol response element transcription factor 1 (SREBF1) and thyroid hormone responsive spot (THRSP) have been reported in transgenic mouse models and bovine mammary cell culture. Mammary disruption of SCAP, which is required for sterol response element transcription factor 1 (SREBF1) activation, decreases pup growth and milk fat concentration (Rudolph et al., 2010), and whole body disruption of thyroid hormone responsive spot (THRSP) decreases milk fat concentration approximately 50% (Zhu et al., 2005).