Feeding of BG is still in its infancy with respect to the science. Just like people are different so are BG (even in the same brood). There is no doubt local conditioning as well as bioenergetic , weather and reproductive issues with BG feeding in winter/early spring (water temps below 65F and short photoperiods). It is common in warmwater fish to see feeding activity increase with small changes in water temps over a couple of days. Even in the absence of water temp increase BG (female especially) will start to eat about 30-45 days before the photo period increases much as they are engaged in gamete (egg)development prior to the spawn. So it really does depend. IMO it is important if you are trying to increase BG spawn numbers and survival to try and have them in good condition (via feed if you do feed) coming out of winter.