Getting to know your female is very important to know when she is cycling. Females need to produce follicles inorder to become gravid. If your female decides to go off feed during the winter that's a good sign she has started(or is in) her breeding cycle. Not all females will follow this but many may skip meals. Once again if you study your girls you will learn their quirks.

But don't stop reading studying. the Barkers book also has great BP breeding info as well as the Sutherlands DVD.

Best of Luck