Google Thieves in the Night from which ever Oklahoma university it is that is involved in agriculture research. This file has much better and more accurate information.. You can get this information for nothing except the electricity.
Now you owe me a new monitor because when Storey's Guide to Raising Chickens said that a possum eats the entire bird on sight I blew hot coffee through my nose to keep from choking on it.
Oh well, I suppose you'll find a good use for that book the next time you need to level up a bookcase or something.
Lots of misinformation out there - even in book form.