Not enough revision
This is the 5th edition of a book that was first written in 2000. In my opinion there has not been enough deletion of old information. Instead, new information has been grafted onto existing structures rather than undertaking complete revision.
This book attempts to give a thorough good introduction to raising sheep. It will be of greatest help to someone who is thinking about starting with sheep.
One example is the short essay on Mendel's genetics. Modern attempts to replicate Mendel's work suggest that Mendel probably didn't do the experiments attributed to him, instead gathering his theories from a lifetime of scientific work.
Another place where revision should have been considered is the list of breeds, which I found to be lengthy and jumbled. It barely mentions some of the breeds of sheep favored by new consumers with family backgrounds in the middle east and are preferred because their meat is lean and not marbled or greasy when cooked.
With the focus on breeds derived from European stocks, there is an assumption that most sheep behave in similar way. European and Asian sheep are quite different from each other, especially considering flocking behavior and grazing patterns. These differences mean a great deal when considering fencing, pasturing, predation dangers, dog choices, and protection animal training.
In some places I think the authors could better have referenced professional organizations and their websites rather than present shallow information – on protection animals, for example.
The discussion of vertical integration and large vs small scale farming is under-informed, as is the discussion of meat nutrition.
It several places it seems to me that the insertion of genetic jargon into the text in place of simpler words would put off some less scientifically-trained readers.
I believe that you will find better information from university sources online, your state's sheep association, and local shepherds if there are any.