A casual, discerning, pre-Herriot introduction to the manifold satisfactions of being a farm-and-country veterinarian. McPhee opens with a reference to his own problems more appropriate to an adult book (""I had no clear sense of purpose""), but once he' finds a raison d'Ãªtre in recording the activities of Copake, N.Y., vet George Beneke, the word-and-picture chronicle is crisp, fresh, instructive, unpredictable. ""A cow doesn't just start producing milk at two years of age,"" we're told. ""She has to be pregnant--and kept pregnant on a yearly cycle for maximum milk production."" No sentimentalism here, but, on the other hand--""You don't have to be around cows very long to fall in love with their beautiful faces and gentle eyes,"" as McPhee's photos attest. Other sections discuss environmental stress in terms of freestall vs. stanchion barns; the differing pain tolerance of different animals (and how a vet locates the painful area); mechanization of milking--as well as the more expectable topics of inoculations, operations, and castration. (But why, one Wonders, need we see a horse, a pig, and a bull castrated--with the remark, anent the last, that ""Every man who watches. . . feels it very personally""?) Interspersed are cameo portraits of the Beneke family and farm and--such is the spirit of the book--a random ""gaggle of geese."" Inessential but very ingratiating.