“The writer has been acquainted with ‘the escutcheon theory’ ever since about 1850. During this time he has been a practical dairyman in central New York. At first he approached the study of the escutcheon as a doubter. It seemed to him an absolute absurdity to claim a connection between the growing of the hair and the production of milk, two functions so entirely different.
“At first he examined the herd of cows which he helped milk every night and morning, and was surprised to meet with so many proofs of the truth of the theory. He then observed it upon other herds, and finally extended his observations to various breeds under various circumstances. He was at last compelled to come to the final conclusion that the theory, in the main, was true, but that other points and conditions of the animal must be understood in order invariably to reach a correct judgment:
“1. The breed modifies the quantity and quality of milk production. This is so manifestly true that it needs no argument. A particular order and class of escutcheon indicates a different quantity and a different quality of milk on a Jersey than it indicates on an Ayrshire cow.
“2. The condition of care and feed to which different families of the same breed have been accustomed during long periods modify milk production, and must be taken into consideration. For instance, certain families of Short-Horns have been cared for and fed through several generations with the sole view of beef production; other families have been trained to milk production. Escutcheons upon the former indicate far less quantity of milk than upon the latter. Thus some families with very fine escutcheons give very little milk. The escutcheons in such cases no doubt indicate an original capacity that a few generations of proper treatment might awaken and develop.
“3. The capacity and health of the digestive organs modifies the quantity, and we also think the quality, of milk production. Cows with large, healthy digestive organs will eat and properly digest more food, and give good return at the pail, than one with opposite conditions of the digestive organs. The former may sometimes give the larger quantity of milk, though, indeed, possessed of the poorer escutcheon.
“4. The activity of the nervous system materially affects milk production. This is often seen when the animal is unduly excited. The quiet dispositioned cow that attends to feeding, and is not disturbed by any excitement in the herd or in the surrounding fields, may have the poorer escutcheon, yet give larger quantities of milk than the extremely excitable cow, with the better escutcheon.
“Other conditions will suggest themselves to the observing and reflecting man, that materially affect the quantity and quality of milk production.
“These modifying conditions do not disturb the true theory of the escutcheon. Other things being equal, the escutcheon is indicative of the quantity and quality of milk. Many are misled in estimating the value of the escutcheon, because they have not the patience or the capacity to observe the varying conditions. The escutcheon is of immense practical value. It is easily seen the conditions of flesh do not change it, and animals of all ages, above three months, may be examined by it, and their milking qualities determined with a good degree of accuracy. Other things being equal, the animal with the better escutcheon will invariably make the butter maker. During nearly thirty years of observation, the writer never observed a first class cow that had a poor escutcheon. The escutcheon must be of great value to those who are breeding, and endeavouring to improve thorough-bred cattle of the various milking breeds. It offers a test that may be applied before milking age, and it may be applied to males as well as females. Though the pedigree is ever so long, and though it contains many good ancestors, the animal should be rejected from the breeding herd, unless it has a good escutcheon.”
“One of the Farmers,” a regular correspondent of the American Agriculturist, writes in the number for November, 1878:
“The Value of the Guenon Milk Mirror.—Taken with a good udder and milk-veins, good digestive functions, and capacity for food, good health and thrift, the Guenon milk mirror is a valuable indication of both the quantity and duration of the flow of milk. This seems to be demonstrated by the experience of thousands who have given the subject careful study, and I have never yet met the man who ridiculed it, and called it “folly,” who was able intelligently even to outline the prominent types. The number of calves which do well or ill as milkers, very nearly as indicated by their milk mirrors, is so large, that one of the principal practical uses to which a knowledge of the Guenon system can be applied is in selecting calves to raise, and, of course, to those who buy cows, it comes equally well in use.”