VARIATIONS IN Al 1 1.K. The richness of milk is to a certain extent an individual character istic: i.e. some individuals normally give rich milk, while others. for 110 apparent reason, give milk containing several per cent. more water. The richness of milk has been increased by do nu•stication, care, and breeding, mid certain breeds of cows, sheep. goats, ete., have been pro duced which give a characteristically rich milk. The quality also varies with the stage of lacta tion. The milk given early in the laetation period is usually poorer than that secreted and grows richer toward the close of the period until the anima] 'goes dry.' Young animals give poorer milk and les, of it than after the third o• fourth parturition, and the milk from the first, part of any milking is po(irer than the last part. or 'strippings.' The kind of food has little effect 011 the composition of milk, pro vided it is wholesome and the amount sufficient. Food influences the proportion of the different fatty :rids composing the fat. and so has an effect on the hardness and other qualities of but ter. But the rather prevalent notion that the milk fat. for instance, can be permanently in creased by feeding has been shown by much careful investigation to be it fallacy. Little is known of the physiological processes by which the constituents of the food are transformed into milk constitnents. in some eases there ap pears to be a direct transmissio' of the con stituents from the food to the milk, as is notice able when cows eat garlk. unions, etc. The ex periments of Jordan at the New- York State Kx ieriment Station have shown that milk fat is not derived solely from the fat of the food, for cows fed upon food from whiell the fills were prgetieally completely extracted continued to se crete milk of normal composition for long periods, and, judging from the maintenance of their weight, did not draw upon their body fat to sup ply this ingredient. l'mler the conditions of the
experiuileIltc, the carbohydrates seemed to be utilized to some extent in the elaboration of milk fat. The more the process of milk secretion is understood the more apparent it becomes that richness and the volume of the yield are individual characters, and if cows have a ten deney to give poor milk no amount of feeding will overcome it. The remedy lies in getting better cows. For general statements regarding the com position of the milk of different breeds of cows, :•4•1. UATTI E.
As an illustration of the variation of the milk of ordinary cows of mixed breeding, the data obtained by Van Slvke in New York from the analysis of the mixed milk of 15,000 cows each month from Slay to Oetoher may be cited. The total solids ranged from 11.1i to 13.91 and averaged 12.67 per cent., and the fat from 3.04 to 4.06 and averaged 3.75 per cent. The content of total solids and of fat was lowest during the summer months and increased in the fall. In the analysis of over three thousand samples of milk at the Massachusetts Experiment Station. the total solids varied from 10.02 to 19.55 and averaged 13.57 per cent., and the fat from 1.5 to 10.70 and averaged 4.32 per cent. The anal ysis of eight hundred samples made at the ex periment stations in different parts of the coun try varied in total solids from 9.3 to 19.7 per cent., averaging 12.S per cent.. and in fat from 1.7 to 6.5, averaging 3.7 per cent.