26 MASS. EXPERIMENT STATION BULLETIN 428 



important to the consumer since it is a particularly valuable food which is con- 

 sumed in such large amounts that a great deal is imported from other areas to 

 supplement that produced in Massachusetts. Obviously many factors affect 

 the vitamin content of milk, but recently attention has been largely centered 

 upon the influence of the ration and the effect of sunshine on cow's milk and a 

 study has been made of the vitamin content of goat's milk collected from numer- 

 ous areas of the State. 



The Ratio of Ascorbic. Nicotinic, and Pantothenic Acids, Riboflavin, and Thia- 

 mine in Late Summer Milk. (Arthur D. Holmes, Carleton P. Jones, Anne W. 

 Wertz, Katherine Esselen, and Beula V. McKey ) The milk used in this study 

 was produced by the college herd of Ayrshire, Guernsey, Holstein, Jersey, and 

 Shorthorn cows in the late summer when the pasture grasses were fully mature, 

 but before severe frosts had affected their quality. The pasture ration was 

 supplemented with ground grains (14 percent) at the rate of one pound for each 

 six pounds of milk the cows produced. Fifteen samples of milk, which represented 

 IS days' production, were assayed. The values obtained varied somewhat from 

 day to day, but averaged ascorbic acid 18.4 mg., nicotinic acid 1.1 mg., panto- 

 thenic acid 3.66 mg., riboflavin 1.37 mg., and thiamine 0.44 mg. per liter. Judged 

 by the dietary allowances recommended by the National Research Council, such 

 milk would have to be fortified with ascorbic and nicotinic acids to meet the 

 recommended allowance for infant feeding. 



Effect of Sunshine upon the Ascorbic Acid and Riboflavin Content of Milk. 

 (Arthur D. Holmes and Carleton P. Jones.) It has long been known that sun- 

 shine or strong light tends to destroy ascorbic acid and riboflavin Accordingly, 

 it appeared desirable to determine the extent to which sunshine might reduce the 

 nutritive value of milk by destroying these vitamins. Similar studies had been 

 reported from other laboratories, but unfortunatel}- the authors did not measure 

 the sunshine to which their samples of milk were exposed. Accordingly, milk 

 produced by the college herd was exposed to the action of sunshine for two 

 30- or two 60-minute periods in J^ pint commercial milk bottles. The intensity 

 of the sunshine was measured with a pyrheliometer equipped with an automatic 

 recording device The "sunshine" varied from a total of 4.8 gm. cal. per sq. cm. 

 on a rainy day to 144.6 gm. cal. per sq. cm. on a bright day. The temperature 

 of the milk varied from day to day depending upon the velocity of the wind, 

 greenhouse effect of the milk bottles, and intensity of the sunshine. The destruc- 

 tion of reduced ascorbic acid was verj' rapid. Little, if any, was present after 

 30 minutes' exposure. The riboflavin disappeared more slowly. A 10 percent 

 loss occurred during 60-minutes' exposure on a rainy day and 85 percent dis- 

 appeared during exposure to bright sunshine for 120 minutes. These data show 

 that milk allowed to stand for more than a short period on the consumer's door- 

 step exposed to strong light or sunshine, is likely to lose a large amount of its 

 ascorbic acid and riboflavin. 



The Vitamin Content of Commercial Winter Goat's Milk. (Arthur D. Holmes, 

 Harry G. Lindquist, Carleton P. Jones, Anne W. Wertz, Katherine Esselen, 

 Beula V. McKey, and Evelyn Fuller.) It has been estimated that the retail 

 value of goat's milk produced in this country exceeds $100,000,000 annually. 

 A large portion of the fluid milk is used for infants, for invalids, and for consump- 

 tion in the home of the producer. However, a review of the literature revealed 

 very little information on the vitamin content of goat's milk. Accordingly, 18 

 samples of raw goat's milk from various localities within 100 miles of Amherst 

 were assayed. Data were collected concerning the breed of the goats, their age 

 and stage of lactation, and their ration. The average values obtained were fat 



