1114 EXPERIMENT STATION RECORD. 



to discover a means of diminisihing the difference in fat content between morning 

 and evening niilk when tlie intervals are unequal. Incidentally separate analyses 

 were made of the milk yielded by each quarter of the cow's udder. 



Five cows were milked at 6 a. m. and 3 p. m. during a period of 2 weeks. The 

 average fat content of the morning milk was 2.87 per cent, and of the evening milk 

 4.26 per cent, the ratio between the two being 1:1.484. During the 4 weeks follow- 

 ing the same cows were milked at 5.30 a. m. and 5 p. m. The fat content of the 

 morning and evening milk was, respectively, 3.18 and 3.80 per cent, the ratio being 

 1:1.195. During a third period of 3 weeks with the hours of milking the same as in 

 the tirst jieriod the percentages of fat in the morning and evening milk were, respec- 

 tively, 2.94 and 4.40, the ratio being 1:1.497. The results confirm the generally 

 accepted conclusion that the low fat content of morning milk as compared with 

 evening milk is due to unequal intervals ))etweeu milkings. Following a change 

 from unequal to aj)i)r()ximately equal intervals the difference in percentages of fat 

 gradually lessened. 



The attempt was made to improve the quality <if tlu^ morning milk by methods of 

 feeding, the intervals bi'tween milkings remaining unequal. Cows on pasture were 

 fed a grain mixture consisting of equal parts of cotton-seed meal and corn meal, one 

 grouji receiving 3 lbs. morning and evening, one group 6 1I)S. in the morning only, and 

 one group 6 lbs. in the evening only. The different methods of feeding did not alter 

 very much the relative yield of milk morning and evening. When the grain was 

 fed only in the morning the fat content of the morning milk was increased, from 

 wliich it would seem that where circumstances necessitate unequal intervals this 

 l)lan of feeding would lessen the danger nf tlie morning milk being below the 

 standard. 



The jiiilk from each (piarter of tiie udders of 2 cows was collected separately for 6 

 days and analyzed. The fat content showed no constant variations. In both cases, 

 however, the milk from tiieleft fore (juarter was much smaller in (jnantityand lower 

 in solids-not-fat than that from the other quarters. These results led to tests of the 

 herd of 19 cows, the average ivsults of which are given in the following table: 



Y'idd (tad qiuditi/ of tnilk Jro)ih diff'i'reid qu<trier>i of the udder. 



Solids- 

 not-fat. 



Per cent. 



Right fore quarter I 2.42 3.86 8.78 



Right hind <iuarter 2.47 3.96 8.63 



Left fore quarter 1.85 3.84 8.45 



Left hind quarter 2.50 3.85 8.71 



"The variation in fat in milk from different quarters of the udder is perhaps not 

 surprising when we remember that the fat is ajjparently produced by the breaking 

 down of fat cells in the gland itself; but that different glands, or different parts of 

 the same gland, should be able to elaborate, from the same blood supply, products 

 of different concentration in dissolved matter, appears to the writer to be very 

 remarkal>le. The results should certainly prove of interest to the physiologist, though 

 they perhaps have little practical importance from a dairy point of view." 



Ayrshire herd, tests, F. W. Morse {Neie Hampshire Sta. Bnl. 96, pp. 117-121).- — 

 Tests of Ayrshire cows have been conducted by the station since 1894, some of the 

 data being given in tabular form. The tests made during 1901 and 1902 show a range 

 in the percentages of fat from 3.48 to 4.40, with an average of 3.88 per cent, and a 

 range in the total solids from 11.71 to 13.27, with an average of 12.55 per cent. The 

 author concludes that some of the herds are developing the quantity of milk at the 

 exj)ense of (juality. Of 21 cows tested during the year, 15 gave the maxinnmi fat 

 test in the first month, and 13 the maximum yield of milk in the second month. 



