FEEDING DAIRY CATTLE 233 



by a decrease in milk flow and an increase in the fat content; in 

 cases of severe illness, the percentage of butter fat in the milk, will, . 

 however, be abnormally low. Cows in heat, or handled roughly, 

 chased by dogs, or excited through other causes, will, as a rule, give 

 a greatly diminished amount of milk, which will test very high. 



Temperature and Weather. Both excessively high tempera- 

 tures and cold, heavy rain storms are likely to cause a marked 

 decrease in the percentage of butter fat in the milk. Periods of 

 drought, according to Van Slyke, cause a decrease in the flow of 

 milk and in the contents of casein and albumen, especially the 

 latter, while either no change or an increase in the percentage of 

 butter fat will occur. 6 



Season of Year. The percentage fat content of milk appears 

 to be subject to certain seasonal influences that are independent of 

 the stage of lactation period, the breed of cows, or the system of 

 feeding. The lowest fat content of the milk will, in general, occur 

 during hot weather, in June or July, and from this time on a regular 

 increase occurs, which reaches. its maximum in December or Janu- 

 ary, and a general gradual decrease then takes place until toward 

 midsummer. 7 This seasonal influence appears to depend on the 

 temperature of the air, and is, therefore, to be expected from what 

 was said in the preceding paragraph. 



'Grooming and Exercise. Grooming and moderate exercise 

 stimulate the circulation and tend to cause a slight increase in the 

 milk production and in the percentage of butter fat in the milk. 

 Eesults of German experiments on this point 8 are somewhat more 

 favorable than those of experiments conducted in this country. 9 

 The effect of grooming on the health of the animals and on the 

 condition of the milk are, however, important factors. In dairies 

 producing certified or sanitary milk the cows are curried and 

 groomed regularly, and udders and hindquarters are washed. This, 

 doubtless, is an effective means of promoting the health of the herd 

 and lessening the bacterial content of the milk. 



Influence of Feed on Quality of Milk. Contrary to the 

 opinion held quite generally by dairy farmers up to recent years, 

 the feed does not exert any marked influence on the quality of 

 the milk secretion, so long as the cow receives sufficient nutriment 

 in her ration to maintain her body weight. Given fair amounts 



6 Geneva (N. Y.) Bulletin 68; see also Wisconsin Report, 1895, p. 111. 



7 See Eckles, Milchw. Zentralbl, 1909, p. 488 ; Thorndike, Gue. Br. Jr., 

 1913, p. 35; Storrs (Conn.) Bui. 94. 



8 Jr. /. Landw., 41 (1893), p. 332. 

 "Vermont Report, 1899, 1900. 



