352 BOARD OF AGRICULTURE. [Pub. Doc. 



duce milk with 4 per cent of fat, and families and individual 

 cows of Holstein breed yield milk as rich as do many Jerseys 

 or Guernseys. 



Variations in the quality of milk are due to a variety of 

 causes. 



The substance showing the greatest variation is the fat, 

 while those remaining more nearly constant are the milk 

 sugar and the ash. The milk is generally poorest in quality, 

 i. e., contains the most water, for the first few weeks after 

 calving, and grows gradually richer till within a few months 

 before calving. As the cow becomes dry the solid matter 

 increases quite rapidly. With some cows the composition 

 of the milk remains nearly constant from the fourth week 

 until the end of the sixth month after calving, while with 

 others a gradual increase in richness is observed. Morning 

 milk is quite frequently poorer in fat than evening's milk. 

 This is largely due to the unequal periods between milkings. 

 As a rule, the shorter the time between milkings the richer 

 the milk in fat and vice versa. Cows milked three or four 

 times daily, produce milk richer in fat than those milked but 

 twice. The composition of a single cow's milk will vary 

 from day to day. Such variations are to be attributed to 

 effects of the weather conditions, environment, change of 

 food, etc. 



The quality of milk from different portions of the same 

 milking differs widely. The first part of the milk drawn is 

 poorest in fat and the last richest. 



Feed has no marked effect on the composition of milk. 

 This statement, however, needs to be qualified. An animal 

 that is poorly nourished, by receiving insufficient food or 

 food containing an excess of carbohydrates and a lack of 

 protein, will give milk of somewhat poorer quality than 

 animals normally fed. An excess of fat in the food will tend 

 to increase the fat in the milk, providing the animal is able 

 to digest and assimilate the fat. Feed appears to affect, to 

 an extent, the quality of the fat in the milk. Thus gluten 

 and linseed meals tend to make a softer oily fat, while cot- 

 ton-seed meal produces a hard fat. The other milk ingredi- 

 ents are but little changed. Certain foods also tend to impart 

 objectionable flavors to milk. 



