EFFECT OF WATER IN THE RATION ON THE 

 COMPOSITION OF MILK 



By W. F. Turner, R. H. Shaw, R. P. Norton, and P. A. Wright, of the Dairy 

 Division, Bureau of Animal Industry 



INTRODUCTION 



Experiments conducted at Brownsville, Tex., by the Dairy Division 

 of the Bureau of Animal Industry indicate that the feeding of prickly- 

 pear (Opuntia spp.) lowers the percentage of fat in milk. In comparison 

 with other feeds prickly-pear contains a large amount of water and 

 mineral matter. It was thought by the writers that one or both of these 

 constituents might be responsible for the reduction in fat percentage; 

 consequently experiments were conducted at Beltsville, Md., to deter- 

 mine the influence of the water. Work with the mineral matter is now 

 in progress. 



The literature dealing with the effects of watery feeds or water in the 

 ration upon the quantity and the quality of milk produced contains 

 many conflicting statements. No doubt the difficulty of eliminating all 

 factors except the watery character of the ration is largely responsible 

 for the conflicting nature of these statements. 



Gilchrist (i)^ reports very little difference, if any, in quantity and 

 quality between the milk produced by cows either on pasture only or 

 on a daily ration of mangels in varying amounts up to 86 pounds per 

 cow and that produced by the same cows on a ration of hay and grain. 



Tangl and Zaitschek (12) state, as the result of extensive experiments 

 to determine the influence of watery feeds on milk secretion, that there 

 is no difference between the composition of the milk from cows fed on a 

 watery ration and that from cows fed on a dry one. They state that it is 

 not true that watery feeds cause the production of thinner milk than 

 dry feeds. 



Lauder and Fagan (10, p. 9) reached the following conclusions from 

 experiments extending over a 3-year period, using 60 cows and feeding a 

 large ration of turnips {Brassica rapa) to compare with a dry or concen- 

 trated ration : 



The feeding of a ration containing a large quantity of water does not increase the 

 percentage of water in the milk or reduce the percentage of fat. 



The greater yield of milk was obtained from the cows on the concentrated ration. 

 On the other hand, the milk from the cows on the turnip ration contained a higher 

 percentage of fat, and a greater total weight of fat was secreted in the milk. 



' Reference is made by number to " Literature cited," p. 177-178. 



Journal of Agricultural Research, Vol. VI. No. 4 



Dept. of Agriculture, Washington, D. C. Apr. 24, 1916 



di A— 21 



(167) 



