DAIRY FARMING DAIRYING. 1005 



"(2) During the time when the decrease in body weight takes place cows yield 

 dairy pro(hict in excess of the amount provided for by the food consumed, the 

 excess of yield depending upon the rate of loss in weight of body. In some instances 

 it is more than twice the amount provided for by the available nutriment. 



"(3) The excess yield of dairy products gradually decreases until al)out the 

 eleventh week, when an ecjuilibrium generally obtains between the nutriment con- 

 sumed and dairy products yielded, though in this respect cows differ; those of a 

 pronounced dairy temperament taking less time, while those not strong in dairy 

 temperament decrease more slowly in weight and require more time to reach normal 

 work in milk production. Before such equili))rium is reached the body fat and pos- 

 sibly other substances contribute directly or indirectly to jjroduct. 



" (4) The normal net nutriment requirements to a pound of butter fat is approx- 

 imately 6.25 lbs., with a slight increase by cows yielding milk containing a low per 

 cent of butter fat, and less with cows giving milk containing a high per cent of but- 

 ter fat. 



"(5) The normal net nutriment I'ecjuirements to a pound of milk solids yielded is 

 approximately 2.4 lbs., with a slight increase with cows yielding milk rich in butter 

 fat and less with cows giving milk containing a low per cent of l)utter fat. 



" (6) When the daily nutriment available for product and the products yielded 

 daily are reduced to an approximate common value of energy, it is found that it 

 requires about l.To lbs. of availal)le nutriment to 1 lb. of product; that is, of the 

 available nutriment, 4:5 per cent is expended ni energy and 57 per cent is returned 

 in the milk solids. 



" (7) The daily yield of butter fat in excess of the nutriment supply, by virtue of 

 an average daily loss per cow of 2 lbs. in body weight, was 0.28:5 lb., being a sacri- 

 tice of 7 lbs. in body weight to 1 lb. of butter fat yielded in excess of that ])i-o\ided 

 for in the ration. 



"(S) AVhen the normal working condition of body weight is reached the nutri- 

 ment required to a pound of butter fat and a pound of milk solids remains (piite 

 constant for an indefinite time under proper management." 



A study of rations fed to milch cows in Connecticut, C. 8. Piieij-s {Onmccti- 

 cut Starrs Sfa. Ixpt. 1901, pp. SI- 104). — This work was begun in 1892 and has been 

 reported upon from time to time (E. S. R., 13, p. 983). The objects have been to 

 study the rations in use by farmers, to offer suggestions for the improvement of such 

 rations, and to study the economy of feeding according to the yields of butter fat. 

 During the 7 years previous to 1900, 37 studies were made, the results of which 

 sliowed that too little attention has been paid to the proportion of protein used in 

 feeding cows and too little effort has been made to feed according to the productive- 

 ness of cows. The work during 1900 and 1901 related to feeding according to the 

 yields of butter fat, and is summarized by the author as follows: 



' ' Four herds of cows were studied during the winter of 1900-1901. Two tests were 

 made with each herd, covering periods of 12 days each in all except one test, which 

 lasted 11 days. 



"In the first test the entire herd was fed the ration in use by the dairyman, which 

 usually was nearly the same for all cows of the herd. The amount of protein in the 

 ration varied for the different herds from 1.75 to 2.40 lbs. per cow per day. 



"In the second test the ration was varied according to the yields of butter fat pro- 

 duced in the first test. Two grain mixtures were used in this test; the lirst was 

 included with the coarse fodders in what was called a basal ration, which was 

 planned to contain about the same amount of protein as the average ration used in 

 the first test; the second grain mixture, called a protein mixture, was chiefly made 

 up of concentrated nitrogenous grain feeds, combined in such proportions as to fur- 

 nish in the different cases 0.2 and 0.3 lb. of protein for each pound of the mixture. 

 The plan of feeding in this test was to use the basal ration uniformly for all cows in 



