New York Agricultural Experiment Station. 97 



In this plan we think we have maintained as- nearly as possible 

 constant conditions with respect to all factors involved, except the 

 soluble bran constituents which were purposely changed at the end 

 of the first and fifth periods and the addition of calcium phytate in 

 Period IV. The salient points in the plan of the experiments are: 

 a large decrease of total phosphorus, including soluble organic phos- 

 phorus and inorganic phosphorus; a decrease of magnesium and of 

 potassium in the rations at the end of the first period, and an increase 

 of calcium and phosphorus during the fourth period. This made 

 the first and fourth periods high in phosphorus intake, and the 

 others low, and the fourth distinguished from the first by having 

 calcium phytate added to a ration, otherwise low in phosphorus. 



THE EXPERIMENT IN PROGRESS. 



In regard to the details, the management of the experiment was 

 as like that reported in Technical Bulletin No. 1 of this Station, 

 page 5 et seq., as it could practically be made. The division between 

 the days was made at seven o'clock in the morning. The cow was 

 milked twice a day instead of three times. The attendants for the 

 cow were the same men as were employed for this purpose in the 

 previous experiments. 



The components of the rations were separately mixed and weighed 

 into paper bags, at which time the samples were taken. The oat 

 straw was a baled article purchased in the local market. Two 

 separate batches of straw were used, the first (F6) lasting from 

 April 11 to Tune 2, the other (F14) from June 3 to the end of the 

 experiment. These differed somewhat in their analysis, as is shown 

 in Table 1. (Large quantities of wheat bran were extracted with 

 water and 'dried (F5). The original bran (F2) contained 1.48 per ct. 

 of total phosphorus, of which 73 per ct. of the phosphorus was 

 soluble in 0.2 per ct. hydrochloric acid; the washed bran (F5) used 

 in the second period had a total phosphorus content of 0.326 per ct. 

 This latter bran was later rewashed (Fll, F12, F13) and the phos- 

 phorus reduced to only 0.123 per ct.; this was used in the last three 

 periods. The rice was of good quality, well polished and therefore 

 low in ash constituents. It was ground in a local mill and weighed 

 up at three different times (F7, F9, F15). The analyses of the 

 samples agreed well with one another, and the values used are an 

 average of the three. The wheat gluten was weighed up from two 

 lots (FIO, F36), the latter being introduced in the fifth period. It 

 contained a little more moisture and calcium phosphate but did not 

 differ enough from the first to affect the problem materially. The 

 largest discrepancies introduced by the renewal of the components 

 of the rations are those in the straw, which in terms of grams per 

 day are: Total phosphorus 0.63, soluble phosphorus 0.36, inorganic 

 phosphorus 1.45. 



