1897.] 



PUBLIC DOCUMENT — Xo. 33. 



109 



their cows during a period of lactation. Only by such a 

 course can the unprofitable cows be weeded out, and the herd 

 brouorht to a higher standard. The scales and the Babcock 

 tester are necessary ; mere guess will not accomplish it. 



Table IV. — A^jproximate Estimate of the Amount and Value 

 of Fertilizer Constituents in Excretions of the 6 Cows. 



Percentage increased value of narrow over Avide ration, 



$19 20 



For the sake of comparison, by figuring the value of the 

 nitrogen, phosphoric acid and potash contained in the feeds 

 consumed (less 20 per cent, for the amount retained in the 

 system or otherwise lost) by the market cost of these 

 several ingredients per pound, it will be seen that the 

 manure from the narrow ration has 20 per cent, more value 

 than that from the wide ration. The cause of the increased 

 value lies naturally in the increased amount of nitrogen 

 present. In case of the rations fed in these experiments, 

 the fact that the wide ration has more potash than the narrow 

 is because gluten meal, which served to increase the protein, 

 contains but minimum amounts of this ingredient. If cotton 

 or linseed meal had been used in place of the ghiten meal, 

 the reverse would have been true. While the so-called 

 narrow rations as used in these experiments were extreme 

 ones, it might be said that narrow rations which contain 

 from 2 to 2.J pounds of digestible protein in a day's feed, 

 aside from their causing a 10 per cent, increase in the milk 

 yield, furnish in addition a manure from 10 to possibly 15 

 per cent, more valuable than do wide rations. 



While nan'ow rations will unquestionably produce more 

 milk and butter than wide rations, the relative cost of the 

 milk and butter produced by the two rations will depend 



