130 MASS. EXPERIMENT STATION BULLETIN 236 



This applies to all hay, silage and grain. The feed derived from pastures 

 is not readily measurable in weight. Hence, no formula for its net ther- 

 mal equivalent per ton can be applied. However, pasturage largely takes 

 the place of hay and silage during certain months of the year, and the 

 proportion of the year during which the cows are on grass is known quite 

 accurately. It is also possible to estimate fairly closely the amount of hay 

 and corn fodder fed to cows during the jiastiire season. The feed value of 

 the pasture is then taken to bear the proportion to the value of the hay 

 plus silage used in the non-pasture months that the milk actually produced 

 during the pasture season bears to the milk produced during the rest of 

 the year, due allowance being made for the limited use of cut roughage 

 during the pasture months. L^ncut green feed, such as aftermath, is thus 

 included with the pasture grass. 



Data Available 



Data are available through the Statistical Division of the New England' 

 Milk Producers Association which show the average amount of hay, silage 

 and grain used throughout the year per hundred pounds of milk, and the 

 relative amount of each kind of grain used both in summer and winter. 

 This information is secured from reports made by dairymen in all sections 

 o1' New England excepting Rhode Island and western Connecticut. These 

 reports follow field surveys conducted in 1917 by certain war-time public 

 agencies acting in cooperation with the New England agricultural colleges, 

 the results of which were published by the Boston Chamber of Commerce. 

 The Census supplies data on hay production by counties which afford a 

 good basis for estimating the extent to which certain counties in southern 

 New England depend upon hay brought in from the outside. Observation 

 of the industry shows that in counties in which the total hay production 

 is less than four tons per head of dairy cows, some hay is brought in fron; 

 other regions. Since such shipments are to but very limited extent made 

 from other parts of the same state, it is assumed that each county which 

 produces less than four tons per head of dairy cows makes up the deficit 

 b\ shipping in hay from outside of its state. 1 New England as a whole, 

 however, has sufficient hay for her dairy industry and most of the ship- 

 ments of hay are from the northern to the southern states of this district. 

 Accordingly, in computing the New England average, it is assumed that 

 all the hay used in the dairy industry is home grown. 



Data on the proportion of milk produced in each month are now avail- 

 able for each state through the New England Crop Reporting Service. 

 These data are of service in computing the relation of the feed value in 

 the pasturage to the feed value in other roughage. 



Process of Estimate 



Table 1 shows the pounds of each main class of feeds, except pasturage, 

 used per hundred pounds of milk produced, as an average for each state 

 (except Rhode Island) in the year 1923. 



1 While this is four tons of hay per cow, it is clear that young stock and horses shares 

 in the use of the hay and that each cow consumes a supply of less than four tons.. 



