68 Report of Department of Animal Husbandry of the 



which has been longest used as a general guide gives for the 

 average cow in milk, per 1000 lbs. live weight 



24 lbs. total orgauic matter, 



15.4 lbs. total digestible organic matter, 

 2.5 lbs. total digestible pi'otein, 



12.5 lbs. total digestible carbohydrates; 



with a nutritive ratio of about 1:5.4 and a fuel value of about 

 30,000 Calories. 



These standards have been in large part drawn from averages. 

 Slight individual modifications have therefore been occasionally 

 desirable or without disadvantage. In practice, of course a close 

 conformity may often be unprofitable because of relative market 

 prices. The efficiency, however, of the modified standard ration 

 is the point for first consideration. 



While the results of only a few weeks under a ration will not 

 show its permanent sustaining power, they may perhaps suggest 

 the stimulating effects. To these are often attributed results 

 not fully explained by the knov/n utilization of nutrients in the 

 product and the work of its construction. It is thought that the 

 presence of a supply of protein considerably in excess of the 

 indispensable amount which can be directly accounted for, tends 

 to stimulate milk production. 



In feeding a dairy herd at this Station during several years the 

 common standards were followed in a general way. From the 

 daily records of this herd are drawn the data before referred to. 

 They represent both winter and summer feeding at different 

 times during seven years. Individual records were kept of the 

 food consumed, the changes in live weight and the milk yield. 

 Analyses were made of the foods and of the milk at regular inter 

 vals so that the amounts of the dift'erent constituents in the food 

 and in the milk have been calculated for each cow and averages 

 made from these data. The records for short periods selected for 

 use in these averages were taken at that stage of lactation when 

 only very moderate changes in the milk flow might be expected. 

 Of these limited-period, individual records, 981 have been used in 

 making the averages considered here. When grouped according 



