FEEDING STANDARDS CALCULATING RATIONS 131 



grain and bran, 708 units; roots and beet pulp, 1,166 units; hay and 

 straw, 1256 units; and soiling crops and pasture, 1,294 units. The 

 average production of milk for the year was 7,429 Ibs. and of butter fat 

 239.9 Ibs. For each 100 feed units consumed, the cows produced on the 

 average 140.7 Ibs. of milk, containing 4.5 Ibs. butter fat. 



The cows in the association having the best returns were fed 5,733 

 feed units per cow for the year and produced on the average 8,650 Ibs. 

 milk, containing 295.2 Ibs. butter fat. The cows in the poorest associa- 

 tion received an average of only 4,920 feed units, and their average yield 

 was but 6,261 Ibs. milk and 200.0 Ibs. butter fat. The cows in the best 

 association produced 5.1 Ibs. butter fat from 100 feed units, while those 

 in the poorest association, which were fed less liberally and probably 

 also were of lower productive capacity, yielded only 4.1 Ibs. butter fat 

 for each 100 feed units consumed. The best herds thus produced 1 Ib. 

 more butter fat from 100 feed units consumed than did the poorer 

 herds a difference of over 24 per ct. in favor of the heavier feeding 

 and better cows. 



These results show the manner in which Scandinavians have utilized 

 the feed-unit system for comparing individual cows, herds, and associa- 

 tions to the great betterment of their dairy industry. The same compari- 

 sons can be made by means of the Armsby system of net-energy values. 

 Except where the rations fed to different animals vary widely in pro- 

 portion of concentrates to roughages, a fair comparison may also be 

 made by using the total digestible nutrients in the ration, as given for 

 each feed in Appendix Table III. 



181. The feed-unit standard for dairy cows. Hansson 15 has proposed 

 the following standard for dairy cows, according to the feed unit 

 system : 



Hansson feeding standard for dairy cows 



Digestible 



Dry matter protein Feed units 



Lba. Lbs. 



Maintenance of 1,100-lb. cow 17.6-24.2 0.72 7.3 



1,100-lb. cow yielding 11 Ibs. milk 19 . 8-28 .7 1 . 10 11.0 



1,100-lb. cow yielding 22 Ibs. milk 22.0-33.1 1.65 14.6 



1,100-lb. cow yielding 33 Ibs. milk 24 . 2-35 .3 2 . 20 18 . 3 



1,100-lb. cow yielding 44 Ibs. milk 26.4-37.4 2.76 22.0 



This standard fails to take into consideration the fact that the feed 

 requirements of a dairy cow depend not only on the amount of milk 

 produced, but also on the quality of the milk; i. e., its richness in fat. 

 It is therefore less accurate when applied to animals of different breeds 

 than the modern American standards. (174, 182, 183, 184, 185, 189) 



VII. AMERICAN STANDARDS FOR DAIRY Cows 



182. The Haecker standard. As the result of long years of intimate 

 study with a high-grade working dairy herd at the Minnesota Station, 18 



"Utfodringslara, 1916, p. 707. "Minn. Buls. 71, 79, 140. 



