80 PRINCIPLES OF FEEDING FARM ANIMALS 



to equal a pound of mixed grain in nutritive effect, while in the case 

 of a poor quality of this hay it will take 3 pounds to equal a feed 

 unit, etc. 



The value of pasture may vary between 6 and 12 units per day, 

 according to the production of the cows and the kind and the con- 

 dition of the pasture. The former figure may be applied in case 

 of dry cows, or for scant or largely dried-up pastures; the latter 

 for heavy-producing cows on luxurious pasture. 



A simple example will readily explain the application of the 

 system. We will suppose that a cow ate 750 pounds of hay, 150 

 pounds of wheat bran, and 90 pounds of ground corn during a cer- 

 tain month. 



The cow consequently received 750 divided by 2.5, or 300 feed 

 units in the hay eaten; 



150 divided by 1.1, or 136 feed units in the bran, and 



90 feed units in the corn, 



making a total feed consumption of 526 feed units for the month. 

 If she yielded 30 pounds of butter fat during the month on this feed, 

 she produced 30 -r- 5.26, or 5.7 pounds of butter fat per 100 feed 

 units. 



By the use of the unit values given, the feed consumption of in- 

 dividual cows for an entire year may be obtained and compared 

 with their production, thus enabling a farmer to determine whether 

 a cow is a sufficiently high and economical producer to remain in 

 the herd, and the net returns for the feed which each cow in the herd 

 has yielded. It also makes it possible to compare the results obtained 

 in different herds, and furnishes valuable data for studies of the 

 relation of feed to dairy production. 



The Feed-Unit Standard. The following feeding standard for 

 dairy cows, according to the feed-unit system, has been proposed by 

 Hansson, of the Royal Swedish Academy, for a 1000-pound cow per 

 day: 



For maintenance, 0.65 pound digestible protein and 6.6 feed units. 

 For production, 0.045 pound to' 0.05 pound digestible protein and y 3 

 feed unit per pound of milk. 1 



Example. A 1000-pound cow received 30 pounds silage, 8 

 pounds clover hay, 3 pounds corn meal, and 3 pounds gluten feed. 

 How many feed units does she receive in her feed, and how many 

 units are required per 100 pounds of milk and per pound of butter 

 fat ? How much digestible protein and how many feed units should 

 she receive according to the feed-unit standard ? 



1 " Kontrolforen. Arbetsfalt," Stockholm, 1910. 



