4() REpPorT oF DEPARTMENT OF ANIMAL HUSBANDRY OF THE 
EFFECT OF VARIATIONS IN RATION UPON THE MILK, 
Cow 12. Variations in Protein Supply. 
Milk Solids Fat 
Period. CHANGES IN RATION. yield in in 
daily. milk. milk. 
Jan. 380 to Feb. 6... Maximum protein fed (2.6 IbS. zpos. Perct. Perct. 
Cady ise che feces & oie Sle ise biaieleige't 6 a yusO enki p patt Ol enue 
Peb-16,10.16, ... «cues Maxininm Droteinded, ..e.creass 32.2 138.04 3.68 
Feb. 16 to 26....... Protein diminishing, carbohy- 
dratéesvinereasingaisiAt Soe 80.1. 13336 USLe2 
Feb. 26 to Mar. 8... Protein still diminishing, carbo- 
hydrates still increasing...... 28.4 13.37 3.87 
Mar. 8°to 18... 3356) Lrotem At “Minin (1:6 ibs: 
Aldity) pbs Veroe. suk$ qh? ave 26.0 13.47 4.01 
Mar. 18 to 28....... Protein increasing, carbohydrates 
CTLIUISTUIAY ES, Siero iste s o 0! cin erate eee 26.1 °° 13765) ue 
Mar. 28 to Apr. 7.. Protein still increasing, carbo- 
hydrates still diminishing..... 26.5 13.73 4.11 
25 0 Pil! $5 0 ee : Ea Re Protein at maximum (2.6 Ibs. 
Cally) * Pele. eerie wees aie eae 26.1 18.78 4.08 
Cow 10. Variations in Food Fat Supply. 
Jan. 30 to Feb. 6... Normal ration (fat fed daily, Lbs. Perct. Peret. 
evil Th Ogee Sips ot eee eheeee 22.00 i eee 
ep. 6 to, 13:3..8:..5 RAO INCUAN SEU 2. ee de cpsetee 22.8 14.20 4.74 
Feb, 13 -tovZ0ssn 5: ose Rationsunchenred 4 ..n.iee cet. 22:8 14,20 443710 
Feb. 20. to. 27.4% 0.0. bation: unchanged x ce. eee 23.5 18.90 4.46 
Feb.27 to Mar. 6... Food! fab inereasing nn. «a4 sae < 23.4 14.09 4.60 
Mar.6 to 1232... 2a. Food | fat at “maximum 266s 10s. 
UBILV) rats winds « ek AAA eden Ce ae dos oo. 1) eeieg eee 
Mar: 18 to 200h7.:..) Pood fat’ diminishing... 7%. ooeee 24.6 13.81 4.44 
Thre is nothing in these data to warrant the conclusion that 
Supplying more or less protein or more or less fat to a milch 
cow causes. material changes in the milk. In the case of Cow 
12 her milk suffered a gradual and quite constant increase in its 
proportion of solids and of fat, but this change was in no way 
disturbed in its progress by the fall or rise in the proportion of 
protein in the food. 
With Cow 10, the increase of the food fat to 1.4 Ibs. daily, a 
most abnormal quantity, did not raise the milk fat above what 
appeared to be the normal proportion. These results stand in 
accord with the outcome of many other carefully conducted 
investigations. 
The question whether entirely normal milk fat was produced 
with a fat-free ration, or nearly so, is an interesting one. The 
