THE HOG I mm BTR1 . LOO 
These reYolts favor the stock food in aboul the same proportion as 
in the IowaYest. 
DAIRY BY-PRODUCTS. 
The use of the by-products of the dairy and creamery (skim milk, 
buttermilk, and whey) is one of the most interesting subjects of 
study in pork production. The value of the milk is known on every 
farm, although it may Dot !>»' fully appreciated, and anyone who has 
fed pigs knows tin 4 keen appetite that these animals have for milk 
and its products. In the neighborhood of many large dairies pork 
production has become a very prominent and lucrative branch of the 
dairy industry. 
Regarding solely their chemical composition, the by-products of 
the dairy contain most of the indispensable feeding constituents of 
the milk from which they are produced. 
The residue from the separation of cream (skim milk) and that 
from churning (buttermilk) leave two products that contain practi- 
cally all the protein and carbohydrates of the whole milk. In cheese 
making, the whey that is left is the least valuable of the dairy 
by-products, the greater part of the casein and fat of the milk being 
retained in the cheese. While whey is by no means worthless for 
feeding purposes, it can readily be seen that if skim milk and butter- 
milk have higher feeding values for pigs than whey, butter making 
and pig feeding will more profitably accompany each other than will 
cheese making and pig feeding. These bj^-products supply growing 
material to young animals and provide an excellent nitrogenous 
balance in the fattening ration. The constituents that remain in the 
milk after skimming and churning are the most expensive ones, con- 
sidered from the standpoint of feeding and fertilizing value, and it is 
largely due to this fact that dairy farming is so often a profitable 
business when conducted in a thorough manner. 
The value of dairy by-products is not alone in their nitrogenous 
character. They have an effect on the digestion that brings results 
out of all proportion to their nutritive value. Where pigs have been 
for a long time on a monotonous ration, such as corn meal alone, they 
lose appetite, become listless, and sick, and so make very unsatis- 
factory gains. If skim milk is given, even in very small amounts, 
an immediate change for the better is noticed — appetite returns and 
the pigs begin to gain rapidly in weight. As already stated, the gain 
in weight is out of all proportion to the actual amount of nutrient 
material in the milk, and this peculiarity has been remarked upon, 
not only when pigs are fed as indicated above, but also when pigs are 
fed a varied grain ration and skim milk in comparison with others 
on the grain ration only. Just why dairy by-products have this 
effect is not exactly known, but the suggestion has been made that 
