FEEDING OF ANIMALS. 



315 



crease, and on the other for the production of milk. But, as 

 not only do cows of different breeds yield different quantities 

 of milk, and milk of characteristically different composition, 

 but individual animals of the same breed have very different 

 milk -yielding capacity ; and whatever the capacity of a cow 

 may be, she has a maximum yield at one period of her lacta- 

 tion, which is followed by a gradual decline. Hence, in com- 

 paring the amounts of constituents stored up in the fattening 

 increase of an ox, with the amounts of the same constituents 

 removed in the milk of a cow, we must assume a wide range 

 of difference in the yield of milk. 



Accordingly, Table 73 shows — the amounts of nitrogenous Table 73 

 substance, of fat, of non -nitrogenous substance not fat, of explained. 



TABLE 73.— Comparison of the Constituents op Food carried 

 off in Milk, and in the Fattening Increase of Oxen. 



[1 Gallon = 10. 33 lb.] 



Nitro- 

 genous 



sub- 

 stance. 



Fat. 



Non-nitro- 

 genous 



substance 

 not fat 

 (sugar). 



Mineral 

 matter. 



Total 



solid 



matter. 



IN MILK PER WEEK. 



IN INCREASE IN LIVE-WEIGHT PER WEEK.— OXEN. 



If 10 lb. increase 

 If 15 lb. increase 



0.75 

 1.13 



6.35 

 9.53 



0.15 

 0.22 



7.25 

 10.88 



mineral matter, and of total solid matter, carried off in the 

 weekly yield of milk of a cow, on the alternative assumptions 

 of a produce of — 4, 6, 8, 10, 12, 14, 16, 18, or 20 quarts per 

 head per day ; and, for comparison, there is given at the 

 bottom of the table, the amounts of nitrogenous substance, of 

 fat, of mineral matter, and of total solid matter, in the weekly 

 increase in live-weight of a fattening ox, of an average weight 

 of 1000 lb. — first, on the assumption of a weekly increase of 

 10 lb., and, secondly, of 15 lb. 



The estimates of the amounts of constituents in the milk Percentage 

 are based on the assumption that it will contain 12.5 per ^f*l M " 

 cent of total solids, consisting of 3.65 albuminoids, 3.50 mUk. 



