CHAPTBE XXrV. 



THE DAIET COW — SOIENTIFIO FUTDINGS. 



611. Period of gestation. — " The average period of gestation for 

 the cow is 284 days; small cows, heifers with their first calf, and 

 old animals, usually go a day or two less; bulls are carried a day 

 or two longer than cow-calves." ' 



612. Economy of the dairy cow. — Not only is dairying the lead- 

 ing animal industry of our country at this time, but so it must 

 continue indefinitely, for the reason that the cow is a more econom- 

 ical producer of food for human beings than is the ox or the pig. 

 This is ably shown by Lawes and Gilbert' in the following table: 



Comparison of the constituents of food carried off in milk and in the 

 fattening increase of the ox — Lawes and Gilbert. 



(1 Imperial gallon = 4 quarts = 10.33 lbs.) 



Nitrog- 

 enous 

 sub- 

 stance. 



Fat. 



Non-nitro- 

 genous 



substances 

 not fat 

 (sugar). 



Mineral 

 matter. 



Total 

 solid 

 matter. 



In milk per week — C!ow. 



If 4 quarts 

 If 6 quarts 

 If 8 quarts 

 If 10 quarts 

 If 12 quarts 

 If 14 quarts 

 If 16 quarts 

 If 18 quarts 

 If 20 quarts 



per head, 

 per head, 

 per head, 

 per head, 

 per head, 

 per head, 

 per head, 

 per head, 

 per head. 



per day., 

 per day., 

 per day.. 

 per day., 

 per day., 

 per day., 

 per day.. 

 per day., 

 per day.. 



Lbs. 



9.04 

 13.56 

 18.08 

 22.60 

 27.12 

 31.64 

 36.16 

 40.68 

 46.20 



In increase in live weight per week — Ox. 



[f 10 pounds increase.. 

 If 16 pounds Increase.., 



7.26 

 10.88 



We are shown by the table that the fattening steer, gaining 

 15 pounds weekly, yields 1.13 pounds of nitrogenous substance or 



1 Sheldon, Dairy Farming. ' Jour. Roy. Agr. Soc, 1895. 



26 



