CHAPTER XXIV. 



THE DAIRY COW— SCIENTIFIC FINDINGS. 



I. Studies of Animal, Feed, and Water. 



588. Gestation period.— Wing of the New York (Cornell) Sta- 

 tion^ found the average of 182 recorded gestation periods for the 

 cow to be 280 days, ranging from 264 to 296 days. About an equal 

 number of births occurred on each day from the 274th to the 287th 

 inclusive. The gestation period was not different for the sexes, 



589. Birth weight of dairy calves. — Beach of the Connecticut 

 (Storrs) Station- found the birth weight of calves from mature cows 

 of the dairy breeds to be as follows: 



Birth weight of calves of the dairy breeds. 



wt. of calf 

 to dam 



Holstein. 

 Ayrshire. 

 Guernsey 

 Jersey - . . 



Per cent 

 9.0 

 8.0 



7.7 

 7.4 



590. Economy of the dairy cow. — The following table, adapted 

 from Lawes and Gilbert,'* compares the economy of the cow and the 

 ox in converting the products of the fields into human food: 



Relative returi 



the cow and the fattening ox in one weeh. 



Weekly returns from cow when yielding : 



10 lbs. milk daily 



20 lbs. milk daily 



30 lbs. milk daily 



40 lbs. milk daily 



50 lbs. milk daily 



Weekly returns' from ox when gaining: 



10 lbs. weekly 



15 lbs. weekly 



Protein 



Lbs. 



2.56 



5,11 



7,67 



10.22 



12,78 



0,75 

 1.13 



Lbs, 



2.45 

 4.90 

 7,35 

 9.80 

 12.25 



6,35 

 9,53 



Carbohj'^- 

 drates 

 (sugar) 



Lbs. 



3.22 



6,44 



9.67 



12.89 



16,12 



Mineral 

 matter 



Lbs, 



0,52 

 1,05 

 1,57 

 2.09 

 2.61 



0.15 

 0.22 



Total dry 

 matter 



Lbs. 



8,75 

 17,50 

 26,25 

 35.00 

 43.76 



7,25 



10,88 



Bui. 162, 



Ept. 1907. 



■ Jour, Roy. Agr. Soc, Eng,, 1895. 



