486 



NUTRITION OF FARM ANIMALS 



out for eight hours every day without regard to the weather but with 

 some shelter from the wind. The cows consumed feed ad libitum. 

 The exposed lot ate much more grain but somewhat less hay than 

 the sheltered lot and produced 161.1 pounds more milk. No proof of 

 the comparability of the two lots is given. 



Brooks 1 exchanged two lots of cows between an artificially heated 

 stable kept at 55 F. and a cooler, unheated one, the temperature of 

 which is not reported. Rather more milk was produced in the warm 

 stable but its percentage of fat was lower. 



Richards and Jordan 2 recorded the milk yield of a number of cows 

 upon uniform feed in alternate periods in which the stable tempera- 

 ture was maintained, respectively, at about 45 and 55 F. More 

 milk was produced in three cases out of four and more butter fat in 

 two cases out of four at the higher temperature. 



Spier 3 reports experiments at four farms, on a total of 88 animals 

 upon the relation of stable temperature and ventilation to milk yield. 

 He calls attention to the fact that both these factors are involved in 

 experiments upon the influence of shelter. The following table shows 

 the results obtained in two specially cold periods as compared with 

 the average of warmer preceding and following periods and likewise 

 the average results for the entire experiments. The average rations 

 consumed are stated but there is no record of actual feed consumed 

 during the several periods nor of the live weights of the animals. 



TABLE 128. INFLUENCE OF VENTILATION AND STABLE TEMPERATURE 

 ON MILK PRODUCTION 



1 Mass. (Hatch) Expt. Sta., Rpt. 1895, p. 39. 



2 Wis. Expt. Sta., 2ist Rpt., 1903-1904, p. 143. 



3 Jour, of Highland and Agr. Soc., 1909, pp. 255-306. 



