CARE OF DOMESTIC ANIMALS 483 



basins, it is pure, but when it remains long in these, in a 

 stagnant condition and without renewal in the supply, its 

 purity lowers, unless in cold latitudes. Motion is necessary 

 in water under normal conditions in order to maintain its 

 purity. Of the sources of supply named, water obtained 

 from artificial basins or ponds, as they are sometimes called, 

 in which large numbers of animals are allowed to drink 

 from time to time, is the most impure. Such water will 

 not furnish good flavored milk when drunk by cows, and 

 it is prejudicial to the health of sheep. The same is true 

 of water in basins into which the soakage of or seepage 

 from barnyards finds its way. Nor is the stagnant water 

 which collects in marshes wholesome in hot weather, and es- 

 pecially late in the season. Such water is especially injurious 

 to sheep, since it seems favorable to the growth of parasites 

 which prey upon them. Swine seem to be less injured 

 by impure water than other animals, but unquestionably 

 pure water is best for them also. They are oftentimes 

 greatly wronged by the impurities in the water given to 

 them. 



Amount of water required. The amount of water re- 

 quired by animals is influenced : ( I ) By the character of the 

 food; (2) by the nature of the weather; (3) by the copious- 

 ness of the dews and (4) by the nature and extent of the 

 performance. Sometimes these influences act singly, but 

 more commonly they act more or less in conjunction. 



Food influences the consumption of water more 

 through the presence or lack of succulence than in any 

 other way. But the proportion of protein in the food, it is 

 thought, exercises some influence, and the same is unques- 

 tionably true of salt. Salt increases the circulation of the 

 juices of the body and thus favors increase in protein con- 

 sumption. Many experiments have shown that the addition 

 of field roots, corn ensilage or soiling food reduces the 

 consumption of water in at least approximate propor- 

 tion to the extent to which they are fed and to the 

 amount of water they contain. Such food may be given 



