Age of the Domestic Animals. 



INTRODUCTION. 



Age is defined by Webster as " the wliole duration of a 

 being," or " that part of the duration of a being Avliich is 

 between its beginning and any given time." It is not to be 

 confounded with the term as applied to the various periods or 

 epochs of an animal's hfe, as the juvenile, adult, and senile, 

 whicli correspond to organic metamorphosis of distinct character 

 and to a marked change in the degree of functional activity. 

 Tlie age of the domesticated animals is a matter of great impor- 

 ttince in agricultural commerce, as, in tlie limited period during 

 whicli each of them is individually useful, a comparatively short 

 time diminishes greatly the extent of usefulness to which each 

 can be put, and consequently lowers its value as an investment. 

 The means which enable us to judge the age of an animal are 

 based upon certain anatomical and physiological changes which 

 occur in the course of the development of tlie newborn to the 

 adult animal, and in the deterioration of it from its period of 

 perfection to the decrepitude of its last years. Tliese changes 

 are constant, and, while the animal retains its general form and 

 the tissues are chemically identical, there is a constant renewal 

 of the molecules, whicli is rapid early in life and slower later. 

 Age can be divided into three periods: First, juvenile, or the 

 period of growth, which extends from the birth of the animal 

 to its full development, during which it is gaining in size, in 

 strength, and in intelligence, and is constantly increasing in its 

 ([ualities and value. Second, adult, or the stationary i^eriod ; in 

 this the animal is at its best; it has every organ complete in size 

 and perfect in function, working in perfect harmony w4th the 

 rest of the body ; its intellect has the most complete control 

 over its perfectly organized muscles, digestive tract, and other 



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