LIFESPAN OF CATTLE AND HORSES UNDER 



VARIOUS CLIMATIC CONDITIONS AND THE 



REASONS FOR PREMATURE CULLING 



W. Hartwig 



Institutfiir Tierzucht, Martin-Luther-Universitdtf Halle 



In cattle breeding performance can be separated into two 

 major components : (1) the special productivity (of milk, meat, 

 wool), (2) the general performance. General performance 

 means: fecundity, longevity, power of resistance to disease 

 (particularly to those hereditary diseases caused by failure to 

 adapt to environmental changes), food utilization and so on. 

 Certain factors of the general performance, including longevity, 

 also come under our definition of constitution. Besides the 

 increase in special performance, the improvement of the 

 general performance of agricultural domestic animals is a 

 primary object of cattle breeding; in particular increased 

 lifespan must be considered. 



In the determination of the real duration of life of large 

 agricultural domestic animals there are, however, considerable 

 difficulties. First of all domestic animals are kept for their 

 economic productivity; their lifespan is therefore affected by 

 economic considerations and is more or less variable. Factors 

 such as decreased performance, hard milking, price relations 

 between milk and meat, shortage of space, period of feeding, 

 bad fodder in some years, technical developments, etc., may 

 lead to the sale for slaughter of completely healthy animals 

 that could have lived longer. That is why, in considering the 

 average age of living animals, we have to deal not with a real 

 biological parameter, as in human vital statistics, but with 

 arbitrarily biased values. Other conditions are to be found, 



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