64 W. Hartwig 



From research into the family history tuberculosis was 

 found in 41 families, six of which had two or more cases. 

 The authors therefore suppose that there is a hereditary 

 inclination to tuberculosis, as the same phenomenon is to be 

 found in human medicine. 



Martin (1950) performed research on this line on 2,160 cows 

 in Baden. Piel (1951) examined the reasons for culling 2,507 

 brown Wurtemberg cattle from 1939 to 1944, while Ziegen- 

 hagen (1951) examined the causes of death of 5,244 Anglia 

 cows. These authors found that the causes were more or less 

 the same as described above. All these statements clearly 

 demonstrate that sterility, tuberculosis, garget, brucellosis 

 and softening of the bones are the most important diseases and 

 deficiencies that lead to culling of breeding animals and shorten 

 their lifespans and utilization as brood cattle. 



Using black-pied cows of various ages from the Central- 

 German dry region, Spohde (1948) undertook research on 

 death from the three most important diseases (sterility, 

 tuberculosis and garget). Of all the cows culled because of 

 sterility, 78 per cent were aged from 4 to 8 years. Sixty-eight 

 per cent of tuberculous animals were culled between the ages 

 of 5 and 7 years; 78 per cent of the animals infected with 

 garget were also culled at these ages. These three principal 

 diseases cause the relatively premature suppression of animals 

 in the second to fifth years of life, that is to say at an age when 

 their maximum capacity has not yet been reached. 



The different measures that might be taken in order to raise 

 the average age of the animals include breeding, by scrupulous 

 selection, for fecundity, longevity, and intensified resistance 

 to diseases, with simultaneous stress on optimal productivity, 

 as well as improvements in breeding, keeping and feeding. 



Bulls 



In his studies on the ages of bulls in Brunswick slaughter- 

 houses Hogreve (1955) found the following average ages: bulls 

 from the South Hanover-Brunswick region, 3 years, 5 months ; 



