| dc.description.abstract | The influence man has exerted over domestic animals is to make them better serve his wants. On the other hand animals differ widely in their ability to thrive and to perform efficiently under a given set of conditions. This difference in adaptability can be traced back to their origin, where they were developed. Geographic location together with its climatic conditions had selected animals which wore adapted to those environments. After domestication natural selection was followed by artificial selection employed by man to develop individuals with most desirable features. More progress has boon attained in countries with temperate climate, consequently most highly specialized livestock are to be found in those regions. Very slow progress is observed in tropical countries with regerous conditions. Since the performance of livestock in the tropics is relatively low, man is apt to import animals with high producing ability from the temperate zones. This is particularly true of dairy cattle, but it holds also for other producers of animal protein (beef cattle, swine or poultry). In general the adaptability to the now environmental condition: which are markedly different from those in the native home of the imported animals, was not seriously taken into consideration. This point had been frequently overlooked in attempts to improve the quality or productivity of stock in a given arca. As a result much time, effort, and money have been expended, quite often with disappointing results. | id |
