Following crosing the Vietnamese pig with the Polish Landrace and the Polish Large White inbred mating and selection were being conducted to obtain a slow growth rate and quick maturing. Between 1970 and 1980 eight generations were obtained whose body sizes were successively smaller. The body weight of adult animals in the generation F₇ nad F₈ was approximately 45 kg. The selection carried out in the opposite direction than the one commonly used resulted in a small type of pig. Its daily weight gains did not exceed 150 g and had a tendency to an increased fat production.
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