Abstract: This experiment was carried out for the purpose of exploring the matching hybrid method and effect of lean pig combination. The experiment adopted HN121 (Wynn Duroc Pig), HN212 ( Pitland ♂×Wynn Duroc ♀) as the parent samples, and adopted HN204 (Wynn white ♂×the American white ♀) as the mother sample, to carry out matching hybrid test of two combinations of HN323 combination (HN121×HN204) and HN424 combination (HN212×HN204). The results showed that compared with HN323 combination, for HN424 combination, there were no significant differences in sows' litter size, live litter size, piglets birth weight, survival rate of 21-day old piglets and litter weight at 21-day old piglets between HN424 combination and HN323 combination (P>0.05), and the weight backfat thickness was 5.63% lower, the lean percentage was 4.95% higher (P<0.05), the eye muscle area was 33.08% larger(P<0.01), the carnation score was 7.19% lower (P<0.05), the marble grade was 11.30% lower (P<0.01), drip loss rate was 10.63% higher (P<0.01). The difference of other hereditary traits was not significant. Compared with HN204 binary parent line, for HN424 combination, daily weight-gain increased by 9.26% (P<0.05), backfat thickness decreased by 16.41% (P<0.01), feed-to-meat ratio decreased by 8.02% (P<0.05). Compared with HN204 binary parent line, for HN323 combination, daily weight-gain increased by 7.20% (P<0.05), backfat thickness decreased by 11.43% (P<0.01), and feed-to-meat ratio decreased by 5.35% (P<0.05). Therefore, it is believed that both quaternary hybrid combination and ternary hybrid combination had significant effect on "Large×Long" (HN204) binary hybridization in genetic improvement, "Pitland×Duroc×Large×Long" quaternary hybrid combination can significantly improve lean meat rate and eye muscle area, but meat color, marble grade, drip loss rate and other meat quality indicators changed low. Therefore, it is suggested that pig breed genes which can improve meat quality should be added into the matching hybridization of "Pitland×Duroc×Large×Long" quaternary hybrid combination.

Key words: lean pig, combination hybridization, breeding traits, economic traits