The analysis covers findings of performance (tested in vivo) of fat and meat content of 45286 two-breeds crossbreds gilts tested in ten successive years (1995-2004) according to the same methodology observed in those years. Animals were produced in Poland in the area of Bydgoszcz Breeding District, covering Kujawy-Pomorze province. They came from two crossing variants of breeds Polish Large White (PLW) and Polish Landrace (PL): [PLW x PL] and [PL x PLW]; the sow’s breed is given in the first position. Two-factor ANOVA analysis of variance was employed in the research
taking into consideration a crossing variant and ten years, i.e. 1995-2004 (referred to as groups 1-10, respectively) when animals’ performance was tested (in vivo). Computer program Statistica PL was used in calculations. Taking into consideration the total results from ten years (1995-2004) it should be noticed that crossbred gilts [PL x PLW] had significantly thinner backfat measured in P2 and P4 points, lower height of loin eye and higher carcass meat
content (P≤0.01) compared with animals from [PLW x PL] crossing variant. The analysis of the results from year 1995 and year 2004 shows that in the case of crossbred gilts [PLW x PL] backfat thickness in P2 and P4 points decreased by 6.76 and 7.76 mm and meat content increased by 6.65%. Improvement in the mentioned traits occurred also in the case of gilts from the second tested crossing variant, i.e. [PL x PLW], because backfat thickness in P2 and P4 points decreased by 5.41 and 6.00 mm and carcass meat content increased by 4.80 %.
