A NOTE ON THE PERFORMANCE OF THE CC21 GENOTYPE COMPARED TO THE YORKSHIRE AND YORKSHIRE X LANDRACE HYBRID

Growth comparisons were carried out to evaluate the performance of the CC21 genotype; first, in a comparison with Yorkshire (Y) and second, with the F1 Yorkshire x Landrace (YL). For both analysis the informati on of the field performance test was used. On comparing CC21 with Y th e data of 612 females (435 and 176 for CC21 and Y, respectively) that ended the test between January and May 1989 were used. For the CC21 an d YL comparison, 250 and 310 females respectively that ended the test between January and March 1990 were employed. The traits analysed were : final weight (FW) weight for age (WPA), total backfat (TF) and backf at corrected to 100 kg liveweight (CF). The data from each comparison were analysed by least squares using a fixed effect model that took in to account: genotype, contemporary group/genotype and sire/genotype. I n respect to FW, WFA and CF the data were adjusted by linear regressio n to final age on test while for TF the adjustment was for final weigh t. The CC21 showed a poorer performance for FW (72.9 kg and 75.4 kg) a nd WFA (329 g and 341 g respectively) with no differences in the fat t raits while it did not differ from YL in any of the traits studied.