Twelve young bulls of Czech Pied breed (C) and 11 young bulls of Black-Pied breed (N), progenies after 7 sires in both cases, were included in a comparative fattening program in a tie stall with individual feeding. After fattening termination, the bulls at the live weight of 560 to 590 kg were subjected to control slaughters in experimental slaughterhouses of the Research Institute of Animal Production, when not only the weight of dressed carcass (DC) but also the weight of commercial fats, the weight of skin, head, limbs, utilizable stomachs and intestines and intestine length were examined. After cooling, quarters from the right sides of beef were cut into basic parts, and meat, separable fat and bone weight were determined after deboning and the thickness of subcutaneous fat was measured at the level of the 9th vertebra. Measurements were done at three points above the musculus longissimus dorsi (MLD), and the average of the values measured was used for evaluation. The MLD area was calculated by drawing and subsequent planimetric determination in its cross-section between the 8th and 9th vertebra. At technological dissection MLD samples were taken between the 9th and 11th vertebra for chemical analyses and physical determinations. Fat content was determined in a rib-meat sample while the content of dry matter, fat and proteins was determined in a sample of pure MLD. Out of the physical characteristics, pH(24) value and meat color were determined at a wavelength of 685 and 522 nm in 24 hours after slaughter. There were no significant differences in head weight. The average weight 18.21 kg was lower by 0.33 kg only (1.8%) in C bulls than in N bulls. A significant difference (P < 0.01) between the genotypes was found out in limb weight(11.52 kg in C - by 0.77 kg, i.e. by 6.65 higher than in N). There was also a significant difference in skin weight (53.33 kg in C - by 8.23 kg, i.e. by 15.4% higher than in N). The weight of commercial fats shows the same trend both in absolute values and in their percentage from slaughter weight, and it is to note that the N bulls always had higher values. The only significant difference (0.73 kg) between the genotypes was recorded in intestinal fat (N 3.79 kg); when expressed as proportions, the difference Was 0.13%. The highest values out of the total output of commercial fats were measured for kidney fat (N 12.98 kg) with a difference of 1.8 kg between the groups. The total output of commercial fats was relatively high in both groups (N 25.99 kg, between-the-genotype difference 4.18 kg), and the difference amounted to 0.72% as for the proportion out of slaughter weight. As the average weight of the right sides of beef amounted to 164.81 kg (C) and 161.34 kg (N), this difference of 3.47 kg (2.1%) was insignificant. C bulls had the higher yield of prime meat (by 1.83 kg) and of grade II meat (by 2.6 kg), that means of total meat (by 4.43 kg). A significant difference (ca. 1%) was determined in relative values in favor of C cattle in total meat yield (81.40%). Technological dissection yielded a relatively low amount of separable fat with better results in C breed (1.72 kg and 2.82%). C group had a significantly lower bone proportion (1.01%); but expressed in absolute values the differences were insignificant (C 27.42 kg, N 28.50 kg). The ratio of prime meat to grade II meat did not show any difference when 0.96 kg in C cattle and 0. 97 kg in N cattle was adequate to the output of 1 kg of grade II meat. A significant difference between the genotypes in favor of C cattle was found in the meat to bone ratio (C bulls produced 4.92 kg per 1 kg bones while in N bulls it was 4.56 kg meat). The thickness of subcutaneous fat at the point of rib-meat was insignificantly lower in N bulls (7.27 mm) than in C bulls (7.46 mm). The meat of C bulls had pH 5.62, in N bulls it was 5.55. Both values, in spite of significance of the difference, indicate good-quality meat. The values of reflectance determining meat color are balanced and document the balanced quality of both genotypes. Differences in the resultant values of chemical analysis were not statistically significant. The values of the eye-muscle areas in cross-section were insignificantly different, with between-the-genotype difference 3.04 cm(2).
