THE PERFORMANCE OF BULLS-CROSSBREDS OF THE BLACK-PIED AND LIMOUSIN BREEDS

A group of bullocks-offsprings of the Limousin breed and of dams of the Black-Pied breed (BP x Li) and a group of bullocks of the Lowland Black-Pied breed (BP) were included in a fattening scheme in practical farming conditions. Loose housing on deep litter was used. The diet consisted of 10 to 20 kg of maize silage and 3 to 6 kg of pelleted feed in dependence on bullock weight. Fattening performance, carcass and technological analysis parameters were evaluated, some traits of meat quality were assessed in a sample of the eye-muscle. As for the fattening performance, in which the differences were insignificant, the BP x Li crossbreds (Tab. I) had by 25 g lower weight gains (0.683 kg) until the outset of fattening, but their weight gains were higher by 72 g in the course of fattening (0.979 kg) and by 22 g (0.828 kg) over the period from birth to slaughter. The crossbreds reached the pre-slaughter weight of 526.73 kg (-5.75 kg) at their younger age, that means by 9.30 days sooner (649.76 days). Their better muscling resulted in the higher weight of dressed carcass (DC) (316.57 kg) by 0.91 kg, hence in the higher converted weight (DC x 1.8) by 7.98 kg (576.16 kg) and in the net weight gain higher by 15 g (0.494 kg). There were no significant differences between the groups in their body conformation evaluated on the basis of average data on the base dimensions. The BP x Li group had the slightly larger body frame with withers height, height in hips and body length larger by 2.01 cm, 3.06 and 0.80 cm, respectively. The larger width dimensions result from the chest width (+0.56 cm). Tle crossbreds had the lower values of chest depth and girth (-1.90 and -7.60 cm). The smaller cannon bone girth by 0.46 cm indicates their more subtle skeleton. There were also insignificant differences in the parameters of carcass analysis between the groups. The crossbreds had the lower proportion of head by 0.18 % (2.95 %) and of limbs by 0.07 % (1.76 %) while the skin proportion (8.11 %) was identical. Tallow output was relatively low in both groups, while the values were slightly higher in the crossbreds. As to the total tallow output, the difference made 1.10 kg and 0.09 % with the proportions of 10.45 kg and 1.72 kg. The technological analysis of the sides of beef revealed significant differences in the proportion of first-rate meat and in the subcutaneous fat thickness (Tab. IV. The BP x Li group had the first-rate meat proportion higher by 1.10 % (40.76 %), and the total meat proportion higher by 1.04 % (83.13 %), while the second-rate meat proportion was lower by 0.12 % (42.33 %). The more subtle skeleton was characterized by the lower proportion of bones - by 0.93 % (15.98 %). The DC coverage with fat was clearly higher in the crossbreds. Their subcutaneous fat thickness (8.91 mm) was higher by 4.53 mm. There were insignificant differences between the groups in the parameters of meat quality (Tab. V). As a result of the better evaluation of DC meatiness, the crossbreds had the larger eye-muscle area by 9.66 cm2, the average area being 99,39 CM2 . The pH24 values of 5.62, and also the other physical parameters demonstrate a higher quality of meat. The chemical analysis of an eye-muscle sample with the slightly lower dry matter content (24.31 %) also documented somewhat lower fat content (1.42 %) and on the other hand, the higher content of crude protein (3.38 %).