Technological quality of bull carcasses in relation to a commercial type

The goal of the present paper was to analyze the carcass value of fattened bulls-crossbreds with the most important beef breeds. Bulls were products o f commercial crossing (F-1 generation) of a domestic milked population of d airy cows with dual-purpose efficiency and bulls of specialized commercial meat types of these breeds: Aberdeen Angus (Aa), Blonde d'Aquitaine (Ba), B elgian Blue-White (Bm), Charolaise (Ch), Limousine (Li) and Meat Simmentale r (Si). The progeny of breeding bulls of Czech Pied breed (C) was used as a control group. Evaluation of the basic performance parameters of 238 bulls indicated statistically significant differences (P < 0.05) in daily weight gains between the C animals (974 g/day) and the groups C x Ch (1 043 g/day ) and C x Si (940 g/day). The significantly lowest net weight gain and dres sing percentage (P < 0.05) were determined in control group C (571 g/day; 5 7.30%). Fattened bulls C x Si had the highest weight of dressed carcass (34 9 kg; P < 0.01). They were followed by the progeny after bulls Ch C Ba Li A a while the lowest weight of dressed carcass was determined in bulls C x Bm (Table 3). The group C x Aa received the lowest evaluation (2.04) when the bulls were included in slaughter classes on the basis of meatiness; its va lue was significantly different from the values of groups C x Ch (1.79) and C x Li (1.68). Evaluation of fatness of dressed carcasses to include them in classes on the basis of this trait resulted in the highest value 1.12 in groups C and C x Ch, and in the lowest value 1.00 in groups C x Bm and C x Li. No statistically significant differences were determined between the g roups. Group C x Li had the highest proportion of lean cuts in carcass (81. 68%; P < 0.01). With respect to the quality of butchers cuts, meat was incl uded in the category of prime cuts (meat of round and rump, loin and sirloi n, shoulder and filet) and in the category of grade II (meat of the other b utchers cuts). The significantly lowest proportion of meat (P < 0.05) class ified as prime cuts (36.63%), and the highest proportion of grade II meat ( 43.31%) were determined in the progeny after Aa bulls. As expected, the gro up C x Bm had the highest proportion of prime cuts (39.44%); it was almost by 3% more than in the progeny after Aa sires. The significantly lowest pro portion of bones (17.30%; P 0.01) was determined in the group of progeny af ter sires of Limousine breed (C x Li). This progeny after Li sires had the highest meat to bone ratio in forequarters (P < 0.05) and hindquarters (P < 0.01), and in the whole carcass. The lowest values of the weight and propo rtion of butchers bones (bones of the axial skeleton without skull, i.e. sp inal bones) in dressed carcass (19.12 kg; 6.33%) were observed in group C x Li. On the contrary, the highest values were determined in group C x Si (2 8.87 kg; 7.55%). The weight of technical bones (limb bones) in the carcass ranged from 33.97 kg (C x Li) to 39.83 kg (C x Si). There were statisticall y highly significant differences (P < 0.01) between group C x Li and groups C, C x Ba, C x Ch and C x Si, and significant differences between group C x Li and group C x Aa (P < 0.05). The highest percentage of technical bones was recorded in group C (12.07%); it was by 1.10% more than in group C x L i.