It is well known that the quality of meat products, their nutritional and biological value are largely determined by the development of the muscle tissues of the carcass, the specific weight of which in well-fed animals exceeds 65 %. Likewise, the development of the muscle tissues and, to some extent, their quality are characterized by their size and the cross-section area (the “muscle eye”) of the rib eye.
Our results for the muscles morphometric examinaion show the effect of the bull-calves’ genotype on their development (Table 1). The purebred young Simmentals in group I and the crosses (½ Simmental x ½ red steppe) in group II were inferior to them in terms of the depth of the muscle by 4.9 % and 10.3 %, and in terms of the width of the muscle by 9.8 % and 21.8 %, respectively. While, the leading position in terms of the studied parameters was taken by the crossbred (½ Simmental x ½ black-motley) bull-calves from group III. The differences between the groups in terms of the size of the rib eye determined the unequal area of the “muscle eye” with the predominance of the crossbred bull-calves in group III with superiority in terms of the analyzed parameter over the purebred Simmental bull-calves in group I was 8.4 cm2 (12.6 %, P < 0.01), and over the crossbred young animals (½ Simmental x ½ red steppe) in group II 18.6 cm2 (P < 0.001).
The minimum morphometric parameters for the rib eye were observed in the crossbred bull-calves (½ Simmental x ½ red steppe) in group II that were inferior to the purebred Simmental bull-calves in terms of the muscle depth by 5.2 %, in terms of the width by 10.9 %, and in terms of the “muscle eye” area by 10.2 cm2 (18.1 %, P < 0.001).
The quality of carcasses is largely characterized by the meatiness index of the natural anatomical parts of the carcasses, which shows the yield of boneless meat (the edible part of the carcass) per kg of bones. The obtained data and their analysis showed the influence of the anatomical and topographic location of individual carcass cuts on the value of the analyzed parameter (Table 2).
The cervical natural anatomical cut of the semi-carcass had the maximum characteristic meatiness index as its value in this cut was greater than the scapulohumeral cut by 4.70 – 6.21 kg (111.1 % – 167.6 %, P < 0.001), greater than the back-and-ribs cut by 5.42 – 6.70 kg (159.4 % – 215.4 %, P < 0.001), greater than the lumbar cut by 0.95 – 2.93 kg (12.1 % – 42.6 %, P > 0.05 and greater than the leg-and-hip cu by 3.60 – 4.80 kg (69.0 % – 95.8 %, P < 0.05 – 0.01).
On the other hand, the lumbar natural anatomical part of the semi-carcass also had a high meatiness index. In the scapulohumeral cut, the analyzed parameter was lower than the lumbar cut by 2.76 – 4.17 kg (67.0 % – 112.7 %, P < 0.05 – 0.01), lower than the back-and-ribs cut by 3.48 – 4.76 kg (102.3 % – 153.0 %, P < 0.05), and lower than the leg and hip cut by 1.66 – 2.86 kg (31.8 % – 53.5 %, P > 0.05.
Table 1: Rib eye measurements in the bull-calves in the experimental groups at the age of 18 months.
Table 2: The meatiness index of individual natural anatomical parts of semi-carcasses of the bull-calves in the experimental groups at the age of 18 months, kg.
Table 3: The grade composition of the boneless meat for semi-carcasses of the bull-calves in the experimental groups at the age of 18 months (following the sausage classification).
Comparative assessment of the meatiness index of the leg and hip natural anatomical part, the scapulohumeral and the back-and-ribs part showed less significant difference for its value in favor of the leg and hip part cut. It noticed that the scapulohumeral part was inferior to it in terms of the analyzed parameter by 0.89 – 1.52 kg (21.6 – 41.1, P > 0.05), and the back-and-ribs part by 1.61–2.11 kg (47.3 % – 67.8 %, P > 0.05. The differences in the meatiness index of the scapulohumeral and the back-and-ribs natural anatomical parts were non statistically significant. At the same time, the scapulohumeral cut tended to be superior over the back-and-ribs cut in terms of the analyzed parameter.
The obtained data and their analysis showed the influence of the bull-calves genotype on the meatiness index of the natural individual anatomical parts of the semi-carcasses. Within that, the leading place in terms of the meatiness index belonged to the crossbred (½ Simmental x ½ black-motley) bull-calves in group III. The Simmental bull-calves in group I and the crossbred bull-calves (½ Simmental x ½ red steppe) in group II were inferior to them in terms of the meatiness index of the most valuable cuts for the lumbar and the leg-and-hip ones by 0.77 kg (10.8 %), 0.99 kg (14.4 %) and 0.11 kg (2.2 %), 0.21 kg (4.2 %), respectively.
A similar observation was observed during analyzing the differences between the groups in terms of the meatiness index of other natural anatomical parts of the semi-carcasses. Our results revealed that the crossbred bull-calves (½ Simmental x ½ black-motley) in group III exceeded the purebred young Simmental cattle in group I and the crosses (½ Simmental x ½ red steppe) in group II in terms of the meatiness index of the back-and-ribs cut by 0.20 kg (6.3 %) and 0.29 kg (9.3 %), of the scapulohumeral cut by 0.21 kg (5.4 %) and 0.43 kg (11.6 %), and of the cervical cut by 0.79 kg (8.8 %) and 0.99 kg (11.2 %).
The data analysis shows that the minimum level of the meatiness index of all the natural anatomical parts of the semi-carcasses was observed in the crossbred bull-calves (½ Simmental x ½ red steppe) in group II. They were inferior to their purebred Simmental peers in terms of the analyzed parameter in the leg-and-hip cut by 0.10 kg (2.0 %), in the lumbar cut by 0.22 kg (3.2 %), in the back-and-ribs cut by 0.09 kg (2.9 %), in the humeroscapular cut by 0.22 kg (5.9 %), and in the cervical cut by 0.20 kg (2.3 %).
The materials obtained during trimming and sorting of the edible part of the carcasses showed the influence of the young cattle’ genotype on the yield of individual meat grades (Table 3). The best grade composition was observed in the meat products obtained during slaughtering of the crossbred bull-calves (½ Simmental x ½ black-motley) in group III as they exceeded the purebred Simmental bull-calves in group I and the young crossbred cattle (½ Simmental x ½ red steppe) in group II in terms of the absolute weight of top-grade meat by 2.4 kg (11.2 %, P < 0.05) and 4.7 kg (24.6 %, P < 0.01), and in terms of the relative weight by 0.7 % and 1.1 %, respectively. Similar differences between the groups were observed in terms of the yield of first-grade meat. as noticed that the purebred Simmental bull-calves in group I and the crosses (½ Simmental x ½ red steppe) in group II were inferior to their crossbreed peers (½ Simmental x ½ black-motley) in group III in terms of the absolute weight of first-grade meat by 5.8 kg (10.8 %, P < 0.01 and 11.6 kg (24.2 %, P < 0.001), and in terms of the relative weight by 1.6 % and 2.7 %, respectively.
It was found that the lowest values that characterize the grade composition of the meat product were found in the crossbred (½ Simmental x ½ red steppe) young calves in group II that were inferior to their purebred Simmental peers in group I in terms of the absolute weight of top-grade meat by 2.3 kg (12.0 %, P < 0.05), of first-grade meat by 5.8 kg (12.1 %, P < 0.01), and of relative weight by 0.4 % and 1.1 %, respectively. While for second-grade meat, in terms of the absolute weight, it was in the range of 1.6 – 1.7 kg (4.6 % – 4.9 %), was superior in the crossbred bull-calves (½ Simmental x ½ black-motley) in group III and the purebred young Simmentals in group I, while, in terms of the relative weight of second-grade meat, they were inferior to their crossbred peers (½ Simmental x ½ red steppe) in group II by 1.5 – 3.8 %.