The area of loin eye in bulls of the Ukrainian Black-and-White dairy breed and its relationship with beef characteristics

. The relevance of the work was to determine whether the loin eye area of m. longissimus dorsi as a criterion for evaluating the yield of high-value cuts from beef carcasses, is associated with beef characteristics from bulls of the Ukrainian Black-and-White dairy breed. The purpose of the study was to establish correlations between the loin eye area and the slaughter characteristics by the chemical composition, sensory, physical and technological properties of beef. The correlation between the cross-sectional area


Introduction
To improve food quality and consumer safety, it is important that the quantitative and qualitative characteristics of meat from Ukrainian cattle meet international standards.Beef of different cuts has different nutritional quality, since it varies under the influence of many factors, and affects the cost of products.It is technologically difficult to determine their number during the life of an animal.Therefore, it is relevant to establish methods for predicting the slaughter characteristics, chemical composition, physical, technological and sensory properties of beef from animals of common Ukrainian breeds by the area of the loin eye of m. longissimus dorsi.
The loin eye area is the cross-section of the oblong muscle between the 12 th and 13 th ribs, which is determined by dividing the carcass into quarters.As noted by A. Ugnivenko et al. (2022), the loin eye area of m. longissimus dorsi in cattle depends on the breed of animals.Thus, bulls of the Korean Hanvoo breed at the age of 30 months have an average loin eye area of 87.4 cm 2 (Bhuiyan et al., 2017), and Ukrainian meat cattle aged 22 months -133.5 cm 2 (Ugnivenko et al., 2022).Data on the loin eye area of m. longissimus dorsi is used to determine the optimal growth parameters of dairy cattle during their rearing for meat, determine the age and live weight for slaughter, and predict the resulting beef and its belonging to a certain variety through a direct connection with valuable carcass cuts.A linear positive correlation between the loin eye area of m. longissimus dorsi and pre-slaughter live weight and carcass weight were established by M.S.A. Bhuiyan et al. (2017) in bulls of the Hanvoo meat breed.
According to A. Ugnivenko et al. (2022), in Ukrainian beef cattle, the loin eye area of m. longissimus dorsi has a linear significant correlation with slaughter weight (r = 0.614; P > 0.95) and slaughter yield (r = 0.653; P > 0.95).This indicates a better effect on the development of muscle tissue in the carcass.Similar results were obtained (Naserkheil et al., 2021;Pimentel-Concepción et al., 2024) in studies of genetic correlations of the yield of primary cuts with qualitative features of the carcass and it was found that genetic correlations with the carcass weight and the loin eye area of m. longissimus dorsi were moderate to very strong; while low, moderate, and negative correlations were observed between primary cut characteristics with marbling and subcutaneous fat thickness.The relevance of these studies is also confirmed by G. Bittante (2023), since beef quality chartacteristics cannot be directly measured on live animals, unlike traits related to growth, productivity, and disease resistance, the study of (r = -0.401),dry matter (r = -0.403),acidity (r = -0.458),muscle tissue colour (r = -0.126),conformation (r = -0.127),penetration (r = -0.477),taste (r = -0.214)and aroma (r = -0.363) of boiled meat, tenderness (r = -0.256),residue after chewing (r = -0.442), the thickness of broth (r = -0.207),and to a linear correlation -with the amount of tendons and ligaments (r = 0.331), marbling (r = 0.162), the colour of fat tissue on the carcass (r = 0.276), transparency of the broth (r = 0.180).The practical significance of the data is to obtain knowledge that allows formulating marketing strategies for predicting food quality, quantity of premium and first-grade beef, its technological properties and intended use based on the correlation between the loin eye area of m. longissimus dorsi Keywords: meat productivity; conformation; marbling; carcass quality traits; sensory characteristics of meat correlation of the loin eye area of m. longissimus dorsi with qualitative characteristics of beef would allow predicting its quality.Thus, with the same weight of carcasses and the content of fat tissue in them, an increase in the cross-sectional area of the oblong muscle indicates an increase in the yield of valuable cuts and a larger weight of steaks from them, which are the most profitable to sell.These are the features that manufacturers and processors are interested in.
According to I. Randhawa et al. (2021), consumers make their choices based on the nutritional value and sensory characteristics of beef.Therefore, A. Ugnivenko et al. (2022) determined of the relationship between the qualitative characteristics of beef and the loin eye area of m. longissimus dorsi in animals of the Ukrainian meat breed.It was found that there is a tendency to a weak inverse correlation (r = -0.193) between the cross-sectional area of the oblong muscle and the tenderness of meat, the content of dry matter in it (r = -0.345).The depth of the loin eye most correlates with the technological properties of beef.Data on the correlation between the loin eye area of m. longissimus dorsi with the qualitative characteristics of beef in animals of meat breeds is not enough to interpret dairy cattle.According to J. Soulat et al. (2022), the management approach that allowed for the best ratio between carcass and meat quality was intermediate rearing over a long fattening period, with the diet mainly based on hay and a high amount of concentrated feed.Such conditions allowed producing carcasses with a high conformation, smooth grain of meat, more uniform colour, darker and tastier meat, and low moisture content.The purpose of the study was to establish correlation relationships between the cross-sectional area of m. longissimus dorsi and slaughter characteristics, chemical composition, and qualitative characteristics of meat in bulls of the Ukrainian Black-and-White dairy breed, which is used in Ukraine both for the production of milk and beef.

Materials and Methods
The study was conducted on 34 bull carcasses at the "Zhuravushka" farming enterprise (FE) in the Brovary District, Kyiv Oblast.The animals were kept in groups of 25 units from birth to the age of 4 months.They were then reared and fattened to slaughter at the age of 18-24 months at the fattening facility based on their age.The farm's feed needs were met by its own fodder base.The bulls had free access to roughage, juicy, green, concentrated feed and mineral supplements, which were fed from the self-feeders in accordance with the developed rations.The cattle were slaughtered in the slaughterhouse in Kalynivka village following the Council Regulation (EC) No. 1099/2009 (2009).The animals were stunned with an electric current before exsanguination.Carcasses were suspended vertically on hooks by the fusion between the calcaneus bone and Achilles tendon.After evisceration, the carcasses were divided into halves and cleaned of excess fat and meat.
Carcasses were weighed and visually evaluated for conformation and subcutaneous fat development in accordance with the Commission Regulation (EC) system (2009).The conformation of carcasses was classified on a scale of 5 classes: from E (very high muscle development) to P (very low muscle development).Subcutaneous fat development was evaluated on a scale of 5 classes: from 1 (lean) to 5 (very fat).Next, the carcasses were sawn in half, and the half-carcasses were cut at the level of the 12 th rib.The colour of muscle and fat tissue was determined using a 7-point scale, the marbling of meat was determined on a 12-point scale, and the thickness of subcutaneous fat on the carcass was measured between the 12 th and 13 th ribs in accordance with the JMGA method (2000).The length and depth of the loin eye were measured between the 12 th and 13 th ribs with a ruler (Fig. 1) immediately after dividing the half-carcasses into quarters.( where S -loin eye area, cm 2 ; a -loin eye length, cm; b -loin eye depth, cm; 0.8 -coefficient. The penetration of raw meat was determined using an automatic penetrometer according to the method given in the paper (Guts & Koval, 2007).The content of bound moisture was studied by the "press method" by the amount of water that was released from the suspension of 0.3 g of crushed meat under the action of pressing and absorbed into the filter paper, forming a wet spot.The total area of the stain formed under the compressed meat and the released moisture absorbed by the filter paper was determined using a planimer.The difference between the total area of the spot and the occupied meat determined the area of the wet spot.The ability of meat to retain water was investigated by the content of bound water as a percentage of the weight of meat.
To determine the residual weight of beef after boiling down, rectangular pieces of meat weighing 150 g were cut out of m. longissimus dorsi.They were weighed on a THB-600 scale with an accuracy of 0.01 g.Next, they were placed in a 5-litre pot and 2-3 litres of cold distilled water were poured.The water was brought to a boil and cooked over low heat for 90 minutes.After cooking, the pieces were removed from the water, cooled to 20°C and weighed.The amount of meat lost in boiling was determined by equation ( 2) (Shkurin et al., 2002).
where Sm -amount lost in boiling of meat, %; Cm -weight of boiled down meat, g; Rmweight of raw meat sample, g.The chemical composition of beef was studied in the laboratory of the Department of Meat, Fish and Seafood Technology of the National University of Life and Environmental Sciences of Ukraine (NUBiP) in accordance with the methods described in Table 1.The characteristics of aroma, juiciness, tenderness, ease of chewing boiled beef, colour, taste, and strength of broth from it were determined by the tasting commission in the amount of 8 people in the laboratory of "Meat quality" of the Department of Milk and Meat Production Technologies of the NUBiP of Ukraine.

Table 1. Methods for determining the chemical composition of m. longissimus dorsi in bulls
The data were processed statistically using Microsoft Excel 2016 in combination with XL-STAT.They were evaluated using correlation coefficients calculated using appropriate methods (Osadcha, 2021).The correlation between the loin eye area and the above-mentioned quantitative and qualitative characteristics of all the studied carcasses and separately in the meat of 21-month-old bulls was calculated to compare the results obtained.The age difference in the group between them was up to 5%.Animal studies were conducted in accordance with the "General ethical principles for conducting animal experiments", approved by the First National Congress on Bioethics (Law of Ukraine No. 3447-IV "On the Protection of Animals from Cruelty", 2006), and the provisions of the "European Convention for the Protection of Vertebrate Animals used for Experimental and other Scientific Purposes" (1986).

Results and Discussion
In bulls aged 18 to 24 months and 21 months, a linear significant correlation was found between the loin eye area of m. longissimus dorsi and such traits as pre-slaughter live weight and carcass weight, the amount of muscle tissue, including the highest and first grades (Table 2), which mainly constitute the nutritional value of beef.A positive insignificant correlation was established between the loin eye area and the amount of tendons and ligaments in the carcasses of 21-month-old bulls.As for the amount of bone tissue in the carcasses of experimental animals, there is no correlation.

Table 2. Correlation coefficients between the loin eye area of m. longissimus dorsi and slaughter characteristics and morphological composition of carcasses in bulls
There is also a tendency for a linear correlation between the cross-section of m. longissimus dorsi and the contents of tendons and ligaments in the carcass.There is practically no correlation between the number of bones in the carcasses of slaughtered animals and the loin eye area.This can be explained by the fact that the growth of muscle tissue (including m. longissimus dorsi an fat in the ontogenesis of cattle proceeds relatively faster, and the skeletonslower, then the correlation between the area of the studied muscle and the content of bones is much lower.There is a reverse correlation (P > 0.95) between the cross-sectional area of m. longissimus dorsi and the amount of second-class beef, which has a significant amount of fat that The area of loin eye in bulls... is not separated from the muscles during dressing.The obtained linear significant correlation coefficients between the loin eye area and quantitative characteristics of meat productivity on 21-month-old bulls better reflect the relationship between them than in the period from 18 to 24 months.Thus, the data obtained by the authors confirm the results of the study by V. Vinay-Vadillo et al. (2014), who reported that the loin eye area of m. longissimus dorsi can be used to predict the production of a certain amount of muscle tissue in the carcass, including by its belonging to the appropriate grade.
A similar relationship between the above-mentioned indicators was established in dairy breeds (Pogorzelska-Przybyłe et al., 2014) and meat breeds (Ugnivenko et al., 2022).So, according to R. Pogorzelska-Przybyłe et al. (2014), linear close correlation coefficients (r = 0.80) exist between the loin eye area of m. longissimus dorsi and the amount of muscle tissue in the carcasses of Holstein cattle, including the highest grade (r = 0.69).In animals of the Ukrainian meat breed, there is only a tendency to a positive relationship (r = 0.614) between the cross-sectional area of the oblong muscle, and the slaughter weight (carcass) and its output (r = 0.653).
The established linear significant correlation between the loin eye area and the slaughter weight (carcass), the amount of muscle tissue, including the highest and first grades, can be explained by the fact that the m.longissimus dorsi muscle is located mainly in the thoracic and lumbar regions, which are the most valuable cuts of carcass and its muscle tissue makes up a significant share.There is a linear significant correlation between the loin eye area and the total amount of fat tissue in the carcass.A similar correlation between the loin eye area of m. longissimus dorsi and the fat content in the carcass was also obtained by A. Oler et al. (2015).
Determining the correlation coefficients between the qualitative characteristics of beef carcasses evaluated in accordance with international standards, an inverse relationship was established between the loin eye area and the development of subcutaneous fat (Table 3).

Source: compiled by the authors
There was only a tendency for a linear correlation between the cross-sectional area of m. longissimus dorsi and the colour of fat tissue in bulls from 18-24 months of age and a high correlation (P > 0.999) at 21 months.This can be explained by the significant content of feed rich in carotene -green (28.3%), silage (9.6), hay (8.6), haylage (4.7), and relatively small (18.5%) -concentrated.According to A. Clinquart et al. (2022), in cattle that were fattened

Table 3. Correlation coefficients between the loin eye area of m. longissimus dorsi and other qualitative features of bull carcasses
on concentrated feed without greens, subcutaneous fat had a more yellow colour.There is a tendency for both a weak inverse correlation in bulls aged 18 to 24 months and a linear correlation (in 21-month-old animals) between the loin eye area of m. longissimus dorsi and the thickness of subcutaneous fat, conformation, and muscle tissue colour.From 18 to 24 months, the growth rate of the longest muscle passes regardless of the fleshiness of carcasses, the thickness of subcutaneous fat, and the colour of beef.This indicates that m. longissimus dorsi develops better with the worse fatness of carcasses.A. Oler et al. (2015) also proved that in the presence of a significant amount of subcutaneous fat, the slaughter yield (carcasses) and some of the edible parts in muscle tissue are reduced.That is, a greater development of subcutaneous fat on the carcass (its fatness) inhibits the development of the loin eye area of m. longissimus dorsi, and therefore, simultaneously reduces the number of valuable edible parts in it.In addition, (Kruk et al., 2023) found that the best development of fat tissue under the skin does not correlate with the sensory characteristics of boiled beef and broth from it and water retention, penetration, and marbling.According to the obtained data, there is a linear weak correlation between the loin eye area of m. longissimus dorsi and marbling of meat, which does not guarantee its good sensory characteristics.The marbling of beef is the main factor determining its sensory quality (Sakowski et al., 2022).According to T. O'Quinn et al. (2024), no factor has a more beneficial effect on the taste of beef than its marbling content.
In the study, there is no correlation between a certain loin eye area and the rate of water loss (Table 4).The water-binding capacity is influenced by glycolysis metabolism.It is closely related to the juiciness of beef.The lack of correlation between the loin eye area and the water-binding ability of beef affects its further technological processing, and the yield of the product made from it, which is important in cattle breeding, since the preservation of more meat during its preparation (boiling down) is an important feature.So, the technological feature of beef -boiling down -inversely correlates with the loin eye area, which indicates an increase in waste during cooking.Therefore, the cross-sectional area of m. longissimus dorsi can be used as an indicator of boiling down of beef from bulls of the Ukrainian Black-and-White dairy breed, since it correlates with it inversely and significantly.The correlation coefficients between the cross-sectional area of m. longissimus dorsi and its penetration stress were average and inverse.With an increase in the loin eye area of m. longissimus dorsi in beef, the content of the main elements of its chemical composition decreased (Table 5).That is, evaluating carcasses for this trait does not imply an increase in important nutrients for human health.

Table 4. Correlation coefficients between the loin eye area of m. longissimus dorsi and technological features of beef in bulls
The area of loin eye in bulls...The correlation between the loin eye area and acidity, the amount of dry matter, protein content, and total ash weight is inverse and average, and between the loin eye area and the total fat content -weak.A trend towards an inverse correlation between the loin eye area of m. longissimus dorsi and the acidity of beef indicates that in meat with a larger cross-section of the loin eye, the pH decreases faster to normal (<5.8) and receives microbial stability earlier.Sensory evaluation of the juiciness, tenderness, taste, and aroma of boiled meat determined its acceptability for the consumer.By analysing the sensory properties, a detailed description of how boiled beef and its broth are perceived by the human senses was provided.
However, G.A. Ferreira et al. (2024) conducted a study in Brazil to assess the percep-tion of beef with different pH values.It was found that beef consumers do not devalue steaks in terms of its freshness even at pH≥6.0.The chemical composition of beef depends on the type of breed productivity, the age of animals at slaughter (Hoa et al., 2022), type of muscle and fat tissue (Vázquez-Mosquera et al., 2023).The results of evaluating the sensory characteristics of boiled meat conducted by a group of tasters from 8 people are shown in Table 6.In bulls aged from 18 to 24 months, an inverse significant correlation was established between the loin eye area of m. longissimus dorsi and the juiciness of beef.The correlation between the cross-sectional area of the muscle and the taste, aroma, tenderness, and residue after chewing cooked meat was reverse and weak.An inverse significant correlation between the sensory properties of beef and muscle tissue growth was established by I. Albechaalany et al. (2024).A number of factors had a negative impact on the results of the tasters' evaluation of boiled beef from the loin eye area of Results of the studied correlation coefficients between the loin eye area of m. longissimus dorsi in bulls and the signs of tasting beef broth are presented in Table 7.The linear positive correlation (r = 0.587; P > 0.95) between the loin eye area and the taste and aroma of broth was affected by feeding the bulls a significant amount of green, coarse, and juicy feed.

Source: compiled by the authors
There is a tendency for a relatively weak inverse correlation between the loin eye area of m. longissimus dorsi and the strength of the broth.The inverse relationship between the loin eye area and the strength of the broth was conditioned by the fact that with a decrease in the content of dry matter, protein, total fat, and total ash in the muscles, fat diffuses less from the endomysium and pericardium cells into the boiled water, and less proteins, extractives, and mineral salts are transferred to the broth.
Thus, the qualitative trait of carcassesthe loin eye area of m. longissimus dorsi in bulls of the Ukrainian Black-and-White dairy breed aged 18 to 24 months -is directly correlated with the slaughter characteristics, the weight of muscle tissue, including the highest and first grades, and the weight of fat tissue in the carcass.There is a tendency to worsen the chemical composition of muscle tissue with an increase in the size of the loin eye.The bone content in animal carcasses did not correlate with the cross-sectional area of the long back muscle.Assessing correlation coefficients between the lin eye area of m. longissimus dorsi with the qualitative characteristics of beef carcasses evaluated in accordance with international standards, there is a tendency for both weak inverse and linear relationships with their conformation, the development of subcutaneous fat and its thickness, colour and marbling of muscle tissue.Comparison of results with data from literature sources on correlations between the loin eye area of m. longissimus dorsi and the animal slaughter indicators, technological and sensory properties of meat from animals of

Table 7. Correlation coefficients between the loin eye area of m. longissimus dorsi and sensory characteristics of beef broth in bulls
The area of loin eye in bulls... different breeds in most cases coincide.This indicates the possibility of using this method to predict the composition of carcasses and the sensory and technological properties of beef.
Among the characteristics of carcasses, an increase in the loin eye area of m. longissimus dorsi indicates only an increase in quantitative characteristics of muscle tissue yield in cuts, including those of the highest and first grades.It has no correlation with the moisture retention capacity of meat, which determines the technological quality of many meat products during thermal (boiling) processing.
Since the loin eye area of m. longissimus dorsi has a linear correlation with the quantitative characteristics of beef, rather than sensory characteristics that depend on the chemical composition, including the content of total fat in the middle of the muscle, in many countries of the world, the loin eye area is supplemented by the severity of meat marbling when assessing the quality of cattle carcasses.Thus, beef marbling is determined in the carcass quality assessment systems of the USDA (2001), JMGA (2000) and MSA (2015).In Ukraine, the demand for low-fat and biologically complete beef is growing.Such meat in the required amount is obtained from animals of the Ukrainian Black-and-White dairy breed.The biological feature of this cattle is that the beef from it is lean.At the age of 21 months, bulls of this breed have a mid-muscle fat content of only 2.6%.The curved relationships between meat tenderness, juiciness, taste, and muscle fat scores are aligned with its content of 15 to 17% (Thompson, 2004).Such cattle respond to satisfactory feeding with a significant growth of muscle tissue and late accumulation of fat.Since the quality characteristics of carcasses compared to beef quality are more sensitive to changes in animal husbandry management, J. Soulat et al. (2022) suggest that the same quality of carcasses or meat can be achieved under different conditions of keeping.According to R. Leighton et al. (2023), relying solely on their estimates by trained individuals may provide limited insight.Therefore, the findings of these researchers indicate that it is possible to manage the quality of carcass and beef using various methods of breeding, feeding, and housing.For Ukraine, it is currently important to develop ways to simultaneously improve the quantitative and qualitative characteristics of beef from animals of common breeds in the country.

Conclusions
Development of the loin eye area of m. longissimus dorsi in Ukrainian Black-and-White bulls aged from 18 to 24 months does not allow predicting the content of only quantitative characteristics in beef: slaughter weight (carcass), number of cuts of the highest and first grades, the content of fat tissue and tendons and ligaments in the carcass, but not qualitative characteristics, including sensory and physical characteristics, chemical composition of meat.
There is a direct correlation between the loin eye area and the pre-slaughter live weight of animals (r = 0.409; P > 0.95), the slaughter weight (r = 0.404; P > 0.95), the amount of muscle tissue (r = 0.355; P > 0.95), including the highest (r = 0.680; P > 0.999) and the first (r = 0.501; P > 0.99) grades, the content of fat tissue in the carcass (r = 0.477; P > 0.99); the data obtained confirm the possibility of using the cross-sectional area of the transverse muscle to predict the production of beef of a certain variety.The loin eye area of m. longissimus dorsi correlates inversely (r = -0.607;P > 0.95) with the amount lost when boiling beef, an important technological indicator, the amount of second-class muscle tissue (r = -0.377;P > 0.95), the development of subcutaneous fat (r = -0.395;P > 0.95), which protects the carcass from the penetration of pathogenic microflora, weathering and drying, affects the juiciness and tenderness of beef, the total weight of ash (r = -0.560;P > 0.95), juiciness of boiled meat (r = -0.522;P > 0.95), taste and aroma of broth (r = -0.587;P > 0.95).There is a tendency for an inverse correlation between the loin eye area and the total fat content in beef (r = -0.119),protein (r = -0.401),dry matter (r = -0.403),acidity (r = -0.458),colour of muscle tissue (r = -0.126),conformation (fleshiness) of carcasses (r = -0.127),penetration (r = -0.477),taste of cooked meat (r = -0.214),its aroma (r = -0.363),tenderness (r = -0.256), the residue after chewing (r = -0.442), the strength of the broth (r = -0.207),and to a linear relationship -the amount of tendons and ligaments (r = 0.331), marbling (r = 0.162), colour of fat tissue on the carcass (r = 0.276), transparency of the broth (r = 0.180).In the future, a study should be conducted to determine the management factors for raising and fattening animals of other breeds of cattle common in Ukraine, the correlation between the loin eye area of m. longissimus dorsi and quantitative and qualitative characteristics of beef, and to substantiate the qualitative characteristics of carcasses that would be combined with sensory, physical and technological properties evaluated with the participation of consumers.
Its area was calculated in accordance with Order No. 290 "On Approval of the Instruction on Evaluation of Boars and Sows for the Quality of Offspring in Specialised Testing Stations" (2004) (equation 1): S = a x b х 0,8;

Figure 1 .
Figure 1.Schematic division of bull carcasses into zones Notes: Length (1) and depth (2) of the loin eye, (3) subcutaneous fat thickness Source: compiled by the authors

Table 6 .
Bulgaru et al. (2022)nts between the loin eye area of m. longissimus dorsi and sensory properties of beef m. longissimus dorsi.The main reason for the inverse relationship between the development of the loin eye area of m. longissimus dorsi and the sensory properties of beef is the weak inverse correlation between this trait and the total fat content in muscle tissue, and the direct correlation with the marbling of meat.According to A.Listrat et al. (2020), juiciness, which has a positive effect on the quality of beef consumption and which in the mouth is characterised by the amount of juice during chewing, also closely correlates with the fat content inside muscles.Increasing the area of the loin eye of m. longissimus dorsi partially contributes to the reduction of a valuable technological property -the tenderness of meat.Optimal distribution of total fat content inside muscle tissue can improve the tenderness of beef.V.Bulgaru et al. (2022)found that tenderness is significantly affected by the content of soluble proteins, fats, and collagen.Increase in the diameter of muscle fibres, due to which the loin eye area of m. longissimus dorsi increases, can be one of the main reasons for the deterioration of beef tenderness.