Dr. Claudio C. Fioretti
Director of Genetics, Stays and Cabaña Las Lilas SA
The composition of the carcass is controlled genetically
The weight of the housing, ribeye area, subcutaneous fat and degree of marbling are highly heritable characteristics that significantly affect the yield and quality butcher, giving farmers the opportunity to improve the final product, the meat .
The composition of the response is critical in determining the performance and meat quality, including tenderness, flavor and juiciness. The eventual implementation of a value base from the meatpacking plants-system by which a price is assigned to each animal according to the composition of his response, benefit troops with good marbling (intramuscular fat) and optimal termination, also allowing the genetic potential for higher returns is reflected in economic terms.
In our production systems, the termination of the estate, as measured by the coverage or subcutaneous fat, traditionally fluctuates with supply forage for different seasons. Within this context, the troop slaughtered experience also indicates the need for improved uniformity, throughput and quality of the cuts obtained.
There are different assessments about how to control the body composition of the farm for slaughter. Many consider that the solution is only for food. Nutrition, with its variants, undoubtedly affects the composition of the cabinet, but these settings alone do not follow the trend of the consumer market. Therefore, the relationship between nutrition and lack of uniformity and quality musculature slaughtered troops deserves
Before production, the farm must be maintained and adapted to the environment. This means that after completion of maintenance requirements, excess nutrients can be used for the growth and development of body tissues, the main bone, muscle and fat. Among these, bone and muscle have priority over the use of nutrients, fat deposited last.
This explains why young animals grow rapidly accumulating a minimum proportion of fatty tissue. Upon reaching maturity, growth and development of skeletal muscle significantly decreases or stops, using extra supply of nutrients and energy storage in the form of fatty deposits.
It is important to note that the percentages of bone, muscle and fat dependence within each sex-age and physiological state of the animal genetic potential to produce possess. While the muscle tissue is rich in proteins, they increased above normal requirements, it is not in cattle with outstanding musculature. Excess protein intake is stored as fat and transforms, because the muscle building is governed by genetic codes. The same applies to the behavior of fat tissue: if the nutrient levels are adequate for rapid and efficient, the percentage and fat distribution is determined genetically.
There is scholarly consensus about the medium and high heritability with that express the characteristics of the response. This means they are little influenced by the environment (nutrition and management) that respond to genetic selection. Within these features include the weight of the carcass, the rib eye area and the thickness of subcutaneous fat and muscle as indicators of accumulated fat, respectively, and the degree of marbling, as quality indicator butcher. Table 1 shows the average heritabilities for each of these features.
Table 1. Heritability of the response characteristics
Degree of marbling
Undoubtedly, a uniform and good quality is desirable for the industry and the consumer market. This is achieved by weight fishing troops defined and uniform in type.
In our country, much of the lack of uniformity in the task is due to the various categories that accepts the market: from the ‘calf ball “through the heifer and steer consumption, and ending with the heavy export. These animals not only differ in their slaughter weight but also in body composition.
Another important aspect to consider is the genetic diversity. While this contributes to the productive efficiency through planned crossbreeding, especially where there is complementarity of races, it is worth remembering that the latter is not a guarantee of excellence. Crosses, in general, improve the characters of low heritability-playing, for example, but slightly above the parental lines that originated them. Moreover, heterosis or hybrid vigor is low in animal growth, and nonexistent in carcass characteristics. Therefore, it may be more advisable to use detours selected by the productivity of a strain, that breeding programs based on genetic resources mediocre.
The cut yield (kilos of meat obtained on the total weight of the carcass) is a good measure of the percentage of boned and ready for sale. This rate is strongly affected by the amount of animal fat-especially the subcutaneous and intermuscular (located between the main muscle mass) – and to a lesser extent by the musculature and weight of the animal. Therefore, the performance, as such, is a key element in determining the commercial value of the carcass.
The weight of the casing is highly heritable and is a good estimate of the total weight of the cuts despostados. The ribeye area (eye muscle), meanwhile, is an important indicator of weight and percentage yield of cuts, and is also the largest muscle and greater economic value of the res. That is, with increasing the ribeye area, so does the cutting performance. Therefore, it is important to note that if two animals have similar weight, the largest ribeye area will have better performance boneless cuts.
The association between performance and subcutaneous and intermuscular fat is strongly negative, indicating that higher fat thickness, the lower the percentage of “clean meat”. Fat accumulation varies with nutrition plans and genetic makeup, age and sex of the animal. However, there are significant differences in the total amount and configuration of fatty deposits in animals with equal power and physiological state. These differences are heritable and can be modified using genetic selection.
The most important factor in determining the quality butcher’s degree of marbling or veining. While intramuscular fat is deposited on the lesser amount, its presence greatly improves the palatability of the meat. This feature is highly heritable and is influenced mainly by physiological maturity (earliness) of the carcass.
There are some interpretations about showing that to achieve good grain, the troops must accumulate excess subcutaneous fat. Research does not indicate precisely this objective. Certain genetic strains accumulate enough grain with minimal fat cover, while others require a significant layer of fat to achieve a marbled acceptable. Again, these effects are due to genetic differences between animals, making it unlikely to modify nutrition and management. Another widespread belief is that the grain appears suddenly after a certain period of concentrates rich diet. That assessment does not coincide with labor studies, which indicate that the development of intramuscular fat in sufficient quantities match the physiological maturity of the animal. This explains why the farm of moderate size and early maturity fattening requires less time to achieve the same end as the larger body, whether they are of the same age and sex.
The racial composition and genetic variability are largely responsible for the performance and quality butcher. Fortunately, carcass traits respond to genetic selection, giving farmers the opportunity to improve the product obtained.
The more predictable production cuts, increased competitiveness will beef, both domestically and internationally, compared to other animal proteins. The collection and use of data indicative of the composition of the animal, as conventional progeny testing (slaughtered animals) or the use of ultrasound (live animals) are extremely important for the genetic progress of these features.
Dr. Claudio C. Fioretti
Address Genetics, stays
and Cabaña Las Lilas S.A.