Veterinary-sanitary inspection of cattle meat affected with benign tumor

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Veterinary-sanitary inspection of cattle meat affected with benign tumor

Ivan G. Seregin¹, Evgeniya S. Baranovich¹, Vladimir E. Nikitchenko²*, Dmitry V. Nikitchenko³, Ekaterina O. Rystsova²

'Russian State Agrarian University -- Moscow Timiryazev Agricultural Academy, Moscow, Russian Federation

²Peoples' Friendship University of Russia (RUDN University),

Moscow, Russian Federation

³Ostankino Meat Processing Plant, Moscow, Russian Federation

Abstract

The rate of benign tumor detection in slaughtered cattle was studied. Tumor pathology was detected on average in 0.04% of the studied livestock. Manifestations of various new growths in this animal species have specific features. Tumors are detected 2--3 times more often in cows and bulls than in young animals. The veterinary and sanitary characteristics of cattle meat affected with benign tumors were compared with those of animal meat without tumors. Affected meat had deviations in physical properties, chemical composition of meat affected with tumors, content of primary protein breakdown products, volatile fatty acids (+0.05 mg/KOH) and amino-ammonium nitrogen (+0.54 mg/%) compared with meat of healthy cattle. It was revealed that the samples of meat affected with tumors were highly contaminated with microorganisms (0.28.. .0.80* 10²), including coliforms and St. aureus. Pathogenic bacteria of the genera Salmonella, L. monocytogenes, Cl. perfringensetc. were not detected in the test samples. In meat affected with tumors, relative bioavailability decreased by 4.99.13.87% and safety -- by 5.89.13.89% as compared to meat of healthy cattle. Based on the data obtained, proposals were developed on the most rational and safe use of meat from animals affected by benign tumors for food and feed.

Key words: Cattle, meat, tumor, detection frequency, veterinary and sanitary inspection, physical and chemical characteristics, microbiological research

Аннотация

veterinary sanitary quality meat neoplasm

Обоснования ветеринарно-санитарной оценки мяса крупного рогатого скота при доброкачественных опухолях

И.Г. Серегин¹, Е.С. Баранович¹, В.Е. Никитченко²*,

Д.В. Никитченко³, Е.О. Рысцова²

'Российский государственный аграрный университет --

МСХА имени К.А. Тимирязева, Москва, Российская Федерация ²Российский университет дружбы народов, Москва, Российская Федерация ³ОАО Останкинский мясоперерабатывающий комбинат,

Москва, Российская Федерация

Изучена частота выявления доброкачественных опухолей у убойного крупного рогатого скота. Опухолевая патология выявляется в среднем у 0,04% исследуемого поголовья. Отмечены особенности проявления различных новообразований у данного вида животных. В тушах коров и быков опухоли выявляются в 2--3 раза чаще, чем у молодняка. Определены ветеринарно-санитарные показатели мяса крупного рогатого скота при выявлении доброкачественных опухолей в сравнении с показателями мяса животных без поражения опухолями. Обнаружены при опухолях отклонения в физико-химических свойствах и химическом составе мяса, а также в содержании продуктов первичного распада белков, летучих жирных кислот и амино-аммиачного азота по сравнению с мясом здорового скота. В образцах мяса животных, пораженных опухолями, выявлена повышенная контаминация микроорганизмами (0,28...0,80^х10²), в т.ч. бактерии группы кишечных палочек и St. aureus.Патогенные бактерии рода Сальмонелла, L. monocytogenes, Cl. perfringensи др. в исследуемых образцах мяса не обнаружены. Отмечено снижение относительной биологической ценности на 4,99.13,87% и безвредности мяса животных, пораженных опухолями, на 5,89.13,89% по сравнению с мясом здорового скота. Полученные данные позволили разработать авторам предложения по использованию в пищевых и кормовых целях мяса животных, пораженных доброкачественными опухолями.

Ключевые слова: крупный рогатый скот, мясо, опухоли, частота обнаружения, ветеринарносанитарная экспертиза, физико-химические показатели, микробиологические исследования, ветеринарно-санитарная оценка

Introduction

Questions of benign and malignant neoplasms in animals are of great interest both from the general biological and medical, as well as from the veterinary points of view. According to several authors, benign and malignant tumors are found in different animal species. Tumors in domestic carnivores are detected in 0.7...1.4% of cases. According to literature data, tumors in slaughtered animals reveal 0.02...0.04% of the number of killed livestock [1--4].

The increased interest in the study of tumors is due to a noticeable increase in the frequency of their detection and economic losses in animal husbandry, which are associated with culling and slaughter of productive livestock in tumor diseases [5--8].

The study of the spread and frequency of detection of tumors in animals of different species is one of the important directions in research on the problem of cancer. The statistical data on the spread of tumor diseases in animals in different countries are quite contradictory. This is due to the fact that in some countries the diagnosis of tumors and registration of patients with tumors of animals is carried out more strictly, while in others this disease remains poorly understood and is not recorded [1,9, 10].

Information about tumors in animals that live to an extreme age (dogs, cats, horses, cattle, etc.) more fully reflects actual state of the problem under consideration, while information about tumors in other animals which are prone to slaughter at a younger age (pigs, sheep, goats, rabbits) is limited. It is known that various neoplasms are more common in animals in the second half of their life, i.e. in adulthood and old age. The infection of such animals by tumors is about 0.08...0.21%. But more often fattening animals are sent to meat processing plants at a young age, in which tumors are diagnosed less often. This makes it difficult to make a correct conclusion about the incidence of tumors in various animals, especially young cattle, sheep, goats, and pigs [11, 12].

According to clinical signs and pathological anatomical picture, tumors in animals are divided into benign and malignant. This classification is of great importance in the veterinary-sanitary examination of carcasses and organs of sick animals. When examining the products of slaughter, it is taken into account that benign or mature tumors consist of cells similar to tissue cells in which they develop. They are surrounded by their own membrane and have a feature -- central slow growth, while compressing the surrounding healthy tissues. Benign tumors can reach large sizes, while they do not have metastases and relapses. Benign tumors do not cause cachexia, except for tumors that violate patency in the gastrointestinal tract and in other pathways of various organs (bile duct, urinary tract). However, benign tumors, depending on their location, can also have a negative effect on affected organ and body as a whole.

Malignant tumors have a number of properties and pathological indicators that distinguish them from benign tumors. Malignant tumors grow much faster, without reaching large sizes and do not have a shell or a capsule. The histological picture of malignant tumors is significantly different from the tissue from which they develop. One of the characteristic signs of tumor tissue is anaplasia, i.e. return to a more primitive type. Malignant tumors are characterized by a characteristic growth, including ingrowth into healthy tissue, which leads to destruction of target cells. With such tumors, the body usually dies from cachexia and intoxication, which develop quite intensively. Malignant tumors are characterized by relapses and metastases [3, 13, 14].

The results of histological studies of organs and tissues of 11 357 patients with animal tumors conducted by T.P. Kudryavtseva [4] showed that neoplasms of various genesis in cattle are mainly represented by the following types of tumors: fibrosarcoma -- 543 cases (31.4%), spindle cell sarcoma -- 256 (15.2%), fibroma -- 248 (12.4%), neurofibroma and neurosarcoma -- 367 (31.0%), adenoma and adenosar- coma -- 106 (6.1%), angioma -- 58 (3.4%), cancer (oat cell, brain, etc.) -- 45 (2.6%), adenocarcinoma (glandular cancer) -- 72 (4.1%), myoma and myofibroma -- 19 (1.1%).

Tumors in farm animals cause some economic damage, because productivity decreases, which leads to culling and sending animals to slaughter [15, 16]. At veterinary sanitary examination organs affected with tumors are removed. Uninfected parts of carcasses and organs, according to the Rules of Veterinary Sanitary Inspection, are sent for processing. With extensive tumor damage, the carcass and organs are sent to the scrap.

Considering that carcasses are used for food purposes in case of tumors after removing, the need arises to conduct a comparative analysis of the quality and safety of meat from healthy and tumor infected cattle. This served as the basis for the study of cattle meat affected by neoplasms in a comparative aspect with meat of healthy animals of the same age groups [17, 18].

Materials and methods

The detection rate of benign tumors was determined in slaughterhouse during veterinary examination of cattle carcasses and organs.

Meat samples were taken in accordance with the requirements of the Rules of Veterinary Sanitary Meat Examination and GOST 7269--2015. Meat.Sampling methods and organoleptic methods for determining freshness.

Sensory assessment of meat was carried out on a 9-point scale developed by VNIIMP and according to GOST 9959--2015. Meat products.General conditions for organoleptic assessment.

Physico-chemical studies of meat were carried out according to GOST 23392--2016. Meat. Methods of chemical and microscopic analysis of freshness and in accordance with paragraph 13. 5 of Appendix 1 of the Rules of Veterinary Examination of meat and meat products (1988).

Microbiological studies of meat were performed according to GOST R 54354--2011. Meat and meat products.General requirements and methods of microbiological analysis.

Histological examinations were carried out according to GOST 31931--2012. Poultry meat.Methods of histological and microscopic analysis.

The relative biological value and harmlessness of meat was determined in experiments on Tetrachimenapyriyormis ciliates in accordance with the methodological recommendations [19, 20].

Results and discussion

Examination of cattle carcasses and organs of different age groups showed that benign tumors were usually detected in slaughter products of adult and old animals. These data are given in table 1.

Table 1 BenignTumor Detection Rate

Table 2 The results of organoleptic meat evaluation

The data from table 1 indicate that in the study of 16,680 carcasses of slaughtered cattle of different age groups, 7 carcasses with benign tumors were detected, which was 0.04% of the examined number. Tumors were found on skin, in individual internal organs and on nerve fibers of carcass. When examining the products of calves slaughter, tumors were not detected. In young animals, tumors were detected in 0.02% carcasses, in heifers -- 0.08%. Tumors were found 2--3 times more often in carcasses and organs of cows and bulls, and it amounted to 0.13...0.16%, which confirmed increase in cases of tumor pathology with increasing age of animals.

In cases of tumor detection, meat samples were taken and subjected to laboratory analysis. In the organoleptic evaluation of meat, all sensory research methods provided for by a 9-point scale were used. The data obtained are given in table 2.

The table 2 shows that cattle meat of different age groups affected with tumors received a score of 0.1...0.37% lower than meat of healthy animals. In general, such a deviation in all sensory indicators was about 0.99 points. The most pronounced deviations were identified when assessing the type, color and aroma of meat. These data allow to conclude that according to organoleptic indicators, meat of animals affected with benign tumors does not significantly differ from the meat of healthy cattle. This gives reason to use such meat under certain conditions for food purposes.

Physicochemical studies of meat were carried out on the day of the slaughter of animals. The results of a comparative analysis of meat of healthy and tumor-affected animals are given in table 3.

Table 3. Physico-chemical characteristics of cattle meat in tumors

Table 3 shows that, according to the physicochemical properties, meat of animals in presence of benign tumors does not have pronounced differences compared to meat of healthy animals. For example, the pH value did not exceed the values of benign meat. The lowest pH was observed for samples No. 2 and 5 and amounted 6.26 ± 0.03 and 6.24 ± 0.05, respectively. The highest pH was in samples No. 1 and 3 and amounted to 6.28...6.29 ± 0.05. The pH did not exceed 6.02 ± 0.04 in meat of healthy animals.

Peroxidase reaction also showed that meat with benign tumors meets the requirements of regulatory documents; there is no intensive accumulation of microorganisms in it. In four of five samples, the reaction showed a positive result -- the solution turned blue-green, which after a while turned brown. And only in sample No. 3, a dubious reaction was noted; the solution first remained transparent, then acquired a greenish color, which with a delay turned brown.

In the reaction of broth with a solution of copper sulfate, samples No. 1, 2, 4, 5 showed a negative result -- in all cases the broth was transparent. In sample No. 3, the mixture became unclear, which indicates initial processes of protein breakdown in this meat sample.

The formalin reaction with all meat samples had a negative result, i.e. the solution in all tubes remained clear.

When detecting tumors, the amount of volatile fatty acids (VFA) in the studied meat samples was 2.51...2.59 mg/KOH, in the control samples it was 2.49 mg/KOH.

In the content of amino-ammonia nitrogen in meat with benign tumors, there were no regular deviations from the control.

Fat acidity value in tumor-affected meat was 1.71...1.92 mg%, and 1.72 mg% in meat of healthy cattle.

These data reveal that meat of diseased cattle has slight deviations from meat of healthy animals and can be used for further processing for various meat products.

The results of studying chemical composition in meat with benign tumors are given in table. 4.

Table 4Chemical composition of cattle meat affected with benign tumors

Table 5Microbiological parameters of meat affected with tumors

The data in table 4 indicate that the highest moisture content was in meat sample No. 3 (74.68%). Samples No. 1, 2, 4, 5 showed approximately the same values for this indicator (74.01, 74.06, 74.22, 74.22%, respectively). The moisture content in the control meat samples did not exceed 74.14%.

The protein content was approximately at the same level in all samples and amounted to 19.82...20.36. Moreover, deviations in the tumor-affected meat indices did not exceed 0.54% as compared with the control.

The fat content in meat of all samples was also almost the same. A lower fat content was observed in all meat samples (4.29...4.78%) compared with meat of healthy cattle (4.52%).

For the ash content, the studied meat samples had no significant differences. Deviations in the content of ash elements were not more than 0.01...0.02%.

Analyzing the data, we can conclude that meat of cattle affected with benign tumors is not significantly different in chemical composition from the control, therefore, it can be used for food purposes.

The results of comparative microbiological study of meat are given in the table 5.

The data from Table 5 shows that the total microbial number (TMC, CFU/g) in all meat samples did not exceed the upper limits indicated in SanPiN 2.3.2. 1078--01, and amounted to no more than 28--80 microbial cells in 1 g or 0.28 ... 0.80 x 10² TMC, CFU/g. The highest microbial contamination rate was found in muscles of samples No. 3 and 4 (0.80 x 10², 0.76 x 10², respectively). Saprophytic microorganisms were detected in all the variants, but St. aureus was only in two meat samples; cells of coliform bacteria were detected in muscle tissue of sample No. 3. Such pathogens as Salmonella, Cl. perfrin- gens and Listeria monocytogenes were not detected in the studied meat samples. Only saprophytic microorganisms in the amount of 0.23...0.28 x 10² TMC, CFU/g were detected in control meat samples.

Conducted microbiological studies indicate that all five meat samples had bacterial contamination that did not exceed the requirements of regulatory documents.

However, some meat samples contained opportunistic pathogenic microflora, including coliform bacteria cells and Staphylococcus aureus.The presence of opportunistic pathogenic microorganisms in meat reguires limiting its implementation in case of tumor damage. Such meat must be sent for industrial processing with thermal disinfection, ensuring death of coliform and Staphylococcus bacteria, or sent to production of sausages and canned food.

For the scientific substantiation of the veterinary-sanitary inspection of cattle meat affected with benign tumors, we conducted additional studies on Tetrachimenapuri- yormis ciliates. Therefore, we determined the relative biological value of meat and its harmlessness. The results of the study are given in table 6.

Table 6. Relative biological value and harmlessness of tumor-affected meat

The experiments showed that in the nutrient medium with extract from fresh beef meat of sick animals, the intensity of infusoria cell accumulation was different and tended to decrease compared to the meat of control animals. The accumulation of infusoria in 1 ml of culture medium containing meat from animals affected by tumors decreased by 2.67 x 10⁴...6.01 x 10⁴ cells of protozoa (5.89...13.89%) compared to meat of healthy cattle. At the same time, cell shape and mobility were preserved and did not have significant differences from the control.

Total biological value of cattle meat affected with tumors was 4.99...13.87% lower compared to meat of healthy animals.

These data indicate that relative biological value of cattle meat with benign tumors is lower by 4.99...13.87%, and safety is lower by 5.89... 13.89% compared to meat of healthy cattle.

Conclusions

Analyzing the results of our studies and considering current data on tumor pathology in farm animals, we can conclude that tumors in animals have a certain distribution. Identified benign tumors are diverse in pathogenesis, shape and structure, but they are similar in clinical manifestation and effect on the animal's body.

Neoplasms in animals are still poorly studied, they constitute a special group of diseases and are of great importance for the veterinary-sanitary meat inspection and offal of slaughtered livestock. Benign neoplasms are found in cattle in 0.02...0.16% of cases from the number of practically killed livestock. In this case, the calves have no tumors. Nevertheless, since the true causes of tumors are still unexplored and scientific substantiation of veterinary evaluation of animal meat affected by tumors has not yet been developed, the need arises to determine the safest and most rational use of such meat for food purposes. However, consuming meat affected with tumors, we cannot assume what effect it has on the human body. Therefore, when tumors are found, carcasses and offal must be cleaned, unaffected parts and organs should be sent not for free sale, but for processing, followed by mandatory thermal disinfection. Such meat can be used for production of sausages, meat loaves or canned goods. In absence of such a possibility, after stripping, meat and offal should be sent to boil-down or to make jellied meat and jelly. Blood and endocrine raw materials for medical purposes are not collected. Skins must be processed and generally preserved by salting or brine. Feeding carnivorous pets with raw meat with tumors is not allowed, it should be utilized. Carcasses and offal having dystrophic changes in muscles and organs are sent to the scrap. When processing such meat, conditions of increased hygiene are created and personnel hygiene are more strictly observed.

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