Carcass Mass Research Articles

Forest Environmental Conditions Shape Carcass Mass but Not Antler Investment of Red Deer Stags (Cervus elaphus L.)—Study from Western European Populations

Population stability depends on environmental conditions and their changes, as well as the availability of energy resources. Animals allocate their energy to maintenance, growth, reproduction, and energy storage; therefore, trade-offs are expected between life history traits. Access to abundant resources is expected to manifest itself in the investment of male individuals in sexually selected traits, such as carcass mass and antler size. The study aimed to analyze environmental climate conditions on the carcass and antler mass, as well as on antler form in red deer (Cervus elaphus L.) populations. We analyzed the carcasses and the antler masses and forms of 550 red deer stags from three populations in Central–Western Europe that differ in climate conditions that were hunter-harvested between the 2017 and 2021 hunting seasons. Our data indicated that carcass mass was shaped by the location of the population, stag age, precipitation, and temperature, as well as the number of frost days from January to the harvest date. Antler mass and antler investment depended on stag age but not climatic factors. Regular antler forms were more often observed in the harsh environmental conditions. Our observation confirms that resource trade-off is related to carcass mass of red deer.

The impact of stalking hunt season on long-term stress in big game

BackgroundThe frequent presence of hunters in hunting areas may have a negative impact on wild animals, which may disturb their welfare. Stressors may long affect individual animal species in different ways. Therefore, the study aimed to compare cortisol level in the hair of male mouflons, red deer, and wild boars harvested at the end of the stalking hunting season depending on the age and carcass mass. The cortisol level was determined using the DetectX® Cortisol ELISA Kits.ResultsThe concentration of cortisol in the hair of mouflons was almost six times lower than that of red deer and wild boars. Carcass mass and age researched animals did not affect cortisol levels.ConclusionsStalking hunts most likely do not impact the welfare of big game. There is probably habituation to long-term stress in the animals studied. Mouflons have the ability to respond effectively to specific stressors and are more resistant to long-term stress.

Comparison of Cortisol Levels in the Hair of Male European Roe Deer at the Beginning and End of the Stalking Hunting Season.

Roe deer (Capreolus capreolus), as a representative of the Cervidae family, are particularly sensitive to negative environmental stimuli due to their need to maintain increased vigilance during feeding. Intensive hunting seasons are undoubtedly also a stressful factor for this species. The aim of this study was to analyze the cortisol levels in the hair of male roe deer collected at the beginning and the end of the hunting season in eastern Poland. In total, hair samples from 26 individuals collected in May and 31 individuals collected in September were analyzed. The concentration of cortisol in the hair was determined using the EIA kit. It was shown that the concentration of cortisol was significantly higher in samples collected in September compared to those collected in May (Pr. > |t| = 0.0017). Moreover, the age of animals and carcass mass did not significantly affect the concentration of the tested hormone. In summary, the concentration of cortisol in the fur of male roe deer depended on the season and was not influenced by the carcass mass or age of the animals studied.

Features of growth and meat productivity of Hereford and Kalmyk bull calves

Abstract The purpose of the research is to study the peculiarities of growth and meat productivity of Hereford and Kalmyk bull calves bred in the conditions of the foothill zone of the Central Caucasus. The object of the research were Hereford (group I) and Kalmyk (group II) bull calves. A more complete realization of the genetic growth potential of Hereford cattle took place by the end of the research – at the age of 18 months, when the superiority of animals of this breed over the Kalmyk breed representatives was 22.6 kg (P>0.99). Heavier hot carcasses of Herefords with a difference of 18.8 kg (P>0.99) testified to their greater fullness. As a result of the differences in the mass of the hot carcass and internal fat, the highest slaughter weight and its yield were obtained from representatives of the Hereford breed, who surpassed their peers of the Kalmyk breed in these indicators by an average of 21.4 kg (P>0.99) and 2.8 abs.% (P>0.99), respectively.

The Levels of Cortisol and Selected Biochemical Parameters in Red Deer Harvested during Stalking Hunts.

As a reactive species, the red deer is sensitive to both negative exogenous and endogenous stimuli. An intensive hunting period may have a particularly negative impact on game animals. The aim of this study was to determine the plasma cortisol level and biochemical parameters in 25 wild red deer (Cervus elaphus) harvested during stalking hunts in correlation with the sex and age of the animals. The mean cortisol concentrations in the stags and hinds analyzed in this study were similar (20.2 and 21.5 ng/mL, respectively). Higher HDL cholesterol values were found in the blood of the hinds than in stags (p < 0.05). Similarly, the mean levels of LDL cholesterol, lactate dehydrogenase, and alanine aminotransferase were higher by 21%, 16%, and 42%, respectively, in the blood of the hinds. In contrast, the levels of alkaline phosphatase, bilirubin, and aspartate aminotransferase were higher in the stags (by 30%, 49%, and 36%, respectively). There was a negative correlation of the cortisol concentration with urea and bilirubin and a positive correlation between cortisol and aspartate aminotransferase in the stags (p < 0.05). In turn, a negative correlation was found between the cortisol and urea levels in the hinds (p < 0.05). In summary, the stress caused by stalking hunts and the characteristic behavior of red deer during the mating season had an impact on chosen biochemical parameters. The increased concentration of cortisol resulted in a decrease in the carcass mass, which may lead to the deterioration of the physical condition of animals on hunting grounds.

Morphological changes in the liver of bulls after the use of adaptogens

The paper presents the results of a study of the influence of adaptogens of plant and animal nature on the productive qualities of Kazakh white-headed bulls and morphological changes in their liver. 40 6-month-old beef bulls were selected for the study, which were divided into 4 groups: I (control) group of bulls consumed only the basic diet, II — adaptogen leucea safflower, III — drone homogenate, IV — pantocrine at the rate of 0.01 ml per 1 kg of animal body weight. At 18 months, a control slaughter of 3 animals from each group was carried out. During the experiment, it was found that the mass of the paired carcass in the bulls of the experimental groups increased by 11.1–21.7 kg (4.25–8.31%, р ≤ 0.05), the slaughter weight by 11.7–23.0 kg (4.24–8.34%, р ≤ 0.05–0.01), the slaughter yield by 0.9–1.9%. The analysis of the morphological composition of the carcass indicates an increase in the specific weight of its edible part of the carcass: by weight of muscle tissue by 4.0–7.7 kg (4.66–8.97%, р ≤ 0.05–0.01), fat — by 0.7–1.4 kg (4.67–9.33%, р ≤ 0.05). There is a high degree of maturity and high nutritional value of the meat of bulls of the experimental groups. Histological studies of the liver of bull calves indicate that when using tincture from drones, the liver structure corresponds to the norm, while in the control group animals some signs of dystrophic changes without pronounced infiltrations and signs of stagnation were found.

Influence of Hydroponic Feed With Phytobiotic Action on the Poultry Slaughter Parameters

The article describes the study of feeding birds by adding fenugreek plants, licorice root, amaranth grains to the feed ration of chickens, which have a phytobiotic effect and hydroponic grown grains of corn, barley, amaranth and fenugreek, which have high nutritional qualities and influence on the slaughter performance of birds in farms and private farms. The main indicators of the slaughter yield of the products of slaughter of young hens are analyzed: slaughter live weight, the mass of non-stranded carcass, the mass of half-gutted carcasses, the mass of gutted carcasses, and also the slaughter yield. Studies have established that the live weight of broilers of the experimental group before slaughter is higher by 13.19% (p≤0.001), an indicator of the control group. The differences are established due to the positive influence of chelating microelements on the biochemical processes in the bird's body, which in turn leads to the effective assimilation of the nutritional components of the diet, as well as the feed supplement, do not cause changes in the clinical state, pathological changes at macro- and microscopic levels in the body of broiler chickens.

Influence of carcass mass on decomposition rate: A medico‐legal entomology perspective

AbstractBody decomposition is influenced by various factors, including temperature, rainfall, body mass, and the activities of insects and carnivores in areas where carcasses are abandoned. However, the specific impact of carcass mass on the decomposition rate remains unclear. Therefore, this study aimed to compare the effects of carcass mass on decomposition rate with controlled domestic environmental conditions. Carcasses were categorized as small and large. Decomposition patterns were evaluated using a visual scatterplot to illustrate the relationship between total body scores and log accumulated degree days (ADD). To quantitatively compare decomposition rates, a linear regression model was employed to analyze differences between the two carcass groups. Regardless of carcass mass, a similar oviposition period for flies (Diptera) was observed, and the external appearance of the carcass remained relatively stable until 1.8 logADD, marking the emergence of maggots. However, decomposition dramatically accelerated after reaching 1.8 logADD, coinciding with maggots hatching from eggs and their commencement of scavenging. In contrast to larger ones, the hastened decomposition of small carcasses can be attributed to the relatively substantial volume of Diptera larvae within the small carcasses, expediting colonization and utilization. Therefore, carcass mass should factor into postmortem interval estimation based on the degree of body decomposition.

Effects of Dietary Allitol and D-Allulose on Body Fat Accumulation and Cecal Short-Chain Fatty Acid Production in Rats Fed a High-Fat Diet.

We investigated the effects of a single and simultaneous intake of allitol and d-allulose on body fat accumulation and cecal short-chain fatty acid (SCFA) production and accurately assessed the contribution of rare sugars to body fat in rats fed a high-fat diet that led to obesity. Thirty-two male 3-week-old Wistar rats were randomly divided into four groups: control, allitol, d-allulose, and allitol + d-allulose. The rats were fed experimental diets and water ad libitum for 11 weeks. High doses of allitol or d-allulose can induce diarrhea in rat; hence, each group of rats was acclimated to 1-5% allitol and d-allulose incrementally for the initial 20 days. After the feeding period, all rats were euthanized and collected tissues. Perirenal, mesenteric, and total intra-abdominal adipose tissue weights were significantly reduced by dietary d-allulose, whereas dietary allitol tended to decrease these adipose tissue weights. Both allitol and d-allulose significantly decreased carcass and total body fat mass. We confirmed that both dietary allitol and d-allulose inhibited body fat accumulation; however, d-allulose did not inhibit hepatic lipogenesis and no synergy was observed between dietary allitol and d-allulose in terms of anti-obesity effects. Dietary allitol significantly increased cecal SCFA levels and these effects were more potent than those of dietary d-allulose. The antiobesity effect of allitol may be due to the action of SCFAs, especially butyric acid, produced by the gut microbiota. Many of the effects of allitol as an alternative sweetener remain unknown, and further research is required.

ВЛИЯНИЕ СЕЛЕНА НА МЯСНУЮ ПРОДУКТИВНОСТЬ БРОЙЛЕРОВ

The research results have been given in the article on selenium containing preparation influence on broilers meat production. Determined that the preparation using in broiler rations (experimental group 1 — 0.7 mg of preparation per 1 kg of feed, experimental group 2 — 0.9 mg/kg and experimental group 3 — 1.1 mg/kg) promoted eviscerated carcass mass increasing by 2.52%; 5.46% (P&lt;0.01) and 4.03% (P&lt;0.05) respectively; carcass edible parts mass by 3.08%; 6.64% (P&lt;0.01) and 5.02% (P&lt;0.05); breast muscles mass by 3.20%; 6.77% (P&lt;0.05) and 5.04% (P&lt;0.05) in comparison with the control group. Meat quality has improved in broilers of experimental groups: dry matter content in breast muscles has increased by 0.12%; 0.24% (P&lt;0.01) and 0.19% (P&lt;0.05); protein content has increase by 0.25% (P&lt;0.05); 0.44% (P&lt;0.01) and 0.33% (P&lt;0.05); fat content by 0.06%; 0.11% (P&lt;0.05) and 0.13% (P&lt;0.01). The best traits of meat yields and quality has been found in broilers that have received 0.9 mg of selenium containing preparation per 1 kg of feed.

КОРМОВАЯ ДОБАВКА ИЗ ОТХОДОВ РАСТИТЕЛЬНОГО СЫРЬЯ

Some new feed ingredient search and balancing feed additives development at these ingredients base are one of the main tasks for agricultural animals and poultry full value nutrition. Spent grain has been considered as perspective raw material for poultry feeding. Spent gray is by-product of beer production. This component has high biologic potential in accordance with the modern researches due to alimental fiber and beta glucan content. These matters contribute modulate balance and microbial populations activity in animal intestine. Spent grain usage is advisable in combination with mineral complex that stimulate poultry production. The results of complex feed addition usage have been given in the article for Texas white breed laying quail ration. This feed additive contains modified spent grain, mineral sorbent and probiotic microorganisms. Given data shows that such additive usage has helped to increase laying quails egg production by 12.9%, quail livability by 5.0%, eviscerated carcass yield by 3.0%, breast muscles mass in eviscerated carcass mass by 1.4% and also to reduce feed cost per 10 eggs by 9.3% and first egg age by 3 days. The additive feeding didn’t influence negatively on blood serum biochemical traits and poultry internal organs development. The quails had no structural and functional pathologies.

Improving Shelf Life and Content of Unsaturated Fatty Acids in Meat of Lambs Fed a Diet Supplemented with Grape Dregs.

This study was conducted to evaluate the potential effects of dietary grape residue levels on the slaughter indicators, meat quality, meat shelf-life, unsaturated fatty acid content, and expression of fatty acid deposition genes in the muscle of lambs. Sixty 30-month-old male Dorper and Small-Tailed Han F1 hybrid lambs were assigned to a single factor complete randomized trial design and fed with four different diets including 0%, 8%, 16%, and 24% grape dregs, respectively. The findings regarding meat production efficacy in the lambs revealed substantial differences. The control group showed notably lower dressing percentage, carcass weight, net meat weight, meat percentage concerning carcass, meat-to-bone ratio, relative visceral and kidney fat mass, and rib eye area compared to the other groups (p < 0.05). Additionally, the meat shearing force of lambs fed a diet with 16% grape pomace (GP) was significantly higher than that of the 24% GP group (p < 0.05), while the 24 h meat color parameter a* value of the control group was notably higher than that of the 8% GP group (p < 0.05). In addition, compared to the control group, lambs fed with a diet containing 16% GP had higher levels of oleic acid (C18:1n-9c), linoleic acid (C18:2n-6c), behenic acid (C22:0), tricosanoic acid (C23:0), lignoceric acid (C24:0), and conjugated linoleic acid (CLA), at a ratio of ∑CLA/TFA, ∑n-6, ∑MUFA, and ∑PUFA in the longissimus dorsi muscle (p < 0.05), but the reverse case was applicable for Total Volatile Basic Nitrogen (TVB-N) content (p < 0.05). GP supplementation did not substantially affect the expression of stearoyl-CoA desaturase (SCD), peroxisome proliferator activated receptor alpha (PPARα), and peroxisome proliferator-activated receptor gamma (PPARγ) genes (p > 0.05). The findings indicated that incorporating grape dregs in the diets of fattening lambs leads to notable enhancements in meat production and the antioxidant capacity of lamb meat, and effectively extends the shelf life of the meat.

PRODUCTIVE AND INTERIOR INDICATORS OF KALMYK BEEF CATTLE BULLS IN THE FOOTHILL ZONE OF DAGESTAN

The results of the cultivation of Kalmyk cattle bulls of different birth periods in the conditions of the foothill zone of the Republic of Dagestan are presented. It was noted that the young of the I – spring season of birth to weaning at the age of 8 months had a live weight of 182.1 kg, and the peers of the II group reached 195 kg. The differences in live weight indicators in bulls of the winter birth season were 12.9 kg or 7.1 % more at P≤0.05. At 18 months of age, bulls of the winter birth period with a live weight of 454.4 kg were removed from fattening, and peers 425.8 kg, respectively. The advantage of bulls of the winter period of birth in live weight over their peers was 28.6 kg, or 6.7 % (P≤0.001). Animals of the winter birth season also outperformed their peers in average daily growth by 51 g, or by 6.8 %. The animals of the winter period of birth had heavier carcasses with uniform watering compared to the bulls of the spring period of birth. According to the mass of the paired carcass, the difference was 22.01 kg, in favor of the young animals of the winter period of birth, or it was 9.9 % more in comparison with the bulls of the spring period of birth. At the same time, the slaughter yield was 56.6 % for the first group, and 58.2 %, for the second group, or it was in favor of the bulls of the experimental group of the winter period3a4 birth by 1.6 %. It has been established that animals of the winter birth season, fed using the cow-calf technology in the foothill province of Dagestan, have higher productivity indicators compared to analogues of the spring period.

Estimating energy utilization in laying hens: what are the best response criteria?

An experiment was conducted to evaluate the effects of varying dietary energy on the performance and energy storage in laying hens from 36 to 52 wk of age. A total of 252 Hy-Line W-36 laying hens were housed in cages with 3 birds per cage and 12 replicate cages per treatment. Birds were control fed 1 of 7 experimental diets ranging in dietary energy from 2,750 to 3,050 kcal/kg with a 50 kcal/kg difference among each of the diets. Egg production, energy intake, feed intake, egg weight, egg mass, and feed efficiency were calculated every 2 wk so that performance data could be analyzed every 2 wk using repeated measures analysis. Hens were weighed every 4 wk for repeated measures analysis and carcass total, lean, and fat mass were determined at 52 wk using dual X-ray absorptiometry. Correlations between dietary energy and energy intake with performance parameters, and body composition were generated. Dietary energy (kcal/kg) was significantly correlated with all performance parameters except hen housed egg production (HHEP; P = 0.07) and lean carcass mass (P = 0.60). For dietary energy, the highest correlations were total carcass mass (r = 0.60) and carcass fat mass (r = 0.54). Energy intake (kcal/d) was significantly correlated with all performance parameters except feed intake (P = 0.18). The highest correlations were between energy intake and total carcass mass (r = 0.63) or body weight (r = 0.51). These results suggest that dietary energy has a more pronounced effect on body mass and fatty tissue over the short run (16-wk period) before direct performance responses are observed. Therefore, hen body weight and composition can be used as a more sensitive measurement of shorter-term hen energy status than egg production or feed efficiency.

Transcriptome Analysis Reveals the Age-Related Developmental Dynamics Pattern of the Longissimus Dorsi Muscle in Ningxiang Pigs.

The growth and development of the Longissimus Dorsi muscle are complex, playing an important role in the determination of pork quality. The study of the Longissimus Dorsi muscle at the mRNA level is particularly crucial for finding molecular approaches to improving meat quality in pig breeding. The current study utilized transcriptome technology to explore the regulatory mechanisms of muscle growth and intramuscular fat (IMF) deposition in the Longissimus Dorsi muscle at three core developmental stages (natal stage on day 1, growing stage on day 60, and finishing stage on day 210) in Ningxiang pigs. Our results revealed 441 differentially expressed genes (DEGs) in common for day 1 vs. day 60 and day 60 vs. day 210, and GO (Gene Ontology) analysis showed that candidate genes RIPOR2, MEGF10, KLHL40, PLEC, TBX3, FBP2, and HOMER1 may be closely related to muscle growth and development, while KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis showed that DEGs (UBC, SLC27A5, RXRG, PRKCQ, PRKAG2, PPARGC1A, PLIN5, PLIN4, IRS2, and CPT1B) involved the PPAR (Peroxisome Proliferator-Activated Receptor) signaling pathway and adipocytokine signaling pathway, which might play a pivotal role in the regulation of IMF deposition. PPI (Protein-Protein Interaction Networks) analysis found that the STAT1 gene was the top hub gene. Taken together, our results provide evidence for the molecular mechanisms of growth and development and IMF deposition in Longissimus Dorsi muscle to optimize carcass mass.

Meat productivity of bulls of the Simmental breed and crossbreeds with blood relationship (? Simmental + ? Aberdeen-Angus), (? Simmental + ? Kalmyk)

The aim of the study was to establish the characteristics of the meat productivity of steers obtained from crossing Simmental cows with Aberdeen-Angus and Kalmyk bulls, depending on the cultivation technology. Scientific and economic experiments were conducted in three farms of the Karachay-Cherkess Republic: LLC firm Hammer (experience 1); SEC PZ Zarya -1 (experience 2) LLC Yugagrohim (experience 3) in 2021-2022. For the entire period of cultivation in crossbreeds (? Simmental + ? Aberdeen-Angus) in the first experiment, the average daily increase was 711 g, 8.5 energy feed units were spent on 1 kg of increase, while the increase in Simmental bulls was 655 g per day, 10.4 EQ was spent on 1 kg of increase, or 22.35% more. The crossbreeds (? Simmental + ? Kalmyk) were closer to the bulls of the Simmental breed in terms of growth and payment of feed. In the first, second and third experiments, the crossbreeds (? Simmental + ? Aberdeen-Angus) outperformed purebred simmentals by: pre-slaughter live weight by 29.7 (P&gt;0.999), 12.1 and 13.9 (P&gt;0.99) kg; the mass of the paired carcass by -18.5, 8.9 and 8.6 kg (P&gt;0.99 – 0.999); internal fat weight by – 3.1 (P&gt;0.999), 0.6 and 2.4 (P&gt;0.99) kg; slaughter weight by – 21.6, 9.5 and 10.2 kg (P&gt;0.99–0.999); slaughter yield by -1,07,0,66 and 0.49 abs.%; half-carcass weight by 9.1, 4,5. and 4.5 kg (P&gt;0.99–0.999); muscle mass by -6.13 (P&gt;0.999), 3.0 (P&gt;0.95) and 3.74 (P&gt;0.99) kg; adipose tissue by–3.75 (P&gt;0.99), 1.91 and 0.58 kg, respectively.

Growth energy and quality of beef from bulls of Maine-Anjou, Chianina, and Santa Gertrudis breeds grown in Ukraine

Zonal genotypes have already been created using imported breeds to increase the number of meat cattle in Ukraine, but not enough studies related to the specific features of breeding and feeding imported genotypes in the Steppe zone of Ukraine have been conducted, which is relevant. The purpose of the study is to examine the productive and slaughter indicators of bulls of imported meat breeds of various ecological and genetic origins in the climatic conditions of the steppe zone of Ukraine. Zootechnical, morphometric, biometric, and statistical methods were used in the research. The results of an analysis of the meat productivity of bulls of imported meat breeds of Maine-Anjou, Chianina, and Santa Gertrudis in the age aspect in the conditions of the steppe of the Dnieper region of Ukraine are presented. It was identified that when slaughtering experimental animals at the age of 18 months, the mass of paired carcasses of Maine-Anjou and Chianina was quite high and amounted to 324.2 and 311.3 kg, respectively, and the Santa Gertrudis – 233.3 kg, which is 1.39 and 1.33 times less than the young animals of Maine-Anjou and Chianina, respectively. It is proved that to use livestock more efficiently and obtain high-quality beef to improve the supply of meat to the population, it is advisable to grow them up to 18-24 months of age. Maine-Anjou animals dominate in terms of growth energy, age of reaching live weight during key growing periods, and feed conversion. In addition, due to the pronounced massiveness and habit of the body, have a larger carcass mass, the amount of internal fat, offal, as a result of which, the slaughter yield is higher. Based on the conducted studies, the possibility of effective breeding of Maine-Anjou bulls up to 12 months of age is proved, since during this period they reach a live weight of 400 kg and are characterised by the high production rate of lean beef, and for Chianina breed – up to 18 months of age and bigger weight conditions

Hygienic assessment of 90Sr and 137Cs contamination of water and fish in the lakes of the head part of the peripheral zone of the East Ural radioactive trace

Introduction. The article presents the results of studies of the specific activity of 90Sr and 137Cs in the water and fish of the Irtyash and Kazhakul lakes located in the peripheral zone of the head of the East Ural Radioactive trace in 2014-2017.&#x0D; Materials and methods. Determination of the levels of specific 90Sr and 137Cs in the water and the body of the resource-forming species of Siberian roach (soroga, chebak) Rutilus rutilus lacustris (Linnaeus, 1758) from the studied lakes was carried out over the period of 2012–2017. The measurements were carried out using standardized methods adopted in in the Federal State Budgetary Institution of Health “Central Medical and Sanitary Unit No. 71 of the Federal Medical and Biological Agency of Russia” (FGBUZ TsMSCH No. 71 of the Federal Medical and Biological Agency of Russia) and the Southern Ural.&#x0D; Results. The research was carried out over 2014 to 2017. Since the accident at the Mayak enterprise in the fall of 1957, the specific radioactivity of the water in the studied lakes was found to decrease. The concentration of 90Sr in the water of Irtyash lake was 0.019±0.008, and 137Cs – 0.028±0.009, and in Lake Kazhakul – 0.19±0.06 and 0.14±0.06, respectively. These values are much lower than the level of intervention according to NRB-99/2009. &#x0D; The water of the lakes is used to meet household needs. The water of Lake Irtyash is used for drinking water supply of the city of Ozersk. The specific activity of the raw mass of a roach carcass from the Irtyash and Kazhakul lakes for the accumulation of 90Sr is 2.7± 1.7 and 64.5±19 and 137Cs – 1.68± 0.8 and 38±33.5Bq/kg, respectively. All the samples studied separately according to 90Sr and 137Cs had levels of radioactive contamination at or below the regulatory compliance indicator (SanPiN 2.3.2.1078–01). At the same time, taking into account the absolute extended uncertainty (with a coverage factor of k = 2) roach from Kazhakul lake has a significant excess of the limit level of radioactive contamination.&#x0D; Limitations. Hydrochemical parameters of the aquatic environment in various reservoirs can vary significantly over time and affect the accumulation of radionuclides by hydrobionts. Therefore, the research results are relevant only for the research period. To obtain more reliable results, long-term comprehensive monitoring is necessary.&#x0D; Conclusion. Over the past 60 years after the accident at the Mayak enterprise in 1957, the levels of radioactive contamination of water and fish in the studied lakes Irtyash and Kozhakul have decreased by more than 10 times. Calculation of doses of ionizing radiation for certain groups of the population of areas contaminated as a result of accidents, living near lakes, is a complex task, for which additional research is needed.

Raised in changing climatic conditions arid conditions of the Volga region

The author proved the high adaptive abilities of sheep of the Stavropol breed, indicators of meat productivity and meat quality, as well as the possibility of further breeding of this breed in arid conditions. The research was conducted in CJSC "New Life" of the Novouzensky district of the Saratov region. The object of research was purebred rams of the Stavropol breed of different intrabreed productivity types. It was found that sheep of wool and wool-meat types grew equally from birth to weaning from mothers, but at 7.5 months the wool-meat type had a live weight of 4.83% higher compared to wool. Morphobiochemical parameters in young animals of both groups were within acceptable norms, but a slight excess was found in the wool-meat type. Sheep of the wool-meat type were superior to wool in pre–slaughter live weight by 4.83%, the mass of the paired carcass – 9.22%, in slaughter yield - 1.73%. The young animals of the wool-meat type had more protein by 0.60%, the wool-fat by 0.70%, so their meat is more complete.

Hunting for ecological indicators: are large herbivore skeleton measures from harvest data useful proxies for monitoring?

Hunter-collected data and samples are used as indices of population performance, and monitoring programs often take advantage of such data as ecological indicators. Here, we establish the relationships between measures of skeleton size (lower jawbone length and hind-leg length) and autumn carcass mass of slaughtered individuals of known age and sex of the high Arctic and endemic Svalbard reindeer (Rangifer tarandus platyrhynchus). We assess these relationships using a long-term monitoring dataset derived from hunted or culled reindeer. The two skeleton measures were generally strongly correlated within age class. Both jaw length (R2 = 0.78) and hind-leg length (R2 = 0.74) represented good proxies of carcass mass. These relationships were primarily due to an age effect (i.e. due to growth) as the skeleton measures reached an asymptotic size at 4–6 years of age. Accordingly, strong positive correlations between skeleton measures and carcass mass were mainly evident at the young age classes (range r [0.45–0.84] for calves and yearlings). For the adults, these relationships weakened due to skeletal growth ceasing in mature animals causing increased variance in mass with age—potentially due to the expected substantial impacts of annual environmental fluctuations. As proxies for carcass mass, skeleton measurements should therefore be limited to young individuals. Although body mass is the ‘gold standard’ in monitoring large herbivores, our results indicate that skeleton measures collected by hunters only provide similar valuable information for young age classes, particularly calves and yearlings. In sum, jaw length and hind-leg length function as proxies identical to body mass when documenting the impacts of changing environmental conditions on important state variables for reindeer and other herbivores inhabiting highly variable environments.