Residual chlorinated pesticides and polychlorinated biphenyls in the eggs and adipose tissue of wild birds

In 1983 and 1984, in the State Veterinary Institute at Jihlava, 129 samples of eggs of wild birds of 14 species were analyzed coming from different regions of the Czech Socialist Republic for the presence of residues of chlorinated pesticides and polychlorinated biphenyls (PCB). Apart from this, nine samples of hawk fat and 27 samples of buzzard fat were examined. The method of gas chromatography with a detector of electron capture was used for the analysis. The analyzed samples were found to contain residues of PCB, DDT (and mainly its metabolite DDE), HCB, alpha-HCH, gamma-HCH. No residues of other chlorinated carbohydrates were detected. The residue levels of these substances in the eggs and fatty tissues of different species of wild birds vary within a very wide range. A significant influence is exerted on these levels by the differences in food spectrum, the age of the birds, lack of food causing mobilization of food reserves, and mainly the environment where the birds live. The highest levels of residues were found in the eggs and fatty tissues of predatory birds with a narrow spectrum of food, i.e. those feeding on other birds (sparrow-hawk 33.00 mg.kg-1 in the dry matter of eggs, hawk 239.98 mg.kg-1 in fat) or those associated with water (great crested grebe 11.97 mg.kg-1, sea-gull 11.24 mg.kg-1 in the dry matter of eggs). Much lower levels of the residues of the chemicals were recorded in the species feeding mainly on small rodents (kestrel 0.681 mg.kg-1, buzzard 2.456 mg.kg-1 in the dry matter of eggs and 11.398 mg.kg-1 in fat). Some of the samples under study contained dead embryos. These embryos had particularly high residue levels, often higher than the levels regarded in literature as toxic.     

Chlorinated pesticide residues and polychlorinated biphenyls in fish from various locations in Czechoslovakia

Samples of 14 fishes (175 samples on the whole) were examined in 1984 to 1986 for residues of chlorinated pesticides and polychlorinated biphenyls. Residues of the given substances were present in all the samples. The contents of chlorinated pesticide residues in fish are influenced mainly by the food spectrum; significant influence was also exerted by the contamination of the environment where the fish lived, by the age of the fish, and by the amount of their body fat in which the lipophile chlorinated carbohydrates are stored. No tolerance limits have been proposed in Czechoslovakia for the residues of chlorinated carbohydrates in fish bodies, except for the sum of DDT = 2.00 mg per kg of fat. When the data on the fish samples were compared with the highest admissible content of chlorinated pesticides per unit mass of fish muscle tissue tolerated in the FRG and the content of PCB tolerated in the USA, the fish from the Vltava river downstream of Prague fail to comply with these FRG and US regulations; all fish from all other places comply with them. Owing to large differences in the contents of fat in muscle between different fishes, it is more conclusive from the point of view of food hygiene to express the results as data per 1 kg of muscular tissue; these data represent real contents in fish as foodstuff.     

Studies on the effect of chlorinated hydrocarbons content in the compound animal feeding stuffs on the residues in turkey carcasses and efficiency of slaughter turkeys rearing

An increasing demand for turkey meat requires intensification of rearing, while almost permanent presence of stable chlorinated hydrocarbons in the environment, feeds, living organisms, including humans, to force undertaking studies on the wholesome safety of food of animal origin. The objective of the present study was therefore to evaluate selected cereals of different origin in terms of the content of chlorinated hydrocarbons (DDT, DDE, DDD, and HCH) as well as to determine the content of these compounds in turkey carcasses and their effect as feed material on the rearing efficiency. The investigations were carried out in 2002 on 100 one-day-old Big-6 turkey hens randomly allocated to 4 groups. For the period of 16 weeks, the animals were fed ad libitum with diets based on wheat and barley originating from different regions and characterized by different agricultural and industrial properties. Chlorinated hydrocarbons were determined in: animal feeding stuffs compound (wheat, barley, meat meal, extracted soybean meal), turkey blood, breast muscles, skin with external fat, and in abdominal fat by means of gas chromatography with an electron capture detector (ECD). The results obtained confirmed high contents of the examined compounds in feed material and in fat obtained from carcasses of the birds investigated.     

Higher Chlorinated Dioxins Implicated in the Mortality of Young Pigs Kept on a Pentachlorophenol-treated Wooden Floor

Young pigs raised on a pentachlorophenol-treated wooden floor showed a high mortality. The deaths ceased when the original treated wood was covered with untreated plywood. Analysis of the wood, mother's milk, and young pig tissues was carried out for pentachlorophenol and chlorinated dibenzo-p-dioxins. Pentachlorophenol was found in the wood and mother's milk but not in the young pig tissues. Concentrations of the higher chlorinated dioxins were found in the wood at the ppm level, in the mother's milk at the low ppt level and in the skin and liver of the young pigs at the ppb level. A comparison of the concentrations of hexa-and hepta-dioxin isomers in the wood, and in the piglet skin and liver indicated that a selective absorption and/or metabolism of these isomers had occurred. The results of this case history implicate the higher chlorinated dioxins in the mortality of the young pigs and underline the danger of using technical pentachlorophenol for wood treatment in association with food producing animals.     

Expression of adiponectin and its receptors in swine

Adiponectin is an adipocyte-derived hormone that plays an important role in lipid metabolism and glucose homeostasis. Objectives of this study were 1) to determine the presence and distribution of adiponectin and its receptors 1 and 2 (adipoR1 and adipoR2) in porcine tissues; 2) to characterize pig adiponectin, adipoR1, and adipoR2 mRNA levels in various fat depots from three different breeds of pigs; and 3) to study, in stromal-vascular cell culture, the effects of leptin and tumor necrosis factor-alpha (TNFalpha) on pig adiponectin, adipoR1, and adipoR2 gene expression. To this end, fat Chinese Upton Meishan (UM, n = 10), lean Ham Line (HL, n = 10), and Large White (LW, n = 10) gilts were used. We report the isolation of partial cDNA sequences of pig adipoR1 and adipoR2. Porcine-deduced AA sequences share 97 to 100% homology with human and murine sequences. Pig adipoR1 mRNA is abundant in skeletal muscle, visceral fat, and s.c. fat tissues, whereas adipoR2 mRNA is predominantly expressed in liver, heart, skeletal muscle, and visceral and s.c. fat tissues. Pig adiponectin mRNA levels in s.c. and visceral fat tissues were not associated with plasma insulin and glucose in fasting animals. Subcutaneous (r = -0.44, P < 0.05), visceral (r = -0.43, P < 0.05), and total body fat (r = -0.42, P < 0.05) weights were negatively correlated with adiponectin mRNA levels measured in visceral, but not s.c., fat. Pig adipoR1 and adipoR2 mRNA levels, in visceral fat, were less expressed in fat UM gilts than in the lean HL gilts (P < 0.05). Inverse associations were found between s.c. (r = -0.57, P < 0.01), visceral (r = -0.46, P < 0.05), and total body fat (r = -0.56, P < 0.01) weights and adipoR2 mRNA levels in visceral fat only. We were unable to find such associations for adipoR1 mRNA levels in the overall gilt population. The current study demonstrated that TNFalpha downregulates adiponectin and adipoR2, but not adi-poR1, mRNA levels in stromal-vascular cell culture. Moreover, leptin significantly decreased adiponectin mRNA levels, whereas there was no effect on adiponectin receptors. We conclude that adiponectin and adi-poR2 mRNA levels, but not adipoR1, are modulated in pig visceral fat tissues. Furthermore, our results indicate that TNFalpha interferes with adiponectin function by downregulation of adipoR2 but not of adipoR1 mRNA levels in pigs.     

Residues of chlorinated pesticides and polychlorinated biphenyls in pork and ham in past years and today

The contents of the residues of chlorinated pesticides and polychlorinated biphenyls (PCB) were investigated in 682 samples of ham and 926 samples of pork that were collected in the export meat plants. The investigation, based on the gas chromatography method with an EC detector, was performed in 1986. The tolerance of the residues of chlorinated pesticides was exceeded in 0.4% of the hams and 0.3% of the pork samples in that year. The PCB limit, proposed for pork (1.0 mg per kg of fat) was exceeded in 0.7% of the hams and 0.8% of pork samples; it can be seen from these data that the residue contents were considerably reduced in comparison with the year 1983 when this limit was exceeded in 7.0% of the hams and 6.2% of the pork samples. This decrease is due to the fact that the production of PCB was stopped, their use has been restricted, and the persons working with preparations containing PCB have been better informed about the chemical persistence, problems of residues and the like. The meat of wild boars is more contaminated than is the meat of the domestic pigs reared in large herds; this applies, first of all, to the residues of the DDT series (12.7% of the meat samples of the wild boars exceeded the limit of 2.0 mg per kg of fat) and also to the residues of HCB, lindane, and PCB. As for the PCB residues, the maximum tolerated residue content was never exceeded. A decrease in the contents of chlorinated pesticide and PCB residues resulting from the limited use of these chemicals is faster in the meat of the domestic pigs than in that of the wild boars.     

Identification of Differentially Expressed Genes and Lipid Metabolism Signaling Pathways between Muscle and Fat Tissues in Broiler Chickens

In this study, signaling pathways and key differentially expressed genes (DEGs) involved in lipid metabolism in muscle and fat tissues were investigated. Muscle and abdominal fat tissues were obtained from 35-day-old female broilers for RNA sequencing. DEGs between muscle and fat tissues were identified. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of DEGs were performed. A total of 6130 DEGs were identified to be significantly enriched in 365 GO terms, most of which were involved in biological processes, cellular components, and molecular functions in muscle and fat tissues. Three important lipid signaling pathways (pyruvate metabolism, the insulin signaling pathway, and the adipocytokine signaling pathway) were identified among the fat and muscle tissues of broilers. The key common DEGs in these pathways included phosphoenolpyruvate carboxykinase 2 (PCK2), acetyl-CoA carboxylase 1 alpha and beta (ACACA and ACACB), and the mitogen-activated protein kinase (AMPK) gene family. Hence, our findings revealed the pathways and key genes and gene families involved in the regulation of fat deposition in the muscle and fat tissues of broilers.     

Decrease in stearic acid proportions in adipose tissues and liver lipids in fatty liver of dairy cows

Samples of liver and perirenal, mesenteric and subcutaneous fat were collected from 16 sick necropsied dairy cows to evaluate the fatty acid profiles in the hepatic and adipose tissues associated with advanced fatty liver or hepatic lipidosis. Hepatic triglyceride and eight fatty acids were measured in the hepatic and adipose tissues. Six cows had more than 3% triglyceride on fresh weight in their livers and were classified as having fatty liver. Stearic and linoleic acid proportions in the liver decreased markedly with increased hepatic triglyceride levels, while the proportion of palmitic and oleic acids increased. The most striking fluctuations in hepatic lipidosis were manifested as decreased stearic acid in the adipose tissues including subcutaneous fat with the trend of decreasing stearic acid. Palmitic acid was elevated in hepatic and perirenal fat in fatty liver cows. In instances of advanced hepatic lipidosis, palmitoleic acid increased in only subcutaneous fat and not in perirenal or mesenteric fat. In addition to the proportions of hepatic fatty acids in fatty liver, this study also clarified the fluctuations observed in the profiles of fatty acids of the adipose tissues in cows with advanced hepatic lipidosis, particularly the decline in the proportions of stearic acid.     

Correlations between carcass traits and mRNA levels of CGI-105 and CCAAT/enhancer protein α genes in steers of Korean cattle

To understand the molecular mechanisms that regulate intramuscular fat deposition (marbling), cDNA clones expressed in adipose tissues of Korean cattle were identified and characterized. One clone had a total length of 1262 nucleotides coding for 314 amino acids. It was identified as one encoding bovine homolog of human CGI-105 mRNA. CGI-105 is a member of fumarylacetoacetate hydrolase family. Comparison of the deduced amino acid sequences of bovine CGI-105 with those of human revealed more than 89% identity. High levels of CGI-105 mRNA expression were detected in muscle, heart, and kidney tissues among various bovine tissues. Carcass traits, including backfat thickness, rib eye area, yield index, marbling score, and quality grade were analyzed in steer of Korean cattle. A CCAAT/enhancer binding protein alpha (C/EBPα) is one of adipocyte differentiation factors that may affect deposition of fat in muscle. mRNA levels of CGI-105 and C/EBPα genes were determined in the loin muscle tissues of steers. Correlation between carcass traits and mRNA levels of the genes was estimated by Pearson's correlation coefficient. The mRNA levels of C/EBPα showed strong positive correlation (r = 0.83, p < 0.01) with marbling scores. The results of the present study indicate that the manipulation of the expression of the C/EBPα gene may contribute to the development of a method for enhancing intramuscular fat deposition in beef.     

Effect of the starch sources barley, corn, potatoes and their ration fractions on the nutrient digestibility and energy utilization in ruminants. 1. Comparative studies of nutrient digestibility in cattle and sheep]

Rations with energy parts of 50, 25 and 10% from barley, maize and potatoes were investigated comparatively by means of total metabolism experiments with oxen with a view to arriving at a more precise estimation equation of net energy fat for cattle. Parallel to the investigations with oxen the energy and nutrients digestibility of the rations in wethers was measured. The crude fibre content of the rations ranged from 166 to 271 g and the starch content from 69 to 330 g/kg DM. The daily starch intake of the oxen ranged from 575 to 2739 g on nutrition level (NL) 1.7 and from 365 to 1804 g on NL 1.1. The energy digestibility of the rations in oxen with energy parts of 50% barley, maize and potatoes was on average 73.5, 73.9 and 75.3%, of the rations with energy parts of 25% on average 72.2, 71.6 and 72.4% and of the rations with energy parts of 10% on average 68.8, 69.5 and 69.8%. The digestibility of energy and nutrients in cattle and sheep was in good agreement excepted crude protein and crude fat; these were digested 4-5%-units lower from cattle than from sheep. The increase of the nutrition level by one unit lowered the digestibility of rations with energy parts of 50 and 25% from concentrates in cattle about 3-6 units and of rations with energy parts of 10% from concentrates about one %-unit. Information about rumen physiological data is given comparatively between cattle and sheep.     

绵羊β3肾上腺素能受体基因在脂肪组织中的表达研究

旨在对绵羊β3肾上腺素能受体基因在脂肪组织中的表达进行研究。本研究通过real-time PCR和免疫组化的方法检测了2个绵羊群体皮下脂肪、大网膜、小网膜、腹膜后脂肪、肠系膜和肾周等6种脂肪组织中ADRB3基因mRNA及其蛋白的表达量与分布情况。结果表明:ADRB3蛋白位于脂肪细胞的细胞膜中。ADRB3基因mRNA及其蛋白在皮下脂肪组织的表达丰度最小(0.159和0.139),在腹膜后脂肪组织的表达丰度最大(2.911和2.225),深层脂肪组织中ADRB3基因mRNA表达量要显著高于皮下脂肪组织(P<0.05),表明皮下脂肪组织的脂肪分解率要低于深层脂肪组织。品种对ADRB3基因mRNA的表达没有显著影响,但对于ADRB3蛋白的表达影响显著。不同脂肪组织中ADRB3表达丰度的差异反映了山西肉用绵羊的遗传稳定性较差。本研究的结果与已知的ADRB3调节脂肪分解和产热的功能是一致的,为利用ADRB3基因作为候选基因进行绵羊新品种的培育提供理论依据。     

Foreign substances in the meat and organs of bulls and pigs fed with pastes made from household and food industry waste in addition to pastes made from poultry droppings

The residues of antimicrobial substances, some chlorinated and organophosphate pesticides and chemical elements were studied in the meat and organs of a group of bulls fed food-waste paste for 240 days and a group of bulls fed the same paste with an addition of poultry waste. These residues were also studied in the tissues of pigs fed the food-waste paste for 135 and 151 days until slaughter. The feed ingredients were also examined during the feeding trials. Although some of the residues under study were found in the tissues of the test animals at increased amounts, their concentrations were diluted in the tissues in the majority of cases when the feed pastes were administered. All residue contents recorded in the tissues remained below the permissible limits as given in valid instructions and directives so that the products, i. e. meat and organs, could be deemed digestible on the basis of hygienic evaluation. Hence, from the point of view of the occurrence of residues of foreign substances in edible tissues, the administration of food-waste pastes to farm animals can be considered as admissible.     

Lolitrem B residue in fat tissues of cattle consuming endophyte-infected perennial ryegrass straw.

Lolitrems are neurotoxins found in endophyte-infected perennial ryegrass. Lolitrems, primarily lolitrem B, are the causative agents of ryegrass staggers in livestock. To guarantee the safety of meat produced from cattle consuming endophyte-infected perennial ryegrass, lolitrem B concentrations in tissues of Japanese Black cattle were determined using high-performance liquid chromatography. Lolitrem B was not detected in muscle, liver, kidney, or cerebrum of a Japanese Black cow with signs of ryegrass staggers. In contrast, perirenal fat contained 210 ppb lolitrem B. Three cows that received half as much perennial ryegrass straw as the cow with ryegrass staggers showed no clinical signs of ryegrass staggers. However, low concentrations of lolitrem B (less than 150 ppb) were detected in their fat tissue. These observations indicate that human exposure to the neurotoxic effect of lolitrem B through beef is unlikely. The amount of lolitrem B consumed by cattle can be estimated by the determination of lolitrem B in fat tissue.     

CPT-1基因在湘西黄牛不同组织中的发育性表达研究

[目的]为了比较分析肉碱脂酰转移酶-1(carnitine palmitoyltransferase 1,CPT-1)基因在湘西黄牛不同组织中的发育性表达规律,以探讨CPT-1基因与肉牛脂肪代谢的关系。[方法]试验选取湖南德农牧业集团有限公司国家级保种场不同月龄(6月龄、18月龄和30月龄)湘西黄牛各4头,利用实时荧光定量PCR检测肝脏、背最长肌、皮下和腹腔脂肪组织CPT-1基因的相对表达量。[结果]结果表明,(1)CPT-1基因在湘西黄牛肝脏、背最长肌、皮下脂肪和腹腔脂肪的4个部位中的表达量随月龄增加依次极显著降低(P<0.01)。(2)在6月龄、30月龄时,CPT-1基因在湘西黄牛肝脏、背最长肌、皮下脂肪和腹腔脂肪的4个部位中的表达量无显著差异(P>0.05)。(3)在18月龄时,CPT-1基因在皮下脂肪中的表达量显著高于背最长肌(P<0.05),肝脏与腹腔脂肪中CPT-1基因的表达量与其他3个组织中CPT-1基因的表达量无显著差异(P>0.05)。[结论]说明CPT-1基因对湘西黄牛机体脂肪代谢具有重要作用,CPT-1基因在湘西黄牛主要脂肪代谢部位(肝脏、背最长肌、皮下脂肪和腹腔脂肪)均有表达,且CPT-1基因的表达量随月龄与部位的不同,存在月龄间差异性和组织间相似性与差异性。     

蜕皮激素诱导家蚕蜕皮激素受体和超气门蛋白基因的表达变化

昆虫蜕皮激素受体(ecdysone receptor,EcR)是一种核内受体,为蜕皮激素的分子靶标。用0.002 g/L蜕皮激素溶液浸泡过的桑叶饲喂家蚕5龄幼虫,采用双跟踪标定定量PCR(dual-spike-in qPCR)方法,检测家蚕蜕皮激素受体基因BmEcR-A、BmEcR-B1和超气门蛋白(ultraspiracle,USP)基因BmUSP在家蚕幼虫马氏管、脂肪体、中肠组织的转录水平变化,分析蚕体组织以及BmEcR和BmUSP基因在蜕皮激素代谢过程中的作用与表达调控特征。结果表明:家蚕EcR的2种同工型基因BmEcR-A和BmEcR-B1的mRNA转录水平均变化显著,在脂肪体中的转录水平最高,其它组织相对较低;BmUSP的mRNA转录水平同样变化显著,且在脂肪体中的转录水平最高,马氏管次之,中肠最低。另检测正常情况下4龄眠期和5龄末期BmEcR-A、BmEcR-B1和BmUSP的mRNA转录水平相对于其它发育时期较高,且脂肪体中的转录水平要明显高于其它组织。BmEcR-A、BmEcR-B1和BmUSP均在家蚕幼虫脂肪体中高水平表达,表明了脂肪体在蜕皮激素代谢过程中的重要性。     

Radioimmunoassay of the anabolic agent zeranol. IV. The determination of zeranol concentrations in the edible tissues of cattle implanted with zeranol (Ralgro)

Rapid solvent extraction combined with a radioimmunoassay using a monoclonal antibody raised against a derivative of zeranol has been used to measure the residues of the anabolic agent zeranol in the edible tissues (muscle, liver, kidney and fat) of cattle treated with Ralgro. Calibration curves, both with and without, tissue extracts exhibit good parallelism. Regression analysis for the extraction of zeranol from tissues dosed with standard amounts of zeranol have correlation coefficients of 0.979, 0.991, 0.986 and 0.985 for muscle, liver, kidney and fat, respectively. The limits of decision defined as the mean value + 3 SD for the concentrations apparently observed (noise) in tissues from animals not treated with Ralgro were 278, 121, 373 and 110 ng/kg for muscle, fat, liver and kidney, respectively. In the tissues of 4 cows implanted with Ralgro (36 mg), and sampled 70 days after implanting, the highest concentration of zeranol in each tissue was 232 ng/kg (muscle), 391 ng/kg (liver), 287 ng/kg (kidney) and 293 ng/kg (fat), and residues were detected in all samples of fat (4), 3 kidney samples and 1 liver sample.     

Relationship between fat accumulation in the liver and energy intake, milk fat yield and blood metabolites in dairy cows

In the present study, 42 multiparous Holstein cows were used to investigate the relationship between fat accumulation in the liver and dry matter intake, milk yield and blood metabolites. Based on the percentage of fat in the liver cell at 2 weeks post‐parturition, the cows were classified into three groups. These groups were: (i) less than 10% of fat (normal group, n = 29); (ii) 10–20% of fat (mild group, n = 6); and (iii) more than 20% of fat (moderate group, n = 7). The bodyweight of the moderate group was high (771 kg) before calving. The sufficiency rates of total digestible nutrients (TDN) were remarkably decreased (approximately 65%) in early lactation. The milk fat yield and milk fat composition of the moderate group were higher (P < 0.05) than the other groups at 1 and 2 weeks post‐parturition. It was suggested that non‐esterified fatty acids (NEFA) mobilized from adipose tissues was directly used by the mammary gland for synthesis of milk fat. The percentage of bromsulfalein (BSP) retention of the moderate group was high (21.1%) at 30 min, and it showed that the BSP clearance function was significantly decreased. The concentrations of NEFA, β‐hydroxybutyric acid and glucose were appropriate indicators of energy status; however, aspartate aminotransferase, γ‐glutamyl transpeptidase and total bilirubin were not sensitive indicators of a moderate fatty liver. Thus, high‐yielding cows that calve in an overweight condition are more likely to develop excessive fat accumulation in the liver because of great mobilization from adipose tissues post‐parturition. In cows with a moderately fatty liver, a decrease in TDN sufficiency rates, an increase of milk fat yield and a reduction of liver function were observed in early lactation. The increase of serum NEFA and milk fat composition resulting from mobilization of adipose tissues helped to diagnose moderate fatty liver.     

吐鲁番黑羊MSTN/Smad信号通路基因表达的发育性变化

为探讨MSTN/Smad信号通路基因对吐鲁番黑羊肌肉生长发育的影响,采用实时定量PCR法,分别对1～6月龄吐鲁番黑羊的腿肌和尾脂MSTN/Smad信号通路基因进行检测.结果表明：MSTN/Smad信号通路基因在腿肌和尾脂组织中均有表达,MSTN/Smad信号通路基因在吐鲁番黑羊不同生长阶段的腿肌和尾脂中的表达没有出现随月龄的增加而一直增加或下降的趋势.