Green Livers Research Articles

An Explorative Study of the Causal Pathogenesis of Green Liver Discoloration in Organically Reared Female Bronze Turkeys (Meleagris gallopavo) Considering the Infectious Risk Factors

A recent study revealed that organically raised Bronze turkeys showed a high prevalence of green liver discoloration. This alteration is commonly associated with the Turkey Osteomyelitis Complex and potentially caused by opportunistic bacteria. Therefore, 360 organically fattened Bronze turkeys were examined post-mortem throughout two fattening trials with two examinations each to determine possible infectious risk factors and reduce disease prevalence. Clinical and pathoanatomical examinations were performed on every hen. Histopathological, bacteriological, parasitological, and virological examinations were performed on at least six hens without and, if applicable, six hens with green livers on each examination date. Overall, 9.0% of all hens had a green liver without a correlation with bacterial or parasitological findings but multiple health impairments. The discoloration correlated significantly with the detection of immunosuppressive turkey hemorrhagic enteritis virus at the early stage and macro- and histological joint/bone lesions at the late fattening stage, indicating the presence of two different predisposing pathogeneses. Flocks not being vaccinated against hemorrhagic enteritis but having a virus-positive sample showed the highest prevalence of green liver discoloration and developed worse in various parameters. In conclusion, an adequate vaccination schedule and the prevention of field infections may lead to a decreased risk of performance reduction and improved animal health.

Khảo sát tỷ lệ nhiễm và sự đề kháng kháng sinh của vi khuẩn Escherichia coli trên vịt tại tỉnh Đồng Tháp

This study was carried out from October 2015 to September 2016 in four districts of Dong Thap province. The purpose of this research was to determine the ratio of E. coli infection in the analysis samples, to define the serotypes of pathogenic bacteria and to test the antibiotic susceptibility of E. coli isolated from ducks in Dong Thap province. In Dong Thap, the ducks for eggs are breeded mainly on the field, while the ducks for meat are raised in the captive way. The investigated results on 60,135 ducks showed that 18.36% of the ducks could be suspected by the E. coli infection. The ratios of the appearance of white-green diarrhea, swelled eyes, and neurology symptoms were 99.07%, 68.22%, and 20.69%, respectively. The E. coli infection ratio of the ducks was 99.53% with 81.22% lesion air sacs, 71.36% swell livers, and 12.21% green livers and edematous lungs. The E. coli infection ratios of different breeding methods, ages of duck, purposes of use, or farming seasons do not have statistically significant. The E. coli highly existed in the ducks, mainly was O78 (9.29%), and resited to several antibiotic with MDR phenotype.

ブロイラー鶏における緑色肝と骨髄炎との関連性

The green livers (GL) of broiler chickens were examined for a connection with osteomyelitis. More than 95%of broiler chickens with GL had osteomyelitis, often with multiple occurrences or occurrences in the proximalpart of the tibia and head of the femur. Staphylococcus hyicus, Salmonella Infantis, Escheria coli were often isolatedfrom osteomylitis lesions. These bacteria were also isolated from visceral organs. This suggests thatbroiler chickens with GL are septic and GL can be an effective marker for septic broiler chickens.

Genomic Identification and Characterization of Avian Adenoviruses Associated with Inclusion Body Hepatitis

Four pathogenic avian adenovirus isolates associated with inclusion body hepatitis and mortality in commercial broiler chicks and chickens were characterized and identified. These group I avian adenovirus isolates were classified as group E (serotypes 6, 7, 8, and 9) avian adenoviruses on the basis of the restriction enzyme patterns of their viral DNA. Isolate 3718 was neutralized by a serotype 6 reference avian adenovirus antiserum and isolates 8193, 8380, and 8565 were all neutralized by a serotype 8 reference avian adenovirus antiserum by virus neutralization assays. Infectivity and virulence such as mortality, hemorrhages, enlarged green livers with intranuclear inclusion bodies, stunting, intestinal sloughing, and poor feathering were observed in specific-pathogen-free chicken embryos and were identical for all four isolates when embryos were inoculated via the yolk sac and/or chorioallantoic membrane. Complete mortality was observed within 72 hr postinoculation in specific-pathogen-free (SPF) chickens inoculated intramuscularly for all four avian adenovirus isolates.

The effect of a second dexamethasone treatment on turkeys previously challenged in an experimental Escherichia coli respiratory model of turkey osteomyelitis complex

In two separate experiments, turkeys that had survived immunosuppression with dexamethasone (DEX) and air sac inoculation with low numbers of Escherichia coli at 5 wk of age were maintained until 13 wk of age, at which time they were given a second treatment with DEX. All mortalities and birds that were necropsied 8 and 15 d (Experiment 1) and 21 d (Experiment 2) after the last DEX injection were scored for air sacculitis/pericarditis and turkey osteomyelitis complex (TOC). In both experiments, all of the lesions that characterize TOC were reproduced, including osteomyelitis of the proximal tibia, synovitis/tendonitis, abscesses in the soft tissues, and green liver. In Experiment 1, all mortalities after Day 7 had TOC lesions, whereas 44% of mortalities had green livers. Staphylococcus aureus was isolated from 90% of all TOC lesions cultured. In Experiment 2, the incidence of mortality, air sacculitis, TOC, and green liver as well as the heterophil:lymphocyte ratio were significantly higher in birds that had previously been treated with DEX but had never been challenged with E. coli than in birds that had survived both treatment with DEX and challenge with 25 or 50 cfu of E. coli. Staphylococcus aureus was isolated from 73% of TOC lesions cultured, whereas E. coli was isolated from only 5.4% of the lesions. These studies suggest that TOC incidence may be related to a stress-induced susceptibility to opportunistic infection.

Distribution of Arthritis and Osteomyelitis in Turkeys with Green Liver Discoloration

The distribution of arthritis and osteomyelitis (OM) was studied in turkeys with green liver (GL) discoloration collected in a processing plant; the turkeys originated from seven commercial farms. Overall occurrence of GL, arthritis, and OM in the 25,320 inspected toms was 264 (1.04%), 123 (0.49%), and 107 (0.42%), respectively, and in the 16,690 inspected hens was 24 (0.14%), 0%, and 13 (0.08%), respectively. Prevalence of GL, OM, and arthritis varied among the studied farms. Arthritis and/or OM were detected in 168 (58.3%) of 288 turkeys with green discolored livers. Of the 168 turkeys with OM and/or arthritis, 48 (28.6%) had only arthritis, 45 (26.8%) had OM only, and 75 (44.6%) had both lesions. Arthritis and OM were detected in single and multiple sites and were unilateral and bilateral. Distribution of OM in the 120 OM-positive turkeys with and without arthritis was 77 (64.2%) in proximal tibia, 29 (24.2%) in proximal humerus, 28 (23.3%) in proximal femur, 13 (10.8%) in rib cage, and 4 (3.3%) in distal femur. Distribution of arthritis in the 123 arthritis-positive turkeys with and without OM was 77 (62.6%) in shoulder, 45 (36.6%) in stifle, and 25 (20.3%) in hip joints. Findings in this study suggest that arthritis and osteomyelitis are two distinct lesions and that they may develop independently in the same bird.

A Longitudinal Study of Green-Liver Osteomyelitis Complex in Commercial Turkeys

Two flocks of Nicholas tom turkeys from separate farms with histories of above-average condemnations for turkey green-liver osteomyelitis complex (TOC) were studied throughout a 16-week growout. Fifty birds from each farm were necropsied each week for 15 weeks, and birds that had green livers, osteomyelitis in the proximal tibia, or swollen joints were cultured for aerobic bacteria along with an equal number of control birds. At processing, TOC lesions and green livers were obtained for bacterial culture and histopathology. Green-liver-associated TOC was not observed until the turkeys were 9 or 10 weeks of age. The incidence of TOC was higher on one farm, which also had a higher incidence of airsacculitis, higher early and weekly mortality, seroconversion to Newcastle disease virus and Mycoplasma meleagridis, and significantly higher average body weights, relative spleen weights, and relative liver weights. Both farms had a high incidence of intestinal lesions and infestation with Ascaridia dissimilis. Histological evaluation of green livers revealed hyperplasia of bile ducts, dilation of sinusoids, and pigment-containing Kupffer's cells, some of which stained positive for iron. The bacterial isolates most frequently cultured from bones and livers were pleomorphic gram-variable coccobacilli, which grew visible colonies only after a series of subcultures and extended incubation.

The role of hormones in initiation of sexual maturation in male river lampreys ( Lampetra fluviatilis, L.): Gonadotropin and testosterone

Previous experiments with implantation of sex hormones indicated that development of increased sensitivity toward sex hormones in the peripheral tissues responsible for secondary sex characteristics is an essential feature in initiation of normal sexual maturation. The extent to which this sensitivity change depends on hormones from the pituitary gland was investigated by implanting testosterone pellets into 15 hypophysectomized (pro- and mesoadenohypophysis) immature male lampreys. Fin changes and growth of the urogenital papilla were elicited by testosterone in all hypophysectomized males, but were delayed in some in comparison with intact males. The testosterone-stimulated rate of growth of the urogenital papilla was slow in the hypophysectomized lampreys, but eventually normal size (8 mm) was reached. In untreated hypophysectomized lampreys the liver never turns green as it does in the majority of intact males, but testosterone induced green livers in 11 out of 14 hypophysectomized males. Thus it appears that the development in peripheral tissues of sensitivity toward sex hormones can take place without the presence of the pro- and mesoadenohypophysis. Furthermore, together with previous results obtained by hypophysectomy, the results support the idea that gonadotropin from the pro- and mesoadenohypophysis of lampreys is needed for the whole process of sexual maturation to occur, stimulates the rate of development, and allows simultaneous readiness for spawning in the population by especially stimulating slowly developing lampreys. On the basis of recent results and previous data it is suggested that the metaadenohypophysis and the interrenal cells also may be involved in initiation of sexual maturation.

Morphology of the green livers in upstream migrants of Petromyzon marinus L.

A morphological comparison was made of the green livers of male and female lampreys (Petromyzon marinus L.) collected during the upstream (prespawning) migration. Light and electron microscope histochemistry for iron, and both thin sections and freeze-fracture replicas in the electron microscope, revealed some sexual dimorphism in these livers. Ferric iron is much more abundant in the liver of females and is present in the cytoplasmic matrix, in dense bodies, and in vacuoles of hepatocytes. The numerous vacuoles of females may be the deposition site of biliverdin and other bile components that would account for the darker green coloration of the liver compared to males. Hepatocytes in females are also characterized by prominent rough endoplasmic reticulum and Golgi apparatus that reflect the involvement of the cells in vitellogenesis. The presence of numerous lipid droplets in the hepatocytes of males indicates that the liver is an important storage site for fat. The lipid droplets are associated with electron-dense deposits of unknown nature. Large gap junctions typify the parenchymal cells of both male and female livers. Perisinusoidal and sinusoidal cells are similar to those in the nonparenchymal region in other vertebrate livers, namely, endothelial and Kupffer cells, lipocytes (Ito), and some granulated cells. The relationship of lipocytes to fibrous tissue and fibrogenesis is discussed.

Epidermal pigmentation and liver coloration in the southern hemisphere lamprey,Geotria austral isGray

Abstract During metamorphosis from ammocoete to macrophthalmia in the southern hemisphere lamprey, Geotria australis Gray, 2 blue‐green dorso‐lateral stripes develop along the length of the body. These stripes are retained during the marine parasitic feeding stage and are conspicuous when the adults enter fresh water at the beginning of the spawning migration. They disappear as the upstream migration progresses. The blue‐green coloration is present in the epidermal mucous layer and results from the deposition of biliverdin, a bile pigment produced as a breakdown product of haemoglobin. Liver colour changes during the upstream spawning migration. At the beginning of the migration liver colour is predominantly brown or brick‐red, and livers contain the bile pigment bilirubin. Lampreys collected 50 km from the sea had predominantly green livers owing to the presence of the bile pigment biliverdin, and gonad development had not increased from that observed at the beginning of the spawning migration. Pouched males contained dark green livers with biliverdin as the predominant pigment.