Ultrastructural postmortem changes in chicken kidneys at 27 C

Ultrastructural postmortem changes of glomeruli, proximal tubules (PT), distal tubules (DT), and cortical collecting ducts (CD) were studied in adult chickens held at 27 C for 0, 1, 5, 10, 30, 60, or 360 minutes. There were marked ultrastructural alterations in tissues considered normal by light microscopy. The earliest changes, evident in immediately fixed samples, consisted of apical cell swelling of PT and DT epithelium and formation of smaller projections from glomerular capillary endothelium. Swelling increased with time, and gaps in cell membranes of tubular cytoplasmic blebs were evident by 10 minutes postmortem. The urinary space also contained cellular debris in immediately fixed samples and was filled by swollen epithelial cells by 10 minutes postmortem. Organelle changes were pronounced by 5 minutes in PT epithelium and by 10 minutes in DT epithelium. These initial changes consisted of dilation of mitochondrial and endoplasmic reticulum. Flocculent mitochondrial matrix densities were present by 5 minutes in PT epithelium and enlarged and appeared in other tubular segments as the time postmortem increased. Nuclear chromatin margination occurred first in 10-minute samples of PT and DT, and it was present by 30 minutes in glomerular epithelial cells. Chromatin clumping was present in PT and DT epithelium at 30 minutes and was followed by pyknosis and karyorrhexis at 360 minutes. These latter nuclear changes were not found in glomerular cells during the study. Nuclei of CD showed little change during the periods studied. The glomerular basement membrane appeared as a single hyaline membrane by 30 minutes postmortem, but this membrane and podocyte foot processes showed little further change by 360 minutes postmortem.     

Histomorphometry and quantification of nucleolar organizer regions in bovine thyroid containing methylthiouracil residues

In order to study the morphology and morphometry and to characterize and quantify the nucleolar organizer regions (NORs) of bovine thyroids containing methylthiouracil (MTU) residues, five animals were orally treated with a suspension of MTU (5 g/animal/day) for 20 days (group A). This treatment protocol was interrupted 5 days before the the animals were slaughtered. Six animals receiving placebos composed group B. A third group (group C) was composed of normal thyroids obtained from a slaughterhouse. All glands were previously assessed for detection of antithyroid residues by chromatography, and only those glands from MTU-treated animals were positive. Follicles of glands from group A showed wide variation in size and shape. There was a predominance of small follicles covered by multiple layers of columnar cells, sometimes forming papillary projections into the lumen, characterizing severe interfollicular and intrafollicular adenomatosis. Many follicles had vacuolated cells with nuclei showing karyolysis or pyknosis and reduced amounts of a low-density and very excavated colloid. They also showed higher follicular epithelia and larger proportions of their structural components when compared with glands of groups B and C. In the thyroids from group A, the argyrophilic nucleolar organizer region-associated proteins (AgNORs) were greater in number, with small ones scattered all over the nucleus. Although the size of AgNORs in thyroids from groups B and C was variable, these AgNORs were fewer and larger than were those in glands from group A. In conclusion, the MTU induces proliferation and regressive changes in follicular cells, and the AgNOR technique is efficient to distinguish different degrees of thyroid hyperplasia.     

Importance of the medullary macrophage in the replication of lymphoid leukosis virus in the bursa of Fabricius of chickens

Electron microscopy and immunocytochemistry were used to study the development of lymphoid leukosis virus infection in the bursa of Fabricius of experimentally infected chicken embryos and chickens. In embryos infected at 7 days of incubation and killed 10 days later, virus particles and group-specific viral antigen were confined mainly to the connective tissue of the lamina propria of the bursal mucosal folds; a few developing follicles had discrete virions and group-specific antigen between cells. In chickens infected at 1 day of age, infection (as determined by use of electron microscopy and immunocytochemistry) was maximal in 1- to 4-month-old birds, and the greatest concentration of virus and group-specific viral antigen was in the medulla of the follicles. Although lymphoid leukosis virus was released from lymphocytes, epithelial cells, and macrophages, virus replication in the medullary macrophages was more active than that in the other cells. Normal medullary macrophages had cell membrane vesicles (50 to 80 nm in diameter) that covered part of all of the cell membrane surface. In infected chickens, virus particles frequently developed within these vesicles. Comparable vesicles were not found on cortical macrophages. Results of the present study indicated that the medullary macrophage was the principal host cell for replication of lymphoid leukosis virus in the bursa of Fabricius of the chicken.     

Effect of wet feeding on growth performance of broiler chickens in a hot climate

1. The Guinea Savanna in the tropics is characterised by high diurnal temperatures, often beyond the thermo-neutral zone of modern poultry, which imposes heat stress on them. 2. An experiment was conducted to determine the effect of partially (12 h wet mash in the day and 12 h dry mash in the night) or wholly (24 h) feeding wet mash on the growth performance of broiler chickens. 3. Three treatments: dry mash (control), wet mash (day) + dry mash (night) and wet mash (day + night) were tested. At 28 d of age, a total of 120 broiler chickens (Hybro, Netherlands) were randomly divided, using a completely randomised design, into 12 groups of 10 birds, each with mean live weight of approximately 800 g/bird. A maize-soybean based grower mash (200 g CP/kg and 12·5 MJ/kg ME) was fed. The wet mash was prepared daily by addition of 1·3 parts of water to 1 part of dry mash and fed from 28 to 56 d of age. The birds were housed in raised-floor pens. Feed and water were given ad libitum and light provided 24 h. Mean daily room temperature was 28-29°C in the morning and 35-41°C in the afternoon. 4. Mean feed intake of birds fed the wet mash (174 g/day) or wet + dry mash (166 g/day) was higher than that of birds fed the dry mash (152 g/day). Mean live weight gain of birds fed the wet mash (64 g/day) or wet + dry mash (64 g/day) was higher than that of birds fed the dry mash (58 g/day). There were no differences in gain/feed ratios (0·38-0·39) of any of the treatments, neither were there any differences between the feeding of wet mash partly or wholly for all variables. 5. It was concluded that wet feeding, particularly during day-time, had the potential to improve growth performance of broiler chickens in a hot climate.     

Hereditary cerebellar degeneration in three full sibling kittens

Two domestic shorthair littermate kittens had signs of cerebellar dysfunction, first observed between seven and eight weeks of age; a third littermate was unaffected. The signs were progressive and the more severely affected kitten was euthanased after six days. A postmortem examination revealed no gross lesions but the kitten had cerebellar cortical degeneration with extensive loss of Purkinje cells. The second kitten was euthanased at 10 months of age with similar, though more pronounced, changes. One of the two kittens in the next litter of the same parents had similar clinical signs and histopathological findings. The lesions in the cerebellum are interpreted as probably due to genetically determined abiotrophy. In addition, the two older kittens had medullary neuronal changes interpreted as probable neuraxonal dystrophy, and focal vacuolation of the neuropil in the medulla and cervical spinal cord.     

Influence of environmental temperatures on the serologic responses of broiler chickens to inactivated and viable Newcastle disease vaccines

Commercial and specific-pathogen-free (SPF) nonselected broilers were held at environmental temperatures that simulated the cyclic diurnal extremes for either hot (26.6 C-40.7 C) or moderate (18.3 C-32.3 C) summer temperatures. The chicks received either inactivated or viable La Sota Newcastle vaccines at various times after the initiation of the temperature extremes. When held at moderate temperatures for 7 days and then injected with inactivated vaccine, commercial chicks developed slightly higher but not statistically different levels of antibody compared with chicks held in the hot environment. In one experiment, the geometric mean serologic hemagglutination-inhibition responses of SPF chickens housed at extremely high temperatures for 4 days before being injected with inactivated vaccine were significantly greater (P less than or equal to 0.05) than those held at moderate temperatures. The reverse was apparent for chickens that received live vaccine virus after being in the hot environment for any of several lengths of time before vaccination.     

Oral infection with chicken anemia virus in 4-wk broiler breeders: lack of effect of major histocompatibility B complex genotype

The pathologic consequences of chicken anemia virus (CAV) oral inoculation in 4-wk-old broiler breeders of different major histocompatibility B complex (MHC) genotypes were evaluated. MHC B complex was determined by hemagglutination and sequence-based typing. Clinical signs, serology, gross lesions, histopathologic analysis, and CAV genome quantification were used to evaluate disease progression. Clinical disease was not apparent in the inoculated broilers throughout the experimental period. At 14 days postinoculation, antibodies against CAV were detected in 26.4% (29/110) of the inoculated birds. The distribution of percent positive was 34.6% (9/26) and 32.3% (10/31) of the chickens with B A9/A9 and B A9/A4 MHC genotypes, respectively, and seroconversion in six other genotypes was 19% (10/53). These differences among MHC genotypes for specific seroconversion rate were not statistically significant. CAV genomes were detected in the thymus of 87.7% (93/110) of the inoculated birds with no statistically significant differences between MHC genotypes. Mild thymic lymphocytolysis, lymphedema, and medullary hemorrhage were observed in the inoculated chickens. Histomorphometric analysis showed that cortical lymphocyte-to-parenchyma ratios did not differ between inoculated and uninoculated groups or among MHC genotypes. Similar findings have been reported previously in white-leghorn chickens of similar age, suggesting that broilers show a similar resistance to the effects of CAV infection at this age. The absence of significant clinical and pathological changes in the orally inoculated broilers at this age contrasts with CAV-associated thymus damage seen frequently in condemned commercial broilers at harvest.     

Acute airsacculitis in untreated and cyclophosphamide-pretreated broiler chickens inoculated with Escherichia coli or Escherichia coli cell-free culture filtrate.

Ninety commercial broiler chickens were divided into three equal groups; 30 were injected with brain-heart-infusion broth into the cranial thoracic air sacs (controls), 30 were similarly inoculated with a culture of Escherichia coli, and 30 were similarly inoculated with E. coli cell-free culture filtrate. Birds were examined from 0 to 6 hours post-inoculation. E. coli-inoculated and cell-free culture filtrate-inoculated chickens reacted similarly, with exudation of heterophils into the air sac. Microscopically, heterophils were present in low numbers perivascularly 0.5 hour after inoculation and became more numerous by 3 hours post-inoculation. By 6 hours post-inoculation, there was severe swelling of air sac epithelial cells and thickening of the air sac by proteinaceous fluid and heterophils. Ultrastructurally, air sac epithelial cells were swollen and vacuolated, and interdigitating processes were separated. Histologically and ultrastructurally, all features in control chickens were normal, with only rare heterophils in the air sac interstitium. In E. coli-inoculated and cell-free culture filtrate-inoculated chickens, cell counts (predominantly heterophils) in air sac lavage fluids increased markedly at 3 and 6 hours, with only slight increases in counts from lavages of controls. Heteropenia was observed in E. coli-inoculated chickens, whereas heterophilia was observed in cell-free filtrate chickens and controls. Ninety additional chickens were pretreated with cyclophosphamide, subdivided into three equal groups, and inoculated and examined similarly as above. Cyclophosphamide pretreatment reduced inflammatory changes in air sacs, lowered cell numbers in lavage fluids, and abolished hematologic changes; however, it did not prevent epithelial cell changes. These results indicate that cell-free culture filtrate of E. coli induces changes similar to those induced by cultures of E. coli.     

Differential protein profiles in duck meat during the early postmortem storage period

The present study was designed to investigate proteomic differences in duck breast muscle during the early postmortem storage period. The meat quality was evaluated at 0 hr and 24 hr postmortem at 4°C in Pekin ducks, black Muscovy ducks and Mule ducks. Differentially expressed proteins were detected by two‐dimensional gel electrophoresis (2‐DE) and matrix‐assisted laser desorption ionization‐time‐of‐flight mass spectrometry (MALDI‐TOF/TOF MS) at 0 hr and 24 hr postmortem in the three duck breeds. The results showed that 53 proteins spots were differentially expressed at 0 hr and 24 hr postmortem at 4°C in Pekin ducks, 75 spots in black Muscovy ducks, and 72 spots in Mule ducks. A total of 30 (10 spots for each breed) were selected for identification by mass spectrometry. Seven proteins were identified in Pekin ducks, eight in black Muscovy ducks and seven in Mule ducks. Moreover, the above results obtained by 2‐DE and MALDI‐TOF/TOF MS were confirmed by western blotting. To our knowledge, this study is the first to provide insights into the protein profiles of ducks during postmortem storage and provides a better understanding of the biochemical processes that contribute to duck meat quality.     

The effect of lithium chloride on renal structure and sodium-potassium-adenosine triphosphatase activity in dogs

Lithium chloride was given intraperitoneally to dogs at a dosage of 125 mg/kg body weight for three days. Kidneys were removed for morphologic examination and quantitation of sodium-potassium-adenosine triphosphatase (Na-K-ATPase) activities in cortical and medullary tissue. Light microscopy showed no changes in the kidneys, but cytoplasmic vacuolation and dilatation of the cisternae of the endoplasmic reticulum were seen ultrastructurally in the epithelial cells of the distal tubule and cortical and medullary collecting ducts. Mean cortical Na-K-ATPase activity was 1.49 +/- 0.25 and 1.70 +/- 0.31 mumoles inorganic phosphate/mg protein/hour in control and experimental groups respectively. Mean medullary Na-K-ATPase activity was 4.71 +/- 0.41 and 5.01 +/- 0.47 mumoles inorganic phosphate/mg protein/hour in control and experimental groups respectively. It was concluded that lithium produced morphologic changes in the distal nephron, but had no effect on renal Na-K-ATPase activity.     

Phagocytosis and intracellular killing of Campylobacter jejuni by elicited chicken peritoneal macrophages.

In vitro phagocytosis and intracellular survival of Campylobacter jejuni (strains B540 and Clin 1) in chicken peritoneal macrophages were studied. Macrophages were induced with Sephadex G-50 and harvested 48 hr later by peritoneal lavage. The extent of phagocytosis over time was determined by enumerating the intracellular C. jejuni after removal of extracellular C. jejuni with gentamicin. Pre-incubation of C. jejuni with antiserum generally enabled the macrophages to ingest greater numbers of cells than when the organism was pre-incubated in phosphate-buffered saline. C. jejuni were exposed to macrophage uptake for 30 minutes in a 5% CO2 incubator at 42 C. This suspension was then exposed to 12.5 micrograms gentamicin/ml to eliminate extracellular bacteria. Subsequently, the intracellular survival of C. jejuni was examined by monitoring its number within the macrophage at 30 minutes, 3 hr, and 6 hr after phagocytosis. Macrophages from C. jejuni-colonized chickens and from uncolonized control chickens were able to almost destroy the organism within the experimental period.     

The interaction between Newcastle disease virus and Escherichia coli endotoxin in chickens.

The interaction between Newcastle disease virus (NDV) and Escherichia coli endotoxin was studied in cell cultures, embryonated chicken eggs, and 8-wk-old chickens. These interactions were evaluated according to the induction of specific or nonspecific resistance in the host system and the virus titer produced in both chicken embryos and chickens. The endotoxin of E. coli induced a decrease in the size of the bursa of Fabricius in live chickens. Escherichia coli endotoxin given intravenously induced plasma antiviral activity in chickens that was interpreted to be interferon, as detected in a vesicular stomatitis virus plaque reduction assay. Endotoxin failed to produced toxic effects in the chicken embryo fibroblasts (CEFs) or to result in any antiviral effect because no change was noted in the number of NDV plaques formed in CEF cultures. When endotoxin was given 3 days before NDV exposure in chickens, the virus titers were significantly (P < 0.05) decreased from a peak of 10(2) to 10(0.18), 10(2.5) to 10(0.18), and 10(2.5) to 0 in the spleens, lungs, and kidneys, respectively, at 72 hr post-NDV inoculation. When endotoxin was given 24 hr after NDV inoculation, the NDV titer significantly (P < 0.05) increased from 10(2.0) to 10(3.5), 10(2.5) to 10(6.5), 10(2.5) to 10(4.5), 0 to 10(2.5) in the spleen, lungs, kidneys, and liver, respectively, at 72 hr after NDV inoculation. In chicken sera, hemagglutination inhibition (HI) titer to NDV was significantly (P < 0.05) enhanced from 1164 to 3127 when endotoxin was given prior to virus inoculation. However, there was a decrease in HI to NDV from 1164 to 727 without a significant difference in chicken sera when NDV was given prior to endotoxin inoculation.     

interactions between escherichia coli and Newcastle disease virus in chickens

We investigated the interaction between Newcastle disease virus (NDV) and Escherichia coli in cell cultures, embryonated eggs, and 8-wk-old chickens. We measured the interactions on the basis of bacterial adherence and NDV hemagglutination titer in chickens, chicken embryos, and chicken embryo cell culture. Depending on the inoculation order of E. coli, a significant alteration of the growth of NDV was observed in both chickens and chicken embryos. When certain strains of E. coli were given before NDV exposure, the virus titers were lowered. In chickens, the mean virus titer was significantly (P < 0.05) lowered in the crop, the proventriculus, the gizzard, and the jejunum. However, there were no significant differences (P < 0.05) between the two groups for NDV titers in the duodenum, ileum, and cecum. In chicken embryos, when E. coli serotypes O78 and O119:B14 were inoculated before NDV exposure, the mean NDV titers were significantly (P < 0.5) lowered. However, there were no significant differences (P < 0.05) in NDV titer between the two groups when E. coli serotypes O78:K80:NM and O1ab:K NM were inoculated 24 hr before NDV exposure. When NDV was given prior to E. coli exposure, NDV titer was higher in both chickens and chicken embryos. In chickens, when NDV was given 48 hr before E. coli inoculation, NDV was detected in the proventriculus, gizzard, jejunum, ileum, and cecum, whereas no virus was detected in the control groups (NDV only). In the crop, NDV was detected at a significantly (P < 0.05) higher titer in the E. coli-inoculated group when compared with the control group that received NDV alone. In chicken embryos, virus titer was significantly (P < 0.05) higher when NDV was given 24 hr before E. coli inoculation for all three NDV strains used (Ulster and V4 strains). Adherence of E. coli to chicken embryo kidney (CEK) cells was significantly higher (P < 0.05) when the CEK cells were infected first with NDV and then by E. coli. The mean bacterial count per microscopic field in NDV-uninfected monolayers was eight compared with 112 for the NDV-infected monolayers. In approximately 10% of the fields in NDV-infected monolayers, the bacteria were too numerous to count.     

实验性鸡马立克氏病羽髓病变研究

通过光镜1电镜等方法对鸡马立克氏病羽髓组织进行了形态学研究。结果显示，羽髓远端坏死，羽髓中有多量肿瘤细胞浸润，肿瘤细胞呈弥漫性或局部性浸润，电镜观察，肿瘤细胞核异型性明显，核膜凹陷，核内出现假核内包含物，在一些羽髓中，巨噬细胞吞噬肿瘤细胞较多见，而且观察到一些肿瘤细胞发生调亡，结果表明，鸡马立克氏病羽髓病变十分明显，羽髓的形态学变化可用于鸡马立克氏病的诊断。     

Disseminated liposarcoma in a dog.

A 9-year-old, female Mongrel dog was presented for posterior hindlimb weakness, inability to stand, and pain in the lumbosacral and pelvic regions. Radiography revealed a lytic lesion extending from L5 to L6 to the ilium. At necropsy, an 8 x 2 to 3.2 x 3 cm, irregular, white, firm mass was identified extending from the left dorsolateral aspect of the L6 vertebrae to the sacrum, crossing the sacroiliac joint to the ilium, and reaching the acetabulum without affecting the joint cartilage. Tumor masses were also present bilaterally near the costochondral junction of several ribs. White, soft nodules were present in the heart, pericardium, lungs, spleen, and kidneys as well. Histologically, osteolysis with disruption of the cortical bone and reactive bone with the presence of multinucleated osteoclasts was noted. Neoplastic cells consisted of variable, small basophilic round cells (SBRC) with very scant cytoplasm, larger polygonal cells with abundant eosinophilic cytoplasm, and vacuolated cells resembling adipocytes. Within the marrow cavity, vacuolated cells with necrosis predominated, whereas in periosteal areas, polygonal and vacuolated cells that were mixed with a lower percentage of SBRC were more common. In the lungs and heart, SBRC predominated, and in the spleen, polygonal cells were more numerous. Tumor cells stained positive for vimentin and S-100 and stained negative for CD99, neuron-specific enolase, synaptophysin, chromogranin A, cytokeratins, desmin, myoglobin, and actin. This tumor most likely arose from the marrow cavity of the L6 and later invaded through the vertebral body into adjacent vertebrae and various visceral sites.     

Histologic characterization of the involuting bursa of Fabricius in single-comb white Leghorn chickens

Bursas from specific-pathogen-free white leghorn chickens of both sexes were examined at several intervals from hatching to 28 weeks of age. No histologic alterations other than scattered atrophic or cystic follicles were observed through 20 weeks. Obvious involution, first noted at 24 weeks, was in early stages in females and quite advanced in males. Involution was essentially complete by 26 weeks, and only cicatrized vestiges of bursas were present at 28 weeks of age. Gross manifestations included bursal atrophy, variable yellowish discoloration of the mucosa, and matting or total loss of identity of the mucosal plicae. Histologic characteristics of involution are summarized by the following approximate sequence: atrophy and exfoliation of plica epithelium; subepithelial stromal fibrosis; fusion and ultimate collapse of plicae; liquefactive necrosis of first medullary then cortical elements of follicles, which seemed to progress from basal to apical portions of the plicae; progressive proliferation of stromal connective tissue and infiltration of macrophages into areas occupied by necrotic follicles; and, finally, complete fibrous organization of luminal debris, leaving a firm nodule formed by a contracted muscularis surrounding the cicatrized remains of the mucosa.     

Changes in serum ovotransferrin levels in chickens with experimentally induced inflammation and diseases

A competitive enzyme immunoassay was developed to measure the changes in serum levels of ovotransferrin (OTF) during inflammation and infectious diseases in chickens. The assay is based on the competition of serum OTF with a fixed concentration of biotin-labeled OTF to bind to a rabbit anti-chicken transferrin antibody immobilized on microtiter wells. After several washing steps, the antibody-bound biotinylated OTF is probed with streptavidin-horseradish peroxidase conjugate (HRP) followed by a colorimetric detection of the HRP activity. The relative changes in the optical density of color are plotted against the competing concentrations of OTF with logarithmic regression to generate a standard curve that is used to determine the concentrations of OTF in unknown samples. Serum had no effect on the measurement of OTE By this method, the time course changes of serum OTF levels in 4-wk-old male broiler chickens that were subjected to inflammation by croton oil injection were measured. The results showed croton oil-induced inflammation elevated serum OTF levels at 16 hr postinjection. OTF levels reached a peak by 72 hr, remained high through 120 hr, and returned to a basal level of olive oil-injected controls by 240 hr. There were no changes in serum OTF levels at any of the above time points in olive oil-injected control chickens. For studies with poultry diseases, specific-pathogen-free (SPF) male chickens were challenged with known bacterial and viral pathogens, and serum was collected at the height of the infection, i.e., 7 days after the challenge. Compared with uninjected controls, the SPF chickens challenged with Escherichia coli, fowl poxvirus, respiratory enteric orphan virus, infectious bursal disease virus, infectious bronchitis virus, or infectious laryngotracheitis virus had higher levels of OTF in serum. Inflammation-induced changes in serum OTF levels were also evident in the changes in the density of a 65-kD band protein corresponding to OTF. These results demonstrate that serum OTF may be a nonspecific clinical marker of inflammation associated with traumatic or infectious avian diseases.     

Rapid postmortem gut autolysis in infant rats: a potential problem for investigators.

Experiments were designed to determine the rate and nature of postmortem autolysis in the gut of neonatal rats, as necessary baseline information for developing a model of human neonatal necrotizing enterocolitis. We studied 60 animals, including 33 Wistar rats, 18 Sprague-Dawley rats and nine CD-1 mice. The variables examined included age of the animals (2 or 14 days) and length of delay and holding temperature (20 degrees C or 37 degrees C) after sacrifice. At necropsy, bowel was rapidly removed and fixed for histopathological examination. In all instances, bowel removed immediately after sacrifice was normal whereas after delays as short as 30 minutes it was abnormal (P less than 0.001), becoming markedly so after 60 minutes. The prominent features were detachment and lysis of mucosal epithelial cells. The rate of autolysis was not altered in 14 day old animals or in carcasses held at 20 degrees C or 37 degrees C. Investigators of bowel injury syndromes in young rats should be aware that histopathological studies will be valid only if specimens held at room temperature are fixed within 15 minutes of death.     

Inflammation induced by subcutaneous turpentine inoculation of young American alligators (Alligator mississippiensis)

Turpentine-induced skin lesions in young American alligators (Alligator mississippiensis) kept at 25 C were used to study inflammatory response in a reptile. Skin harvested at intervals between 4 hours and 30 days after inoculations were done had no gross changes until days 24 to 26, when superficial skin necrosis was evident. Early responses of congestion and dermal edema (4 to 8 hours) were seen by light microscopy, and these were followed by necrosis and granulocyte migration (1 to 3 days). Later, there was predominance of monocytic cells, including vacuolated macrophages (7 to 30 days). Evident at 14 days and prominent by day 30 were central dermal zones of necrotic debris surrounded by orderly palisades of vacuolated multinucleated giant cells and capillary-laden immature fibrous connective tissue. Systemic illness or visceral lesions were not observed. Controls, given inoculations of sterile saline solution, had no gross or microscopic changes.     

Preliminary investigation on the nutritive value of krill meal in the feed of broiler chickens and laying hens.

Krill meal was used as a protein feed in rations for broiler chickens and laying hens and its nutritional effectiveness was studied in comparison with conventional feed-stuffs of animal origin. In experiments with 650 broiler chickens from 1 to 28 and from 29 to 56 days to fattening krill meal was added to the standard feedmixture in lieu of fish meal, and dried skim-milk, and at higher levels also in lieu of soyabean oilmeal. In the experiment with 22 layer hens kept in individual cages 3% of the fish meal were substituted by 3% of krill meal. The performance of chickens fed on diets with krill meal was lower in comparison with analogical groups fed on fish meal. Higher levels of krill meal, exceeding 15 and 11% in the first and second period of feeding respectively, reduced the weight gains and feed intake of chickens. The fatty acid C14, C18 and C18:1 content of internal body fat was changed in chickens fed on higher levels of krill meal. In the experiment with hens krill meal decreased the feed efficiency, the pigmentation of egg yolks, however, was more intensive and the vitamin A content of yolks was increased in comparison with the control group. The results show that krill meal can be used as a partial substitute of fish meal in the feed of broilers and hens.