Spreading of Salmonella enteritidis in the cecum of chickens

Adhesion and colonization of high (2 x 10(8) CFU) and low doses (2 x 10(2) CFU) of Salmonella enteritidis (phage type 4) was determined in the ceca collected 6 h-4 weeks after inoculation (pi), of 1-d-old White Plymouth Rock orally-inoculated chickens. S. enteritidis was associated with the epithelial surface of the villi in the low-dose group 18 h-7 d pi, the penetration in the cecal lamina propria was observed on day 1 and 10 pi. In the high-dose group, adhesion and colonization was observed in all birds killed 6 h-14 d pi; penetration of the bacteria into the cecal lamina propria was seen 1-21 d pi. Large numbers of macrophage-like cells containing S. enteritidis were observed in the cecal lamina propria on days 3-21 pi. Colonization and migration by S. enteritidis in the intestinal tract of chickens was shown to be dose dependent.

Effect of low and high doses of Salmonella enteritidis PT4 on experimentally infected chicks

Chicks (1-d-old, three groups, each containing 50 chicks) were inoculated with 2 x 10(2) and 2 x 10(8) CFU of Salmonella enteritidis; the third group were kept as uninoculated control. Five birds from each group were euthanized at intervals from 6 h to 4 weeks post-inoculation (pi). In the low-dose group S. enteritidis was isolated from 60% cecal samples at 18 h pi, and from 20% of livers at 3 d pi. Individual variation in the frequency of S. enteritidis recovery was observed in this group. The clearance of salmonella from the organs was faster in the low-dose group, and salmonella was not isolated from the liver and cecum at 21 and at 27 d pi, respectively. However, in the high-dose group, S. enteritidis was isolated from all ceca and 80% of liver 6 h pi, and salmonella was detected in the cecum and liver throughout the experiment. Serous typhlitis and unabsorbed yolk sac were the most prevalent lesions in both groups. Granulomatous nodules in the cecum were found occasionally in some cases in both inoculated groups, which can play a role as reservoirs in carrier chicks.

An unusual manifestation of encephalitozoonosis in chinchilla rabbits

This disease occurred in 6 rabbits in which leukemic changes after infection with the bovine leukemia virus were being studied.

Granulosa-cumulus-corona expansion and aromatase localization in preovulatory follicles in superovulated heifers

Granulosa-cumulus and cumulus-corona expansion as well as aromatase localization within ovarian follicles were monitored during the preovulatory period in superovulated cattle that were blood sampled every 2'nd h for LH analyses. Granulosa-cumulus as well as cumulus-corona expansion were studied by means of transmission electron microscopy and computerized image analysis. Localization of aromatase, an enzyme involved in estrogen synthesis, was determined immunocytochemically using anti-human placental aromatase cytochrome P-450 antisera. Nuclear oocyte maturation was determined by aceto:orcein staining. Significant cell dissociation within the granulosa-cumulus stalk occurred before the breakdown of the germinal vesicle, i.e. the oocyte nucleus, during the period up to 5-7 h after the LH peak, i.e. the highest LH concentration during the surge. Significant increase in intercellular spacing between the cumulus-corona cells occurred at 13-15 and 19-21 h after the LH peak. Before the LH peak all layers of granulosa cells were immunocytochemically stained for aromatase. At 5-7 h after the LH peak, however, only the granulosa cell layers located near the basal lamina were stained, and at all later intervals staining was absent. The granulosa cells of primary and secondary follicles, the interstitial gland cells, the theca interna cells and the oocytes in all follicles were immunocytochemically unstained.

Familial melanoma in the progeny of a Duroc and Slovak white crossbred sow

In three successive litters of a Duroc and Slovak White crossbred sow there was a 7.75% overall incidence of melanoma. Immunohistochemical labelling confirmed the mesenchymal origin of the neoplastic cells, indicated the absence of CD3 lymphocytes in the tumour, and proved the tumorous origin of surrounding non-pigmented cells. An abundance of macrophages (epithelioid cells) with increased endoplasmic reticulum was observed by electron microscopy, but large granular lymphocyte-like cells were few in number.

Lymph node macrophages after application of glucan in calves: an electron microscopical study

The present study was designed to reveal by electron microscopy the dynamics of degradation processes of glucan after phagocytosis in the lymph nodes. A soluble form of glucan at a dosage of 50 mg/kg body weight induced a distinct phagocytic activity. On day 7, after stimulation of the lymph nodes, glucan was gradually degraded through fibrillar, particular components, and finally into a light microscopically invisible content. The ingestive capacity of macrophages was higher compared to phagocytic ability of the sinus-lining and reticular cells. On day 30, after stimulation, the lymph nodes indicated restoration of the architecture of their medullary pulp.

Immunocytochemical localization of aromatase in the ovary of superovulated cattle, pigs and sheep

The localization of aromatase, an enzyme converting androgens to estrogen, in the ovaries of superovulated cattle, pigs and sheep was studied immunocytochemically in the preovulatory and postovulatory period using anti-human placental aromatase cytochrome P-450 antiserum. Immunostaining for aromatase was detected in the granulosa cells of preovulatory follicles of all species studied. Theca interna cells were stained in preovulatory follicles in the pig but not in cattle and sheep. Interstitial gland cells, cumulus cells and oocytes were unstained in all species. In cattle and pig the corpora lutea were unstained whereas they displayed staining in the sheep. Preantral and small antral follicles were unstained during both the preovulatory and postovulatory period in all species. It is concluded that granulosa cells of preovulatory follicles are the main residence for aromatase activity in superovulated cattle, pig and sheep, whereas the activity of theca interna and corpora lutea is species specific.

Immunocytochemical localization of aromatase in the ovary of superovulated cattle, pigs and sheep

The localization of aromatase, an enzyme converting androgens to estrogen, in the ovaries of superovulated cattle, pigs and sheep was studied immunocytochemically in the preovulatory and postovulatory period using anti-human placental aromatase cytochrome P-450 antiserum. Immunostaining for aromatase was detected in the granulosa cells of preovulatory follicles of all species studied. Theca interna cells were stained in preovulatory follicles in the pig but not in cattle and sheep. Interstitial gland cells, cumulus cells and oocytes were unstained in all species. In cattle and pig the corpora lutea were unstained whereas they displayed staining in the sheep. Preantral and small antral follicles were unstained during both the preovulatory and postovulatory period in all species. It is concluded that granulosa cells of preovulatory follicles are the main residence for aromatase activity in superovulated cattle, pig and sheep, whereas the activity of theca interna and corpora lutea is species specific.

Development of rumen metabolism and ruminal epithelium in lambs

The concentrations of volatile fatty acids and the development of rumen epithelium and microflora adhered to rumen wall in suckling lambs were observed. Total VFA concentration increased with age. The differences between the 1st (28.5 mmol.l-1) and 4th week of age (78.7 mmol.l-1) and between 6th (82.1 mmol.l-1 and 10th week of age (117.4 mmol.l-1) were significant (p < 0.01). The highest molar proportion of acetic acid (71.2 mol%) was observed in 1 week-old lambs and the highest molar proportion of propionic acid in 6 week-old lambs (20.8 mol%). Length and surface characteristics of papillae changed dramatically over the 10-week period. In samples from 1-week and 4-week-old lambs, the papilla surface was relatively smooth and epithelial cells were relatively thin and flat. In samples from 6-week and 10-week-old lambs the tissue topography was typically rough. In the 1-week-old lambs the cocci, single rods and short rods in pairs were present at very low population levels. At 4 weeks the epimural community became notably more complex and bacteria were present at a higher population level. The dominant morphotype at 6 weeks was a rod-shaped end-on attached bacterium. The epimural microflora became the most complex at 10 weeks.

The effect of diet composition on the development of rumen digestion in lambs

The effect of composition of feed concentrate on the development of rumen digestion in suckling lambs was investigated. The experimental group of lambs was offered special concentrate diets (SCD I and SCD II), which, compared to routinely produced commercial mixtures CCD 1 and CCD 2, were completely cleared of milk protein, enriched with legumes and alfalfa meal and supplemented with cut alfalfa of the particle size 1 cm. Significantly higher concentrations of total volatile fatty acids (VFA) were recorded in experimental lambs at the age of 7, 9 and 11 weeks. The highest concentration of total VFA was observed at the age of 11 weeks (118.2 mmol.l-1 in the experimental group and 110.2 mmol.l-1 in the control group). The cellulase activity (endoglucanase E.C.3.2.1.4. and cellobiohydralase E.C 3.2.1.91.) of the rumen content of experimental lambs was significantly higher at the age of 9, 11 and 15 weeks, in comparison with the control animals, reaching the highest values at 11 weeks of age (19.32 micrograms.ml-1 in the experimental group, 15.84 micrograms.ml-1 in the control group), while the increase of number of cellulolytic bacteria in experimental lambs was insignificant. Scanning electron microscopy showed more pronounced colonization of the rumen epithelium by adherent rumen microflora in experimental lambs. Average daily weight gains over the whole investigated period reached 0.235 kg in the experimental group and 0.221 kg in the control group.