Age-associated changes of the intrinsic nervous system in relation with interstitial cells in the pre-weaning goat rumen.

In this study, we investigated the neural changes and their relationships with interstitial cells (ICs) in the rumen of pre-weaning goats by transmission electron microscopy, western blot and immunofluorescence (antibody: general neuronal marker-Protein Gene Product (PGP9.5)/ IC marker-vimentin). The immunofluorescence results showed that PGP9.5-positive reaction was widely distributed in neuronal soma (NS) and nerve fibre (NF). The NSs were observed in the ganglia of the myenteric plexus (MP) but not in the submucosal plexus. The mean optical density (MOD) of the whole of PGP9.5-positive nerves and the protein expression level of PGP.5 in the rumen wall both decreased significantly with age. However an obvious increase MOD of PGP.5-positive NFs within the rumen epithelium were observed. In the MP, the nerves and ICs were interwoven to form two complex networks that gradually tightened with age. Furthermore, NSs and nerve trunks were surrounded by a ring-boundary layer consisting of several ICs that became physically closer with aging. Moreover, ICs were located nearby NFs within the ML, forming connections between ICs, smooth muscle cells and axons. This study describes the pattern of neural distribution and its association with ICs in the developing rumen which shed light on the postpartum development of ruminants.

The periparturient period is associated with structural and transcriptomic adaptations of rumen papillae in dairy cattle.

The structural and functional adaption of the rumen epithelium during the transition period is largely undescribed. To characterize the adaptation of the rumen epithelium during transition, multiparous dairy cattle (n=12) fitted with rumen fistulas and fed a low-energy dry cow diet (1.37 Mcal/kg, net energy for lactation) were transitioned abruptly to a high-energy lactating cow diet (1.68 Mcal/kg, net energy for lactation) immediately after parturition. Rumen papillae were biopsied at -3, +1, and +6 wk relative to calving. The histology of morphology of the rumen papillae was evaluated under the light microscope and electron microscope, and mRNA profiling was performed using an Affymetrix GeneChip Bovine Gene 1.0 ST Array (Affymetrix, Santa Clara, CA). Data preprocessing was conducted using the robust multi-array average method, and detection of significant genes was conducted using ANOVA. Also, the Benjamini-Hochberg false discovery rate of 0.1 was applied. Microscopic examination of rumen papillae revealed an increase in epithelial desquamation during early lactation as sloughing scores increased from 1.7 ± 0.2 at -3 wk to 4.1 ± 0.3 and 3.4 ± 0.2 at +1 and + 6 wk, respectively. A total of 1,011 (-3 vs. +1 wk) and 729 (-3 vs. +6 wk) differentially expressed genes were identified (false discovery rate of 0.10, P<10(-3), fold-change ± 1.2 cut-off). A group of differentially expressed genes involved in desmosome assembly (DSG1, CDSN), epidermal growth factor signaling (EGFR, EREG), transforming growth factor ß signaling (TGFB1), and the insulin-like growth factor-axis (GHR, IGFBP2, IGFBP3, CTGF) was also validated using PCR. Gene network analysis found that EGFR, GHR, and TGFB1 were focal points of the top pathways, thereby supporting the importance of these regulatory genes to the adaptive response of rumen papillae in early lactation. The microscopic and transcriptomic changes in this study provide insight into the mechanisms responsible for the rapid rate of cellular and molecular adaptations of rumen papillae tissue during the transition period in dairy cattle. In conclusion, the experimental data support the hypothesis that rumen papillae adapt in early lactation by altering their gene expression patterns and, thus, their epithelial structure.

Histomorphometric and immunohistochemical study of the goat rumen during prenatal development.

This study sought to chart the ontogenesis of the goat rumen by histomorphometric examination, scanning electron microscopy and immunohistochemical analysis. A total of 140 goat embryos and fetuses were used, from the first stage of prenatal life until birth. The appearance of the rumen from the primitive gastric tube was observed at 35 days of prenatal life (CRL 3 cm, 23% gestation). By 38 days (CRL 4.3 cm CRL, 25% gestation) the ruminal wall comprised three layers: an internal epithelial layer, a middle layer of pluripotential blastemic tissue and an external layer or serosa. Ruminal pillars were visible at 46 days (CRL 6 cm, 30% gestation), and by 76 days (CRL 18 cm, 50% gestation) ruminal papillae were starting to appear. Under scanning electron microscopy, by 50 days (CRL 7.7 cm, 33% gestation) small ruminal papillae were observed protruding from the surface. Finally, neuroendocrine cells (synaptophysin, SYP) were detected at 53 days (CRL 9 cm CRL, 35% gestation), while glial cell markers (glial fibrillary acidic protein--GFAP, and vimentin-VIM) were found at 108 days (CRL 31 cm, 72% gestation) and 39 days (CRL 4.4 cm, 26% gestation), respectively. Neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) were detected immunohistochemically at 113 days (CRL 33 cm, 75% gestation) and 120 days (CRL 35 cm, 80% gestation), respectively. In conclusion, histomorphogenesis of the rumen in goats was similar to that reported in deer, but rather slower than observed for sheep or cattle.

Structural, histochemical and immunocytochemical study of the forestomach mucosa in domestic ruminants.

The forestomach plays an important role in the digestion physiology of ruminants. The aim of this study is to clarify the morpho-functional role of the mucosa in each of the three compartments of the forestomach in three domestic ruminants species, viz cattle, buffalo and sheep, by means of structural, histochemical and immunocytochemical methods, including transmission electron microscopy, light microscopy and scanning electron microscopy. These methods were chosen to demonstrate the indirect evidence for the presence of nitric oxide (NO) employing NADPHd and nitric oxide synthase I (NOS I). The various cell layers of the forestomach epithelium are described and illustrated in detail. An intense NADPHd staining was observed in the granulosa, spinosa and basal layers of the epithelium, in particular in the cytoplasm over the nucleus. NOS I immunoreactivity was found in all specimens of the forestomach mucosa. The results of this study might reflect a possible role of NO in delaying the onset of cellular apoptosis in the forestomach mucosa of the domestic ruminants, by playing a role in the production of cell energy.

Dietary regulation of ruminal bovine UT-B urea transporter expression and localization.

Facilitative UT-B urea transporters have been located in the gastrointestinal tract of numerous mammalian species. We have previously identified UT-B urea transporters within the epithelial layers of the bovine (b) rumen. The aim of this study was to test the hypothesis that ruminal bUT-B urea transporters are regulated by dietary intake. Six Limousine-cross steers (initial BW = 690 +/- 51 kg) were separated into 2 groups fed a basic silage-based diet (RS) or a concentrate-based diet (RC) for 37 d and compared for ruminal morphology, content, and bUT-B expression. Analysis by reverse transcription-PCR showed that ruminal bUT-B2 mRNA expression was greater in RC-fed than RS-fed animals. Utilizing an anti-bUT-B antibody, we also detected a significant increase in bUT-B2 protein expression in RC-fed rumen (P < 0.05, n = 3). In agreement with these findings, immunolocalization studies of RC-fed ruminal tissue showed strong bUT-B signals throughout all epithelial layers, in contrast to weaker staining in RS-fed rumen that was more localized to the stratum basale. This study therefore confirmed that ruminal bUT-B urea transporter expression and localization were indeed altered by changes in dietary intake. We conclude that UT-B transporters play a significant role in the dietary regulation of bovine nitrogen balance.

The intraruminal papillation gradient in wild ruminants of different feeding types: Implications for rumen physiology.

Browsing and grazing ruminants are thought to differ in the degree their rumen contents are stratified-which may be due to different characteristics of their respective forages, to particular adaptations of the animals, or both. However, this stratification is difficult to measure in live animals. The papillation of the rumen has been suggested as an anatomical proxy for stratification-with even papillation indicating homogenous contents, and uneven papillation (with few and small dorsal and ventral papillae, and prominent papillae in the atrium ruminis) stratified contents. Using the surface enlargement factor (SEF, indicating how basal mucosa surface is increased by papillae) of over 55 ruminant species, we demonstrate that differences between the SEF(dorsal) or SEF(ventral) and the SEF(atrium) are significantly related to the percentage of grass in the natural diet. The more a species is adapted to grass, the more distinct this difference, with extreme grazers having unpapillated dorsal and ventral mucosa. The relative SEF(dorsal) as anatomical proxy for stratification, and the difference in particle and fluid retention in the rumen as physiological proxy for stratification, are highly correlated in species (n = 9) for which both kind of data are available. The results support the concept that the stratification of rumen contents varies among ruminants, with more homogenous contents in the more browsing and more stratified contents in the more grazing species.

Physical characteristics of rumen contents in two small ruminants of different feeding type, the mouflon (Ovis ammon musimon) and the roe deer (Capreolus capreolus).

In domestic ruminants, the stratification of forestomach contents - the results of flotation and sedimentation processes - is an important prerequisite for the selective particle retention in this organ. A series of anatomical and physiological measurements suggests that the degree of this stratification varies between browsing and grazing wild ruminants. We investigated the forestomach contents of free-ranging mouflon and roe deer shot during regular hunting procedures. There was no difference between the species in the degree by which forestomach ingesta separated according to size due to buoyancy characteristics in vitro. However, forestomach fluid of roe deer was more viscous than that of mouflon, and no difference in moisture content was evident between the dorsal and the ventral rumen in roe deer, in contrast to mouflon. Hence, the forestomach milieu in roe deer appears less favourable for gas or particle separation due to buoyancy characteristics. These findings are in accord with notable differences in forestomach papillation between the two species. In roe deer, particle separation is most likely restricted to the reticulum, whereas in mouflon, the whole rumen may pre-sort particles to a higher degree. The results suggest that differences in forestomach physiology may occur across ruminant species.

Alterações morfológicas induzidas por butirato, propionato e lactato sobre a mucosa ruminal e epiderme de bezerros: II. Aspectos ultra-estruturais / Lactate, propionate, and butyrate induced morphological alterations on calf ruminal mucosa and epidermis: II. Ultra-structurals aspects

Avaliou-se o efeito de ácidos graxos voláteis (AGV) sobre a integridade do epitélio no rúmen, no plano nasolabial, na epicera e no perioplum traseiro e dianteiro de bezerros e validou-se a feitura de biópsias tegumentares como indicadores de alterações morfológicas da mucosa ruminal. Dezessete bezerros, com sonda no rúmen, receberam infusões intra-ruminais de AGV ou salina, durante 37 dias. Aos 89 dias de vida, após o abate, foram colhidas amostras dos tecidos. Os AGV aumentaram a área de epitélio total e a área de células metabolicamente ativas no epitélio ruminal, embora o butirato não tenha induzido ao desenvolvimento papilar. A área de epitélio não queratinizado no plano nasolabial foi reduzida pela infusão de AGV. Butirato e lactato foram mais indutores de alterações patológicas no epitélio ruminal. Não foram observadas lesões histológicas nos epitélios do plano nasolabial, da epicera e do perioplum, mostrando que essas são conseqüências do efeito direto dos AGV sobre o epitélio ruminal. Os efeitos indireto e direto dos AGV sobre a morfologia dos tecidos epiteliais queratinizados não foram iguais. Biópsias tegumentares podem ter utilidade como indicadores de alterações morfológicas da mucosa ruminal.

The effect of volatile fatty acids (VFA) on rumen wall, epidermis of nasolabial surface, perioplum, and epicera of calves was evaluated. The experiment also aimed to validate the procedure of tegument biopsies as indicators of ruminal mucosa alterations. Seventeen neonatal calves with foley catheters received intraruminal infusions of VFA or saline, during 37 days. At 89-day-old, the animals were slaughtered and tissue samples were collected from rumen, nasolabial surface, epicera, and perioplum from face and hindquarters. VFA infusion increased total epithelium area and metabolically active ruminal cell area; although butirate did not induce the papilar development. The effect of nasolabial surface VFA infusion was the opposite to that observed in the rumen. No histological lesion was observed on nasolabial surface, epicera, and perioplum, demonstrating that these are consequences of VFA direct effect on ruminal epithelium. Butyrate and lactate induced more alterations on the ruminal epithelium. Indirect and direct VFA effects on keratinized epithelium tissues morphology were not identical. Tegumentary biopsies may be useful as indicators of morphological alterations of ruminal mucosa.

Mucous Membrane of the Rumen of Ovines, Fed With Spineless, Forrage Cactus or Palm (Barbary Fig) (Opuntia ficus indica Mil): Hystochemical Study by Means of Light Microscopy / Membrana Mucosa del Rumen de Ovinos, Alimentados con Forraje de Cactus Sin Espinas o Palmeras (Barbary Fig) (Opuntia ficus indica Mil): Estudio Histoquímico por Medio de Microscopía de Luz

The mucosa of the rumen performs the functions of absorption, transportation, metabolism and protection, due to the presence of microorganisms in this compartment of the digestive tract, which are responsible for the digestion of approximately 60% of the organic material apparently digested. The histological structure and the histochemical profile of glicoconjugate of the mucosa of the stomach of sheep that were being fed with forrage cactus or palm (Giant Palm - Opuntia ficus indica Mil)1. Twelve sheep were used, with approximately 14 months old, which were oddly distributed in four diets: D1- 60.0% forrage palm + 40.0% concentrated ration; D2- 47.5% forrage palm + 12.5% elephant, napier grass + 40.0% concentrated ration, and D3 - 34,8% forrage palm + 25.2% elephant, napier grass + 40.0% concentrated ration and D4 - 60.0% elephant, napier grass + 40.0% concentrated ration. The experience period lasted 90 days, and, at the end, the animals were euthanized and fragments of different compartments of their stomachs were taken right after. The animals having consumed diets D1, D2 e D3 presented more developed papillas, while the ones of diet D4, presented less developed papillas. The stratum corneum of the epithelium of the rumen coating of the animals in diet D1 presented a slight erosion, when compared to those in diets D2, D3 and D4.

La mucosa del rumen actúa en la absorción, transporte, metabolismo y protección, debido a la presencia de microorganismos en este compartimiento del tracto digestivo, los cuales son responsables de la digestión de aproximadamente el 60% de material orgánico aparentemente digerido. Se analizó la estructura histológica y el perfil histoquímico de las estructuras de glicoconjugados de la mucosa del estómago de las ovejas que fueron alimentadas con forraje de cactus o palmeras (Giant Palm - Opuntia ficus indica Mil)1. Fueron utilizadas 12 ovejas, con aproximadamente 14 meses de edad, las cuales fueron distribuidas de manera impar en cuatro dietas: D1- 60.0% forraje de palmera + 40.0% ración concentrada; D2- 47.5% forraje de palmera + 12.5% hierba alta africana + 40.0% ración concentrada, y D3 - 34,8% forraje de palmera + 25.2% hierba alta africana + 40.0% ración concentrada y D4 - 60.0%hierba alta africana + 40.0% ración concentrada. La experiencia duró 90 días y al final, los animales fueron sacrificados y fragmentos de diferentes compartimientos de sus estómagos fueron directamente recogidos. Los animales que habían consumido dietas D1, D2 y D3 presentaron papilas más desarrolladas, mientras que los alimentados con dieta D4 presentaron papilas menos desarrolladas. El estrato córneo del epitelio del rumen de los animales de la dieta D1 presentaron pequeña erosión, cuando fueron comparados con los animales sometidos a las dietas D2, D3 y D4.

Functional organization of the bovine rumen epithelium.

The functional organization of the bovine rumen epithelium has been examined by electron and light microscopy combined with immunocytochemistry to define a transport model for this epithelium. Expression of connexin 43, an integral component of gap junctions, the tight-junction molecules claudin-1 and zonula occludens 1 (ZO-1), and the catalytic alpha-subunit of Na(+)-K(+)-ATPase was demonstrated by SDS-PAGE and Western blotting. From the lumen surface, four cell layers can be distinguished: the stratum corneum, the stratum granulosum, the stratum spinosum, and the stratum basale. Both claudin-1 and ZO-1 immunostaining showed plasma membrane staining, which was present at the stratum granulosum with decreasing intensity through the stratum spinosum to the stratum basale. The stratum corneum was negative for claudin-1 immunostaining. Transmission electron microscopy confirmed that occluding tight junctions were present at the stratum granulosum. Plasma membrane connexin 43 immunostaining was most intense at the stratum granulosum and decreased in intensity through stratum spinosum and stratum basale. There was intense immunostaining of the stratum basale for Na(+)-K(+)-ATPase, with weak staining of the stratum spinosum. Both the stratum granulosum and the stratum corneum were essentially negative. Stratum basale cells also displayed a high mitochondrial density relative to more apical cell layers. We conclude that epithelial barrier function may be attributed to the stratum granulosum and that cell-cell gap junctions allow diffusion to interconnect the barrier cell layer with the stratum basale where Na(+)-K(+)-ATPase is concentrated.

A macro- and light microscopical study of the pathology of Calicophoron microbothrium infection in experimentally infected cattle.

Twelve Tuli weaner steers aged 1 year were randomly subdivided into three groups of four animals and infected with different doses of Calicophoron microbothrium metacercariae. Each animal in Group I received a low dose (LD) of 5 000 metacercariae, Group II a medium dose (MD) of 15 000 metacercariae, Group III a high dose (HD) of 25 000 metacercariae and one additional animal was kept as an uninfected control (C). After infection, one animal from each group was slaughtered on Day 28, 42, 56 and 84 post infection (pi) and samples from the ileum, jejunum, duodenum, abomasum and the rumen were collected for histopathological and cytological examination. On Day 28 pi, the gross pathological lesions observed in the duodenum of the LD and the MD animals were similar and comprised duodenal thickening, corrugation, hyperaemia, petechiation and ulceration. In the HD animal the duodenal lesions were similar but more severe. The abomasal folds were severely oedematous in the MD group and nearly occluded the abomasal lumen. Moderate oedema of the abomasal folds was also present in the LD and HD animals. The gross pathological lesions regressed in all the infected groups with increasing age of infection and had disappeared completely by Day 56 pi. On Day 28 pi the histopathological lesions in the duodenum and jejunum of the LD and MD groups were similar, comprising subtotal villous atrophy, hyperplasia of Brunner's glands and Peyer's patches and moderate infiltration of eosinophils, mast cells and a few globule leukocytes, basophils and lymphocytes in the lamina propria. The HD group had total villous atrophy, severe hyperplasia and cystic dilatation of Brunner's glands, which had expanded to cover the entire submucosa. On Day 42 pi the histopathological lesions were still present in the MD and the HD groups comprising subtotal villous atrophy and hyperplasia of Brunner's glands. Heavy infiltrations of eosinophils, moderate amounts of mast cells and a few basophils, globule leukocytes and lymphocytes were still present in the lamina propria of all three groups. On Day 56 pi, a few glands were still cystic in the MD and the HD groups. Moderate cell infiltrations were still present in the lamina propria of all the three groups and by Day 84 pi complete regeneration had occurred in all animals.

The influence of different fibrous supplements in the diet on ruminal histology and histometry in veal calves.

The aim of this study was to determine whether the administration of four different solid feeds would influence selected morphological and morpho-functional aspects of the rumen mucosa in veal calves. The fibrous supplementation of the liquid diet of veal calves has been provided by recent EU formulation (EC Council Directive 91/629/1991; EC Council Directive 97/2/1997). Twenty-five Holstein calves were assigned to either exclusively liquid diet (milk replacer, control), or pelleted feed, corn silage, extruded feed, dried corn silage. The morpho-functional effects of the fibre-containing diets were examined evaluating histological and histometrical characteristics of ruminal mucosa after the slaughter of calves. There were slight to severe histological abnormalities in the rumens of all animals examined. The severe histological abnormalities were present in calves given pelleted feed, corn silage, and extruded feed. Dried corn silage caused less ruminal damage. We found that the length and epithelial thickness of ruminal papillae were higher in control veal calves than in dietary fibre-supplemented animals. The results of the present study, even if partially, support the EU prescription in the use of fibre diets in veal calves as integration of the traditional milk replacer diet.

Morphological changes associated with the development of the rumino-reticulum in growing lambs fed different rations.

Morphological changes associated with rumino-reticular development was compared in two groups of SA Mutton Merino lambs (n = 12) fed different diets at 3-5 weeks, 17-19 weeks and 31-33 weeks of age. Diet groups were identified as MMH or MHH according to the sequence at which the full-milk replacement (M) or hay (H) diet were fed to the lambs over the three study phases (phases I, II and III) preceding each age period. Prominent differences in the morphology (size and volume) and function (pH, proteolytic activity and microbial population) of the rumino-reticulum were observed in indicator lambs (n = 2) killed at every age period and also between milk-fed and hay-fed lambs. The size of the rumino-reticulum was rudimentary at 3-5 weeks of age and remained underdeveloped in lambs at 17-19 weeks of age which had received a full-milk replacement diet during phase II. One lamb, slaughtered at 3 weeks of age, showed a large distended rumen with severe sloughing of the surface cells of the stratum corneum. The size of the rumino-reticulum increased in size (2 x) in lambs which were fed hay relative to the milk-fed lambs during phase II and reached adult proportions in all lambs at 31-33 weeks of age. Ultrastructural examination showed that rumen papillae were more developed in lambs fed hay during phase II when compared to those of milk-fed lambs. Rumen papillae were best developed in phase III lambs.

Influence of dietary concentrate to forage ratio on the development of rumen mucosa in calves.

Effects of structural and non-structural carbohydrates on the development of rumen fermentation and ruminal mucosa in calves were examined during the weaning period. Barley/soybean meal (SBM) group was fed a concentrate starting from 2 weeks of age, whereas alfalfa group received a mixture of concentrate and alfalfa hay in which the proportion of the latter was gradually increased from 20% to 70% between weeks 2 and 9 of age. The total volatile fatty acid concentration in rumen fluid of calves increased with age, but at 9 weeks there were no significant differences between the two diets (barley/SBM group 153 mmol/l, alfalfa group 150 mmol/l). Rumen papillae at 9 weeks of age, as compared to 6 weeks of age, were longer and fewer in number per square centimetre mucosa, with larger cut surface. This resulted in a higher surface of papillae per square centimetre mucosa at 9 weeks (barley/SBM group 286 mm2/cm2, alfalfa group 245 mm2/cm2) than at 6 weeks of age (barley/SBM group 217 mm2/cm2, alfalfa group 198 mm2/cm2). At 9 weeks of age, the pH (barley/SBM 5.0, alfalfa 5.7), the acetate to propionate ratio (barley/SBM 2.2, alfalfa 3.2) as well as the length of the papillae in the ventral ruminal sac (barley/SBM 1.96 mm, alfalfa 2.37 mm) were increased in the alfalfa group when compared to the barley/SBM group (P < 0.1). In the former group, the proportion of butyrate revealed significantly increased values at 4 and 6 weeks of age. In animals of the barley/SBM group at 9 weeks of age, characteristic protrusions with proliferated thick epithelium occurred on the papillae and increased the surface for absorption. On the epithelium (Stratum corneum) desquamating cells with parakeratosis could be observed. In the alfalfa group the papillae of the ventral ruminal sac were longer, without protrusions. The morphotypes of the adhering rumen microflora differed between the groups. It can be concluded that feeding greater amounts of non-structural carbohydrates increases the surface for absorption of the rumen epithelium in calves. The absence of hyperkeratosis and rumenitis in the barley/SBM group indicated that there is no reason to limit high starch diets in the early weaning period of calves.

Morphological study of the forestomach of the Japanese serow (Capricornis crispus).

Details of the morphology of the forestomach of the Japanese serow (Capricornis crispus) were examined macroscopically, and by light and scanning electron microscopy. The rumen was sac-like in shape, and the right accessory longitudinal groove was not visible externally. The reticulum was relatively small, while the omasum was oval and large. Inside the rumen, even in the dorsal sac, the ruminal papillae were densely distributed, although absent on the pillars. The caudodorsal coronary pillar was indistinct. In the ruminoreticular fold, ruminal papillae were observed even on the reticulum side. In the reticulum, the primary reticular fold was apparent and the ill-defined secondary folds were also detected in some reticular cells. In the omasum, the omasal laminae of four sizes were recognized. The fourth order of laminae was occasionally absent. Histological sections of ruminal papillae revealed that softly keratinized epithelium covered the entire ruminal mucosa. In the reticulum, soft keratinized epithelium was observed throughout, with the exception of the tips of reticular papillae on which the epithelium showed evidence of hard keratinization. The epithelium of the omasal laminae was moderately keratinized. On the floor of the reticular groove, interlaminar area and in the omasal groove, the accumulations of numerous eosinophilic cells were observed in the superficial region. Under the scanning electron microscope, shallow transverse grooves were seen on the surface of the ruminal papillae. In general, the surface structure seemed to be similar to that of sheep rather than cattle. Cellular formations of the collagen fibrils were observed at the subepithelial region. In conclusion, examination of the forestomach allows classification of the Japanese serows as requiring an intermediate type of feeding habit and being between concentrate selectors and grass-roughage eaters from a morphological view.

[Hyperplasia of the ruminal villi in three wild roe deer]. / Pansenzottenhyperplasie bei drei Rehen aus freier Wildbahn.

In autumn 1994 a hyperplasia of ruminal villi in three roe deer out of one hunting ground was diagnosed. The ruminal villi were three to five times longer than normal and partially stuck together. The case history and a comparison of the pathomorphological and histological findings with similar symptoms in domestic ruminants lead to a discussion on feeding as the cause of the disease.

Is lamina muscularis mucosae present in the ruminal mucosa of cattle? Immunohistochemical and ultrastructural approaches.

The cells in the condensed fibrous layer in the lamina propria of the ruminal mucosa of the calves and cows were studied at the light microscopic level. Abundant actin-immunoreactive cells were detected both in the calves and cows, while desmin-immunoreactive cells were moderate in frequency in the cows and low or absent in the calves. Vimentin-immunoreactive cells were abundant in the cows but moderate to low in frequency in the calves. These cells were distributed to form a condensed layer being more abundant in the ruminal papillae than the interpapillar mucosae in the cows and equal in the papillae and interpapillar mucosae in the calves. At the ultrastructural level, smooth muscle cells and fibroblasts were abundant in the deep core of the ruminal papilla of the cows. The present results suggest that the condensed fibrous layer revealed in the ruminal mucosae contains smooth muscle cell population which could be regarded as the specialized lamina muscularis mucosae.

Análisis morfológico comparado de la región fúndica entre un cánido (canis familiaris) y un camélido sudamericano (lama glama) / Comparative morphological analysis of the fundic region between a canidae (canis familiaris) and a southamerican camelidae (lama glama)

Los hábitos alimentarios que presentan los cánidos (monogástricos) respecto de los camélidos (poligástricos), son diferentes. Los primeros consumen dietas pobres en fibras, en tanto que los camélidos consumen una dieta rica en fibra que consiste en pastos cortos y duros (bofedal). Sin embargo son capaces de aprovechar eficientemente estos alimentos. Por ello, fueron analizados comparativamente las regiones fúndicas de ambas especies, donde encontramos diferencias morfológicas adaptativas. Para la realización del presente trabajo, se obtuvieron muestras de las regionnes fúndicas, provenientes de estómagos de perro (Canis familiaris) y de llama (Lama glama), adultos. estas muestras fueron procesadas de acuerdo a las técnicas histológicas corrientes e histoquímica de Picrosirius y analizadas comparativamente al microscopio óptico. Los resultados revelaron que existen diferencias importantes en las regiones fúndicas de ambas especies en estudio. Estas diferencias se encuentran especialmente a nivel de la mucosa, donde la profundidad de las glándulas fúndicas, número de células parietales (oxínticas) y la irrigación sanguínea son mucho mayores en la llama. La pared abdomasal presenta un refuerzo de tejido conjuntivo compacto de haces paralelos, entre la serosa y la muscular longitudinal externa. Estas adaptaciones redundarían en una mayor eficiencia digestiva por parte de los camélidos, dadas las características de su dieta habitual

Actin in stratified squamous keratinized epithelium.

Actin filament distribution patterns were revealed in a stratified squamous keratinized epithelium using phalloidin-fluorescent and immunogold labeling techniques applied on bovine ruminal pilar as a model tissue. In non-keratinized cell types, actin concentrates on the microfilament-rich cellular cortex as well as on cytoplasmic processes and protrusions. In cornified cells labeling is distributed diffusely over the amorphous cytoplasm. A constant feature in all cell types is plasmalemmal labeling. Desmosomes exhibit deposition on their plasmalemmal leaflets, the dense central stratum and plaques. Desmosomal as well as cytoplasmic keratin filament bundles also label for actin, the latter often in a cross-banded manner. These cellular distribution patterns of actin filaments are discussed with respect to the significance of the microfilaments in the process of cell shape determination, stratification, and cell adhesion.

In vitro ouabain-sensitive respiration and protein synthesis in ruminal epithelial papillae of Hereford steers fed either alfalfa or bromegrass hay once daily.

Seven Hereford steers (457 +/- 8.5 kg BW) with ruminal cannulas were fed either long or short chopped bromegrass (B) or alfalfa (A) hay at 90% of a 3-h ad libitum intake once daily between 0900 and 1200 in a 4 x 4 complete and 3 x 4 incomplete Latin square design. After evacuation of ruminal contents, papillae from the ventral sac of the rumen were excised at 0900, 1200, and 2100 and placed in oxygenated media. Oxygen consumption was determined polarographically, after which either 10(-4) M ouabain or 10(-4) M cycloheximide was added for determination of ouabain-sensitive (OSO2) or cycloheximide-sensitive (CSO2) O2 consumption, respectively. Additionally, protein synthesis was measured by uptake of [3H]phenylalanine. Twenty-four-hour patterns of ruminal fluid pH, osmolality, ammonia N, and VFA were also determined. Steers fed A exhibited a rapid rise in total O2, OSO2, and CSO2 immediately after consumption of a meal; the respiration patterns of ruminal epithelial papillae from animals fed B lagged behind those observed for animals fed A. Patterns of O2 consumption for both diets paralleled those observed for ruminal concentration of products of fermentation; those fed A had a larger magnitude of change in both O2 consumption and fermentation products. Ruminal epithelial O2 consumption seems to be determined by substrate availability and products of fermentation, and Na+,K+ATPase and protein synthetic activity each account for one-fifth of ruminal papillae O2 consumption. Fractional rates of protein synthesis were unaffected by type of forage consumed.