[Endoscopy in cattle]

Endoscopy in the field of buiatrics has gained growing importance in recent years. Parts of the upper respiratory and gastrointestinal tract, the urethra and urinary bladder, the abdomen and the teat are all accessible by means of endoscopy. The direct visualisation of inner or outer organ surfaces allows for rapid diagnosis and even prognosis of different pathological conditions. Flexible endoscopes of different dimensions are used for endoscopic examination of the upper respiratory tract. Examining this region, endoscopy is in some cases superior to other imaging techniques because of the direct visualization of surfaces and their pathological conditions and the possibility of collecting biopsies under visual control. The same is documented for diseases of the oesophagus. On the other hand, rumenoscopy is of experimental character so far. Urethrocystoscopy is mainly performed for diagnostic purposes with either flexible or rigid optics. Theloscopy represents the "gold standard" for surgical intervention in cases of disturbance of milk flow, since mucosal tissue can be removed under visual control. Therefore, this indication is one of the most important applications for endoscopy performed by practitioners. Another important field for the application of therapeutic endoscopy is the treatment of left displaced abomasum by repositioning and fixation to the abdominal wall under endoscopic control.

Ultrasonographic assessment of change in abomasal position during the last three months of gestation and first three months of lactation in Holstein-Friesian cows

OBJECTIVE

To determine changes in abomasal position and dimensions during the last 3 months of gestation and first 3 months of lactation via transabdominal ultrasonography and determine whether surgical correction of left-displaced abomasum (LDA) by right flank omentopexy alters abomasal position within the abdomen in Holstein-Friesian cows.

DESIGN

Observational study.

ANIMALS

20 heifers and 20 cows with no history of an LDA and 7 cows that had been treated for LDA via right flank omentopexy during an earlier lactation. Procedure-Ultrasonographic measurements were obtained 8 times during the last 3 months of gestation and first 3 months of lactation. Abomasal length, width, and volume were calculated from these measurements.

RESULTS

The abomasum was always wider than it was long and located predominantly to the right of the midline. The presence of a right flank omentopexy had no effect on the measured parameters. Abomasal length decreased and width increased during the last 3 months of gestation, resulting in a more transverse orientation of the abomasum within the abdomen. These changes appeared to be in response to cranial expansion of the gravid uterus. The abomasum returned to a more caudal and right sagittal position within 14 days after parturition.

CONCLUSIONS AND CLINICAL RELEVANCE

Abomasal dimensions, position, and volume change markedly during the last 3 months of gestation and first 3 months of lactation. Results permit detection of abnormal abomasal position in ill cows and indicate that the preferred location for abomasopexy is 20 cm caudal to the xiphoid process and 5 to 10 cm to the right of the ventral mid-line.

Position of the abomasum in dairy cows during the first six weeks after calving

The position of the abomasum in six cows was examined by ultrasonography at regular intervals for six weeks after they had calved. Its position was established by determining the distance between the margin of the left side of the abomasum and the ventral midline at two sites. During the last weeks of pregnancy, the abomasum was positioned in a small region of the left ventral side of the abdominal cavity. At parturition it was positioned high on the left side and then descended. The abomasum was furthest from the midline immediately after parturition. Its position was related to the interval after calving, the cow's feed intake, and the pH and osmotic pressure of the rumen fluid. There was considerable variation between the cows in the position of the abomasum, which was in part due to analytical variation, and in individual cows it had a circadian rhythm.

Effect of short-term underfeeding on weight of splanchnic organs in ewes

We assessed the effect of short-term underfeeding on weight and protein mass of splanchnic tissues in adult ewes submitted to a factorial experimental design. In a pre-experimental period, 18 ewes divided into 2 groups of 9 were fed a second cut of natural grassland hay during 4 weeks at 112 or 38% of their energy maintenance requirements. Three ewes of each group were then fed the same hay during 4 weeks at either low (group L), moderate (group M) or high intake (group H), corresponding to 38, 75 or 112% of their energy maintenance requirements, respectively, then slaughtered. Fresh weight and protein mass of splanchnic organs were measured. No carry-over effect of the pre-experimental level of intake on weight and protein mass was observed for any splanchnic organs. Splanchnic tissues contributed at 10.7 and 8.6% to the decrease in live weight for groups M and L, respectively. The decrease in weight of splanchnic tissues (-15%) was mainly attributed to reticulorumen (-23%), liver (-21%), and at a lesser extent small intestine (-11%). No large change in the mass ratio between mucosa and muscular-serosa in both dorsal and ventral sacs occurred in the rumen wall. These results are discussed together with previous published results on long-term underfed ewes, and suggest that the decrease in energy expenditure in whole animal induced by underfeeding is mainly related to the decrease in splanchnic weight at short-term, and to the decrease in other tissues at long-term, splanchnic weight being stabilized.

Proliferation in the gastric epithelium of bovine abomasum during foetal development as revealed by Ki-67 immunocytochemistry

For the first time, proliferative cells in the abomasal mucosa of 30 bovine foetuses with a crown-rump length of 34 to 1000 mm (approximately 45-250 days of gestation) were detected using the antibody MIB-1 against the (human) nuclear-associated protein Ki-67. At the beginning of mucosal development, the epithelium is stratified and MIB-1 positive cells are scattered all over the epithelium. With the formation of gastric pit/gland invaginations, the proliferative cells are mostly confined to the basal half or third of the gastric pit/gland unit, both in the regio glandulae propriae and in the regio glandulae pyloricae. From the 27th week in the regio glandulae propriae and the 30th week in the pyloric gland region, respectively, the proliferative cells move upwards and are situated in the bottom of the pit and the upper part of the gland, whereas the base of the gland is free of labelling.

Anatomical subdivisions of the stomach of the Bactrian camel (Camelus bactrianus)

Twenty stomachs of Bactrian camels (Camelus bactrianus) were studied by gross dissection. Based on the configuration of the stomach and the structure of the mucous membrane, the stomach was divided into three ventricles that differ from the arrangement described for ox and sheep. The first and second ventricles of the proventriculus of camel form one stomach rather than two different stomachs. These ventricles of the proventriculus do not correspond to the rumen and reticulum of ox and sheep. The third ventricle appears to be the abomasum. One part of the abomasum has reticular mucosal folds that indicate it is not the reticulum. A second part of the abomasum has longitudinal mucosal folds suggesting it is not the omasum. Three glandular sac areas associated with the preventriculus and abomasum are also described.

Ultrasonographic examination of the abomasum of 50 cows

The purpose of this study was to determine the position, appearance and dimensions of the abomasum of 50 healthy cows by ultrasonography. The ventral abdominal region caudal to the xiphoid process was examined with a 3.5 MHz linear transducer. The abomasum could be visualised from both sides and from the ventral midline of 47 of the cows. The abomasum could be clearly differentiated from adjacent organs because of its contents, which appeared as a heterogeneous, moderately echogenic structure with echogenic stippling. However, the wall of the abomasum appeared, if at all, as a narrow echogenic line. Parts of the abomasal folds were visible occasionally as echogenic structures within the abomasum. Slow movement of the feed in the abomasum was also often visualised. The pylorus was positively identified in only one cow. The cranial margin of the abomasum was situated up to 15 cm caudal to the xiphoid process. The abomasum was between 7.4 and 42.9 cm long, and its maximal extent, measured from the ventral midline to the left, was from 5.0 to 26.0 cm in the cranial region and from 5.0 to 16.0 cm in the caudal region. From the ventral midline to the right, it was from 5.0 to 33.0 cm in the cranial region and from 28.0 to 36.0 cm in the caudal region. The minimal dorsoventral dimension of the abomasum ranged from 0.7 to 7.2 cm, and its maximal dorsoventral dimension ranged from 3.6 to 11.1 cm.

The stomach of the sambar deer (Cervus unicolor unicolor)

In New Zealand, the sambar deer is reported to feed on a variety of grasses and browse material. In the specimens studied, the average volume of the sambar rumen was about 151. Thick, non-papillated pillars divided the rumen into a saccus dorsalis and a saccus ventralis. The lining of the rumen was covered with papillae; those in the roof area were short and poorly developed. The omasum was a well-developed organ with 47-71 (mean 57) laminae. These were covered with short and poorly developed papillae. It is concluded that these sambar deer stomachs were typical of a grass-roughage feeder. This contrasts with the previous classification of the sambar deer as an intermediate feeder.

Normal laparoscopic anatomy of the bovine abdomen

Three laparoscopic procedures were performed on each of 6 adult Jersey cows in the first trimester of gestation to describe normal laparoscopic anatomy of the bovine abdomen. Also, a technique for laparoscopy of the cranioventral portion of the abdomen was described. Right paralumbar fossa, left paralumbar fossa, and cranioventral midline laparoscopy were performed 72 hours apart of each cow. Physical examination findings, CBC, serum biochemical analysis, and peritoneal fluid analysis before and 72 hours after the first surgery were used to assess the effects of the procedures on the cows. Exploratory celiotomy was performed 2 weeks after the last laparoscopy. The cows were then reexamined 6 weeks after the last procedure. The t-test for paired data was used for statistical analysis; the level of significance was P < 0.05. Laparoscopy was performed without complication in all cows. Adverse effects of laparoscopy, individually or serially, were not observed. Significant differences were not found between CBC, serum biochemical, and peritoneal fluid variables taken before and 72 hours after surgery.

The stomach of the Kafue lechwe (Kobus leche kafuensis)

The Kafue lechwe is endemic to the Kafue Flats area of Zambia. It is semi-aquatic in habit, feeding upon grasses above and below the waterline. The volume of the lechwe rumen is 17 L in the male and 14 L in the female. It has strong and definite pillars. The interior of the rumen is papillated except in the roof area and on the pillars. The omasum has more than 70 laminae which are papillated on the reticular end. The anatomy of the lechwe stomach is similar to the stomachs of other water dependent grazers such as Bohor Reedbuck, Waterbuck, Uganda Kob and Puku.

Do the cardiac glands exist? 7. The cow

The glands distributed in the narrow region of the abomasum contiguous to the omasum of the cow have been described as cardiac glands. We doubted this assertion and therefore performed histological and histochemical investigations of the glands to clarify their characteristics. 1. All glandular cells except the parietal cells in a few glands contiguous to the omasum react strongly to PAS, AB(pH 2.5), and PAS-AB(pH 2.5) staining, and moderately to AB(pH 0.5) staining. 2. Glandular cells at the base of these glands contain fine pepsinogen granules and a few parietal cells are distributed in these glands, indicating that they are undifferentiated gastric glands and that the so-called cardiac glands do not exist in the cow stomach. 3. Glandular cells in undifferentiated gastric glands are filled with PAS, AB(pH 2.5 and 0.5) and PAS-AB(pH 2.5) positive substances. Which gradually decrease and finally disappear with differentiation, remaining only in the neck (mucous neck cells) and the cells in the upper part of the glandular body (immature chief cells), in mature gastric glands. 4. Mature chief cells in differentiated gastric glands are distributed in the middle and lower bodies and base of the glands and contain a number of PAS and PAS-AB(pH 2.5) positive granules and a large number of coarse pepsinogen granules, while pepsinogen granules in the mucous neck cells and immature chief cells are finer. 5. In the cow the region in which undifferentiated gastric glands are located is very narrow. 6. Parietal cells in the cow stomach are numerous.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgery of the bovine abomasum

Intensive management of cattle has resulted in an increased incidence of abomasal disorders. Many of these disorders require surgical intervention for the best outcome. This article reviews the anatomy and physiology of the abomasum, abomasal disorders that may be treated by surgery, and the advantages and disadvantages of various surgical approaches to those disorders.

Post-mortem changes in the abomasal mucosae of sheep infected with Haemonchus contortus compared with those in uninfected sheep

Progressive post-mortem changes were observed, with fibre optic endoscopy, in the abomasum of uninfected sheep and sheep infected with H. contortus. Loss of epithelial cells was observed 14 to 16 min after death in the uninfected sheep. The loss exposed the underlying lamina propria. This loss became more widespread as the time after death increased. Epithelial cell loss was observed earlier (as early as 6 min after death) in the infected sheep. Three of the infected sheep also displayed dispersal of alkaline phosphatase activity 30 min after death. The present work shows that post-mortem changes can occur quite quickly in animals, especially infected animals, and emphasizes the importance of rapid removal of tissue from animals after death.

Distribution of the muscle coat at the omasoabomasal junction and its vicinity in cattle

Detailed studies on the distribution of the muscle coat at the omasoabomasal junction in cattle, especially in the pila omasi, were carried out in order to clarify the mechanism of closing of the ostium omasoabomasicum. Anatomical and histological observations revealed that the muscle coat forming the circumference of the ostium omasoabomasicum is composed of inner circular and outer longitudinal layers. The former was particularly thickened at the end of the sulcus omasi (pila omasi). Joined to the pila omasi was a thick muscle bundle which extended from the labium sinistrum (left lip) of the sulcus reticuli and ran obliquely along the floor of the sulcus omasi. Moreover, on the abomasal side of the ostium omasoabomasicum, vela abomasi were formed in such a manner as to surround the ostium omasoabomasicum. These were continuous with the edges of the sulcus omasi. Judging from its location and muscular structure, the pila omasi may contract in accordance with the contraction of the reticulum. As a result, the ostium omasoabomasicum may be narrowed and the vela abomasi pulled toward the omasum, perhaps obstructing the ostium omasoabomasicum. Accordingly, it is presumed that the retention of contents in the omasum may effectively prevent abomasal contents from moving backward into the omasum.

Influence of ration physical form and nitrogen availability on ruminal morphology of growing bull calves

Male Holstein calves were fed complete diets containing three physical forms (ground and chopped hay and all concentrate) and three rumen degradable protein percent. Calves were slaughtered at 20 wk of age. Weights of reticulorumen with and without contents wee recorded. Proportions of mucosa and muscle and gross morphology were determined on excised rumen wall. From nine additional calves rumen epithelial tissue was obtained for light microscopic examination of papillae to determined length, width, surface area, and morphological condition. Weights of reticulorumen with contents were heaviest for calves fed ground hay and tissue weights heaviest for calves fed concentrate. Ruminal content volume was greater for calves fed diets containing hay compared to all concentrate. Hay contents tended to be drier and less dense than concentrate contents. Ruminal epithelial lining was heavier in concentrate-fed and had more mucosa to muscle compared to rumen of calves fed ground or chopped hay. However, papillary length, number of papillae per field, and surface area/field was greater in calves fed hay. Morphological abnormalities of the rumen epithelium occurred more frequently in calves fed concentrate. Reticulorumen measures were unaffected by degradable protein percent. Absorptive capacity of calves fed all concentrate diets decreased compared to calves fed diets with 40% hay.

Ultrastructural changes in the abomasal mucosa of lambs experimentally infected with Trichostrongylus axei

The normal ultrastructure of the abomasal fundic glands in sheep is described and compared with those of sheep infected experimentally with T. axei. Alterations were observed in mucous, mucous neck and zymogen cells and the results are compared with a similar study in normal and infected calves.

The ultrastructural changes in the abomasal mucosa of calves experimentally infected with Trichostrongylus axei

The normal ultrastructure of the fundic gastric glands of cattle is described and compared with those from calves infected with T. axei. Loss and alterations in structure of zymogen and parietal cells are observed and are related to changes observed by light microscopy. The significance of these changes is discussed.