Changes in the feed intake, pH and osmolality of rumen fluid, and the position of the abomasum of eight dairy cows during a diet-induced left displacement of the abomasum

During the last six weeks of the dry period, eight Holstein-Friesian cows were fed a restricted amount of grass silage; after calving, a mixture of maize silage and concentrates was offered in a feeding regimen designed to induce a displacement of the abomasum. In the first month after calving, the cows were monitored for the following variables: feed intake and composition, milk production, the position of the abomasum, and the pH and osmolality of the rumen contents. In five of the eight cows, a left displacement of the abomasum occurred between four and 21 days after calving in the absence of other diseases. The displacement was temporary, lasting between five and 36 consecutive hours and one or two days in two of the cows (floaters), and for three or more days in the other three. Before these three cows developed the displacement, their abomasum was 4.3 to 7.9 cm higher, its contents had a higher mean osmolality (+19.2 mosmol/kg), and the ratio of roughage to concentrates in their feed was lower (-0.87) than in the three cows that did not develop clinical signs of a displaced abomasum. There were no significant differences in these variables between the floaters and the healthy cows.     

Motility of the rumen after feeding sheep pelleted rations]

In an experiment with wethers the effect of the feeding with pelleted feed rations and the partial replacement of coarse fodder by non-treated beech sawdust on the motorial activity of the rumen was observed. The rumen motility was measured through a rumen fistula by means of the balloon method with the help of a capacitator primary unit, an electric manometer and a recording instrument. Over a period of 24 weeks the animals consumed 1.3 kg dry matter per day. It consisted of 41.8% meadow hay, 25.3% barley, 15.4% sawdust, 15.0% molasses, 1.3% urea, 0.76% mixed minerals and 0.48% hexametaphosphate in the form of pellets (test group) or the traditional classical form (control group). The feeding of pellets diminished the frequency (P less than 0.001) and the intensity of rumen contractions before and 1, 3 and 5 hours after feeding. Maximal frequency values were registered one hour after the food intake. During this time the number of secondary contractions of the rumen increased; differences of the frequency were, however, not registered, which means that the different physical form of the diet had no influence on the motorial activity of the rumen and that the food intake as such is the decisive factor. The diminished rumen motility in further hours after feeding was effected by treating the feed (grinding and pelleting).     

Surgery of the abomasum.

Abomasal diseases are common in cattle. Many of these diseases can be managed surgically. This article briefly discusses the various classifications of abomasal diseases. It focuses on the surgical treatment of these diseases. Surgical principles of conventional surgery and minimally invasive techniques are discussed.     

Ultrasonography of the reticulum, rumen, omasum, and abomasum in 10 calves before, during, and after ingestion of milk

The reticulum, rumen, omasum, and abomasum were assessed via ultrasonography before, during, and 15, 30, and 120 minutes after feeding milk to 10 healthy calves. The ultrasonographic examinations were conducted using a 5.0 MHz linear transducer. Loops were recorded on video for further evaluation. The reticulum could be visualised before feeding in seven calves. Its appearance and pattern of contractions were similar to those in adult cattle, although the amplitude (1.7 ± 0.75 cm) and velocity (2.7 ± 1.34 cm/s) of the first contraction were smaller than in adult cattle. The reticulum could not be visualised in any of the calves during feeding as it was displaced cranially and laterally and therefore being obscured by the lungs as the abomasum expanded with the ingested milk. 2 hours post ingestion it remained obscured in 5 individual and was visualized again the other 5. The position and size of the entire rumen including the dorsal and ventral sacs and the ruminal contents were assessed. There were no changes in the ultrasonographic appearance of the rumen during or after feeding. Except for its smaller size, the ultrasonographic appearance of the omasum of calves was similar to that of adult cattle. Milk flow through the omasum could not be seen in any of the calves, and there were no changes in the appearance of the omasum during and after feeding. The abomasum was seen to the left and right of the ventral midline before feeding in all calves; it occupied considerably more space on the left than the right. The flow of milk into the abomasum and milk clotting, which occurred 15 minutes after feeding, could be seen in all calves. The milk clots started to slowly disintegrate 30 minutes after the start of feeding, and by 2 hours post feeding, this process was greatly advanced but remained incomplete. Ultrasonography is an ideal tool for the evaluation of the reticulum, rumen, omasum, and abomasum before, during, and after the ingestion of milk in calves.     

Evaluation of rumen transfaunation after surgical correction of left-sided displacement of the abomasum in cows

OBJECTIVE: To evaluate rumen transfaunation after surgical correction of left-sided displacement of the abomasum (LDA) in cows. DESIGN: Prospective clinical trial. ANIMALS: 20 multiparous cows with LDA. PROCEDURES: Cows with LDA were treated surgically (day 0). On days 0 (immediately after surgery) and 1, 10 cows each received 10 L of rumen fluid (transfaunated group) or 10 L of water (control group) via a stomach tube. Postoperative dietary dry-matter intake and milk yield of each cow were recorded daily for 5 days, beginning immediately after surgery. Blood and rumen fluid samples were collected prior to surgery and on days 1, 3, and 5 after surgery. Serum nonesterified fatty acid and beta-hydroxybutyrate concentrations were measured. Volatile fatty acid and ammonia concentrations and pH of rumen fluid were determined. Urine specimens were collected and tested for ketones at 8 AM and 4 PM. Cows with ketonuria were treated with 50% dextrose solution administered i.v. at the time ketonuria was first detected. Cows with ketonuria were treated twice daily until ketonuria resolved. RESULTS: All cows survived and completed their lactation. Daily and cumulative dry-matter intake and milk yield of cows in the transfaunated group were significantly greater than those of cows in the control group. Cows in the transfaunated group had significantly lower serum concentrations of beta-hydroxybutyrate and significantly lower acetate-to-propionate ratios in rumen fluid on day 1 after surgery, compared with cows in the control group. Cows that received transfaunate required a significantly lower total volume of dextrose administered i.v. than control cows. CONCLUSIONS AND CLINICAL RELEVANCE: Benefits of rumen transfaunation of cows after surgical correction of LDA included a lesser degree of ketonuria, greater feed intake, and higher milk yield, compared with nontransfaunated cows.     

Ultrasonography of the reticulum, rumen, omasum and abomasum before, during and after ingestion of hay and grass silage in 10 calves

The reticulum, rumen, omasum and abomasum were assessed via ultrasonography in 10 healthy female calves before, during and 2h after feeding hay and grass silage. The evaluations were made using an ultrasound machine with a 5.0MHz linear transducer. The reticulum could be visualized before feeding in all the calves. Its appearance and pattern of contractions were similar to those in adult cattle, although the amplitude (5.2±1.06cm) and velocity (3.5±1.42cm/s) of the first contraction were markedly less than in adult cattle. The position and size of the entire rumen including the dorsal and ventral sacs and the ruminal contents were assessed. Except for its smaller size, the ultrasonographic appearance of the omasum of calves was similar to that of adult cattle. The abomasum was seen to the left and right of the ventral midline before feeding in all calves; it occupied considerably more space on the left than the right. Compared with its appearance before feeding, the ultrasonographic appearance of the rumen, omasum and abomasum did not change during or after feeding. Ultrasonography is an ideal imaging tool for evaluating the reticulum, rumen, omasum and abomasum before, during and after feeding in calves.     

Effects of breed, diet and sex on the alkaline phosphatase activity in walls of the bovine rumen and abomasum

Alkaline phosphatase (APase) activity in tissue samples, with adherent bacteria, was measured from two sites in the rumen and from two sites in the abomasum of 57 yearling Angus and Hereford bulls and heifers fed a high or a low energy diet. In the rumen, APase activity was higher at the caudoventral blind sac than at the dorsal sac in animals of both breeds fed the high energy diet and in Angus bulls fed the low energy diet, but the reverse was observed in Hereford bulls fed the low-energy diet (P less than .01). In the abomasum, APase levels were higher for bulls than heifers (P less than .01) and higher at the fundic than at the pyloric region (P less than .01). Morphological studies also showed that rumen samples from animals fed a high energy diet exhibited a more widely distributed APase activity and an increase in the digestive recycling of epithelial cells that produced some "pitting" of the tissue. The higher APase activity of the epithelial tissue of animals fed the high energy diet may be explained by the greater rate of cell death and renewal indicated by the higher mitotic index reported by other researchers who have studied the cell cycle of the rumen epithelium in ruminants fed high and low energy diets.     

Histomorphometric analysis of the rumen of sheep during development.

Histomorphometric and scanning electron microscopic analyses were carried out on 74 embryos and fetuses and 20 sheep (early postnatal to adult age). Histodifferentiation of the rumen took place at 33 days of fetal life. Ruminal pillars were observed at 42 days, and at 61 days, ruminal papillae appeared as evaginations of the epithelial stratum basale. Neutral mucopolysaccharides first appeared in epithelial cells at 46 days of fetal life; thereafter, numbers decreased gradually and subsequently stabilized in postnatal life. Acid mucopolysaccharides, mucins, and mucoid compounds were not detected. Age and diet were recognized as factors that determine the structure of the ruminal mucosa. Growth curves and formulas were set out for each tissue layer.     

Origin of abomasum gas in the cows with displaced abomasum

The gas composition of the rumen and the abomasum were investigated in 71 cows including 25 cows with displaced abomasum. The ratio of methane (CH4) to CO2 in the abomasum gas was higher than that in the rumen. In the incubated mixtures of fresh rumen fluid, CH4 was detected at a high concentration, while a small amount of CO2 and CH4 was found in incubated mixtures of fresh abomasum fluids. Hence, it was suggested that the gas in the abomasum originated not from the abomasum itself but from the rumen. In cows fed with mixed roughages and concentrates, the rumen CO2:CH4 ratio was higher compared with cows fed with roughages alone. Marked changes in rumen gas composition were presumed to be associated with changes in abomasum gas composition. Consequently, it is possible that feeding a large quantity of concentrates may increase the flow rate of the ingesta through the forestomach, so that the return rate of gas separated from the ingesta in the abomasum to the forestomach may also increase. Therefore, the frequent accumulation of a large amount of gas with concomitant changes in the total volatile fatty acid (VFA) concentration in the abomasum caused abomasal atony and subsequently displaced abomasum.     

Nitrogen balance in lambs fed low-quality brome hay and infused with differing proportions of casein in the rumen and abomasum

Twenty wether lambs (46 +/- 2 kg) fitted with ruminal and abomasal infusion catheters were used in a completely randomized design to determine the effects of differing proportions of ruminal and abomasal casein infusion on N balance in lambs fed low-quality brome hay (0.8% N, DM basis) for ad libitum intake. Wethers were infused with 0 (control) or 10.7 g/d of N from casein with ratios of ruminal:abomasal infusion of 100:0 (100R:0A), 67:33 (67R:33A), 33:67 (33R:67A), or 0:100% (0R:100A), respectively, over a 12-d period. Total N supply (hay N intake + N from casein infusion) was greater (P = 0.001) in lambs receiving casein infusion than in controls. Urinary N excretion (g/d) was greater (P = 0.001) in lambs receiving casein infusion than in controls. Urinary N excretion decreased as casein infusion was shifted from 100R:0A to 33R:67A and then slightly increased in lambs receiving 0R:100A (quadratic, P = 0.02). Total N excretion was greater (P = 0.001) in lambs receiving casein infusion than in controls and decreased linearly (P = 0.005) as casein infusion was shifted to the abomasum. Retained N (g/d, % of N intake, and % of digested N) was greater (P = 0.001) in lambs receiving casein than in controls. Retained N increased as infusion was shifted from 100R:0A to 33R:67A and then slightly decreased in lambs receiving 0R: 100A (quadratic, P < 0.07). Based on regression analysis, the predicted optimum proportion of casein infusion to maximize N retention was 68% into the abomasum. The regression suggests that supplementation with undegradable intake protein had an additional benefit over supplementation with ruminally degradable intake protein (100R:0A) and that changing the percentage of ruminally undegradable intake protein in supplemental protein from 33 to 100% resulted in minimal differences in N retention. Apparent N, DM, OM, and energy digestibility (% of intake) was greater (P < 0.03) in lambs infused with casein than controls but did not differ among casein infusion groups. These data suggest that feeding protein supplements containing a portion (greater than 0%) of the crude protein as ruminally undegradable intake protein, as compared to 100% ruminally degradable intake protein, to lambs consuming low-quality forage increases N retention and the efficiency of N utilization without influencing total-tract nutrient digestion.     

Nitrogen balance in lambs fed a high-concentrate diet and infused with differing proportions of casein in the rumen and abomasum

Twenty-five wether lambs (34 +/- 0.9 kg) fitted with ruminal and abomasal infusion catheters were used in a completely randomized design to determine the effects of differing proportions of ruminal and abomasal casein infusion on N balance in lambs fed a high-concentrate diet (85% corn grain, 1.6% N; DM basis) for ad libitum intake. Wethers were infused with 0 (control) or 10.4 g/d of N from casein with ruminal:abomasal infusion ratios of 100:0, 67:33, 33:67, or 0:100% over a 14-d period. Feed, orts, feces, and urine were collected over the last 5 d. Total N intake and excretion were greater (P < 0.01) in lambs infused with casein than in controls; however, N retention did not differ in lambs infused with casein compared with controls, suggesting that N requirements were met without casein supplementation. Total N intake and total N excretion did not differ among casein infusion treatments. Urinary N excretion decreased linearly (P = 0.07) with decreasing ruminal infusion of casein. Site of casein infusion quadratically (P = 0.06) influenced N retained (g/d), with the greatest retention observed in the 33:67 ruminal:abomasal infusion treatment. Dry matter intake from feed decreased from 1,183 to 945 g/d (P = 0.02) in lambs infused with casein compared with controls, but apparently digested DM did not differ among treatments. These data indicate that decreasing the ruminal degradability of supplemental protein above that required to maximize N retention results in decreased urinary excretion of N without greatly affecting apparent diet digestion.     

Iatrogenic hypocalcaemia during parenteral fluid therapy of diarrhoeic calves

Acid-base balance and electrolyte concentrations, including ionised calcium, were monitored during intravenous fluid therapy of 11 collapsed diarrhoeic suckler calves aged five to 10 days. Six healthy calves of similar age and type were used to provide control data. All the diarrhoeic calves were severely acidotic (TCO2<12 mmol/litre). Isotonic sodium bicarbonate (1-3 per cent) was administered until the metabolic acidosis was half corrected, as indicated by the TCO2 increasing to 17 to 24 mmol/litre when the infusion was changed to an extracellular volume replacement fluid containing 144 mmol/litre Na+, 35 mmol/litre HCO3-, 4 mmol/litre K+ and 113 mmol/litre Cl- which was administered until the calf was discharged. Milk feeding was started as soon as the calf had a suck reflex. The treatment was successful in 10 calves. At admission the diarrhoeic calves were hypocalcaemic compared with the control calves, but their ionised calcium was significantly higher, with significantly less calcium being protein bound. Treatment with isotonic sodium bicarbonate resulted in a significant improvement in acid-base balance, but both total and ionised calcium decreased significantly, the decrease in ionised calcium being proportionately greater owing partly to a significant increase in the protein binding of calcium. The mean total, bound and ionised calcium concentrations were all significantly lower in the treated calves after they had received isotonic sodium bicarbonate than in the control calves. Further treatment with replacement fluid had no significant effect on any of the parameters apart from pCO2 which increased significantly. Milk feeding had no significant effect on plasma calcium concentrations. The calves' mean ionised calcium concentration was significantly lower at the end of the treatment than before it, but there was no difference in the mean total and bound calcium concentrations. The calves' mean plasma potassium and magnesium concentrations decreased significantly during the course of the treatment.     

Corpus alienum in the abomasum of cattle.

In a field study consisting of about 7000 adult cattle 36 cases of corpora aliena (CAA) in the abomasum were found. After recording the clinical symptoms such as recurrent slight ruminal tympany and abdominal pain after eating, the metal specimens were found by a detector, with which the sound of the moving metal could be followed behind the xiphoid cartilage region. The diagnoses were confirmed by operation in 10 cases, when the specimens were found in the abomasum and removed. Four of these operations were performed directly near the linea alba and in six cases the specimens were removed by hand and magnet through the reticulo-abomasal opening after attempting the routine hard ware operation. In an additional 16 cases the foreign body could not be caught hold of and removed by a ruminal operation due to passage difficulties through the reticulo-abomasal opening. The results of the direct or indirect operations when the CAA was removed, were good. It is concluded that CAA can occur in some 5 per mille of the patient population and in some 50 per cent of these cases a traumatic reticulitis is also found. In most cases the clinical symptoms are vague. Only if the symptoms are painful and recurrent is the operation indicated.     

Effect of diet on Shiga toxin-producing Escherichia coli (STEC) growth and survival in rumen and abomasum fluids

The gastrointestinal tract of ruminants is the main reservoir for Shiga toxin-producing Escherichia coli (STEC) strains, potentially pathogenic for humans. We used for the first timerumen fluid in which no exogenous carbon source or other supplement was added to compare acid resistance and growth of STEC in physiological physico-chemical conditions. We showed that acidic conditions resulting from the combination of high volatile fatty acid concentration and moderately acidic pH did not alter the survival of STEC, and that human non-O157:H7 STEC isolates were able to persist in the rumen contents in spite of acid stress, low oxygen availability and nutrient deprivation, in the same manner as bovine STEC isolates do. Furthermore, our results support the hypothesis that a grain-rich diet may induce mechanisms of STEC acid resistance in the rumen that allow STEC survival in the abomasum.     

Metabolic aspects in the etiology of displaced abomasum.

Results of studies on metabolic variables that exist prior to the diagnosis of displaced abomasum (DA) indicate that subclinical ketosis is a risk factor for DA. Serum aspartate aminotransferase activity, serum and milk betahydroxybutyric acid concentrations, and milk fat-to-protein ratios were often elevated before the diagnosis of DA, and these variables may be used to predict DA. Prevention of subclinical ketosis may prevent DA.     

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.