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PubMed1994

Nutrient transport by ruminal bacteria: a review.

Fermentation pathways have been elucidated for predominant ruminal bacteria, but information is limited concerning the specific transport mechanisms used by these microorganisms for C, energy, and N sources. In addition, it is possible that changes in ruminal environmental conditions could affect transport activity. Five carrier-mediated soluble nutrient transport mechanisms have been identified in bacteria: 1) facilitated diffusion, 2) shock sensitive systems, 3) proton symport, 4) Na+ symport, and the 5) phosphoenolpyruvate phosphotransferase system (PEP-PTS). Several regulatory mechanisms are also involved at the cell membrane to coordinate utilization of different sugars. Recent research has shown that predominant ruminal bacteria are capable of transporting soluble nutrients by several of the mechanisms outlined above. Megasphaera elsdenii, Selenomonas ruminantium, and Streptococcus bovis transport glucose by the PEP-PTS, and S. ruminantium and S. bovis also possess PEP-PTS activity for disaccharides. Glucose PTS activity in S. bovis was highest at a growth pH of 5.0, low glucose concentrations, and a dilution rate of .10 h-1. The cellulolytic ruminal bacterium Fibrobacter succinogenes uses a Na+ symport mechanism for glucose transport that is sensitive to low extracellular pH and ionophores. Sodium also stimulated cellobiose transport by F. succinogenes, and there is evidence for a proton symport in the transport of both arabinose and xylose by S. ruminantium. A chemical gradient of Na+ seems to play an important role in AA transport in several ruminal bacteria. Studying nutrient transport mechanisms in ruminal bacteria will lead to a better understanding of the ruminal fermentation.

Amino Acids↗
PubMed1990

Effect of diseases, production, and season on traumatic reticuloperitonitis and ruminal acidosis in dairy cattle.

Logistic regression was used to investigate the effects of host characteristics, production, and 23 veterinary diagnoses on the risks of two reticuloruminal disorders, ruminal acidosis and traumatic reticuloperitonitis among 61,124 Finnish Ayrshire cows. Lactational incidence risks were .3% for ruminal acidosis and .6% for traumatic reticuloperitonitis. The relative risk of ruminal acidosis was not related to parity, whereas the risk of traumatic reticuloperitonitis decreased with increasing parity. The risk of traumatic reticuloperitonitis was not related to milk yield of individual affected cows in their current or previous lactation (305-d, 4% FCM), whereas the risk of ruminal acidosis increased with current milk yield. Ketosis, early metritis, nonparturient paresis, and acute and chronic mastitis were risk factors for both reticuloruminal disorders. Parturient paresis was a risk factor for ruminal acidosis. Foot and leg problems were risk factors for traumatic reticuloperitonitis. Herd milk yield in the current or previous lactations was not a risk factor for either disorder nor were the two disorders risk factors for each other. Ruminal acidosis, but not traumatic reticuloperitonitis, had significant seasonal variation with the risk being least in summer. The low risk of ruminal acidosis in summer was not due to seasonality of calving.

Acidosis↗
PubMed2003

Control of peste des petits ruminants: classical and new generation vaccines.

Peste des Petits Ruminants is a highly contagious disease of domestic and wild small ruminants. It seems to be the major constraint in the development of small ruminant production in areas where it is endemic. Included in the list A of the International Zoosanitary Code, it is also part of the FAO EMPRESS programme. Classically, it is characterised by fever, nasal and ocular discharges, diarrhoea, respiratory distress, mucosal erosive lesions and death in 40-80% of acute cases. All these clinical signs, apart from the respiratory symptoms, are very similar to those of rinderpest. The causal agents of both diseases are closely related and belong to the Morbillivirus genus. In the absence of homologous vaccine, and taking advantage of the close relationship between the two viruses, the attenuated tissue culture rinderpest vaccine has been used for a long time to protect small ruminants against PPR. At the end of 1980s, a PPRV strain was successfully attenuated by serial passages in Vero cells. Demonstrated to be very efficient in the protection of sheep and goats against a virulent challenge, this avirulent PPRV is now widely used in the control of PPR. Its thermostability has been dramatically improved by freeze drying. However, animals inoculated with this vaccine cannot be distinguished serologically from those infected with the wild type viruses. With the reverse genetics technique, it is now possible to engineer PPR marker vaccines which can allow such a differentiation. The genes of the PPRV immune protective proteins, the fusion and the haemagglutinin proteins, have been introduced into the genome of a capripox vaccine strain. The generated viruses have proved to be effective as a dual vaccine to protect against two major diseases of small ruminants: peste des petits ruminants and capripox infections.

Animals↗
PubMedDate not supplied

Placental vascular corrosion cast studies: a comparison between ruminants and humans.

The microvasculature of both the ruminant placentomes of cattle, sheep, and goats and the human placenta were compared, using corrosion casts of blood vessels and scanning electron microscopy. The fetal vascular trees of ruminant and human placenta differ in form and size, which correlates with the degree of ramification; however, their architecture of stem, intermediate, and terminal villi is similar. In the human, the system of serially linked capillary convolutions of terminal villi is longer than that in ruminants. Therefore, in guaranteeing blood flow against flow resistance, the human vessels particularly need a straight course, anastomoses, and sinusoidal dilations. Specifically in the ruminants studied, the venous vessels outweigh the arterial ones by volume and by number. They are suggested to be absorptive for substances metabolized in the zone of the capillary complex. The most extreme interspecies difference relates to the maternal vasculature, which, in contrast to the fetal system, is a closed system in the ruminant septas and an open lacunal intervillous space in the human. Converging and differing morphological vascular phenomena of ruminants and human placenta are discussed in terms of maternofetal exchange related to placental efficiency. In summary, the ruminant placenta, concerning the fetal vascular tree, in many aspects is workable as a model for the human.

Animals↗
PubMed2003

Inter-species comparisons of hepatic cytochrome P450 enzyme levels in male ruminants.

Our current knowledge about the biotransformation enzymes in wild ruminants is limited. The present study aimed to compare basic levels and specific activities of cytochrome P450 isoforms (CYP1A, 2A, 2B, 2C, 2D, 2E, 3A, 4A) in males of red deer ( Cervus elaphus), fallow deer ( Dama dama), roe deer ( Capreolus capreolus) and mouflon ( Ovis musimon). The proteins from the major cytochrome P450 (CYP) subfamilies were detected in all ruminant species by Western blotting, using polyclonal antibodies raised against rat or human CYP enzymes. The immunochemical data seem to suggest that humans and wild ruminants share some similar hepatic CYP enzymes corresponding to members of subfamilies 2 and 3; ruminant liver samples also contained two proteins cross-reacting with anti-rat CYP1A antibodies. High activities of CYP1A enzymes found in liver microsomes of male fallow deer and roe deer are indicative of increased susceptibility of these species towards promutagens that are metabolically activated by these CYPs. On the other hand, low activities of CYP1A-dependent alkoxyresorufin O-dealkylase activities were detected in male mouflons. Oxidative metabolism of testosterone was significantly higher in wild ruminants than the values previously reported from bulls. Androstene-3,17-dione and 6beta-hydroxytestosterone were the most important products of testosterone oxidation in liver microsomes of all the ruminant species under study. The highest CYP3A-dependent testosterone 6beta-hydroxylase activity was found in mouflons and fallow deer. A different pattern of CYP activities towards testosterone was found in roe deer, which showed high activities of testosterone 2beta-hydroxylase and lower production of androstene-3,17-dione. An increased activity of CYP4A-dependent laurate 12-hydroxylase found in roe deer and mouflons might indicate a higher metabolic turnover of fatty acids. The data on CYP activities indicated that high metabolic rates of steroids, fatty acids, and xenobiotics may occur in male wild ruminants. The highest hepatic activities specific for CYP3A, CYP2C, CYP2D, and CYP2E enzymes were found in mouflon, suggesting that this species has the highest biotransformation capacity.

Animals↗
PubMed2003

Effects of seasonal changes in food quality and food intake on the transport of sodium and butyrate across ruminal epithelium of reindeer.

Transport of 22Na and 14C-butyrate across the ruminal epithelium of captive reindeer fed a concentrate diet in summer (n=5) and in winter (n=5) and from free-ranging reindeer taken from summer (n=3) and winter pasture (n=5) was measured in vitro in Ussing chambers. Significant amounts of both Na+ and butyrate were transported across the isolated epithelium without any external driving force. The ruminal transport of Na+ and butyrate were interacting, as evidenced by both the observed amiloride-induced reduction of net butyrate-transport and by the positive correlation between net transport of butyrate and Na+. Amiloride also reduced the net transport of Na+ without significantly affecting the short-circuit current, indicating the presence of an apical Na+/H+ exchanger in the ruminal epithelium of reindeer. The captive reindeer increased the dry matter intake of a constant quality concentrate from winter to summer, but this neither affected their ruminal transport capacity nor their ruminal surface enlargement factor (SEF). Free-ranging reindeer increased their ruminal transport capacity for Na+ and butyrate from summer to winter but simultaneously reduced their ruminal SEF. The present data indicate that this food-induced increase in transport capacity was attributed to changes in the nutrient composition of the diet.

Amiloride↗
PubMed1987

Rumination and vomiting in the developmentally disabled: a critical review of the behavioral, medical, and psychiatric treatment research.

Medical and psychiatric research regarding the treatment of vomiting and rumination among developmentally disabled individuals was selectively reviewed. Because of serious methodological flaws which pervade the psychiatric literature, claims for the effectiveness of psychiatric interventions for vomiting and rumination cannot be justified. Medical interventions (e.g., pharmacological and surgical interventions) were found to be effective when rumination was attributable to a specific organic pathology. In the absence of identified organic pathology for rumination, medical interventions are of questionable efficacy and because of the risks and side effects associated with these procedures, are seldom the intervention of first choice for functional rumination. Behavioral procedures for the treatment of vomiting and rumination are described and critically reviewed for their efficacy, side effects, and the generalization and maintenance of their effects. Although methodological weaknesses limit conclusions regarding the efficacy of some behavioral interventions, several procedures have sound experimental support including oral hygiene, differential reinforcement of incompatible behaviors, and food satiation procedures. These behavioral interventions are the treatments of choice when organic causes of rumination cannot be identified. Suggestions for future research and applications are discussed.

Adolescent↗
PubMed2006

The relationship between rumination, avoidance and depression in a non-clinical sample.

Recent commentaries have proposed conceptualizations of rumination in terms of both cognitive and behavioral avoidance. This study examined the relationship between rumination, avoidance and depression using a newly developed self-report measure of avoidance in depression, the Cognitive-Behavioral Avoidance Scale (CBAS) [Ottenbreit, N.D., & Dobson, K.S. (2004). Avoidance and depression: The construction of the cognitive-behavioral avoidance scale. Behaviour Research and Therapy, 42, 293-313]. A non-clinical sample (N=104) of undergraduate students completed self-report measures of depression, anxiety, rumination and avoidance. Rumination, avoidance and depression were all significantly correlated. Rumination and behavioral avoidance remained intercorrelated when anxiety was controlled, confirming an association that is independent of anxiety. By contrast, the relationship between cognitive avoidance and rumination disappeared when anxiety was partialled out. Notably, avoidance predicted unique variance in depression scores, over and above anxiety and rumination. Consistent with the proposal of Ottenbreit and Dobson [Avoidance and depression: The construction of the cognitive-behavioral avoidance scale. Behaviour Research and Therapy, 42, 293-313], our findings support the value of clinicians and psychopathologists giving consideration to avoidance in their conceptualization of depression.

Adaptation, Psychological↗
PubMed2006

Worry and rumination: differential associations with anxious and depressive symptoms and coping behavior.

Worry and rumination are closely allied cognitive processes that impact on the experience of anxious and depressive symptoms. Using a prospective design, this study examined overlapping and distinct features of worry and rumination in relation to symptoms and coping behavior in a nonclinical sample of Singaporean college students. Worry and rumination were highly correlated, but they retained distinct components that predicted anxious and depressive symptoms differentially within and across time. Specifically, worry was uniquely associated with anxious and depressive symptoms whereas rumination was uniquely related to depression. In comparison to rumination, worry emerged as the dominant cognitive vulnerability factor that predicted increments in symptoms over time. With regards to coping behavior, low perceived coping effectiveness partially mediated the relation between worry and increases in anxiety and depression. Conversely, rumination uniquely predicted higher disengagement from problems, which resulted in further exacerbation of depressive mood. These results demonstrated not only the distinct features of worry and rumination on coping behavior, but also the different coping pathways by which they differentially impact on subsequent symptoms.

Adaptation, Psychological↗
PubMed2005

Reduced specificity of autobiographical memory: a mediator between rumination and ineffective social problem-solving in major depression?

BACKGROUND: Depressed individuals display a deficit in effectively solving social problem situations (e.g., []). Recent research suggests that rumination may interfere with such effective problem-solving (e.g., []). However, little is known, as yet, about the mechanisms that are underlying this relation between rumination and poor problem-solving. The present study investigated the role of reduced specificity of autobiographical memories as a mediator of this relationship. METHODS: 24 depressed patients (15 women) completed the Autobiographical Memory Test (AMT), the Means-Ends Problem-Solving Task (MEPS), the Ruminative Response Scale (RRS) and the Rumination on Sadness Scale (RSS). RESULTS: Consistent with previous studies, rumination, ineffective problem-solving and reduced memory specificity were significantly associated. Regression analyses further extended these findings by showing that reduced memory specificity mediated the association between rumination and problem-solving effectiveness. LIMITATIONS: The correlational nature of this study limits to some extent the conclusions that can be drawn on the directionality of the observed relationships. CONCLUSIONS: Results offer support for the idea that lack of autobiographical memory specificity mediates the known relationship between rumination and poor problem-solving.

Autobiographies as Topic↗
PubMed2004

Effect of the ionophore antibiotic monensin on the ruminal biotransformation of benzimidazole anthelmintics.

The benzimidazole (BZD) anthelmintics, netobimin (NTB) pro-drug and albendazole sulphoxide (ABZSO) are reduced to albendazole (ABZ) by ruminal microflora. The aim of the current work was to evaluate the influence of the ionophore monensin (MON) on the in vitro biotransformation of NTB and ABZSO by sheep ruminal fluid. Ruminal fluid, collected from Corriedale sheep, was preincubated (24 h) either without (control) or with known MON concentrations (0.5, 1.5 and 3.0 microg/mL) at 38 degrees C under a CO2 atmosphere. Afterwards, aliquots from both MON-pretreated and control ruminal fluid samples were incubated (30 and 60 min) with 2 microg/mL of either NTB or ABZSO. Incubated samples were chemically extracted and analysed by High Performance Liquid Chromatography to quantify the metabolites formed. The rate of ABZ production after 30 min of NTB incubation with control ruminal fluid was 0.023 microg/min. Conversely, the rates of ABZ formation were significantly (P<0.05) lower (0.009, 0.011 and 0.013 microg/min) when NTB was incubated with ruminal fluid pretreated with MON (at 0.5, 1.5 and 3.0 microg/mL, respectively). After both incubation periods, the reduction of ABZSO to ABZ was 22 to 70% lower when the ruminal fluid was preincubated with the different MON concentrations. The lower ABZ production observed in the presence of MON may result in a modified availability of this molecule in the gastrointestinal (GI) tract and hence, on its anthelmintic efficacy against GI nematodes.

Albendazole↗
PubMedDate not supplied

Effective treatment of rumination with Nissen fundoplication.

Rumination is a syndrome characterized by the effortless regurgitation of recently ingested food. It has been linked to severe medical and psychosocial conditions including malnutrition, aspiration pneumonia, and complete social withdrawal. Psychotherapy, the current treatment modality for rumination, may improve symptoms but requires significant motivation and is rarely curative. We hypothesized that a complete fundoplication would eliminate, or at least impair, the ability to regurgitate gastric contents through the esophagogastric junction. We performed a Nissen fundoplication in five patients with a classic history of rumination. In all cases, symptoms had been resistant to medical and psychiatric intervention prior to fundoplication. Formal preoperative testing included esophageal manometry, 24-hour pH monitoring, endoscopy, and upper gastrointestinal barium swallow studies. All patients reported their primary symptom to be effortless recurrent postprandial regurgitation for 1 to 2 hours after meals consistent with rumination. Four (80%) of the five patients had low resting lower esophageal sphincter pressures with evidence of gastroesophageal reflux disease on 24-hour pH monitoring. All patients reported complete cessation of ruminating behavior after Nissen fundoplication. We report, for the first time, complete elimination of rumination symptoms after a Nissen fundoplication. Although further trials are needed to confirm our results, we recommend considering a Nissen fundoplication for treatment of rumination refractory to behavioral and medical interventions.

Adolescent↗
PubMed2001

Rumination and cigarette smoking: a bad combination for depressive outcomes?

Ruminative coping has been shown to heighten the risk and severity of depression. The authors hypothesized that ruminators who smoke would experience greater depressive symptoms than ruminators who do not. The rationale is that, by heightening attentional focus, nicotine may increase ruminators' ability to focus on negative thoughts, augmenting depressed mood. Participants (N = 145) self-reported smoking status, rumination, and current and lifetime depressive symptoms, including depressed mood. Results showed that rumination accounted for a larger amount of variance in current and past depressed mood and severity of lifetime depressive symptoms among smokers than nonsmokers. Noncorrelational, experimental research should directly test whether nicotine worsens depressed mood among ruminative smokers. Such evidence would be surprising because it would contradict the assumption that nicotine dispels negative moods.

Adaptation, Psychological↗
PubMed2006

Influence of fish oil on ruminal biohydrogenation of C18 unsaturated fatty acids.

Dietary cis-9, trans-11-conjugated linoleic acid (CLA) is generally thought to be beneficial for human health. Fish oil added to ruminant diets increases the CLA concentration of milk and meat, an increase thought to arise from alterations in ruminal biohydrogenation of unsaturated fatty acids. To investigate the mechanism for this effect, in vitro incubations were carried out with ruminal digesta and the main biohydrogenating ruminal bacterium, Butyrivibrio fibrisolvens. Linoleic acid (LA) or alpha-linolenic acid (LNA) was incubated (1.67 g/l) with strained ruminal digesta from sheep receiving a 50:50 grass hay-concentrate ration. Adding fish oil (up to 4.17 g/l) tended to decrease the initial rate of LA (P=0.025) and LNA (P=0.137) disappearance, decreased (P<0.05) the transient accumulation of conjugated isomers of both fatty acids, and increased (P<0.05) the accumulation of trans-11-18:1. Concentrations of EPA (20:5n-3) or DHA (22:6n-3), the major fatty acids in fish oil, were low (100 mg/l or less) after incubation of fish oil with ruminal digesta. Addition of EPA or DHA (50 mg/l) to pure cultures inhibited the growth and isomerase activity of B. fibrisolvens, while fish oil had no effect. In contrast, similar concentrations of EPA and DHA had no effect on biohydrogenation of LA by mixed digesta, while the addition of LA prevented metabolism of EPA and DHA. Neither EPA nor DHA was metabolised by B. fibrisolvens in pure culture. Thus, fish oil inhibits ruminal biohydrogenation by a mechanism which can be interpreted partly, but not entirely, in terms of its effects on B. fibrisolvens.

Animal Feed↗
PubMed1979

[The supply of wild ruminants with major and trace elements. 1. The cadmium content of winter grazing and the cadmium status of red deer, fallow deer, roes and moulons].

The Cd-determination of 10 different winter grazings for wild ruminants in seven different biotopes showed significant differences of the habitats resulting from the previous Cd-emission of metallurgy smelting non-ferrous metals. The winter grazing of the Tharandt Forest and the Harz mountains contained significantly more Cd than that of the Lower Flaming hills, the western Erzgebirge and the northern agrarian areas. The bark and the tips of conifer twigs, twigs of oak and mountain ash, bilberry and heather plants, i. e. perennial plants resp. parts of plants proved to be particularly rich in Cd. On an average, wild ruminants consume more Cd than domesticated ruminants, which do not consume parts of perennial plants. The rumen contents of all wild ruminants contained, with 0.20 to 0.25 mg/kg dry matter more Cd than could be expected from the content of the grazing. In the Cd-contaminated areas the amount of Cd in the rumen contents too showed the Cd-load. The kidneys, livers and the covering hair of a total of 172 head red deer, roes and mouflons reflected the Cd-load and the dependence of the Cd-level on the age. The Cd-concentration ascertained in the organs of the wild ruminants was compared with that of sheep and cattle. The, on an average, higher Cd-load of the wild ruminants was confirmed. The kidneys of wild ruminants older than five years should, as a general principle, not be eaten and neither should the livers of animals from Cd-contaminated biotopes. The limb defects of mouflons from Cd-contaminated areas are discussed in connection with Cd-induced secondary Cu-deficiency resp. Mn- and Zn-deficiency. A reference is made to further works.

Animal Nutritional Physiological Phenomena↗
PubMed1986

[Eating and ruminating behavior of sheep. 2. Experiments in pregnant and lactating ewes fed with a straw-concentrate mixture].

Fertility oriented ewes in the late stage of gestation and during the lactation period received 19 feeding regimes on the basis of straw-concentrate mixtures, which essentially differed in the feedstuff structure. The ewes fed ad libitum on average used between 5 and 6 hours per day feed intake in the 86 measuring periods. The average daily ruminating time ranged from 398 to 502 minutes. An increasing straw content resulted in significantly longer ruminating periods and a higher number of masticatory movements, additional quotas of long straw had non effect. But even the most unfavourable feeding variants (straw-concentrate mixtures with 40% straw meal treated with NaOH) elicited 21 100 ruminating masticatory movements in 5 hours of ruminating. There were no significant differences between the absolute consumption and ruminating activities in the late stage of gestation and the lactation period; with reference to feed and crude fibre intake the ruminating expenditure in the late stage of gestation was always significantly higher. Rations with a low structural effect resulted in a more unbalanced distribution of consumption and ruminating activities in the course of the day than well structured rations.

Animals↗
PubMed1987

[Consumption and ruminating behavior in sheep. 3. Experiments on infertile female sheep of different breeds with reference to feed type and feeding duration].

Ewes of the breeds merino fattening sheep, Stavropol merino and fertility hybrid were studied as to their consumption and ruminating behaviour after receiving a pelleted straw-concentrate mixture, maize silage and wilted silaged grass. During the feeding periods of 2 X 45 min or 2 X 180 min/d unlimited rations were available to the animals. With 86 min/d the sheep used the short feeding period nearly completely for feed intake. In the longer feeding period the sheep consumed 18% more feed in 161 min/d, ate more slowly, however, and ruminated somewhat less. In comparison with the straw-concentrate mixture, the silage rations were ruminated for shorter periods and less effectively, the number of ruminating movements per day and cycle was reduced, the breaks between bites became longer. The wilted grass silage stimulated ruminating even less than chopped maize silage. There were significant differences between the breeds in the ruminating frequency, which affected the number of ruminating movements per day and cycle.

Animal Feed↗
PubMed1980

Effect of heat treatment on ruminal degradation and escape, and intestinal digestibility of cottonseed meal protein.

The effect of heat treatment of ruminal protein degradation and escape was studied using in vitro incubations with autoclaved and commercial cottonseed meal (CSM) samples. Incubations using high ratios of protein to ruminal fluid appeared to overestimate ruminal degradation of CSM protein relative to casein. A biexponential model, assuming CSM contained two protein fractions degraded at two different rates, was used to interpret data from in vitro incubations conducted using ratios of protein to ruminal fluid similar to those expected in vivo. The first fraction was degraded at rates (0.68-1.19/hour) which were 2--3 1/2 times greater than that of casein (0.34/hour). Degradation rates of the second fraction were much slower (0.011-0.093/hour). The effect of heat treatment was to decrease the proportion of the rapidly degraded fraction and to both increase the proportion and to decrease the degradation rate of the more slowly degraded fraction. Estimated ruminal escape increased with each increment of heat treatment. Intestinal protein digestibility (ruminal escape times true digestibility) increased to maximum at 60 minutes autoclaving, and then declined. Estimates of intestinal protein digestibility averaged 30.6 and 50.3% for solvent-extracted and screw-press CSM, respectively. These and previous results suggest heat treatment decreases ruminal degradation partly by blocking reactive sites for microbial proteolytic enzymes and partly by reducing protein solubility.

Animals↗