Risk factors, clinical indicators, and pathological findings of abomasal ulcers in tropical dairy buffaloes.

The current study aimed at identifying the risk factors and initial diagnostic aids for abomasal ulcers. The risk factor analysis confirmed a significant association (P < 0.05) of abomasal ulcers with concentrate-rich diets (OR, 4.795; CI, 1.212-15.974) and concurrent disorders (OR, 2.978; CI, 0.987-8.980), while the buffaloes in early lactation (OR, 2.777; CI, 0.703-10.972) showed a higher tendency (P = 0.078) for the disorder. The depressed demeanour, dark or black manure (melena), anemia, tachycardia, decreased milk production, anorexia, tachypnea, absence of rumination, abdominal guarding, kyphosis, and tachypnea were the most frequent clinical signs. Subjecting the abomasal fluid for cultural isolation, gram staining, and stormy clot fermentation test identified the presence of clostridium perfringes, while screening through uniplex PCR detected cpa toxin. The buffaloes affected with type-3 and 4 abomasal ulcers exhibited a higher peritoneal fluid to serum ratio of total protein, albumin, and glucose with a low (P < 0.01) serum-ascites albumin gradient (SAAG) concentration compared to reference values of healthy buffaloes. The first two principal components of PCA explained 54.50% of the total variances with lymphocytes, creatine kinase, and rumen chloride levels as the top contributors to dimension I, and albumin, total protein, sodium, and methylene blue reduction time (MBRT) for rumen liquor as the major contributors to dimension II. The vector plot revealed lymphocytopenia, decreased hemoglobin, hypoalbuminemia, hypokalemia, decreased rumen pH, neutrophilia, eosinophilia, leucocytosis, greater MBRT, and higher rumen chloride, serum creatine kinase, and blood urea nitrogen as the major indicators for abomasal ulcers. Histopathological studies revealed infiltration of inflammatory cells in the mucosa along with multifocal areas of necrosis, degeneration, and eroded muscle structure. The study projected a few high-scored clinical signs and extremely variable clinical indicators as initial diagnostic aids of abomasal ulcers, which can be confirmed by ultrasonography and peritoneal fluid examination.

Nasoruminal endoscopy of the rumen and reticulum in buffaloes (Bubalus bubalis) - a preliminary study.

Twenty apparently healthy buffaloes were withdrawn of feed and water for 48 hours. Buffaloes were administered with fluids and were subjected to endoscopy every 12 hours. Olympus™ [GIF V70] flexible video endoscope was passed through the ventral nasal meatus, the pharynx, oesophagus and then into the reticulo-rumen in physically restrained buffaloes. The entire reticulum and part of the rumen could be visualized, when the animals were off feed and water for at least 48 hours and evacuations of rumen contents were done even after 48 hours of starvation to visualize the rumen in six buffaloes. The reticulum appeared light brown to pink coloured with honeycomb shape and the rumen appeared smooth, shiny pink, with numerous papillae throughout its surface. The procedure was well tolerated by all the buffaloes and satisfactory reticular and ruminal images could be obtained including biopsy.

Niacin mitigates rumen epithelial damage in vivo by inhibiting rumen epithelial cell apoptosis on a high concentrate diet.

To investigate the effects of niacin on rumen fermentation, rumen epithelial antioxidant activity, and rumen epithelial cell apoptosis on high concentrate (HC) diets, nine male Hu sheep were randomly fed one of three diets: low concentrate diet (LC; concentrate: forage (C:F) = 20:80, high concentrate diet (HC; C:F = 80:20), and HCN diet (HC diet + niacin at 800 mg/kg diet air-dry matter). Compared with the LC group, the HC group had a lower rumen pH, higher volatile fatty acids and lactic acid in the rumen, reduced activity of antioxidant enzymes and total antioxidant capacity, and increased malondialdehyde content in the rumen epithelium (P < 0.05). Rumen epithelial papilla morphology was decreased, and apoptosis-related indicators and serum inflammatory cytokines were increased in the HC group over the LC group (P < 0.05). Compared with the HC diet, the HCN diet increased rumen pH, rumen epithelium antioxidant capacity, and rumen epithelial papilla morphology, decreased rumen lactate content, serum inflammatory cytokines, and apoptosis-related indicators (P < 0.05). Therefore, adding 800 mg/kg niacin helped protect against rumen epithelial damage by avoiding drastic changes in the rumen environment and improved rumen epithelial antioxidant capacity to inhibit rumen epithelial cell apoptosis in sheep on a HC diet.

Forestomach developmental failure in an 11-month-old Japanese Black steer with severely retarded growth and chronic ruminal tympany.

This study reports findings from the pathological examination of the forestomach of an 11-month-old Japanese Black steer with severely retarded growth (41% of expected weight) and chronic ruminal tympany. The ruminal papillae were weakly formed (0.3-0.5 cm long) and unevenly distributed. The cellulae and cristae reticuli were underdeveloped; the cristae were 0.4-0.7 cm in height and milky white. The keratinized layer in the stratified squamous epithelium was thickened. Ruminal pH was 5.25, and ruminal volatile fatty acid concentration was 11.7 mM. The steer's severely retarded growth was considered to be caused by malnutrition due to developmental and functional failure of the forestomach.

Poisoning by Enterolobium contortisiliquum pods in calves showing photosensitization and digestive lesions / [Lesões digestivas e fotossensibilização em bezerros intoxicados pelas favas de Enterolobium contortisiliquum]

Este trabalho descreve um surto de rumenite e abomasite decorrente de sobrecarga de carboidratos em um rebanho de 238 bezerros, com idades entre 12 e 15 meses, causada pela ingestão dos frutos de Enterolobium contortisiliquum. As taxas de morbidade, mortalidade e letalidade foram de, respectivamente, 12,7%, 5,2% e 42,1%. Clinicamente, os bovinos apresentaram fotossensibilização, salivação e diarreia. Os achados de necropsia foram semelhantes nos dois bezerros necropsiados e consistiram de fotodermatite e rumenite ulcerativa multifocal, subaguda a crônica, e abomasite. A relevância deste relato é que, pela primeira vez, foi possível associar a ocorrência da rumenite devido à sobrecarga de carboidratos com a intoxicação espontânea por E. contortisiliquum em bovinos, confirmando achados anteriormente descritos em experimentos realizados com ovinos.(AU)

The deliberate killing of a sheep with a fire extinguisher: a case report and experimental reconstruction study.

The morphological findings of a sheep deliberately killed with a powder fire extinguisher in an act of cruelty are described. The animal was orally insufflated with the powder of a 6 kg fire extinguisher having the working pressure of 15 bar. This led to rupture of the esophagus and rumen, followed by rupturing of the abdominal wall. Furthermore, powder was applied rectally into the large intestine and vaginally into the genital tract. For a better understanding of the lesion patterns and of the course of events, fire extinguishers were used in an experimental case reconstruction study on sheep carcasses. Rupture of the rumen and abdominal wall could only be reproduced after intraesophageal insufflation but not after oral insufflation. Therefore, an esophageal application has to be considered in the killed sheep. Esophageal rupture in sheep carcasses could not be reproduced by oral or by esophageal application of the fire extinguisher. Nevertheless, in isolated fresh ovine esophagi, compressed air of less than 1 bar was sufficient to induce tissue separation in the esophageal wall. The described case reveals parallels with findings in rarely reported accidents with or in suicides committed with chemical fire extinguishers.

Thiamine ameliorates inflammation of the ruminal epithelium of Saanen goats suffering from subacute ruminal acidosis.

This study aimed to examine the role of thiamine in the local inflammation of ruminal epithelium caused by high-concentrate diets. Eighteen mid-lactating (148 ± 3 d in milk; milk yield = 0.71 ± 0.0300 kg/d) Saanen goats (body weight = 36.5 ± 1.99 kg; body condition score = 2.73 ± 0.16, where 0 = emaciated and 5 = obese) in parity 1 or 2 were selected. The goats were randomly divided into 3 groups (n = 6/group): (1) control diet (concentrate:forage 30:70), (2) high-concentrate diet (HC; concentrate:forage 70:30), and (3) high-concentrate diet with 200 mg of thiamine/kg of dry matter intake (THC; concentrate:forage 70:30). Goats remained on experimental diets for 8 wk. On the last day of 8 wk, ruminal and blood samples were collected to determine ruminal parameters, endotoxin lipopolysaccharide, and blood inflammatory cytokines. Goats were slaughtered to collect ruminal tissue to determine gene and protein expression of toll-like receptor 4 (TLR4) signaling pathways. Thiamine supplementation increased ruminal pH (6.03 vs. 5.42) compared with the HC group. Propionate (21.08 vs. 31.61 mM), butyrate (12.08 vs. 19.39 mM), lactate (0.52 vs. 0.71 mM), and free lipopolysaccharide (42.16 vs. 55.87 × 103 endotoxin units/mL) concentrations in ruminal fluid were lower in THC goats compared with HC goats. Similar to plasma interleukin 1ß (IL-1ß) concentration (209.31 vs. 257.23 pg/mL), blood CD8+ percentage (27.57 vs. 34.07%) also decreased in response to thiamine. Compared with HC goats, THC goats had lower ruminal epithelium activity of the enzymes myeloperoxidase and matrix metalloproteinase (MMP) 2 and 9. In contrast to HC, THC had downregulated mRNA expression of nuclear factor-κB (NFKB), TLR4, IL1B, MMP2, and MMP9 in ruminal epithelium. Thiamine supplementation led to lower relative protein expression of IL-1ß, NF-κB unit p65, and phosphorylated NF-κB unit p65 in ruminal epithelium. Taken together, these results suggest that thiamine supplementation mitigates HC-induced local inflammation and ruminal epithelial disruption.

Niacin Protects against Butyrate-Induced Apoptosis in Rumen Epithelial Cells.

The effects and underlying mechanisms of butyrate and butyrate+niacin on apoptosis in sheep rumen epithelial cells were investigated. Cells were exposed to butyrate (0-140 mM) for 6 h. A low concentration (20 mM) of butyrate increased cell viability and promoted growth whereas high concentrations (40-140 mM) inhibited proliferation. Cells were then cocultured with 120 mM butyrate and niacin (0-100 mM) for 6 h. Niacin addition attenuated butyrate-induced cellular damage and promoted proliferation at 20-80 mM; 40 mM presented the optimal effect. Higher concentrations (100 mM) of niacin resulted in low cell viability. Subsequent experiments confirmed that 120 mM butyrate increased intracellular reactive oxygen species (ROS) production and reduced the intracellular total antioxidant capacity (T-AOC) versus the untreated control. Compared with 120 mM butyrate, cotreatment with 40 mM niacin significantly reduced the intracellular ROS content and increased the intracellular T-AOC. Flow cytometry analysis revealed that 120 mM butyrate increased the proportion of apoptotic cells by 17.8% versus the untreated control, and 120 mM butyrate+40 mM niacin treatment reduced the proportion of apoptotic cells by 28.6% and 39.4% versus the untreated control and butyrate treatment, respectively. Treatment with 120 mM butyrate increased caspase-9 and p53 mRNA levels and decreased the expression of Bcl-2 and Bax, and the Bcl-2/Bax ratio versus the untreated control. Treatment with 120 mM butyrate+40 mM niacin downregulated the expression of caspase-3 and p53 and increased the expression of Bcl-2 and Bax versus butyrate treatment alone but had no effect on the Bcl-2/Bax ratio. Thus, high concentrations of butyrate may induce rumen epithelial cell apoptosis by increasing oxidative stress and inducing caspase-9 and p53 expression. Cotreatment with niacin regulates apoptosis-related gene expression by reducing intracellular ROS production and DNA damage and downregulating caspase-3 and p53 expressions to protect rumen epithelial cells against butyrate-induced apoptosis.

Rumen impaction in cattle associated with ingestion of the pupal cocoons of Gonometa spp. in Botswana.

Mortality in cattle associated with ingestion of cocoons (matlhoa in Setswana) of both Gonometa postica and Gonometa rufobrunnea is rare and has only previously been reported in South Africa, Zimbabwe and Namibia. A case history of gradual weight loss, bloat, dyschezia with dry faeces and laboured gait, resulting in sudden death after drinking water and associated with ingestion of pupal cocoons of Gonometa spp., was reported by keepers at Mmaditau crush in Botswana in 2013. The crush was a shared holding in a communal area with 15 registered animal keepers. The objective of this study was to profile the history, clinical signs, post-mortem findings, morbidity and mortality from the outbreak using the descriptive study method. Altogether, 81 cattle out of a total of 507 died of impaction from August to December 2013. On autopsy, a loosely connected mass of ingesta, intertwined in ropy silky strands, was observed. It was concluded that there is no readily accessible and available form of treatment at crush level, leaving only evasive husbandry practices as the feasible option. To aid evasive husbandry management practices, temporal and spatial monitoring of population dynamics of Gonometa spp. is recommended, particularly during a drought spell when animals are prone to develop pica, as the basis for an early warning system to farmers.

Evaluation of blood adiponectin levels as an index for subacute ruminal acidosis in cows: a preliminary study.

The objective of this study was to evaluate blood levels of various hormones and compounds related to energy metabolism in cows with subacute ruminal acidosis (SARA). We investigated 11 lactating cows presumed to have SARA based on duration of ruminal pH <5.6 and reticulum pH <6.3 in 2015-2016. Kraft pulp (KP) was used to supplement feed of 7 of the cows studied in an effort to reduce SARA. We continuously monitored ruminal pH and measured blood concentrations of hormones and metabolites related to energy metabolism. Blood measurements included glucose (GLU), total cholesterol (TC), free fatty acid (FFA), insulin, adiponectin (ADN), malate dehydrogenase (MDH), and lactate dehydrogenase (LDH). Additionally, we analyzed milk data (milk yield, milk fat percentage, milk protein percentage, milk urea nitrogen, and protein fat ratio) and reproduction data. The results demonstrated that ADN levels at 4 weeks post-parturition correlated with the total amount of time that the ruminal or reticulum fluid pH was under the threshold during 1 week post-parturition, as well as the numbers of days the cows were diagnosed with SARA (SARA-positive days) up to 30 days post-parturition. SARA-positive days in 2016 were higher than those in 2015. In both years, numbers of SARA-positive days for cows supplemented with KP were lower than those for cows without KP. Increased ADN levels may be a compensatory reaction to frequent SARA which modulates the inflammatory response against high LPS levels and improves insulin resistance caused by LPS. ADN may serve as an estimative index for SARA.

[Paramphistomidosis - an overview on epidemiology and clinical signs]. / Paramphistomidose ­ eine Übersicht zu Epidemiologie und klinischer Symptomatik.

Paramphistosis is a globally occurring parasitic disease in various ruminants caused by a range of rumen flukes (including Paramphistomum cervi, Calicophoron daubneyi and Paramphistomum leydeni). In Europe, local occurrences of rumen fluke infection in domestic and wild ruminants have been described for decades. There is now evidence that paramphistomidosis is gaining in importance, because high prevalence rates were reported in the United Kingdom, Ireland, France, Spain, Belgium and The Netherlands. Current prevalence data from Germany are lacking. In recent investigations in northern Germany, Hesse and Bavaria, C. daubneyi was detected, which is currently the most prevalent rumen fluke in Europe. The development of therumen fluke is linked to aquatic snails as intermediate hosts. C. daubneyi and the liver fluke Fasciola hepatica share in the course of their development the same intermediate snail host, Galba truncatula. The definitive ruminant host takes up infective metacercaria. In the small intestine, the young flukes excyst and attach to the duodenum. Subsequently, they migrate to the rumen, where, as adults, they begin to release eggs. The infection can lead to severe diarrhea during the intestinal phase and death at high infection intensity. Ruminal paramphistomidosis is subclinical in most cases. Currently, coproscopic detection by the sedimentation method is the available diagnostic tool. Because of similar morphology, there is a risk of confusion with the eggs of the liver fluke F. hepatica. Paramphistomidosis can be treated with oxyclozanide. There are conflicting results regarding the effectiveness of other drugs. Therefore, prophylaxis of this parasitosis is important. Because of the similar epidemiology, control recommendations are based on those for the prevention of fasciolosis. Whether paramphistomidosis is also an emerging infectious disease in Germany cannot be currently assessed.

Dynamic changes in rumen fermentation and bacterial community following rumen fluid transplantation in a sheep model of rumen acidosis: implications for rumen health in ruminants.

Over the years, rumen fluid transplantation (RT) has been successfully applied to treat acute rumen acidosis in ruminants, but how it functions in the ruminal microbial homeostasis and host function remains largely unknown. Here, we investigated the dynamic changes of rumen fermentation and bacterial communities following RT and its beneficial effects on rumen epithelial morphology and function in a sheep model of rumen acidosis. The results showed that RT resulted in dynamic changes in rumen fermentation and increased the concentrations of total volatile fatty acid, acetate, propionate, and butyrate, but it decreased the levels of lactate and LPS in the rumen. Illumina MiSeq Sequencing data showed that RT facilitated rapid rebuilt of ruminal bacterial homeostasis (8 d in control vs. 2 d in RT) from a markedly dysbiotic acidosis state to a healthy level (similar with those of donors). At the genus level, RT increased the relative abundance of unclassified Bacteroidales, unclassified Prevotellaceae, unclassified Ruminococcaceae, and Acetitomaculum. Additionally, RT also accelerated recovery of the predicted metagenomic function of ruminal bacteria. Rumen papillae morphology results showed that RT alleviated the damage of rumen epithelia induced by acute rumen acidosis and increased the length of rumen papillae. Furthermore, real-time PCR results showed that RT modulated mRNA expression of genes related to cytokines and tight junctions in the rumen epithelia. In summary, these results reveal that RT accelerates recovery of rumen fermentation and bacterial homeostasis and modulates rumen epithelial morphology and function for sheep suffering from rumen acidosis.-Liu, J., Li, H., Zhu, W., Mao, S. Dynamic changes in rumen fermentation and bacterial community following rumen fluid transplantation in a sheep model of rumen acidosis: implications for rumen health in ruminants.

Esophageal groove dysfunction: a cause of ruminal bloat in newborn calves.

BACKGROUND: Esophageal groove dysfunction is one of the major causes of ruminal bloat. This condition is fatal in new born calves if it is not treated early. In healthy, suckling calves, milk should bypass the forestomach (rumen and reticulum) and enter into the abomasum where enzymatic digestion of milk proteins takes place. However, failure of the esophageal groove allows milk to enter into the forestomach, which results in the production of excess gases by microbial fermentation. Consequently, this increase in abdominal distention particularly on the left side in ruminants is an imminent manifestation of excess gases in the foresomach. CASE PRESENTATION: A 10-day-old crossbred male calf presented with a distended left abdomen and manifesting dyspnea at a dairy farm. The calf was weak, reluctant to move, and had visibly congested mucus membranes. Regarding the calf's feeding, milk was the only thing ingested and the calf had not started on dry feeds (hay, concentrates, and roughages). According to the herdsman of the farm, the calf had a mild-to-moderate form of bloat and 3-5 h after milk feeding the bloat would disappear spontaneously. During bloat, an increase in pulse rate, respiratory rate (tachypnea), and shallow breathing was noted. Physical examination revealed severe distention of the left side of the abdomen, and on percussion, accumulation of gases mixed with fluid in the left abdomen was detected. An attempt was made to release gases from forestomach by introducing a stomach tube with oral antibiotics; however, the case was not resolved. The calf suffered from frequent recurrence of bloat after every milk feed, and in response to the refractory outcome to conventional treatment, a rumenostomy was indicated and a better treatment response was achieved. In addition, IV fluid and other supportive therapy were provided while milk was withheld. However, considering the fact that milk is a natural feed that should not be taken away from every calf at this age, we had to encourage calf to consume milk as it would not result in bloat as far as rumen fistula is being created. Furthermore, encouraging calves to consume starter feed (fresh grasses and hay) earlier than usual recommended period whilst decreasing milk intake would hasten the rumen function. CONCLUSIONS: Cases like this are successfully managed by a rumenostomy when conventional options fail.

Multiple episodes of 1080 (sodium monofluoroacetate) intoxication in a California calf-raising operation.

Over a 1-y period, a California calf-raising operation experienced 4 separate episodes of sudden death in 4-6-mo-old steers. Each episode occurred in 1-3 contiguous pens on 1 of 3 properties owned by the operation, but eventually all 3 properties were involved. In each episode, animals appeared normal at the evening feeding but at the subsequent morning feeding were found dead or dying. Remaining live calves had a stiff gait and were often dribbling urine, but did not show respiratory signs until they were down and agonal. At postmortem examination, calves consistently had moderate-to-large numbers of ecchymotic and suffusive hemorrhages on the epicardial surface and moderate-to-large amounts of fluid in the pericardial sac. Pulmonary edema and/or moderate amounts of watery fluid in the thoracic and abdominal cavities were present in a smaller percentage. On histologic examination, the myocardium had variable myofiber degeneration characterized by hypereosinophilia and fragmentation with mild interstitial infiltrates. Testing of heart and liver samples for monensin found levels lower than in previous cases of monensin toxicity. Rumen content was negative for oleandrin and grayanotoxins. Sodium monofluoroacetate (trade name: 1080) was consistently detected at ⩾10 ppb in kidney and liver, and was concluded to be the cause of the intoxication.

Technical note: The development of a methodology for ruminal and colon tissue biopsying of young Holstein dairy calves.

The objectives of this study were to develop a methodology for biopsying the rumen and colon of young dairy calves and to collect suitable quality tissue samples for microscopic and gene expression analysis. Six Holstein dairy bull calves (45.0 ± 1.5 kg birth weight) were ruminally cannulated during the second week of life and weaned at the end of wk 6. Ruminal and colon tissue samples were collected at the end of wk 5, 6, 7, 8, and 12. Calves were not sedated but were restrained in a chute for sampling. The endoscope (100 cm length, 9.8 mm diameter) was introduced through the rumen cannula to harvest ruminal tissue. Endoscopic biopsies of the rumen with endoscopic biopsy forceps were unsuccessful 85% of the time because they were unable to shear the ruminal tissue. Thereafter, an Allis clamp was used to retrieve the blind sac through the rumen cannula to perform direct tissue biopsying with surgical scissors. To biopsy the colon, the lubricated distal tip of an endoscope was slowly inserted into the calf's anus. A total of 6 colon tissue samples (12.6 ± 0.74 mg) were collected per calf per time point from the distal colon 30 to 40 cm from the calf's anus using endoscopic biopsy forceps, which were inserted through the instrument channel. A new forcep was used between sites and calves. Between calves, the outside of the endoscope was washed with 4% chlorohexidine and rinsed with water and the instrument channel was washed with distilled water and 70% ethanol. Colon and ruminal samples were processed for histological measurements, and RNA was isolated and sequenced. High-quality RNA (RNA integrity number 8.8 ± 0.08) was collected from samples, and light and electron microscopy was performed on samples. In conclusion, endoscopic biopsying can be used for tissue harvest in the colon of young calves. However, it was found that collecting ruminal tissue by retracting the rumen from the cannula and taking samples with surgical scissors was more successful than an endoscopic biopsy. This method allows for tissue collection of the same animal throughout time, which can help the research community investigate the effect of weaning regimens, feed rations, and age on the structure and function of the gastrointestinal tract.

Clinical and laboratory findings in 503 cattle with traumatic reticuloperitonitis.

BACKGROUND: The study evaluated the results of clinical examination and haematological and serum biochemical analyses in 503 cattle with traumatic reticuloperitonitis (TRP). RESULTS: The most common clinical findings were abnormal demeanour and general condition (87%), decreased rumen motility (72%), poorly digested faeces (57%), decreased rumen fill (49%), fever (43%) and tachycardia (26%). In 58% of the cattle, at least one of three tests for reticular foreign bodies (pinching of the withers, pressure on the xiphoid and percussion of the abdominal wall) was positive, and in 42% all three tests were negative. The most common haematological findings were decreased haematocrit in 45% of cattle and leukocytosis in 42%. An increase in the concentration of fibrinogen in 69% of cattle and total protein in 64% were the main biochemical findings. The glutaraldehyde test time was decreased with coagulation occurring within 6 min in 75% of cattle. CONCLUSIONS: In many cases, a diagnosis of TRP is not possible based on individual clinical or laboratory findings because even the most common abnormalities are not seen in all cattle with TRP.

High-Concentrate Diet-Induced Change of Cellular Metabolism Leads to Decreases of Immunity and Imbalance of Cellular Activities in Rumen Epithelium.

BACKGROUND/AIMS: In animals, the immune and cellular processes of tissue largely depend on the status of local metabolism. However, in the rumen epithelium, how the cellular metabolism affects epithelial immunity, and cellular processes, when the diet is switched from energy-rich to energy-excess status, with regard to animal production and health, have not as yet been reported. METHODS: RNA-seq was applied to compare the biological processes altered by an increase of dietary concentration from 10% to 35% with those altered by an increase of dietary concentration from 35% to 65% (dietary concentrate: the non-grass component in diet, including corn, soya bean meal and additive. High concentrate diet composed of 35% grass, 55% corn, 8% soya bean meal and 2% additive). In addition to the functional analysis of enriched genes in terms of metabolism, the immune system, and cellular process, the highly correlated genes to the enriched metabolism genes were identified, and the function and signaling pathways related to the differentially expressed neighbors were compared among the groups. RESULTS: The variation trends of molar proportions of ruminal SCFAs and those of enriched pathways belonging to metabolism, immune system, and cellular process were altered with the change of diets. With regard to metabolism, lipid metabolism and amino acid metabolism were most affected. According to the correlation analysis, both innate and adaptive immune responses were promoted by the metabolism genes enriched under the 65% concentrate diet. However, the majority of immune responses were suppressed under the 35% concentrate diet. Moreover, the exclusive upregulation of cell growth and dysfunction of cellular transport and catabolism were induced by the metabolism genes enriched under the 65% concentrate diet. On the contrary, a balanced regulation of cellular processes was detected under the 35% concentrate diet. CONCLUSIONS: These results indicated that the alterations of cellular metabolism promote the alterations in cellular immunity, repair, and homeostasis in the rumen epithelium, thereby leading to the switch of concentrate effects from positive to negative with regard to animal production and health.

Subacute ruminal acidosis affects fermentation and endotoxin concentration in the rumen and relative expression of the CD14/TLR4/MD2 genes involved in lipopolysaccharide systemic immune response in dairy cows.

The first objective of this study was to investigate the effects of subacute ruminal acidosis (SARA) on fermentation, ruminal free lipopolysaccharides (LPS), and expression of the cluster of differentiation 14 (CD14), toll-like receptor 4 (TLR4), and myeloid differentiation protein 2 (MD2) complex in white blood cells involved in the systemic immune response in dairy cows. The second objective was a study of whether increased expression of the LPS receptor complex led to increases in the concentrations of plasma high-density lipoprotein (HDL) and serum Ca. Three hundred five dairy cows located in 13 Polish high-yielding dairy commercial farms were selected according to their days in milk (40-150 d; average = 75), 305-d milk yield (10,070-12,041 kg; average = 10,940), and number of lactations (primiparous, n = 139 and multiparous, n = 166). Next, the herds were segregated into 3 groups based on the percentages of cows with an assigned value of ruminal fluid pH: SARA-positive, SARA-risk, and SARA-negative herds. Moreover, 305 selected dairy cows were divided according to the classification based on ruminal fluid pH into 3 groups as healthy (pH >5.81), risk (pH 5.8-5.6) and acidotic cows (pH <5.6). Rumen fluid samples were collected via rumenocentesis. In the AC group, we recorded higher concentrations of ruminal free LPS [4.57 Log10 endotoxin units (EU)/mL; 42,206 EU/mL] compared with the healthy group (4.48 Log10 EU/mL; 34,179 EU/mL). Similarly, the concentration of ruminal free LPS was higher in SARA-positive herds (4.60 Log10 EU/mL; 43,000 EU/mL) compared with SARA-negative herds (4.47 Log10 EU/mL; 32,225 EU/mL). The relative mRNA abundance of genes associated with the function of LPS receptors, such as CD14, TLR4, and MD2, in white blood cells differed between all experimental groups on both cow and herd levels. In the acidotic group, we recorded higher concentrations of HDL (78.16 vs. 68.32 mg/dL) and serum amyloid A (10.80 vs. 9.16 µg/mL) and lower concentrations of Ca (8.26 vs. 10.16 mg/dL) and haptoglobin (470.19 vs. 516.85 ng/mL) compared with the healthy group. Similar results were obtained in the SARA herd status analysis, but the concentration of lipopolysaccharide-binding protein differed statistically. Moreover, the pH of ruminal fluid was negatively correlated with relative mRNA abundance of genes such as CD14, TLR4, MD2, and concentrations of serum HDL and serum amyloid A, although positively correlated with serum Ca. The results indicated that decreases in ruminal fluid pH increased the release of free LPS into the rumen and stimulated the expression of the LPS receptor complex and immune response. Moreover, an increase in the expression of the LPS receptor led to higher concentrations of plasma HDL and lower serum Ca, which may be a protective mechanism against endotoxemia. However, the biological significance of these results needs to be investigated further in larger field trials.

Microbial community and ovine host response varies with early and late stages of Haemonchus contortus infection.

The interactions between gastric microbiota, ovine host, and Haemonchus contortus portray the ovine gastric environment as a complex ecosystem, where all factors play a pertinent role in fine-tuning each other and in haemeostasis. We delineated the impact of early and late Haemonchus infection on abomasal and ruminal microbial community, as well as the ovine host. Twelve, parasite-naive lambs were divided into four groups, 7 days post-infection (dpi) and time-matched uninfected-control groups; 50 dpi and time-matched uninfected control groups were used for the experiment. Six sheep were inoculated with 5000 H. contortus infective larvae and followed for 7 or 50 days with their corresponding uninfected-control ones. Ovine abomasal tissues were collected for histological analysis and gastric fluids were collected for PH value measurements, microbial community isolation and Illumina MiSeq platform and bioinformatic analysis. Our results showed that Haemonchus infection increased the abomasal gastric pH (P = 0.05) and resulted in necrotizing and inflammatory changes that were more severe during acute infection. Furthermore, infection increased the abomasal bacterial load and decreased the ruminal microbiome. A 7-day infection of sheep with H. contortus significantly altered approximately 98% and 94% of genera in the abomasal and ruminal bacterial profile, respectively (P = 0.04-0.05). However, the approximate altered genera 50 days after infection in the ovine abomasal and ruminal microbiome were about 62% and 69%, correspondingly (P = 0.04-0.05) with increase in some bacteria and decrease in others. Overall, these results indicate that Haemonchus infection plays a crucial role in shaping stomach microbial community composition, and diversity.

Diagnostic Approach to Forestomach Diseases.

Primary diseases of the forestomach are caused by disruptions in the ruminal wall and contraction cycle or by a disruption in the normal flora and fermentation processes. Secondary disease of the reticulorumen is caused by abnormalities in rumen contraction and/or fermentation secondary to other systemic illnesses. Rumen function is complex, and the contraction cycle and fermentation are inter-related, which allows for overlapping results in diagnostic tests. Physical examination, combined with diagnostic tests such as rumen fluid analysis, radiography, and ultrasonography, can be used to categorize and diagnose ruminant forestomach disease.