Cardiac biomarkers as tools in the prediction and diagnosis of traumatic pericarditis and traumatic reticuloperitonitis in cattle and buffaloes.

BACKGROUND: In the livestock industry, Foreign Body Syndrome is a devastating disease condition. Feeding management, lacking of food discrimination, and eating chopped food increase the risk of swallowing sharp foreign bodies in bovine species. In addition to the honeycomb cells shape of the reticulum, the contractions of the reticular wall, gravid uterine pressure, and parturition efforts, foreign bodies can penetrate the reticular wall, causing cascade of problems including traumatic reticulitis, traumatic reticuloperitonitis, and traumatic pericarditis. The present study was carried out to evaluate the diagnostic significance of cardiac troponin I rapid test cassette and other cardiac biomarkers including serum cardiac troponin I (cTn I), creatine kinase-myocardial band (CK-MB), lactate dehydrogenase (LDH), and aspartate aminotransferase enzyme (AST), in confirmed cases of traumatic pericarditis (TP) and/or traumatic reticuleoperitonitis (TRP) in cattle and buffaloes. METHODS: A total number of 30 animals (22 cattle and 8 buffaloes) with different signs such as anorexia, jugular distension, brisket edema, and signs of pain (reluctance to move, arching back, and abduction of the forelimbs) were included in the present study. Based on case history, clinical signs, ferroscopic, pericardiocentesis, radiographic and ultrasonographic examinations, TP were confirmed in cattle (n = 10) and buffaloes (n = 8) while TRP were confirmed only in cattle (n = 12). Additionally, 20 clinically healthy animals (n = 10 cattle and 10 buffaloes) were used as a control group. Blood samples were collected for determination of blood level of Tn-I, and activity of CK-MB, LDH, and AST. RESULTS: The obtained results revealed a highly significant increase in serum cTn I in diseased cattle with TP and TRP (P = 0.00), while buffaloes with TP showed no significant changes in serum cTn I (P = 0.111). Both diseased cattle and buffaloes showed increased serum activities of CK-MB, AST, and LDH enzyme. On the other hand, cardiac troponin I rapid test cassette failed to detect cTn I in diseased animals. CONCLUSION: The study concluded that the cardiac troponin I rapid test cassette did not have a diagnostic significance and could not be used as a point-of-care under field condition for diagnosis of TP and TRP in large ruminants. However, the serum troponin I level is helpful in diagnosis of TP and TRP in cattle. Although cardiac biomarkers have some diagnostic values in TP and TRP, the traditional diagnostic methods (clinical, radiography and ultrasonography examinations) are crucial for thorough evaluation of TP/TRP cases in bovine.

Assessment of serum calprotectin as a marker of inflammation in cattle with traumatic reticuloperitonitis.

Calprotectin (CP) is an inflammatory marker. The aim of the current study was to investigate oxidative stress and changes in CP in cattle with traumatic reticuloperitonitis (TRP). The study was divided into two groups, experimental (TRP) and healthy control group, with 10 animals in each group. Total leucocyte count, neutrophil and lymphocyte counts were higher in the TRP group compared to the control group and this increase was statistically significant (P < 0.001). The level of malondialdehyde (MDA) in TRP group was statistically significantly higher than the control group (P < 0.001). The level of glutathione (GSH) in the TRP group was statistically significantly lower than in the control group (P < 0.001). Serum Amyloid A (SAA) and CP values were higher in the TRP group and this difference was statistically significant (P < 0.001). It was concluded as a result of ROC analysis that CP, which has similar values with SAA, can be used diagnostically to confirm the inflammatory status in cattle with TRP.

Diagnostic reliability of clinical signs in cows with traumatic reticuloperitonitis and abomasal ulcers.

BACKGROUND: Clinical signs of traumatic reticuloperitonitis and abomasal ulcer are often similar making the disorders difficult to differentiate. The goal of our study was to compare the frequency of individual clinical signs of cows with traumatic reticuloperitonitis and cows with abomasal ulcers and determine their diagnostic significance. The frequency of the findings "rectal temperature, heart rate, respiratory rate, demeanour, signs of colic, arched back, abdominal guarding, bruxism, scleral vessels, rumen motility, foreign body tests, percussion auscultation, swinging auscultation and faecal colour" of cows with traumatic reticuloperitonitis (TRP, n = 503) and cows with type 1 (U1, n = 94), type 2 (U2, n = 145), type 3 (U3, n = 60), type 4 (U4, n = 87) and type 5 (U5, n = 14) abomasal ulcer were compared, and the reliability indices "diagnostic sensitivity and specificity, positive and negative predictive values and positive likelihood ratio" were calculated. A total of 182 healthy cows served as controls (control group). RESULTS: None of the cows in the control group had colic, rumen atony or melena, 99% had no abnormalities in demeanor and appetite and did not have a rectal temperature of ≤38.6 or >  40.0 °C, a heart rate >  100 bpm or a respiratory rate >  55 breaths per min, and 95% did not have an arched back or bruxism. The control group was therefore ideal for comparative purposes. Many signs such as mild increase in rectal temperature, scleral congestion and positive foreign body test were non-diagnostic because they occurred in healthy as well as in ill cows. Likewise, differentiation of cows with TRP and abomasal ulcer was not possible based on single clinical variables; a detailed history and a comprehensive assessment of all clinical findings were required for this. CONCLUSIONS: The findings of the present study serve as a guide for the veterinarian in the differentiation of cows with traumatic reticuloperitonitis and abomasal ulcer.

Modeling reticular and ventral ruminal pH of lactating dairy cows using ingestion and rumination behavior.

The prevention and control of metabolic and digestive diseases is an enormous challenge in dairy farming. Subacute ruminal acidosis (SARA) is assumed to be the most severe feed-related disorder and it impairs both animal health and economic efficiency. Currently, ruminal pH as well as variables derived from the daily pH curve are the main indicators for SARA. The objective of this study was to explain the daily pH course in the ventral rumen and reticulum of dairy cows using ingestion pattern and rumination behavior data gathered by automated data recording systems. The data of 13 ruminally fistulated lactating cows were collected at the experimental station of the Friedrich-Loeffler-Institut (Brunswick, Germany). The data included continuous pH measurements, which were recorded simultaneously in the reticulum by pH-measuring boluses and in the ventral rumen by a separate data logger. In addition, rumination behavior was measured using jaw movement sensors, and feed and water intakes were recorded by transponder-assisted systems. Milk yield and body weight were determined during and after each milking, respectively. For statistical evaluation, the data were analyzed using time-series modeling with multiple linear mixed regressions. Before applying the developed mathematical statistical modeling, we performed a plausibility assessment to ensure data quality. The major part of the mathematical statistical modeling consisted of data preparation, where all variables were transformed into a uniform 1-min resolution. Signal transformations were used to model individual feed and water intakes as well as rumination behavior events over time. Our results indicated that diurnal pH curves of both the reticulum and ventral rumen could be predicted by the transformed feed and water intake rates. Rumination events were associated with a marginal temporal increase in pH. We observed that the pH of the ventral rumen was delayed by approximately 37 min compared with that of the reticulum, which was therefore considered in the modeling. With the models developed in this study, 67.0% of the variance of the reticular pH curves and 37.8% of the variance of the ruminal pH curves could be explained by fixed effects. We deduced that the diurnal pH course is, to a large extent, associated with the animal's individual feed intake and rumination behavior.

An investigation into the development of right displaced abomasum by rolling 268 dairy cows with left displaced abomasum.

Right displaced abomasum (RDA) and abomasal volvulus (AV) are common diseases in cattle. However, presently there is no consensus regarding the pathogenesis and nomenclature of the different positions that the abomasum can adopt in the right side of the cow. Therefore, the objective of this study was to describe the etiopathogenesis of the right displaced abomasum according to the description of the features observed in 268 cows with left displaced abomasum (LDA), which were rolled to induce the movement of the abomasum from the left side to the right (in fact, inducing an RDA in 44% of cases), to facilitate the surgical approach, and immediately surgically treated (abomasal omentopexy from the right side). The observed RDA positions matched previously published descriptions and names, and the authors propose a holistic and simpler nomenclature and a clear hypothesis on RDA etiopathogenesis. In 54.1% of the cases, the abomasum moved to a normal position after rolling. The most common RDA position observed was caudal displacement of the RDA (CdRDA; 70 out of 119 RDA cases; 26.1% of the total number of cows), followed by lateral displacement (LRDA; 32 of 119; 11.9% of all cases), cranial displacement (CrRDA; 8 of 119; 3% of the total), medial displacement (MRDA; 4 of 119; 1.5% of the total), and finally, displacement lateral to the omasum (LORDA; 3 of 119; 1.1% of the total). Adverse events directly due to the rolling procedure were mesenteric root volvulus (3 of 268), cecocolic volvulus (2 of 268) and torsion (1 of 268), and uterus torsion (2 of 10 pregnant cows); 1 abortion (1 of 10 pregnant cows) was also observed. We suggest that CdRDA is the first stage of an RDA that can become an LRDA with increasing pressure. An LRDA can become an AV if rotating counterclockwise, viewed from above. An LDA, CdRDA, or LRDA could be initial forms of LORDA and CrRDA, and occur when forestomachs are empty or when the animal stands up on its front legs first. The LORDA and CrRDA forms can lead to an omasum-abomasum volvulus (OAV) or to a reticulum-omasum-abomasum volvulus (ROAV) when pressure increases. With this study we establish, for the first time, the sequence and incidence of each RDA form and its complications, increasing knowledge of this syndrome and its pathogenesis. This understanding critically aids the surgeon's ability to accurately assess and correct this disease and to predict prognosis.

Developing and evaluating threshold-based algorithms to detect drinking behavior in dairy cows using reticulorumen temperature.

In this study, we assessed for the first time the use of a reticuloruminal temperature bolus and a thresholding method to detect drinking events and investigated different factors that can affect drinking behavior. First, we validated the detection of drinking events using 16 cows that received a reticuloruminal bolus. For this, we collected continuous drinking behavior data for 4 d using video recordings and ambient and water temperature for the same 4 d. After all the data were synchronized, we performed 2 threshold algorithms: a general-fixed threshold and a cow-day specific threshold algorithm. In the general-fixed threshold, a positive test was considered if the temperature of any cow fell below a fixed threshold; in the cow-day specific threshold, a positive test was considered when the temperature of specific cows fell below the threshold value deviations around the mean temperature of the cow for that day. The former was evaluated using a threshold varying between 35.7 and 39.5°C, and the latter using the formula µ-n10σ, where µ = mean of the temperature of each cow for one day, n = 1, 2, …, 20, and σ = standard deviation of the temperature of each cow on that day. The performance of the validation of detection using each of the threshold types was computed using different metrics, including overall accuracy, precision, recall (also known as sensitivity), F-score, positive predictive value, negative predictive value, false discovery rate, false omission rate, and Cohen's kappa statistic. The findings of the first study showed that the cow-day specific threshold of n = 10 performed better (true positives = 466; false positives = 167; false negatives = 165; true negatives = 8,416) than using a general-fixed threshold of 38.1°C (true positives = 449; false positives = 181; false negatives = 182; true negatives = 8,402). With the information gained in this first study, we investigated the different factors associated with temperature drop characteristics per cow: number of drops, mean amplitude of the drop, and mean recovery time. For this, we used data from 54 cows collected for almost 1 yr to build a mixed-effect multilevel model that included days in milk, parity, average monthly milk production, and ambient temperature as explanatory variables. Cow characteristics and ambient temperature had significant effects on drinking events. Our results provide a platform for automated monitoring of drinking behavior, which has potential value in prediction of health and welfare in dairy cattle.

Ruminal fatty acid outflow in dry cows fed different sources of linoleic acid: reticulum and omasum as alternative sampling sites to abomasum.

This study was designed to determine the rumen outflow of fatty acids (FA) and biohydrogenation (BH) extent using alternative sampling sites (reticulum and omasum) to abomasum in dry cows fed different sources of FA. Four Holstein non-pregnant dry cows (≥3 parturitions, and 712 ± 125 kg BW), cannulated in the rumen and abomasum, were randomly assigned to a 4 × 4 Latin square design experiment, containing the following treatments: 1) control (CON); 2) soya bean oil (SO), dietary inclusion at 30 g/kg; 3) whole raw soya beans (WS), dietary inclusion at 160 g/kg; and 4) calcium salts of FA (CSFA), dietary inclusion at 32 g/kg. Rumen outflow of nutrients was estimated using the three markers reconstitution system (cobalt-EDTA, ytterbium chloride, and indigestible neutral detergent fibre [NDF]). Diets with FA sources decreased feed intake and increased FA intake. No differences in nutrient intake and digestibility were detected among cows fed diets supplemented with different FA sources. Diets with FA sources reduced the rumen outflow of DM and NDF, hence decreasing their passage rates. In addition, SO diet reduced the ruminal outflow of DM and NDF in comparison with WS and CSFA. Omasal sampling yielded the highest values of rumen outflow of NDF and potentially degradable NDF (pdNDF), whereas the reticular and abomasal samplings yielded intermediate and least values, respectively. The interaction effect between diet and sampling site was observed for rumen outflow of majority FA (except for C16:0, C18:0, and C18:2 trans-10, cis-12) and BH extension of C18:1 cis, C18:2, and C18:3. Calculations derived from abomasal sampling revealed that WS and CSFA diets had lower BH extent of C18:1 cis and C18:2 in comparison with SO, whereas cows fed CSFA had greater BH extent of C18:3 and lower BH extent of C18:1 cis compared to those fed WS. However, the latter results were not similar when calculations were performed based on the reticular and omasal samplings. Thus, there is evidence that neither reticular nor omasal samplings are suitable for estimating rumen outflow of FA in dry cows. In addition, WS and CSFA diets can increase the abomasal flow of polyunsaturated FA in dry cows.

The precise subcellular localization of Dlg in the Drosophila larva body wall using improved pre-embedding immuno-EM.

Discs-large (Dlg) plays important roles in nerve tissue and epithelial tissue in Drosophila. However, the precise positioning of Dlg in the neuromuscular junction remains to be confirmed using an optimized labeling method. In this study, we improved the method of pre-embedding immunogold electron microscopy without the osmic tetroxide procedure, and we found that Lowicryl K4 M resin and low temperature helped to preserve the authenticity of the labeling signal with relatively good contrast. Dlg was strongly expressed in the entire subsynaptic reticulum (SSR) membrane of type Ib boutons, expressed in parts of the SSR membrane of type Is boutons, weakly expressed in axon terminals and axons, and not expressed in pre- or postsynaptic membranes of type Is boutons. In muscle cells and stratum corneum cells, Dlg was expressed both in the cytoplasm and in organelles with biomembranes. The precise location of Dlg in SSR membranes, rather than in postsynaptic membranes, shows that Dlg, with its multiple domains, acts as a remote or indirect regulator in postsynaptic signal transduction.

Changes in ruminal and reticular pH and bacterial communities in Holstein cattle fed a high-grain diet.

BACKGROUND: Subacute ruminal acidosis (SARA) is characterized by a ruminal pH depression, and microbiota can also be affected by a higher acidity and/or dietary changes. Previous studies have revealed similar patterns in pH reduction in the rumen and reticulum, whereas changes in reticular pH and bacterial community following a high-grain diet are not fully understood. The aim of this study was to investigate the changes in reticular pH and bacterial community structure following a high-grain diet simultaneously with those in the rumen. RESULTS: SARA was diagnosed when ruminal and reticular pH remained under 5.6 for 350 ± 14 and 312 ± 24 min/d, respectively, on the last day of the CON period. During the CON period, lower proportion of acetic acid and higher proportion of butyric acid were observed compared with the HAY period. The proportions of acetic acid and propionic acid were lower and higher, respectively, in the rumen compared with the reticulum. From 454 pyrosequencing analysis, the relative abundance of several genera differed significantly between the two periods and the two locations. During the HAY period, higher relative abundances of Prevotella, Eubacterium, Oscillibacter, and Succiniclasticum and lower relative abundances of Ruminococcus, Clostridium, and Olsenella were identified compared with the CON period. Furthermore, the relative abundance of Eubacterium was lower in the rumen compared with the reticulum. Bacterial diversity indices were significantly different between the HAY and CON periods, being higher in the HAY period. The quantitative real-time PCR showed that the copy numbers of several cellulolytic bacteria (Fibrobacter succinogenes and Ruminococcus albus) were higher during the HAY period. CONCLUSION: A high-grain diet showed similar impacts on the pH, fermentation, and bacterial community structure in the rumen and reticulum. During the CON period, ruminal and reticular pH decreased following the high-grain challenge, and lower bacterial diversity and changes in the bacterial composition, similarity, and bacterial copy numbers were observed due to a higher acidity and dietary changes compared with the HAY period. These changes may influence the fermentative ability of the rumen and reticulum.

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.

Impact of diet composition and temperature-humidity index on water and dry matter intake of high-yielding dairy cows.

The temperature-humidity index (THI) is widely used to characterize heat stress in dairy cattle. Diet composition is known to induce variation in metabolic-associated heat production. However, the relationships between THI and diet are poorly characterized with regard to performance and intake behaviour. Therefore, the objectives were to evaluate the impact of THI on water intake (WI), dry matter intake (DMI) and the frequency of drinking and feeding bouts in lactating dairy cows offered four dietary treatments: each contained 20% grass silage and additionally (i) 20% maize silage, 60% concentrate (M-HC); (ii) 60% maize silage, 20% concentrate (M-LC); (iii) 20% pressed beet pulp silage, 60% concentrate (BPS-HC); or (iv) 60% pressed beet pulp silage, 20% concentrate (BPS-LC) (DM basis). Individual WI and DMI were recorded from April to July 2013. Furthermore, dietary effects on milk production and reticular pH were estimated. Milk yield was lowest for M-LC, while energy-corrected milk was similar for all diets. Milk fat percentage was higher and milk protein amount lower for cows offered both LC diets. Reticular pH below 6.3, 6.0 and 5.8 lasted longest for BPS-LC. WI was higher for HC diets. However, the frequency of drinking bouts was not influenced by the ration. Lower DMI occurred for BPS-LC compared to M-LC. Frequency of feeding bouts was significantly higher for LC diets. THI was significantly related to WI, DMI as well as drinking and feeding bouts. Per increasing THI, WI increased slightly more for LC diets and DMI decreased more for HC diets. Frequency of drinking bouts increased slightly higher for BPS rations per rising THI, while the decrease in feeding bouts was highest for M-HC. In conclusion, TMR composition and moderate heat stress impacted WI and DMI of dairy cows, while both dietary energy density and ruminal filling might intensify the THI impact.

Effects of concentrate supplementation in early lactation on nutrient efficiency, ruminal fermentation and reticular pH of zero-grazing dairy cows with differing milk production potentials.

In Switzerland, fresh herbage is a favoured feed for dairy cows due to its high quality and availability and low production costs. However, transition and early lactation are periods characterized by an increased nutrient demand that may not be covered by herbage alone. To compare the effects of concentrate supplementation in early lactation on nutrient efficiency and ruminal fermentation, 24 multiparous Holstein cows were assigned to two performance groups according to their previous lactation milk yield: high- (8,959 ± 984 kg) and low- (6,204 ± 1,000 kg) potential cows. Within this group, cows were allocated to two treatment groups receiving either herbage ad libitum (n = 11) or herbage supplemented with concentrate (n = 13). The experiment started for each cow 2 weeks before the predicted calving date (LW-2) and lasted until lactation week (LW) 8. Milk yield and dry matter intake (DMI) were recorded daily. The reticular pH was measured continuously using a telemetric pH bolus. Milk components and ruminal fermentation traits were analysed in LW-2, LW2, LW4, LW6 and LW8. Supplemented cows (p < 0.001) and high-potential cows (p = 0.015) produced more milk than unsupplemented cows and low-potential cows, respectively. Milk acetone was affected by supplementation (p < 0.001) and milk potential (p = 0.002) and was especially high in unsupplemented, high-potential cows until LW6. Supplementation caused a decrease in herbage DMI (p < 0.001) but resulted in an increased total DMI (p < 0.001), whereas milk potential had no effect on DMI. Associated with an increasing DMI (p < 0.001), ruminal volatile fatty acid concentration (p = 0.024) increased and reticular pH (p < 0.001) decreased from LW2 until LW6. Apart from that, effects on ruminal fermentation and reticular pH were minor. In conclusion, even though apparent nutrient efficiency was high, high-potential cows without supplementation seem to struggle more with reduced nutrient availability than other cows; therefore, they appear to be more prone to metabolic stress and consequently to production diseases.

Microbial community composition along the digestive tract in forage- and grain-fed bison.

BACKGROUND: Diversity and composition of microbial communities was compared across the 13 major sections of the digestive tract (esophagus, reticulum, rumen, omasum, abomasum, duodenum, jejunum, ileum, cecum, ascending colon, transverse colon, descending colon, and rectum) in two captive populations of American bison (Bison bison), one of which was finished on forage, the other on grain. RESULTS: Microbial diversity fell to its lowest levels in the small intestine, with Bacteroidetes reaching their lowest relative abundance in that region, while Firmicutes and Euryarchaeota attained their highest relative abundances there. Gammaproteobacteria were most abundant in the esophagus, small intestine, and colon. The forage-finished bison population exhibited higher overall levels of diversity, as well as a higher relative abundance of Bacteroidetes in most gut sections. The grain-finished bison population exhibited elevated levels of Firmicutes and Gammaproteobacteria. Within each population, different sections of the digestive tract exhibited divergent microbial community composition, although it was essentially the same among sections within a given region of the digestive tract. Shannon diversity was lowest in the midgut. For each section of the digestive tract, the two bison populations differed significantly in microbial community composition. CONCLUSIONS: Similarities among sections indicate that the esophagus, reticulum, rumen, omasum, and abomasum may all be considered to house the foregut microbiota; the duodenum, jejunum, and ileum may all be considered to house the small intestine or midgut microbiota; and the cecum, ascending colon, transverse colon, descending colon, and rectum may all be considered to house the hindgut microbiota. Acid from the stomach, bile from the gall bladder, digestive enzymes from the pancreas, and the relatively low retention time of the small intestine may have caused the midgut's low microbial diversity. Differences in microbial community composition between populations may have been most strongly influenced by differences in diet (forage or grain). The clinical condition of the animals used in the present study was not evaluated, so further research is needed to establish whether the microbial profiles of some bison in this study are indeed indicative of dysbiosis, a predisposing factor to ruminal acidosis and its sequelae.

Effects of body condition, monensin, and essential oils on ruminal lipopolysaccharide concentration, inflammatory markers, and endoplasmatic reticulum stress of transition dairy cows.

Evidence exists that dairy cows experience inflammatory-like phenomena in the transition period. Rumen health and alterations in metabolic processes and gene networks in the liver as the central metabolic organ might be key factors for cows' health and productivity in early lactation. This study made use of an animal model to generate experimental groups with different manifestations of postpartal fat mobilization and ketogenesis. In total, 60 German Holstein cows were allocated 6 wk antepartum to 3 high-body condition score (BCS) groups (BCS 3.95) and 1 low-BCS group (LC; BCS 2.77). High-BCS cows were fed an antepartal forage-to-concentrate ratio of 40:60 on dry matter basis, in contrast to 80:20 in the LC group, and received a monensin controlled-release capsule (HC/MO), a blend of essential oils (HC/EO), or formed a control group (HC). We evaluated serum haptoglobin, kynurenine, tryptophan, ruminal lipopolysaccharide concentration and mRNA abundance of nuclear factor kappa B (NF-κB), nuclear factor E2-related factor 2 (Nrf2), and endoplasmatic reticulum stress-induced unfolded protein response (UPR) target genes in liver biopsy samples from d -42 until +56 relative to calving. Nearly all parameters were highly dependent on time, with greatest variation near calving. The ruminal lipopolysaccharide concentration and evaluated target genes were not generally influenced by antepartal BCS and feeding management. The kynurenine-to-tryptophan ratio was higher in LC than in HC/MO treatment on d 7. Ruminal lipopolysaccharide concentration was higher in HC/MO than in the HC group, but not increased in HC/EO group. Abundance of UPR target gene X-box binding protein 1 was higher in HC/MO than in HC/EO group on d 7. Hepatic mRNA abundance of Nrf2 target gene glutathione peroxidase 3 was higher, whereas expression of NF-κB target gene haptoglobin tended to be higher in LC than in HC/EO cows. The HC/MO cows showed the most prominent increase in the abundance of glutathione peroxidase 3 and haptoglobin after calving in comparison to antepartal values. Results indicate the presence of inflammatory-like phenomena near calving. Simultaneously, alterations in UPR and Nrf2 target genes with antioxidative properties and haptoglobin occurred, being most prominent in LC and HC/MO group.

Modulation of chewing behavior and reticular pH in nonlactating cows challenged with concentrate-rich diets supplemented with phytogenic compounds and autolyzed yeast.

Feeding of concentrate-rich diets impairs chewing behavior and leads to rumen acidosis in cattle. Because of their modulatory effects on ruminal fermentation, phytogenic compounds (PHY) and autolyzed yeast derivatives (AY) may alleviate the negative consequences of high-concentrate diets. Therefore, this research investigated if chewing behavior and the reticular pH dynamics are modulated by AY and PHY supplementation during repeated concentrate-rich challenges used to simulate intermittent rumen acidotic insults. Eight rumen-cannulated, dry, and nonpregnant Holstein cows were assigned to an incomplete double 4 × 3 Latin square design with 3 treatments and 4 experimental runs (n = 8/treatment). Cows were fed concentrates either not supplemented (CON) or supplemented with PHY or AY. Initially, cows were fed a pure forage diet (FD) and switched to a 65% concentrate diet on DM basis for 1 (CONC 1) and 2 (CONC 2) wk. Between CONC 1 and CONC 2, the cows were fed the FD for 1 wk. Chewing activity was measured using noseband sensors and reticular pH by wireless pH sensors. Data showed that cows spent less time ruminating in CONC 1 than in CONC 2. In agreement, reticular pH drop was more pronounced during CONC 1 than during CONC 2. Cows fed with PHY spent 4 h less with reticular pH <6.0 during CONC 1 and 3 h less with pH <6.0 h in CONC 2 as compared with CON cows. Similarly, PHY supplementation extended rumination time with 88 min/d compared with CON cows during CONC 1. The AY supplementation increased DMI by 20% resulting in a longer eating time compared with CON diet during CONC 1. Enhancement of ruminating by PHY and eating time by AY supplementation resulted in longer total chewing time for PHY (474 min/d) and AY (466 min/d) as compared with CON (356 min/d) in CONC 1. In conclusion, cows experiencing 2 intermittent concentrate-rich challenges increased their ruminating behavior during the second challenge, and this effect was associated with higher reticular pH readings. The PHY supplementation enhanced rumination as well as reticular pH during CONC 1. However, the enhanced pH of cows fed with PHY during CONC 2 was not related to greater rumination, suggesting that influencing factors beyond rumination seemed to play a role in modulating reticular pH in PHY cows during CONC 2. The AY supplementation increased DMI without depressing rumination or reticular pH. Effects of both feed additives were more pronounced during CONC 1 challenge when reticular pH was lower.

Rumination time and reticuloruminal temperature as possible predictors of dystocia in dairy cows.

The objectives of this study were to explore changes of rumination time and reticuloruminal pH and temperature of dairy cows and heifers (means ± standard deviation; age = 5.8 ± 1.9; parity = 2.7 ± 1.4; body condition score = 3.2 ± 0.2) with eutocic (EUT, n = 10) and dystocic calving (DYS, n = 8). The recording period lasted from 3 d before calving until 7 d in milk. For the comparison of rumination time and reticuloruminal characteristics between groups, time to return to baseline (the time interval required to return to baseline from the delivery of the calf) and area under the curve (AUC; both for prepartum and postpartum periods) were calculated for each parameter. Rumination time decreased from baseline 28 h before calving both for EUT and DYS cows; after 20 h before calving, it decreased to 32.4 ± 2.3 and 13.2 ± 2.0 min/4 h between 8 and 4 h before delivery in EUT and DYS cows, respectively, and then it decreased below 10 and 5 min during the last 4 h before calving. Until 12 h after delivery, rumination time reached 42.6 ± 2.7 and 51.0 ± 3.1 min/4 h in DYS and EUT dams, respectively; however, AUC and time to return to baseline suggested lower rumination activity in DYS cows than in EUT dams for the 168-h postpartum observational period. Reticuloruminal pH decreased from baseline 56 h before calving both for EUT and DYS cows, but did not differ between groups before delivery. Reticuloruminal pH showed a decreasing tendency and clear diurnal variation after calving for both EUT and DYS cows, with slightly higher AUC values in DYS cows. In DYS cows, reticuloruminal temperature decreased from baseline 32 h before calving by 0.23 ± 0.02°C, whereas in EUT cows such a decrease was found only 20 h before delivery (0.48 ± 0.05°C). The AUC of reticuloruminal temperature calculated for the prepartum period was greater in EUT cows than in DYS cows. During the first 4 h after calving, reticuloruminal temperature decreased from 39.68 ± 0.09 to 38.96 ± 0.10°C and from 39.80 ± 0.06 to 38.81 ± 0.08°C in EUT and DYS cows, respectively, and reached baseline levels after 35.4 ± 3.4 and 37.8 ± 4.2 h after calving in EUT and DYS cows, respectively. Based on our results, continuous monitoring of changes in rumination time and reticuloruminal temperature seems to be promising in the early detection of cows with a higher risk of dystocia. Depressed rumination activity of DYS cows after calving highlights the importance of the postpartum monitoring of cows experiencing difficulties at calving. The effect of dystocia on postpartum reticuloruminal pH was not pronounced.

Reticulo-rumen mass, epithelium gene expression, and systemic biomarkers of metabolism and inflammation in Holstein dairy cows fed a high-energy diet.

Feeding a higher-energy diet by increasing cereal grains at the expense of forage during the last 3 to 4 wk prepartum is a traditional approach to help the rumen "adapt" to the traditional diets fed at the onset of lactation. Increasing grain/concentrate in the diet changes ruminal fermentation and in sheep and goats elicits marked changes in mRNA expression of immune-related genes in ruminal epithelium. Whether such changes at the epithelial and systemic levels occur in dairy cows when the dietary energy content increases at a fixed level of concentrate is unknown. Fourteen nonpregnant, nonlactating Holstein cows were fed a control lower-energy (CON, 1.30 Mcal/kg of dry matter) diet to meet 100% of estimated nutrient requirements for 3 wk, after which half of the cows were assigned to a higher-energy diet (OVE, 1.60 Mcal/kg of dry matter) and half of the cows continued on CON for 6 wk. Levels of forage and concentrate for CON and OVE were 80 and 79% and 20 and 21%, respectively. Plasma samples were collected 1 d before slaughter to examine biomarkers of metabolism, liver function, inflammation, and oxidative stress. The reticulo-rumen mass was recorded at slaughter, and samples of epithelium were harvested from all cows. The expression of 29 genes associated with tight junctions, immune function, and nutrient transport (volatile fatty acids, urea, and trace minerals) was examined. Overfeeding energy led to consistently greater dry matter intake over time, and lowered plasma concentrations of haptoglobin, paraoxonase, bilirubin, fatty acids, and myeloperoxidase (secreted by neutrophils). In contrast, OVE resulted in greater hydroxybutyrate and cholesterol concentrations. A greater reticulo-rumen mass in cows fed OVE did not alter genes associated with tight junctions (CDLN1, CDNL4, OCLN, TJP1), immune function (IL1B, IL10, NFKB1, TLR2, TLR4, TNF), oxidative stress (SOD1, SOD2), or most nutrient transporters. However, feeding OVE upregulated the acute-phase protein SAA3 by 3.5-fold and downregulated a volatile fatty acid transporter (SLC16A1) and a Fe and Cu transporter (SLC11A2). The lack of effect on mRNA expression along with lower plasma concentrations of inflammation biomarkers indicates that long-term intake of a higher-energy diet ad libitum was not detrimental to ruminal epithelium integrity. In that context, a protective function of SAA3 could be envisioned with a role in opsonizing gram-negative bacteria that produce endotoxins. The long-term control of volatile fatty acid absorption and trace minerals from the rumen in cows overfed energy does not seem to be controlled at the gene transcription level. The relevance of these findings to the nutritional management of pregnant dry cows merits further research.

Technical note: A comparison of reticular and ruminal pH monitored continuously with 2 measurement systems at different weeks of early lactation.

Subacute ruminal acidosis is one of the most important digestive disorders in high-yielding dairy cows fed highly fermentable diets. Monitoring of forestomach pH has been suggested as a potentially valuable tool for diagnosing subacute ruminal acidosis. The objective of the present study was to compare continuously recorded measurements of an indwelling telemetric pH sensor inserted orally in the reticulum with those obtained from a measurement system placed in the ventral sac of the rumen through a cannula. The experiment was conducted with 6 ruminally cannulated Holstein cows kept in a freestall barn. Equal numbers of cows were assigned to 2 treatment groups based on their previous lactation milk yield. Cows in treatment CON- were offered a diet consisting of only fresh herbage cut once daily, and cows in treatment CON+ got fresh herbage plus a concentrate supplement according to the individual milk yield of each cow to meet their predicted nutrient requirements. The experiment lasted from 2 wk before the predicted calving date until wk 8 of lactation. During the whole experiment, a pH value was recorded every 10 min in the reticulum using a wireless telemetry bolus including a pH sensor (eBolus, eCow Ltd., Exeter, Devon, UK), which had been applied orally using a balling gun. Simultaneously, in wk 2, before the estimated calving date and in wk 2, 4, 6, and 8 of lactation, the ruminal pH was measured every 30 s for 48 h with the LRCpH measurement system (Dascor Inc., Escondido, CA) placed in the ventral sac of the rumen through the cannula. The readings of the LRCpH measurement system were summarized as an average over 10 min for statistical analysis. The recorded pH values were on average 0.24 pH units higher in the reticulum than in the rumen. The reticular pH also showed less fluctuation (overall SD 0.19 pH units) than pH profiles recorded in the rumen (overall SD 0.51 pH units). Regardless of measurement system, pH was not influenced by treatment, but varied across week of lactation and decreased with advancing lactation. The difference between ruminal and reticular pH varied across week of lactation. Due to this variation, no fixed conversion factor can be provided to make pH measurements in the reticulum comparable with those in the rumen.

Determination of Henry's constant, the dissociation constant, and the buffer capacity of the bicarbonate system in ruminal fluid.

Despite the clinical importance of ruminal acidosis, ruminal buffering continues to be poorly understood. In particular, the constants for the dissociation of H2CO3 and the solubility of CO2 (Henry's constant) have never been stringently determined for ruminal fluid. The pH was measured in parallel directly in the rumen and the reticulum in vivo, and in samples obtained via aspiration from 10 fistulated cows on hay- or concentrate-based diets. The equilibrium constants of the bicarbonate system were measured at 38°C both using the Astrup technique and a newly developed method with titration at 2 levels of partial pressure of CO2 (pCO2; 4.75 and 94.98 kPa), yielding mean values of 0.234 ± 0.005 mmol ∙ L(-1) ∙ kPa(-1) and 6.11 ± 0.02 for Henry's constant and the dissociation constant, respectively (n/n = 31/10). Both reticular pH and the pH of samples measured after removal were more alkalic than those measured in vivo in the rumen (by ΔpH = 0.87 ± 0.04 and 0.26 ± 0.04). The amount of acid or base required to shift the pH of ruminal samples to 6.4 or 5.8 (base excess) differed between the 2 feeding groups. Experimental results are compared with the mathematical predictions of an open 2-buffer Henderson-Hasselbalch equilibrium model. Because pCO2 has pronounced effects on ruminal pH and can decrease rapidly in samples removed from the rumen, introduction of a generally accepted protocol for determining the acid-base status of ruminal fluid with standard levels of pCO2 and measurement of base excess in addition to pH should be considered.

Comparison of different measuring methods for body temperature in lactating cows under different climatic conditions.

The aim of the research described here was to compare different methods of body temperature (BT) measurements in dairy cows. It was hypothesised that reticular temperature (RET) values reflect the physiological status of the animals in an equivalent way to rectal (RT) and vaginal (VT) measurements. RT, VT and RET temperatures of twelve lactating Holstein-Friesian cows were measured over five consecutive days in June and October 2013. While RT and VT were manually measured three times a day, RET was automatically recorded at 10 min intervals using a bolus in the reticulum. For comparison with RT and VT, different RET values were used: single values at the respective recording times (RET-SIN), and mean (RET-MEAN) and median (RET-MED) values of 2 h prior to RT and VT measurements. Overall, body temperatures averaged 38·1 ± 0·6, 38·2 ± 0·4, 38·7 ± 0·9, 38·5 ± 0·7 and 38·7 ± 0·5 °C for RT, VT, RET-SIN, RET-MEAN and RET-MED, respectively. RT and VT were lower than all RET measurements, while RET-SIN and RET-MED were higher than RET-MEAN (P < 0·001). RET-MEAN and RET-MED values were higher in the morning, whereas RT and VT were greatest in the evening (P < 0·001). Overall, records of RT and VT were strongly correlated (r = 0·75; P < 0·001). In contrast to RET-SIN and RET-MEAN, RET-MED was higher correlated to RT and VT. In June, coefficients were higher between all methods than in October. Relation of barn T to RT and VT was stronger when compared to RET measurements. RET-SIN was higher correlated to barn T than RET-MEAN or RET-MED. Correlation between VT and barn T was strongest (r = 0·48; P < 0·001). In summary, RET-MED showed highest correlation with VT and RT. However, single RET measurements (influenced by water or feed intake) can lead to extreme variations and differences to single VT and RT values.