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Pathophysiological evaluation of subacute ruminal acidosis (SARA) by continuous ruminal pH monitoring 
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下载免费PDF全文 Shigeru Sato 《Animal Science Journal》2016,87(2):168-177
Evaluation of the radio‐transmission pH‐measurement system for monitoring the ruminal pH and subacute ruminal acidosis (SARA) in cattle is described. This is done in order to reveal the possible application of this system for detection and pathophysiological research of SARA by continuous ruminal pH measurement. The possibility of using this system for assessment of the ruminal pH in SARA cattle, and the presence of negative correlation between the ruminal pH and ruminal temperature in heathy and SARA cattle were determined. In addition, the 16S rRNA gene pyrosequencing analysis showed that the ruminal microbial community was simpler in SARA cattle, and the bacterial numbers in SARA cattle were lower than those in healthy hay‐fed cattle. Concentrate feeding might have reduced the diversity of the ruminal microbial community. Changes in the ruminal microbial community of SARA cattle might be related to the changes in ruminal pH followed by the decrease in the number of some bacteria. Continuous monitoring of the ruminal pH using the radio‐transmission pH‐measurement system would be applied for detection and prevention of SARA in the field and pathophysiological research of SARA, including ruminal zymology and bacteriology, which have been determined previously by sampling of the ruminal fluid and measuring of ruminal pH. 相似文献
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Karapinar T Dabak M Kizil O Balikci E 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2008,22(3):662-665
BACKGROUND: Thiamine status of ruminants is adversely affected in acidic rumen conditions. However, there have been limited published case study data related to thiamine deficiency of ruminants with acute ruminal lactic acidosis (ARLA). HYPOTHESIS: Thiamine deficiency would occur in sheep with ARLA. ANIMALS: Thirteen Ak-Karaman (white Karaman) sheep with ARLA, aged 1 year (ARLA group) and 10 healthy Ak-Karaman sheep, aged 1 year (control group) were used. METHODS: After clinical examination, rumen fluid samples of all sheep were obtained with a stomach tube and examined immediately. Blood samples were taken from a jugular vein of the sheep. Erythrocytic transketolase enzyme activity and hence thiamine pyrophosphate (TPP) effect were determined according to Clausen's method. RESULTS: History revealed that all sheep in the ARLA group had accidentally consumed excessive amounts of cracked barley. During clinical examination of the ARLA group, disturbed general condition, engorged scleral vessels, moderate to severe dehydration, and ruminal atony were recorded in the sheep. The results of the ruminal fluid analyses of the ARLA group demonstrated characteristics of ARLA. The results of clinical and ruminal fluid examination of control group were normal. The mean TPP effect (%) in the ARLA group (109 +/- 28) was significantly higher than in the control group (22.2 +/- 3.7) (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: The present study revealed that severe thiamine deficiency occurred in sheep with ARLA. This result indicates that thiamine administration to sheep suffering from acute ruminal acidosis caused by overconsumption of readily fermentable carbohydrates could be beneficial in alleviating thiamine deficiency caused by ruminal acidosis. 相似文献
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Highly fermentable diets are rapidly converted to organic acids [i.e., short-chain fatty acids (SCFA) and lactic acid] within the rumen. The resulting release of protons can constitute a challenge to the ruminal ecosystem and animal health. Health disturbances, resulting from acidogenic diets, are classified as subacute and acute acidosis based on the degree of ruminal pH depression. Although increased acid production is a nutritionally desired effect of increased concentrate feeding, the accumulation of protons in the rumen is not. Consequently, mechanisms of proton removal and their quantitative importance are of major interest. Saliva buffers (i.e., bicarbonate, phosphate) have long been identified as important mechanisms for ruminal proton removal. An even larger proportion of protons appears to be removed from the rumen by SCFA absorption across the ruminal epithelium, making efficiency of SCFA absorption a key determinant for the individual susceptibility to subacute ruminal acidosis. Proceeding initially from a model of exclusively diffusional absorption of fermentation acids, several protein-dependent mechanisms have been discovered over the last 2 decades. Although the molecular identity of these proteins is mostly uncertain, apical acetate absorption is mediated, to a major degree, via acetate-bicarbonate exchange in addition to another nitrate-sensitive, bicarbonate-independent transport mechanism and lipophilic diffusion. Propionate and butyrate also show partially bicarbonate-dependent transport modes. Basolateral efflux of SCFA and their metabolites has to be mediated primarily by proteins and probably involves the monocarboxylate transporter (MCT1) and anion channels. Although the ruminal epithelium removes a large fraction of protons from the rumen, it also recycles protons to the rumen via apical sodium-proton exchanger, NHE. The latter is stimulated by ruminal SCFA absorption and salivary Na(+) secretion and protects epithelial integrity. Finally, SCFA absorption also accelerates urea transport into the rumen, which via ammonium recycling, may remove protons from rumen to the blood. Ammonium absorption into the blood is also stimulated by luminal SCFA. It is suggested that the interacting transport processes for SCFA, urea, and ammonia represent evolutionary adaptations of ruminants to actively coordinate energy fermentation, protein assimilation, and pH regulation in the rumen. 相似文献
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Sanae Asano Kohei Aoki Yuna Kaizuka Yuhi Kobayashi Kenta Watanabe Chizuko Kato Chihiro Saito Syuichi Nishimura Toshiaki Kato Motonori Takagi Hiroshi Kajikawa 《Animal Science Journal》2019,90(11):1453-1459
We evaluated the lotus rhizome as a potential ruminant feed by investigating its compositional properties, in situ degradation profile and in vitro fermentation characteristics with ruminal microbes, in comparison with cereal grains (corn, barley and wheat). The antioxidative activities in the lotus rhizome were also estimated. The soluble fraction of dry matter in lotus tuber was >70%, which was higher than those in the grains. The insoluble fraction in lotus tuber was not degraded by ruminal microbes in accord with a first‐order reaction. In an in vitro experiment, lotus tuber showed lower fermentation at 8 hr compared to the grains, but exhibited higher productions of gas and VFA at 48 hr along with a lower lactate and higher pH. The lower value of final lactate production in lotus tuber, indicating the metabolic capacity for lactate utilization retained, suggests a lower risk of ruminal acidosis compared to grains. Lotus rhizome had high antioxidant activities, with the foliar bud showing the strongest ferric reducing antioxidant power, followed in order by the apical bud, node, residual tuber, edible tuber, and nodal root. For ruminants, the lotus rhizome could thus be not only an energy feed but also the source of natural antioxidants. 相似文献
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本试验旨在探究SARA（亚急性瘤胃酸中毒）耐受性不同奶牛的瘤胃上皮形态及其功能差异。选取12头装有永久性瘤胃瘘管的泌乳中期荷斯坦奶牛,饲喂精粗比为4∶6的日粮,并根据瘤胃pH值的高低,分为SARA易感组（SUS,n=4）和SARA耐受组（TOL,n=4）。瘤胃上皮形态及功能分析结果显示,与TOL组比较,SUS组奶牛瘤胃上皮的棘突层和基底层厚度明显增厚（P<0.05）,SUS组奶牛瘤胃上皮组织中参与挥发性脂肪酸（VFA）吸收的PAT1、MCT4和DRA基因表达量较TOL组显著下调（P<0.05）,而H+转运载体NHE1、NHE2、NHE3和调节胞内pH的vH+ATPase和Na+/K+ATPase的表达量显著升高（P<0.05）;对参与调控瘤胃VFA代谢的基因定量结果表明,SUS组PDHA1和SREBP2的表达量显著高于TOL组（P<0.05）,而HMGCL-2的表达量显著降低（P<0.05）;此外,SUS组CDK2、CDK6和Cyclin D1、Bad及Caspase-9等参与瘤胃上皮细胞增殖与凋亡的基因表达量显著高于TOL组（P<0.05）。结果说... 相似文献
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畜牧业集约化养殖越来越普遍。为提高反刍动物生产性能,饲喂大量能量饲料,进而引发亚急性瘤胃酸中毒(SARA),导致动物采食量下降、畜产品产出降低以及动物发生炎症反应。近年研究表明,SARA会改变瘤胃生理状态,而瘤胃健康对反刍动物饲养至关重要。本文综述了反刍动物SARA状态下瘤胃生理生化过程变化,结合瘤胃发酵模式变化和瘤胃微生物的改变,重点阐述了SARA引起的瘤胃上皮细胞形态结构变化、屏障功能改变、瘤胃上皮细胞中物质转运及相关载体表达及其引发的瘤胃上皮细胞炎症通路,为更好指导反刍动物饲养及为瘤胃营养生理生化研究提供参考。 相似文献
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Signals for identifying cows at risk of subacute ruminal acidosis in dairy veterinary practice 下载免费PDF全文
下载免费PDF全文 E. Humer J. R. Aschenbach V. Neubauer I. Kröger R. Khiaosa‐ard W. Baumgartner Q. Zebeli 《Journal of animal physiology and animal nutrition》2018,102(2):380-392
Controlling rumen disorders is critical to ensure successful dairy herd health management. Lactation diets of dairy cows are commonly rich in concentrates and low in physically effective fibre. Feeding of these diets increases the risk of rumen disorders with far‐reaching consequences for cattle health, welfare and sustainability of dairy production. The term subacute ruminal acidosis or SARA is often used as a synonym for poor rumen health. Being subclinical, SARA lacks of clear symptoms and is therefore difficult to diagnose and to control in the practice. This review article summarises common and identifies new direct and indirect cow signals related to SARA. We have performed a scientific evaluation and interpretation of each of these cow signals by highlighting their advantages and disadvantages from the practitioner's point of view. The gold standard of SARA cow signals still remains direct measurement of ruminal pH. However, continuous pH monitoring is cost‐intensive and often biased by sensor drift. Single‐point ruminal pH measurements by oral stomach tubing or rumenocentesis have strong limitations. Therefore, there is a need for reliable and robust markers of SARA that are easily accessible and inexpensive. Such indirect parameters are the observation of chewing and feeding activities, as well as the monitoring of milk, faecal, urine and blood variables. Also, novel technologies that allow rapid and non‐invasive measurement of the rumen mucosa thickness and ruminal motility patterns might provide advantages in SARA diagnosis. Due to several constraints of these indirect diagnostic tools, such as limited specificity and sensitivity, we strongly recommend using a combination of the signals to reliably identify cows at risk of SARA in a dairy herd. 相似文献
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Rika Fukumori Rina Ikeno Kenichi Izumi Kazuya Doi Marina Otsuka Kazuyuki Suzuki Shin Oikawa 《Animal Science Journal》2021,92(1):e13673
The objective of this study was to evaluate effects of sodium-butyrate supplementation on gastrointestinal function and the inflammatory response to ruminal acidosis (RA) challenge in cows. Four nonlactating cows with a rumen cannula were assigned to two treatments in a crossover design. Treatments were ruminal administration of sodium-butyrate (BUT) or control (CON). Sodium-butyrate was provided as Gustor BP70 and administered at a butyrate dose of 0.04% per kg body weight. The CON premix was made by replacing sodium-butyrate with wheat bran. Experimental periods were 28 days long with 21-day washout period separating the treatments. On Day 25 of each period, corn starch was ruminally administered at 0.7% per kg body weight as RA challenge. After RA challenge, ruminal pH was lower, and endotoxin concentration was higher for cows provided with BUT than those with CON, but the increase in fecal starch and the decrease in fecal pH were attenuated by BUT. The effect of butyrate supplementation on serum lipopolysaccharide-binding protein after RA challenge was not found. From these findings, butyrate supplementation mitigated rectal acidosis by reducing the flux of fermentable carbohydrate into the large intestine. An anti-inflammatory effect of butyrate was not observed, possibly due to lower pH and higher endotoxin concentration in the rumen. 相似文献
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Feeding highly fermentable diets to ruminants is one strategy to increase energy intake. The increase in short-chain fatty acid (SCFA) production and reduced ruminal pH associated with highly fermentable diets imposes a challenge to the metabolism and the regulation of intracellular pH homeostasis of ruminal epithelia. The ruminal epithelia respond to these challenges in a coordinated manner. Whereas the enlargement of absorptive surface area is well documented, emerging evidence at the mRNA and transporter and enzyme activity levels indicate that changes in epithelial cell function may be the initial response. It is not surprising that gene expression analysis has identified pathways involved in fatty acid metabolism, ion transport, and intracellular homeostasis to be the pathways dominantly affected during adaptation and after adaptation to a highly fermentable diet. These findings are important because the intraepithelial metabolism of SCFA, particularly butyrate, helps to maintain the concentration gradient between the cytosol and lumen, thereby facilitating absorption. Butyrate metabolism also controls the intracellular availability of butyrate, which is widely regarded as a signaling molecule. Current data indicate that for butyrate metabolism, 3-hydroxy-3-methylglutaryl-CoA synthase and acetyl-CoA acetyltransferase are potential regulatory points with transient up- and downregulation during diet adaptation. In addition to nutrient transport and utilization, genes involved in the maintenance of cellular tight junction integrity and induction of inflammation have been identified as differentially expressed genes during adaptation to highly fermentable diets. This may have important implications on ruminal epithelial barrier function and the inflammatory response often associated with subacute ruminal acidosis. The objective of this review is to summarize ruminal epithelial adaptation to highly fermentable diets focusing on the changes at the enzyme and transporter activity levels, as well as the underlying molecular changes at the mRNA and protein expression levels. 相似文献
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试验研究了在不同非纤维性碳水化合物/中性洗涤纤维（NFC/NDF）比饲粮条件下诱发奶山羊亚急性瘤胃酸中毒（subacute rumen acidosis,SARA）过程中瘤胃微生物区系和瘤胃pH值的变化。该试验选用6只安装了永久性瘤胃瘘管的泌乳期关中奶山羊为试验动物,采用自身对照试验法,共分4期进行,每期10d,依次饲喂NFC/NDF比为1.02（Ⅰ期）、1.24（Ⅱ期）、1.63（Ⅲ期）、2.58（Ⅳ期）的4种饲粮,以逐渐增加饲粮精料的方法诱导奶山羊发生SARA。结果表明,随着饲粮NFC/NDF比的增大,瘤胃pH值显著降低（P〈0.05）,并且瘤胃pH值下降幅度也随之加快;随着饲粮NFC/NDF比的增加,淀粉分解菌的数量增幅最显著（P〈0.01）;饲粮NFC/NDF比为1.63时,瘤胃细菌总数、乳酸杆菌及坏死梭形杆菌的数量显著增加（P〈0.05）,当该比值为2.58时,埃氏巨型球菌和反刍兽新月单胞菌的数量出现显著增多（P〈0.05）;原虫数量在Ⅳ期降至最低,而牛链球菌的数量在整个试验期并未出现明显的波动。饲粮NFC/NDF比为1.63时,瘤胃内与碳水化合物分解有关的多数细菌的数量明显增加,SARA期时增幅更为明显,而此时原虫数量为最低。 相似文献
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Hitoshi MIZUGUCHI Tomoki IKEDA Yumi WATANABE Shiro KUSHIBIKI Kentaro IKUTA Yo-Han KIM Shigeru SATO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(6):905
The effects of anti-lipopolysaccharide (LPS) antibody on rumen fermentation and LPS activity were investigated during subacute ruminal acidosis (SARA) challenge. Eleven Holstein cattle (164 ± 14 kg) were used in a 3 × 3 Latin square design. Cattle were fed a roughage diet on days −11 to −1 (pre-challenge) and day 2 (post-challenge), and a high-grain diet on days 0 and 1 (SARA challenge). For 14 days, 0-, 2-, or 4-g of anti-LPS antibody was administered once daily through a rumen fistula. Ruminal pH was measured continuously, and rumen fluid and blood samples were collected on days −1, 0, 1, and 2. Significantly lower ruminal LPS activity on day 1 was observed in the 2- and 4-g groups than those in the 0-g group. In addition, significantly higher 1-hr mean ruminal pH on SARA challenge period (days 0 and 1) was identified in the 4-g group than in the 0-g group. However, rumen fermentation measurements (total volatile fatty acid [VFA], VFA components, NH3-N and lactic acid) and peripheral blood metabolites (glucose, free fatty acid, beta-hydroxybutyrate, total cholesterol, blood urea nitrogen, aspartate aminotransferase and gamma-glutamyl transferase) were not different among the groups during the experimental periods. Therefore, anti-LPS antibody administration mitigates LPS release and pH depression without the depression of rumen fermentation and peripheral blood metabolites during SARA challenge in Holstein cattle. 相似文献
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Reduced energy density of close‐up diets decrease ruminal pH and increase concentration of volatile fatty acids postpartum in Holstein cows 下载免费PDF全文
下载免费PDF全文 Wenming Huang Yujia Tian Shengli Li Zhaohai Wu Zhijun Cao 《Animal Science Journal》2017,88(11):1700-1708
The objective of this study was to determine the effect of reduced energy density of close‐up diets on ruminal fermentation parameters in transition cows. Fourteen Holstein dry cows were blocked and assigned randomly to three groups fed a high energy density diet (HD, 1.62 Mcal of net energy for lactation (NEL)/kg dry matter (DM)), or a middle energy density diet (MD, 1.47 Mcal NEL/kg DM), or a low energy density diet (LD, 1.30 Mcal NEL/kg DM) prepartum, and were fed the same diet postpartum. The reduced energy density diets decreased the average dry matter intake (DMI) prepartum and tended to increase the DMI postpartum. The ruminal pH of the LD group was significantly higher prepartum and lower during the first week of lactation compared with the other two groups. The reduced energy density diet depressed the average ruminal concentration of propionate and butyrate prepartum, and increased the average concentration of total volatile fatty acids (VFA) postpartum. The LD group had higher populations of Butyrivibrio fibrisolvens and Ruminococcus flavefaciens relative to HD and MD groups on 7 days in milk. In conclusion, the cows fed reduced energy density diet prepartum had higher VFA concentration, but were more susceptible to subacute ruminal acidosis postpartum. 相似文献
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Transfer of energy substrates across the ruminal epithelium: implications and limitations 总被引：1，自引：0，他引：1
Gäbel G Aschenbach JR Müller F 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2002,3(1):15-30
The ruminal epithelium has an enormous capacity for the absorption of short-chain fatty acids (SCFAs). This not only delivers metabolic energy to the animal but is also an essential regulatory mechanism that stabilizes the intraruminal milieu. The epithelium itself, however, is endangered by the influx of SCFAs because the intracellular pH (pHi) may drop to a lethal level. To prevent severe cytosolic acidosis, the ruminal epithelium is able to extrude (or buffer) protons by various mechanisms: (i) a Na+/H+ exchanger, (ii) a bicarbonate importing system and (iii) an H+/monocarboxylate cotransporter (MCT). Besides pHi regulation, the MCT also provides the animal with ketone bodies derived from the intraepithelial breakdown of SCFAs. Ketone bodies, in turn, can serve as an energy source for extrahepatic tissues. In addition to SCFA uptake, glucose absorption has recently been identified as a potential way of eliminating acidogenic substrates from the rumen. At least with respect to SCFAs, absorption rates can be elevated when adapting animals to energy-rich diets. Although they are very effective under physiological conditions, the absorptive and regulatory mechanisms of the ruminal epithelium also have their limits. An increased number of protons during the state of ruminal acidosis can be eliminated neither from the lumen nor the cytosol, thus worsening dysfermentation and finally leading to functional and morphological alterations of the epithelial lining. 相似文献
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Michael A Steele Ousama AlZahal Sarah E Hook Jim Croom Brian W McBride 《Acta veterinaria Scandinavica》2009,51(1):39
A mature dairy cow was transitioned from a high forage (100% forage) to a high-grain (79% grain) diet over seven days. Continuous ruminal pH recordings were utilized to diagnose the severity of ruminal acidosis. Additionally, blood and rumen papillae biopsies were collected to describe the structural and functional adaptations of the rumen epithelium. On the final day of the grain challenge, the daily mean ruminal pH was 5.41 ± 0.09 with a minimum of 4.89 and a maximum of 6.31. Ruminal pH was under 5.0 for 130 minutes (2.17 hours) which is characterized as the acute form of ruminal acidosis in cattle. The grain challenge increased blood beta-hydroxybutyrate by 1.8 times and rumen papillae mRNA expression of 3-hydroxy-3-methylglutaryl-coenzyme A synthase by 1.6 times. Ultrastructural and histological adaptations of the rumen epithelium were imaged by scanning electron and light microscopy. Rumen papillae from the high grain diet displayed extensive sloughing of the stratum corneum and compromised cell adhesion as large gaps were apparent between cells throughout the strata. This case report represents a rare documentation of how the rumen epithelium alters its function and structure during the initial stage of acute acidosis. 相似文献
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Sato S Mizuguchi H Ito K Ikuta K Kimura A Okada K 《Preventive veterinary medicine》2012,103(4):274-279
An indwelling ruminal pH system has been used for the continuous recording of ruminal pH to evaluate subacute ruminal acidosis (SARA) in dairy cows. However this system does not allow the field application. The objective of this study was to develop a new radio transmission pH measurement system, and to assess its performance and usefulness in a continuous evaluation of ruminal pH for use on commercial dairy farms. The radio transmission pH measurement system consists of a wireless pH sensor, a data measurement receiver, a relay unit, and a personal computer installed special software. The pH sensor is housed in a bullet shaped bolus, which also encloses a pH amplifier circuit, a central processing unit (CPU) circuit, a radio frequency (RF) circuit, and a battery. The mean variations of the measurements by the glass pH electrode were +0.20 (n = 10) after 2 months of continuous recording, compared to the values confirmed by standard pH solutions for pH 4 and pH 7 at the start of the recording. The mean lifetime of the internal battery was 2.5 months (n = 10) when measurements were continuously transmitted every 10 min. Ruminal pH recorded by our new system was compared to that of the spot sampling of ruminal fluid. The mean pH for spot sampling was 6.36 ± 0.55 (n = 96), and the mean pH of continuous recording was 6.22 ± 0.54 (n = 96). There was a good correlation between continuous recording and spot sampling (r = 0.986, P < 0.01). We also examined whether our new pH system was able to detect experimentally induced ruminal acidosis in cows and to record long-term changes in ruminal pH. In the cows fed acidosis-inducing diets, the ruminal pH dropped markedly during the first 2 h following the morning feeding, and decreased moreover following the evening feeding, with many pulse-like pH changes. The pH of the cows showed the lowest values of 5.3-5.2 in the midnight time period and it recovered to the normal value by the next morning feeding. In one healthy periparturient cow, the circadian changes in ruminal pH were observed as a constant pattern in the pre-parturient period, however that pattern became variable in the post-partum period. The frequency of the ruminal pH lower than 5.5 increased markedly 3 and 4 days after parturition. We demonstrated the possible application of a radio transmission pH measurement system for the assessment and monitoring of the ruminal pH of cows. Our new system might contribute to accurate assessment and prevention of SARA. 相似文献