奶牛亚急性瘤胃酸中毒的发病机理及其营养调控措施

高淀粉含量的谷物精料能够为奶牛提供较多的能量,因此在奶牛的泌乳期,往往会加大其饲喂比例,但奶牛摄入高含量的精饲料后会导致瘤胃内挥发性脂肪酸和乳酸的含量上升,pH下降,从而引发奶牛亚急性瘤胃酸中毒。此病在临床上没有明显的症状,不易发现,还容易诱发乳房炎、肝脏损伤、蹄炎等多种疾病,给奶牛养殖业带来较大危害。本文对奶牛亚急性瘤胃酸中毒的定义、危害,以及目前行业内较为认可的引发奶牛亚急性瘤胃酸中毒的三种学说进行了概述,同时对预防该病的营养调控措施进行了综合讨论,以期为奶牛场预防亚急性瘤胃酸中毒提供理论参考,促进奶牛养殖业的健康发展。     

奶牛瘤胃酸中毒的发病机理与控制

瘤胃酸中毒是反刍动物特有的疾病,由日粮不平衡导致有机酸在瘤胃内蓄积造成的。分为急性瘤胃酸中毒和慢性瘤胃酸中毒,其中慢性瘤胃酸中毒     

反刍动物瘤胃酸中毒的发病机制及其营养调控

瘤胃酸中毒是反刍动物常见的一种代谢病。其产生的主要原因是日粮中含有大量易发酵的碳水化合物,饲料或者日粮粗纤维含量较低,导致瘤胃产生酸性物质过多,引起瘤胃微生物区系失调和瘤胃功能紊乱。本文就反刍动物瘤胃酸中毒的发病机制及其营养调控措施作一综述。     

反刍动物亚急性瘤胃酸中毒的发病机制及其营养调控方法

反刍动物亚急性瘤胃酸中毒是现代化集约养殖中的一种代谢障碍性疾病,严重危害反刍动物的生长健康和产品质量,给养殖企业带来了较大的经济损失。因此,采取积极有效的预防和治疗措施对畜牧业的健康发展尤为重要。文章就反刍动物亚急性瘤胃酸中毒的危害、病因、临床表现及营养调控方法进行阐述,以期为反刍动物亚急性瘤胃酸中毒的预防提供科学、合理的营养调控方法。 [关键词]反刍动物|瘤胃|酸中毒|营养调控     

奶牛瘤胃酸中毒的防治

奶牛瘤胃酸中毒又叫酸性消化不良、乳酸中毒、瘤胃过食、急性食滞、过食谷物等,是由于饲喂大量易发酵产酸的精料,以瘤胃中乳酸蓄积为特征的全身代谢紊乱的疾病。临床表现以严重的毒血症、急剧脱水、瘤胃停滞和积液及高乳酸血症为主要特征。该病散发,无年龄、胎次之分,一年四季均可发病,但以冬春较多,临产牛产后3天内发病最多,且产奶量愈高,发病率愈高。由于该病发病急骤,病程短,死亡率高,往往因治疗不及时或误诊给广大养殖户造成巨大的经济损失。1发病原因①精料饲喂量过高,粗料比例不当。②随着产奶量增高,精料量相应增加,为了促使下胎泌乳…     

预防亚急性瘤胃酸中毒的营养调控措施

高淀粉、低纤维日粮已成为当前高产奶牛或育肥牛羊的典型营养特征,在提高生产效益的同时,也会增加亚急性瘤胃酸中毒的发病率。本文分析了亚急性瘤胃酸中毒的发病机理、负面影响,并总结了其营养调控措施,旨在为养殖业预防瘤胃酸中毒提供理论参考。     

奶牛瘤胃酸中毒的发病特点、临床表现和治疗措施

奶牛瘤胃酸中毒是由于奶牛突然食入过多含有丰富碳水化合物的谷物饲料,或者长时间饲喂高酸度的青贮饲料或者甜菜等块根类饲料而引起发病.奶牛出现急性发病时,会在采食后的3～5 h内突然死亡,没有任何明显症状;较慢出现发病时,会表现出精神不振,停止采食,肌肉震颤,步态蹒跚,瘫痪卧地,病程后期体温在常温以下,眼窝下陷,眼结膜变成紫...     

奶牛瘤胃酸中毒的诊疗方法

本文介绍了奶牛瘤胃酸中毒发生的直接病因、间接原因,诊断时病牛的三种主要症状和剖检特征以及预防措施、治疗方法。     

奶牛瘤胃酸中毒的治疗

瘤胃酸中毒是反刍动物采食了过量易发酵的碳水化合物饲料 ,在瘤胃内产生大量乳酸并蓄积而引起的以前胃机能障碍为主的一种疾病。近几年来 ,笔者在西宁、民和及贵德等地共治疗奶牛瘤胃酸中毒病 2 3例 ,其中治愈 2 2例 ,死亡 1例 ,现报告如下 :1　病因本病的主要病因有两种类型 :一种是农户散养的奶牛、畜主为了提高产奶量 ,采用增加精料的办法或在奶牛产前产后给牛大量补饲精料 ,突然饲喂大量玉米面或大麦面粉等精料。民和曾有一位农民在奶牛产后的 8ｈ内连续两次给牛饲喂了 12ｋｇ玉米面而发病。另一种是国营或集体奶牛场 ,其主要病因是长期…     

反刍动物亚急性瘤胃酸中毒的营养调控

反刍动物饲喂高谷物日粮时常发生瘤胃酸中毒现象,本文针对反刍动物亚急性瘤胃酸中毒的营养调控进行综述.     

Subacute rumen acidosis in lactating cows: an investigation in intensive Italian dairy herds

Subacute rumen acidosis (SARA) represents one of the most important metabolic disorders in intensive dairy farms that affects rumen fermentations, animal welfare, productivity and farm profitability. The aim of the present study was to study the occurrence of SARA in intensive Italian dairy herds and to determine the relationship between diet composition, ruminal pH and short chain fatty acids (SCFA) concentration. Ten commercial dairy herds were investigated; twelve cows in each herd were selected randomly among animal without clinical signs of disease, with good body condition and between 5 and 60 day-in-milk (DIM), to perform rumenocentesis and obtain rumen fluid. Ruminal pH was determined immediately after sampling and concentration of SCFA in ruminal fluid was determined on samples after storage. An other objective of this research was to study in detail the effects of rumenocentesis on animal health: this study could confirm the extreme validity of this technique as ruminal sampling. Results were subject to anova and correlation analysis using SIGMA STAT 2.03. The results indicated the presence of SARA in three herds (more than 33% cows with rumen pH < 5.5), a critical situation (more than 33% cows with rumen pH < 5.8) in five farms and a normal rumen pH condition in two herds. In particular, dairy herds show on average SCFA concentration of 150, 145, 123 mmol/l for low pH, critical pH and normal pH herds respectively. There were not significant differences among diet composition even if herds with SARA showed a light discordance between initially chemistry composition and residual feed. In the affected herds it was not possible to understand the exact causes of SARA. Animal management seems to be one of the most important factors in developing SARA including total mixed ration preparation.     

一例牛瘤胃酸中毒的诊治

瘤胃酸中毒多发生于牛,特别是奶牛.主要是精饲料喂量过多,精粗饲料比例不当所造成.以1～3胎的奶牛发病最多,7胎后的发病较少.一年四季均可发生,但以冬春季较多.临产牛和产后3 d内的发病较多.产奶量愈多,发病率愈高.笔者于2005年夏季带学生在临夏市某兽医站实习时遇到一病例,现将诊治情况总结如下.     

Responsive changes of rumen microbiome and metabolome in dairy cows with different susceptibility to subacute ruminal acidosis

Subacute ruminal acidosis(SARA)represents one of the most important digestive disorders in intensive dairy farms,and dairy cows are individually different in the severity of SARA risk.The objectives of the current study were to investigate differences in the ruminal bacterial community and metabolome in dairy cattle with different susceptibility to SARA.In the present study,12 cows were initially enrolled in the experiment.Based on average ruminal pH,4 cows with the lowest ruminal pH were assigned to the susceptible group(SUS,pH=5.76,n=4)and 4 cows with the highest ruminal pH assigned to the tolerant group(TOL,pH=6.10,n=4).Rumen contents from susceptible(SUS,n=4)and tolerant(TOL,n=4)dairy cows were collected through rumen fistula to systematically reveal the rumen microbial and metabolic alterations of dairy cows with different susceptibility to SARA using multi-omics approaches(16S and 18S rRNA gene sequencing and metabolome).The results showed that despite being fed the same diet,SUS cows had lower ruminal pH and higher concentrations of total volatile fatty acids(VFA)and propionate than TOL cows(P<0.05).No significant differences were observed in dry matter intake,milk yield,and other milk compositions between the SUS and TOL groups(P>0.05).The principal coordinates analysis based on the analysis of molecular variance indicated a significant difference in bacterial composition between the two groups(P=0.01).More specifically,the relative abundance of starch-degrading bacteria(Prevotella spp.)was greater(P<0.05),while the proportion of fiber-degrading bacteria(unclassified Ruminococcaceae spp.,Ruminococcus spp.,Papillibacter,and unclassified Family_-XIII)was lower in the rumen of SUS cows compared with TOL cows(P<0.05).Community analysis of protozoa showed that there were no significant differences in the diversity,richness,and community structure(P>0.05).Metabolomics analysis revealed that the concentrations of organic acids(such as lactic acid),biogenic amines(such as histamine),and bacterial degradation products(such as hypoxanthine)were significantly higher in the SUS group compared to the TOL group(P<0.05).These findings revealed that the higher proportion of starch-degrading bacteria/lower fiber-degrading bacteria in the rumen of SUS cows resulted in higher VFA-producing capacity,in particular propionate.This caused a disruption in metabolic homeostasis in the rumen which might be the reason for the higher susceptibility to SARA.Overall,these findings enhanced our understanding of the ruminal microbiome and metabolic changes in cows susceptible to SARA.     

Effects of feeding buffering mineral mixture on subacute rumen acidosis and some production traits in dairy cows

This trial was designed in order to evaluate the incidence of subacute rumen acidosis (SARA) during early lactation and to investigate the possibilities for its prevention by use of a buffering mineral mixture. On the beginning of the trial it was found that the pH value of rumen fluid in 4 animals was lower than normal (pH < 6.0) and that 20% of animals have had SARA. The control and the experimental group of cows were fed the same meal with exception of concentrated feed which in the experimental group contained the mineral mix with buffering activity in amount of 1%. Continuous addition of buffering mineral mixture in the amount of 1% in concentrated feed for early lactation cows successfully prevents SARA formation and leads to increased milk production, as well as increased milk fat and protein content.     

Chronic metabolic acidosis in dairy cows]

Complex clinical and clinico-biochemical examination of the blood, urine and rumen liquor in a herd of dairy cows revealed chronical metabolic acidosis accompanied by rumen dysfunction and by a reduced butterfat content of milk. During the first examination of the acid-base state of the blood was almost at a standard level. An increased level of urea in blood plasma and a higher GOT transaminase activity testified to an excessive load on the liver. Urine pH was considerably deviated towards the acidic side and inorganic phosphorus was present in urine in a greater concentration. The pH of rumen liquor was slightly shifted towards alkalinity owing to the release of NH3 from urea in the food ration. The diagnosis--suspect chronical metabolic acidosis--was determined on the basis of the first examination. Chronical metabolic acidosis was definitely proved by the second examination when urea had been excluded from the feed ration. Repeated examinations revealed chronical metabolic acidosis which had originally been accompanied by a higher rumen liquor pH. On the basis of case histories and mechanisms of chronical acidosis, measures were proposed, resulting in an increase of the butterfat content of milk. Chronical metabolic disorders often follow a long-lasting latent pattern, manifesting themselves as a reduced milk yield and lower resistance; the clinical form of disease appears only at a later stage. The system of preventive diagnostics provides information on the changes in the composition of internal medium and of the faeces before a drop occurs in milk and fat production. These measures prevent metabolic disorders and high losses of produce which otherwise remain hidden for a long time.     

奶牛亚急性瘤胃酸中毒的发生与危害

亚急性瘤胃酸中毒（SARA）是一个大多数牛场普遍存在的奶牛代谢性疾病。围产期、干物质采食量（DMI）过高、日粮配制差及采食模式变化过大等奶牛均易发生亚急性瘤胃酸中毒,继而造成干物质采食量下降、纤维素消化率降低、乳成分改变及引发腹泻等疾病。本文对奶牛亚急性瘤胃酸中毒的病因及危害等方面进行了简述。     

亚急性瘤胃酸中毒耐受性不同的奶牛瘤胃上皮形态及功能差异研究

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...     

瘤胃保护性蛋氨酸对奶牛的营养作用

瘤胃保护性蛋氨酸(RPMet)经过瘤胃后在小肠转化为蛋氨酸(Met),可增加进入小肠的Met数量,改善小肠氨基酸平衡,提高血清中必需氨基酸浓度、奶牛氮的利用率及其生产性能等.本文综述了RPMet对奶牛的营养作用.     

瘤胃微生物在奶牛乳脂肪合成中的调节作用研究进展

乳脂肪不仅是牛乳的主要成分之一,同时乳脂肪含量也是评价牛乳质量的重要指标.乳脂肪的合成涉及到日粮营养物质通过奶牛机体转化为乳营养成分的复杂生物学过程,受日粮配方、遗传背景、生理状态、瘤胃微生物等多方面的影响.瘤胃微生物可以通过自身合成的酶类对日粮进行降解,进而对乳脂肪合成前体物质的生成和利用起到一定的调节作用,乳脂肪前...     

The fate of glycerol entering the rumen of dairy cows and sheep

This study investigated the fate of glycerol entering the rumen, in particular whether glycerol could be absorbed across the rumen epithelium. Three non‐lactating rumen‐fistulated cows were used to calculate the overall disappearance rate of glycerol in vivo and evaluate the rate of ruminal glycerol absorption. Rumen epithelial tissues isolated from sheep were used to characterise glycerol transport properties. The rate of rumen microbial degradation of glycerol was then studied in an in vitro system under anaerobic and thermo‐regulated conditions. The results showed that glycerol can be absorbed from the rumen in significant amounts. The fractional rate of absorption of glycerol was not affected by variations in glycerol concentration in the buffer solution in the in vivo study. The glycerol absorption apparently occurred largely by passive diffusion and was probably not facilitated by carriers. Glycerol also disappeared via microbial digestion and outflow from the rumen through the omasal orifice.