Haematological and biochemical findings in cattle with dilatation and torsion of the caecum

A biochemical examination was made of the blood and rumen fluid of 111 heifers and cows suffering from caecal dilatation, with or without torsion. Haematological values were normal in the majority of cattle. Concentrations of chloride were normal in the rumen fluid of 83 per cent of the animals and higher in the remainder. Nine cows that had to be slaughtered had higher bile concentrations than those which recovered. Twenty-eight per cent had increased blood urea concentrations probably due to dehydration.     

Strangulation of the duodenum by the uterus during late pregnancy in two cows.

Two Swiss Braunvieh cows in late pregnancy underwent surgery because of a rare form of ileus due to strangulation of the duodenum at its caudal flexure by the gravid uterus. The whole uterus had passed through a gap between the mesoduodenum and duodenum and with increasing weight had led to strangulation of the duodenum. This was possible since the mesoduodenum and both walls of the greater omentum adjacent to its caudal edge were not connected with the duodenum, probably due to a congenital inhibitory malformation. A transsection and an end-to-end anastomosis of the duodenum were necessary in both cases since it was impossible to retract the gravid uterus through the defect. Postoperative recovering was uneventful in both cows, which were discharged after seven and five days respectively and calved normally about two months later. Copyright Harcourt Publishers Ltd.     

甘露寡糖对围产期奶牛瘤胃微生物区系的影响

试验旨在研究饲粮中添加不同水平的甘露寡糖(MOS)对荷斯坦奶牛围产后期瘤胃微生物区系的影响.选取60头荷斯坦奶牛,随机分4组,每组15头.对照组饲喂基础饲粮,低、中、高剂量组分别在基础饲粮基础上添加5、10、15 g/(头·d)MOS.结果 显示,随着MOS添加量的增加,奶牛产后21 d瘤胃液中微生物蛋白含量、总挥发性...     

保护性赖氨酸对荷斯坦牛挥发性脂肪酸及菌体蛋白的影响

本试验选用3头装有永久性瘤胃瘘管和十二指肠瘘管的荷斯坦牛,分4个阶段,分别饲喂日粮Ⅰ(基础日粮+保护性赖氨酸Ⅰ30g/d)、日粮Ⅱ(基础日粮+保护性赖氨酸Ⅱ30g/d)、日粮Ⅲ(基础日粮+保护性赖氨酸Ⅲ30g/d)和日粮Ⅳ(基础日粮),研究以不同比例棕榈油脂肪粉包被的赖氨酸对瘤胃液挥发性脂肪酸和菌体蛋白的影响。结果表明,添加瘤胃保护性赖氨酸对瘤胃液挥发性脂肪酸和菌体蛋白均无明显影响(P>0.05)。瘤胃保护性氨基酸没有改变瘤胃内环境,不影响瘤胃微生物的生长和菌体蛋白的合成。     

Effects of Fusarium toxin-contaminated wheat grain on nutrient turnover, microbial protein synthesis and metabolism of deoxynivalenol and zearalenone in the rumen of dairy cows

The aim of the present study was to examine the effects of feeding Fusarium toxin-contaminated wheat to dairy cows on nutrient utilization in the rumen and on duodenal flow of deoxynivalenol (DON), zearalenone (ZON) and their metabolites. Six dairy cows fitted with a large rumen cannula and a simple T-shaped cannula at the proximal duodenum was used in two experiments. The experiments included a control period in which the uncontaminated control wheat was fed and a period in which the control wheat was replaced by the Fusarium toxin-contaminated wheat (8.05 and 7.15 mg DON/kg and 0.26 and 0.1 mg ZON/kg in Expts 1 and 2 respectively). The wheat portion of the daily ration amounted to 50% on a dry matter (DM) basis and rations were completed with hay or grass silage. Five of the six cows were non-lactating and the total daily DM-intake ranged between 4 and 12 kg. The pH-values and the concentration of volatile fatty acids in ruminal fluid were not significantly influenced by feeding the contaminated wheat. In contrast, the postprandial ammonia concentration was consistently higher when the mycotoxin-contaminated wheat was fed. Moreover, the flow of microbial protein and utilizable protein at the duodenum were reduced at the same time. The concentrations of DON and ZON and of their metabolites in freeze-dried duodenal digesta were either not detectable or negligible during the control periods whereas distinct concentrations were measured during the periods where the contaminated wheat was fed. DON was nearly completely metabolized to de-epoxy-DON and the flow at the duodenum ranged between 4% and 28% of DON-intake. The ZON metabolites alpha-zearalenol (ZOL) and beta-ZOL were recovered at the duodenum beside the parent toxin ZON. Their recovery as a percentage of ZON-intake ranged between 43% and 132%. In conclusion, feeding of Fusarium toxin-contaminated wheat altered the ruminal protein utilization. The question of whether this effect was a result of the mycotoxin being present in the rumen or of Fusarium growth-related structural (cell wall) changes of the wheat grain needs to be clarified. The low recovery of DON at the duodenum would indicate either a nearly complete degradation of the molecule in the rumen or an absorption by the mucosa of the rumen, whereas the higher ZON recovery would suggest a lower degradation of the parent toxin in the rumen and/or recovery of some bile-originating entero-hepatic cycling ZON/metabolites.     

Effects of fumaric acid on rumen fermentation,milk composition and metabolic parameters in lactating cows

The aim of this study was to determine the influence of fumaric acid (FA) on ruminal fermentation and its effects on the acid‐base balance of seven ruminally and duodenally fistulated multiparous German Holstein cows. The experiment was conducted in a change‐over design with three periods in which the animals were randomly arranged in one of three treatments: Control (C; without FA), 300 or 600 g FA per day. The diets consisted of 7.4 kg DM grass silage, 4.2 kg concentrate mixture and 0, 300 or 600 g FA or wheat starch as isocaloric compensation per day and cow. FA supplementation decreased the rumen pH, acetic acid and butyric acid and increased propionic acid in rumen fluid. The results of the single‐strand conformation polymorphism analysis (SSCP) did not show an influence of FA on the microbial population in the rumen. The beta‐hydroxybutyrate (BHB) concentration in blood and the pH of the urine decreased, while the blood gases were unaffected by supplementation of the acid. The microbial protein per MJ ME decreased in the duodenum with FA supplementation. The milk fat concentration decreased after addition of FA. We conclude that in this study feeding of up to 600 g FA per day did not result in an acidosis. It seems that up to 600 g FA per day did not have a significant influence on the acid‐base balance of dairy cows.     

Effect of cereal straw and alfalfa hay diet on amino acid profile of gastrointestinal digesta in lactating dairy cows

This study was conducted to evaluate the effects of replacing alfalfa hay with rice straw (RS) or corn stover (CS) on amino acid (AA) profiles of gastrointestinal digesta in lactating cows. Eighteen lactating dairy cows were randomly assigned to one of three groups (n = 6) and fed identical concentrate and corn silage with different forages on dry matter basis: (i) 23% alfalfa hay and 7% Chinese wild rye hay (AH); (ii) 30% CS; and (iii) 30% RS. After the 14‐week feeding, a total of 18 cows were slaughtered to collect digesta from four representative organs, including rumen, omasum, duodenum and jejunum. The AA profiles of ruminal microbial fraction were similar among the treatments, except for greater Arg in cows fed RS than in cows fed AH or CS. Most of the analysed AA changed under different diets. Significant differences were found among the microbial fraction, rumen fluid and rumen digesta, with greater essential AA in digesta than in microbial fraction or rumen fluid and greater essential AA in microbial fraction than rumen fluid. Significant differences in individual AA profiles of digesta and relevant fluid were found across the four representative digestive tract parts, including rumen, omasum, duodenum and jejunum, showing much lower Leu proportion in CS and RS than in AH in duodenal fluid. In summary, ruminal microbes may prefer using essential AA, rather than non‐essential AA. The AA profile of ruminal microbes was constant except for Arg. The AA composition of digesta across the four digestive tracts changed dramatically, which indicated differences in the ability and efficiency of AA absorption. The lower duodenum absorbable Leu proportion in cows fed CS or RS indicated the shortage of Leu in CS or RS diets, which might also restrict the balanced AA absorption.     

Diurnal and individual variations in bile acids in the plasma of normal dairy cows

Blood samples were collected every 2 h during a 24 h period from 6 cows of one herd and 10 cows of another herd. In a third herd 9 cows were sampled every 2 h from 6 a.m. to 8 p.m. Concentrations of total bile acids, acetoacetate, glucose and free fatty acids were determined in blood plasma. A marked difference in individual bile acid concentrations and patterns of diurnal variation was found. For most cows the highest bile acid values were observed between 2 and 6 a.m. (overall mean (+/- SD) at 6 a.m.: 104 +/- 84 mumol/l, range: 20-307 mumol/l). Fourteen cows with a bile acid value greater than 90 mumol/l at 6 a.m. ("high BA") were characterized as a group by showing a pronounced decrease in the mean bile acid concentration after morning feeding. In the group of 11 cows with a 6 a.m. bile acid value less than 90 mumol/l ("low BA") the time of day did not contribute significantly to the bile acid variation. For the "high BA" group a nearly synchronous variation between the mean values of the 3 feeding dependent parameters (acetoacetate, glucose and free fatty acids) and the mean values of bile acids was found. The within animal coefficients of correlation between bile acids and the feeding dependent parameters were significantly higher in the "high BA" group than in the "low BA" group. No direct connection was found between bile acid levels and the quantity of concentrates fed or the individual milk yield.     

归芪益母复方制剂对产后奶牛瘤胃微生物和短链脂肪酸的调节

本试验旨在探究归芪益母复方制剂对产后奶牛瘤胃微生物和短链脂肪酸的调节作用。将19头待产的健康荷斯坦奶牛随机分为两组,对照组10头,试验组9头。试验组奶牛产后每天灌服归芪益母复方制剂500 mL,对照组奶牛每天灌服等体积饮用水,连续6 d。产后第7天晨饲前采集瘤胃液,采用16S rRNA高通量测序和GC-MS/MS靶向代谢组学技术对两组奶牛瘤胃菌群的丰度和短链脂肪酸的含量进行了测定。结果表明,与对照组相比,试验组奶牛瘤胃变形菌门(Proteobacteria)、Escherichia-Shigella属和拟杆菌属(Bacteroides)的菌群丰度极显著升高(P<0.01),乳杆菌属(Lactobacillus)和Subdoligranulum属菌群丰度显著升高(P<0.05)。试验组奶牛瘤胃丙酸(P<0.05)和异丁酸(P<0.01)含量明显升高。本研究从瘤胃微生物菌群及短链脂肪酸角度揭示了归芪益母方对产后奶牛的保健机制。     

奶牛分娩前后瘤胃代谢物变化规律及其代谢通路研究

本试验旨在阐明奶牛分娩前后瘤胃代谢物及其代谢通路的变化规律。选取10头体况和胎次相近的健康待产荷斯坦奶牛,分别于分娩前后晨饲前采集瘤胃液,采用UPLC-MS/MS代谢组学技术和MetaboAnanlyst 5.0中的通路分析方法研究奶牛分娩前后瘤胃发酵产物及其代谢通路的变化规律。结果表明,奶牛分娩后瘤胃中57种代谢物含量较分娩前发生了明显变化,其中34种代谢物含量显著降低,23种代谢物含量显著升高,9个代谢通路（牛磺酸和亚牛磺酸代谢、精氨酸和脯氨酸代谢、精氨酸的生物合成、D-谷氨酰胺和D-谷氨酸代谢、淀粉和蔗糖代谢、半乳糖代谢、丙氨酸、天冬氨酸和谷氨酸代谢、嘌呤代谢和维生素B₆代谢）发生了显著变化。本研究表明,奶牛在分娩前7~10 d与氨基酸、糖、核苷酸和维生素相关的瘤胃微生物菌群组成发生了应答性改变。     

Effect of defaunation and refaunation of the rumen on rumen fermentation and N-flow in the duodenum of sheep

In order to confirm earlier fragmentary results, the effect of defaunation and refaunation of the rumen on the fermentation pattern and flow of N-components in the proximal duodenum of two sheep was investigated. Defaunation had no effect on acetic acid as a proportion of the total volatile fatty acids in the rumen, while the proportions of propionic acid increased with a concomitant decrease in butyrate. Refaunation resulted in lower acetic acid and higher butyric acid proportions. The concentration of ammonia N in the rumen was clearly decreased after defaunation, already indicating an effect of the elimination of protozoa on nitrogen metabolism in the rumen. Defaunation also increased significantly the flow of total N, non ammonia N and individual and total amino acids in the proximal duodenum. Defaunation resulted in higher bacterial growth efficiency, significantly in one sheep, but the decrease after refaunation was statistically significant for both sheep. Determination of rumen digestibility of organic matter and acid detergent fibre (ADF) revealed lower values in the absence of the protozoa, while total digestibility was only influenced to a much lower extent. This indicated a shift of digestion from rumen to the lower digestive tract. Finally, earlier work is discussed in the light of the present findings.     

Serum Bile Acid Concentrations in Dairy Cattle With Hepatic Lipidosis

This study was designed to evaluate serum bile acid measurements as indicatory, of liver function and/or hepatic fat infiltration in dairy cattle. Serum bile acid concentrations were measured in healthy dairy cattle at different stages of lactation after fasting or feeding. Bile acid concentrations were compared with liver fat content and sulfobromophthalein (BSP) half-life (T 1/2). Serum bile acid concentrations were higher in cows in early lactation and with higher daily milk production. Compared with prefasting values, bile acid concentrations were decreased at 8,14, and 24 hours of fasting. Blood samples from fed cows at 1 - to 2-hour intervals had wide and inconsistent variations in bile acid concentration. Because serum bile acids correlated well with BSP T 1/2, it is suggested that both measurements evaluate a similar aspect of liver function. Neither bile acids nor BSP T I correlated with differences in liver fat content among cows. Because of large variability in serum bile acid concentrations in fed cows and the lack of correlation of measured values with liver fat content, bile acid determinations do not appear useful for showing changes in hepatic function in fed cows with subclinical hepatic lipidosis nor serve as a screening test for this condition.     

Evaluation of ornithine carbamoyl transferase and other serum and liver-derived analytes in diagnosis of fatty liver and postsurgical outcome of left-displaced abomasum in dairy cows

OBJECTIVE: To evaluate postsurgical outcome in dairy cows with left-displaced abomasum (LDA) with regard to severity of fatty liver and assess the usefulness of preoperative determination of serum ornithine carbamoyl transferase (OCT) activity, bile acids concentration, and other variables for evaluating liver function during the postsurgical convalescence period. DESIGN: Prospective study. ANIMALS: 68 Holstein cows. PROCEDURES: Blood and liver biopsy specimens were obtained during standing LDA surgery. Liver tissue was examined histologically and classified by severity of fatty change. Serum activities of liver-derived enzymes and concentrations of total lipids, triglycerides, bile acids, glucose, beta-hydroxybutyric acid, bilirubin, and nonesterified fatty acids were determined. RESULTS: Most cows with LDA and cows with severe fatty liver were detected within the first month after calving. Postsurgical outcome was related to severity of fatty liver. All cows that died had severe fatty liver. Serum activities of OCT, aspartate aminotransferase, and glutamate dehydrogenase and serum total bilirubin concentration were sensitive indicators of fatty liver. Serum bile acids concentration was not an accurate indicator of fatty liver. CONCLUSIONS AND CLINICAL RELEVANCE: Postsurgical outcome of cows undergoing surgery to correct LDA was related to fatty liver severity. Assessment of serum activities of OCT, aspartate aminotransferase, and glutamate dehydrogenase and serum total bilirubin concentration is recommended for diagnosis of fatty liver in dairy cows with LDA, whereas determination of bile acids concentration is not. The strong correlation between OCT activity and degree of hepatocellular damage supports use of this enzyme for assessing severity of fatty liver and predicting postsurgical outcome in cows with LDA.     

Changes in the serum levels of primary bile acids in dairy cows

Serum cholic acid (SCA) and serum chenodeoxycholic acid (SCDCA) concentrations were determined in healthy dairy cows by radioimmunoassay (RIA). The levels of these two primary bile acids were correlated with the cows' reproductive status. The lowest concentrations were measured in dry cows (SCA: 7.8 +/- 3.3 mumol/l, SCDCA.: 1.5 +/- 1.0 mumol/l). In freshly calved cows SCA and SCDCA was 17.8 +/- 6.9 mumol/l and 2.3 +/- 1.0 mumol/l, respectively, while in milking cows SCA and SCDCA was 15.8 +/- 5.7 and 2.3 +/- 0.8 mumol/l, respectively. SCA concentration showed a characteristic change on the days immediately after calving: on calving day it was close to the mean SCA concentration found for dry cows, then it underwent a striking abrupt rise and reached the value typical of post-parturient cows by post-partum (PP) day 4-5. Cholic acid was found to be the major primary bile acid in the blood of dairy cows. In dry cows the SCA:SCDCA ratio is 5:1. If the serum bile acid concentration rises, the SCA:SCDCA ratio will increase further.     

An analysis of the buffer system in the rumen of dairy cattle.

A method is presented for the analysis of buffer systems in the rumen using the first derivation of titration curves. Bicarbonate and volatile fatty acids (VFA) are the main components of the buffering system in the rumen fluid of dairy cattle under widely different feeding conditions. Phosphate from saliva is of little importance as a buffer, but neutralizes acids produced in the rumen. After studying five cows during the peripartal period a spontaneous and transient increase in the concentrations of VFA and a soluble marker (PEG) as well as a drop in pH and in the bicarbonate concentrations not related to feeding was observed in two animals that were sampled several hours before parturition. The potential risk of provoking rumen disturbances upon feeding animals close to the time of parturition, when buffering capacity may be minimal, is stressed.     

Fatty Acid Metabolism in the Digestive Tract of Lactating Cows Fed Tallow in Increasing Amounts at Two Feed Levels

Abstract

Long-chain fatty acid metabolism in the digestive tract was studied in lactating cows fed at two levels of dry matter intake (L, 8.6 kg DM and H, 12.6 kg DM), with 0, 4 and 6% added tallow at low feed level (L0, L4 and L6), and 0, 2, 4 and 6% fat at high feed level (H0, H2, H4 and H6). Mean fatty acid balance from mouth to duodenum was about zero when corrected for endogenous fatty acids from bile. However, regression analysis showed a microbial synthesis of 68 g at zero fatty acid intake, and a trend which indicated declining de novo synthesis of fatty acids with increasing fat level in the diet. As a mean 68% of the unsaturated C18 fatty acids were hydrogenated in the rumen.

Fatty acid and crude fat true digestibilities decreased with increasing fat intakes owing to a decrease in stearic acid (C18:0) digestibility.     

The Influence of Tallow on Rumen Metabolism,Microbial Biomass Synthesis and Fatty Acid Composition of Bacteria and Protozoa

Abstract

Rumen metabolism, microbial biomass synthesis and microbial long chain fatty acid composition were studied in lactating cows fed at two levels of dry matter intake (L, 8.6 kg DM and H, 12.6 kg DM) with 0, 4 and 6% added tallow at the low feed level (L0, L4 and L6) and 0, 2, 4 and 6% at the high feed level (H0, H2, H4 and H6).

Fibre digestibility was not significantly affected by tallow addition. Increasing tallow level in the diet decreased the total VFA concentration, the ratio of acetic acid to propionic acid and the ammonia concentration in the rumen. Crude fat and fatty acid content in bacterial and protozoal dry matter increased with increased tallow level, especially due to an increase in fatty acids originating from the feeds. Microbial synthesis in the rumen and flow of amino acids to the duodenum was highest for medium fat intake at the high feed level.     

Effects of a pantothenic acid supplementation to different rations on ruminal fermentation, nutrient flow at the duodenum, and on blood and milk variables of dairy cows

To investigate the effects of a dietary pantothenic acid (PA) supplementation on duodenal nutrient flows, blood and milk variables and especially on duodenal PA flows and PA concentrations in blood and milk German Holstein cows, equipped with cannulas in the dorsal sac of the rumen and in the proximal duodenum were used. In the first experiment of the study two dry and six lactating cows received a diet with a forage to concentrate (F:C) ratio of 34:66 (high concentrate, HC), whereas in the second experiment a diet with a F:C ratio of 66:34 (high forage, HF) was fed to four dry and five lactating cows. The cows received both rations with or without 1 g PA/day. By supplementing PA to the HC ration, the molar percentage of acetic acid increased, whereas the concentration of total short chain fatty acids, the efficiency of microbial protein synthesis in the rumen and the serum glucose levels, decreased. With the HF ration the PA decreased the molar percentage of propionic acid and increased the amount of ruminally fermented organic matter. Furthermore, PA supplementation only increased the duodenal PA flow with the HF ration, while the serum and milk PA concentrations and milk PA yields were not affected. Based on the results of the present study, a rumen-unprotected supplementation of PA makes no sense.     

Evaluation of rumen transfaunation after surgical correction of left-sided displacement of the abomasum in cows

OBJECTIVE: To evaluate rumen transfaunation after surgical correction of left-sided displacement of the abomasum (LDA) in cows. DESIGN: Prospective clinical trial. ANIMALS: 20 multiparous cows with LDA. PROCEDURES: Cows with LDA were treated surgically (day 0). On days 0 (immediately after surgery) and 1, 10 cows each received 10 L of rumen fluid (transfaunated group) or 10 L of water (control group) via a stomach tube. Postoperative dietary dry-matter intake and milk yield of each cow were recorded daily for 5 days, beginning immediately after surgery. Blood and rumen fluid samples were collected prior to surgery and on days 1, 3, and 5 after surgery. Serum nonesterified fatty acid and beta-hydroxybutyrate concentrations were measured. Volatile fatty acid and ammonia concentrations and pH of rumen fluid were determined. Urine specimens were collected and tested for ketones at 8 AM and 4 PM. Cows with ketonuria were treated with 50% dextrose solution administered i.v. at the time ketonuria was first detected. Cows with ketonuria were treated twice daily until ketonuria resolved. RESULTS: All cows survived and completed their lactation. Daily and cumulative dry-matter intake and milk yield of cows in the transfaunated group were significantly greater than those of cows in the control group. Cows in the transfaunated group had significantly lower serum concentrations of beta-hydroxybutyrate and significantly lower acetate-to-propionate ratios in rumen fluid on day 1 after surgery, compared with cows in the control group. Cows that received transfaunate required a significantly lower total volume of dextrose administered i.v. than control cows. CONCLUSIONS AND CLINICAL RELEVANCE: Benefits of rumen transfaunation of cows after surgical correction of LDA included a lesser degree of ketonuria, greater feed intake, and higher milk yield, compared with nontransfaunated cows.     

Effect of food deprivation on various parameters of rumen juice and blood of sheep]

In order to find out how short-time denutrition changes the concentration of some substances in the rumen fluid and the blood, tests with full-grown sheep were carried out. Fodder was withheld from sheep with inserted Jarrett fistulae for 48 hours after normal feeding. After 48 hours the animals were given concentrated fodder, after 52 hours exclusively hay. From the 72nd hour onwards the animals were provided with fodder as usual. Samples of the rumen fluid and blood samples were taken at the beginning of the test, after the last normal feeding and then in the 24th, 32nd, 48th, 52nd, 56th, 72nd and 96th hour. We could find out that, during the 48-hour denutrition, the pH-value of the rumen fluid turned alkaline and the concentrations of ammonia, volatile fatty acids and lactic acid decreased. The protein metabolism underwent a rapid change in the organism. The protein content of the blood plasma decreased, above all the albumin content, as well as the concentration of glycoproteins and volatile amino acids. Among the various amino acids, the concentration of glycine increased highly, that of alanine and valine just slightly. The concentration of most amino acids decreased or--of some of them remained the same. Among the paramters that are characteristic of lipid and carbohydrate metabolism, the total content of lipids and cholesterin decreased, and so did the concentration of blood sugar, lactic acid and pyruvic acid in the blood plasma. The results indicate that short-time denutrition has a considerable influence on the rumen fermentation and the intermediary metabolism of ruminants. The quickly arising lack of energy of ruminants slows down the protein synthesis and increases the glyconeogenesis from amino acids. The tissue is supplied with energy by the mobilisation of lipids.