M. Fürll

Increasing intravenous infusions of glucose improve body condition but not lactation performance in midlactation dairy cows

The present study was intended to test whether intravenously applied glucose would elicit dose effects on lactation performance similar to those observed after gastrointestinal glucose application. Six midlactation cows received intravenous glucose infusions (GI), increasing by 1.25% of the calculated net energy for lactation (NE(L)) requirement per day, whereas control cows received volume-equivalent saline infusions (SI). Measurements and samples were taken at surplus glucose dose levels of 0, 10, 20, and 30% of the NE(L) requirement, respectively. Body weight and backfat thickness increased linearly with increasing glucose dose for cows on GI compared with SI. No differences were observed in daily feed intake, milk energy output, and energy-corrected milk yield between treatments. However, milk protein percentage and yield increased linearly with the dose of glucose infused in the GI group. Although milk lactose was not affected by treatment during the infusion period, milk lactose percentage and yield decreased for GI, but not SI, once infusions ceased. Based on 5 diurnal blood samples, daily mean and maximum concentrations of plasma glucose and serum insulin showed linear increases with increasing GI, whereas their daily minimum concentrations were unaffected. At GI of 30% of the NE(L) requirement, marked hyperglycemia and hyperinsulinemia were observed at 1600 h (i.e., 1 h postprandially), coinciding with glucosuria. The revised quantitative insulin-sensitivity check index indicated linear development of insulin resistance for the GI treatment but no such change in SI cows. Glucose infusion decreased daily mean and maximum serum beta-hydroxybutyrate and daily minimum nonesterified fatty acid concentrations relative to SI, whereas serum urea nitrogen was only numerically decreased by GI. No changes were observed in the serum activities of gamma-glutamyl transferase and aspartate transaminase and in the serum concentrations of bilirubin and macrominerals. However, serum phosphorus concentration increased after withdrawal of GI, but not SI. Only in GI cows did glycogen content increase or tend to increase linearly in the liver and skeletal muscle. In conclusion, midlactation dairy cows on an energy-balanced diet directed intravenously infused glucose predominantly to body fat reserves rather than increasing lactation performance. This may suggest that the metabolic fate of glucose is modified by metabolic signals, hormonal signals, or both from the portal-drained viscera when absorbed from the intestine.

Effect of several doses of zeolite A on feed intake, energy metabolism and on mineral metabolism in dairy cows around calving.

The object of the present study was to determine the influence of different zeolite A doses on dry matter intake (DMI) and mineral metabolism, and to evaluate an optimum dosage for preventing hypocalcaemia. Eighty pregnant dry cows were assigned to four groups (I-IV). They were fed a total mixed ration (TMR) ad libitum. Groups II, III and IV received an average daily dose of 12, 23 and 43 g zeolite A/kg DM for the last 2 weeks prepartum. Individually DMI was recorded daily. Blood and urine samples were taken before, during and after zeolite A supplementation. Serum was analysed for Ca, Mg, P(i), K, non-esterified fatty acids and beta-hydroxybutyrate (BHB). Urine was analysed for Ca, Mg, P(i), K and net acid-base excretion (NABE). After calving, milk yield (fat corrected milk) and milk composition were determined. During zeolite A supplementation, mean DMI of Group IV (7.3 +/- 1.3 kg/cow/day) was significantly lower compared to Groups I-III (10.1, 10.9, 9.5 kg/cow/day). The reduced feed intake of Group IV resulted in significantly increased BHB as well as decreased NABE after calving. Zeolite A supplementation in higher doses (III and IV) had a stabilizing effect on Ca metabolism around calving for older cows, whereas cows in Groups I and II showed a subclinical hypocalcaemia. The mean serum Mg concentration decreased significantly in older cows in Group IV at calving. The mean P(i) concentration in cows of Group IV decreased into ranges of hypophosphataemia already 1 week after beginning of zeolite A feeding. The mean DMI postpartum as well as the milk yield was not affected by zeolite A supplementation. Feeding of 23 g zeolite A/kg DM TMR prepartum proved to be an adequate dosage for reducing subclinical hypocalcaemia frequency without significant effects on feed intake and P(i) concentration in serum.

Expression and activity of key hepatic gluconeogenesis enzymes in response to increasing intravenous infusions of glucose in dairy cows

The present study aimed at investigating whether increasing concentrations of glucose supply have a depressive effect on the mRNA abundance and activity of key gluconeogenic enzymes in dairy cows. Twelve Holstein-Friesian dairy cows in mid-lactation were intravenously infused with saline (SI; n = 6) or a 40% glucose solution (GI; n = 6). For GI cows, the infusion dose increased by 1.25%/d relative to the initial NE(l) requirement until a maximum dose equating to surplus 30% NE(l) was reached on d 24. Cows receiving SI received an equivalent volume of 0.9% saline solution. Blood samples were taken every 2 d, and liver biopsies were collected every 8 d. A treatment x quadratic dose interaction (P < 0.01) was observed for the concentration of plasma glucose and serum insulin. The interactions were due to positive quadratic responses of the concentrations of glucose and insulin for GI cows, whereas the concentrations of glucose and insulin did not change over time for SI cows. The concentration of beta-hydroxybutyric acid (BHBA) and serum urea nitrogen (BUN) responded in a treatment x quadratic dose manner, such that greater decreases (P < 0.01) in BHBA and BUN concentrations were observed for cows receiving GI than SI as the dosage increased. Serum NEFA concentration tended to follow a similar pattern as serum BHBA and BUN; however, the interaction was not significant (P = 0.07). The mRNA abundance of gluconeogenesis enzymes followed a linear treatment x dose interaction (P < 0.05) for only pyruvate carboxylase (PC), which was paralleled by a trend for a linear treatment x dose interaction (P = 0.13) for PC enzyme activity. The least PC expression and activity were observed at the largest glucose dosage. The activity, but not mRNA abundance, of fructose 1,6-bisphosphatase (FBPase) showed treatment x quadratic dose interactions (P < 0.05) with decreasing activity at increasing glucose dose. Activities and expression of phosphoenolpyruvate carboxykinase and glucose 6-phosphatase were not affected (P > 0.25) by treatment. In conclusion, hepatic gluconeogenic enzymes are only moderately affected by slowly increasing glucose supply, including a translational or posttranslational downregulation of FBPase activity and a decrease in the mRNA abundance of PC with possible consequences for PC enzyme activity.

Effect of preoperative administration of erythromycin or flunixin meglumine on postoperative abomasal emptying rate in dairy cows undergoing surgical correction of left displacement of the abomasum.

OBJECTIVE To determine whether preoperative administration of erythromycin or flunixin meglumine altered postoperative abomasal emptying rate, rumen contraction rate, or milk production in dairy cattle undergoing surgical correction of left displacement of the abomasum (LDA). DESIGN Nonrandomized, controlled clinical trial. ANIMALS 45 lactating Holstein-Friesian cows with LDA. PROCEDURES Cows were alternately assigned to an erythromycin (10 mg/kg [4.5 mg/lb], IM), flunixin (2.2 mg/kg [1.0 mg/lb], IV), or control group (n = 15/group). Treatments were administered once 1 hour before surgical correction of LDA. D-Xylose solution (50%; 0.5 g/kg [0.23 g/lb]) was injected into the abomasal lumen during surgery, and venous blood samples were periodically obtained to determine time to maximum serum D-xylose concentration. RESULTS Abomasal emptying rate was significantly faster in cows treated with erythromycin (mean +/- SD time to maximum serum D-xylose concentration, 149 +/- 48 minutes) than in control cows (277 +/- 95 minutes) but was not significantly different between cows treated with flunixin (230 +/- 49 minutes) and control cows. Cows treated with erythromycin had significantly greater milk production, relative to production before surgery, on postoperative days 1 and 2 than did control cows. Cows in the erythromycin and flunixin groups had a significantly higher rumen contraction rate on the first postoperative day than did control cows. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that preoperative administration of a single dose of erythromycin increased abomasal emptying rate, rumen contraction rate, and milk production in the immediate postoperative period in cows undergoing surgical correction of LDA.

Prevalence of Endotoxemia in Healthy Postparturient Dairy Cows and Cows with Abomasal Volvulus or Left Displaced Abomasum

Left displaced abomasum (LDA) and abomasal volvulus (AV) occur most commonly in postparturient dairy cows. Our main hypothesis was that endotoxemia occurred more frequently in the peripheral blood of cows with LDA or AV than in healthy cows because increased luminal pressure in AV or LDA, or the presence of a hemorrhagic strangulating obstruction in AV, may have injured the abomasal mucosa, thereby facilitating translocation of luminal endotoxin into the circulation. Therefore, our main objective was to compare the prevalence and magnitude of endotoxemia in healthy postparturient cows with the prevalence and magnitude of endotoxemia in cows with AV and LDA. We examined 60 adult dairy cows in early lactation that were diagnosed with AV (n = 15) or LDA (n = 15) or were healthy on physical examination (control group, n = 30). Jugular venous blood was obtained from cows in all 3 groups, and right gastroepiploic venous blood was obtained during surgical correction of AV and LDA immediately after repositioning of the abomasum. Platelet-rich plasma endotoxin concentrations were measured with a chromogenic limulus amoebocyte lysate assay. Endotoxin was detected in jugular vein plasma in 50% (15/30) of control cows; however, the prevalence of endotoxemia was significantly lower (P < .05) in cows with AV (7%, 1/15) or LDA (20%, 3/15). Endotoxin was detected simultaneously in right gastroepiploic and jugular vein plasma in only 1 cow with LDA and 0 cows with AV. Contrary to our hypothesis, we conclude that endotoxemia is infrequently present in postparturient dairy cows with AV or LDA.

Effect of multiple intravenous injections of butaphosphan and cyanocobalamin on the metabolism of periparturient dairy cows

Abstract Numerous adjunct therapeutic agents have been investigated for the treatment or control of fat mobilization syndrome in periparturient dairy cows. The aim of this study was to determine the effects of multiple i.v. injections of 10% butaphosphan and 0.005% cyanocobalamin combination (Catosal, Bayer Animal Health, Leverkusen, Germany) between 1 and 2 wk antepartum (a.p.) on the metabolism and health of dairy cows. Forty-five late-gestation Holstein-Friesian cows (second pregnancy) were allocated randomly to 1 of 3 groups with 15 cows/group: group C6 (6 daily i.v. injections of butaphosphan at 10mg/kg of body weight (BW) and cyanocobalamin at 5μg/kg of BW in the last 2 wk of gestation); group C3 (3 daily i.v. injections of butaphosphan at 10mg/kg of BW and cyanocobalamin at 5μg/kg of BW in the last week of gestation); and group C0 (equivolume daily i.v. injections of 0.9% NaCl solution). Serum biochemical analysis was performed on jugular venous blood samples that were periodically obtained a.p. and postpartum (p.p.). Health status and milk production were monitored p.p. Serum cyanocobalamin concentration increased in groups C6 and C3 p.p. Multiple daily i.v. injections of Catosal before parturition increased p.p. glucose availability, as evaluated by p.p. serum glucose concentration, and decreased peripheral fat mobilization and ketone body formation, as evaluated by p.p. serum nonesterified fatty acid and β-OH butyrate concentrations. The number of puerperal infections in the first 5 d after calving was decreased in group C6, relative to group C0. We conclude that multiple injections of Catosal during the close-up period have a beneficial effect on the metabolism of periparturient dairy cows. Our results are consistent with the hypothesis that high-producing dairy cows in early lactation may have a relative or actual deficiency of cyanocobalamin.

Biochemical constituents of peritoneal fluid in cows

Samples of peritoneal fluid and jugular venous blood were taken simultaneously from 95 clinically healthy Holstein-Friesian cows. The concentrations of total protein, albumin, glucose, cholesterol, fibrinogen, L-lactate and D-dimer, the activities of lactate dehydrogenase (LDH), alkaline phosphatase and creatine kinase, and the white blood cell count were determined in the samples. Lights criteria, the serum-ascites albumin gradient (SAAG) and the ratios of the concentration of each parameter in peritoneal fluid to its concentration in blood were calculated. The mean concentrations of total protein, albumin and D-dimer, the activity of LDH and the SAAG were different from the reference values for monogastric animals and human beings.

Use of the d-Xylose Absorption Test to Measure Abomasal Emptying Rate in Healthy Lactating Holstein-Friesian Cows and in Cows with Left Displaced Abomasum or Abomasal Volvulus

We determined the abomasal emptying rates of Holstein-Friesian cows at different stages of lactation, with left displaced abomasum (LDA), or immediately after surgical correction of LDA or abomasal volvulus (AV). D-xylose (0.5 g/kg body weight [BW], 50% solution) was injected into the abomasum in healthy cows (group 1, 4-7 days in milk [DIM], n = 7; group 2, 90-120 DIM, n = 7; group 3, > 300 DIM, n = 7) and in cows with LDA (n = 10; group 4). D-xylose was injected into the abomasum during right flank laparotomy in cows with LDA (n = 22; group 5) and cows with AV (n = 15; group 6). The time to maximal serum D-xylose concentration was used as an index of emptying rate. The abomasal emptying rates for cows in groups 1, 2, and 3 were similar, whereas emptying was slower in cows with LDA and in cows after surgical correction of LDA or AV. The abomasal emptying rate of cows with LDA was slowed to a greater extent immediately after surgery, when compared to the rate obtained before surgery. There was no difference in abomasal emptying rate immediately after surgical correction between cows with LDA or AV. The results indicate that the increased incidence of LDA in the first month of lactation is not associated with an intrinsic decrease in abomasal emptying rate in healthy cows. Our findings also demonstrate that surgical correction further slows the emptying rate in cows with LDA.

Diagnostic accuracy of d-dimer and other peritoneal fluid analysis measurements in dairy cows with peritonitis.

BACKGROUND Peritoneal fluid analysis in cattle traditionally includes the classic parameters despite the fact that they have only moderate diagnostic accuracy and often fail to identify the pathogenesis or etiological factors. Therefore additional parameters recently have been established to improve diagnostic precision. In a recent study, reference ranges for several of these parameters have been proposed in dairy cows. HYPOTHESIS/OBJECTIVES The aim of this observational study was to assess the diagnostic value of D-Dimer and other measurements of peritoneal fluid analysis in dairy cows with peritonitis. ANIMALS The study included 110 Holstein-Friesian cows grouped into cows with peritonitis (n = 47) and cows without peritonitis (n = 63). METHODS Peritoneal fluid was obtained by abdominocentesis. Total protein, albumin, glucose, cholesterol, fibrinogen, l-lactate, D-Dimer, lactate dehydrogenase (LDH), alkaline phosphatase, creatine phosphokinase, white blood cell, and red blood cell were determined in peritoneal fluid and venous blood. Serum-ascites albumin gradient (SAAG) and ratios of peritoneal fluid-venous blood were calculated. Sensitivity (SN) and specificity (SP) were calculated and receiver operating characteristic curve analysis performed. RESULTS Peritoneal fluid D-Dimer was most accurate in diagnosing peritonitis in cows (SN and SP>95.0%). Total protein concentration, LDH and LDH ratio, and SAAG had sensitivities between 49.0 and 67.1%, and specificities between 88.4 and 95.5%. A low-peritoneal fluid glucose concentration was found to be highly indicative of septic peritonitis. CONCLUSIONS AND CLINICAL IMPORTANCE Measurement of the recently introduced parameters may increase the diagnostic value of peritoneal fluid analysis and provide additional specific information. Therefore these measurements should be included in the routine procedure.

Einfluss von Zeolith A auf die Futteraufnahme von trockenstehenden Milchkühen, auf den Mengen- und Spurenelementstoffwechsel im peripartalen Zeitraum sowie auf die Milchleistung in der folgenden Laktation

The object of the present study was to determine the influence of zeolite A, a calcium binder from the group of the aluminosilicate, on feed intake, macro and trace element metabolism as well as the milk yield in the following lactation in dairy cows. 46 cows were allotted to 2 groups (A-control group and B-experimental group). They were fed a total mixed ration (TMR) ad libitum 2 weeks before calving. Additionally the cows in group B received 90 g zeolite A/kg dry matter (DM). The individually feed intake was registered daily. The serum was analysed for Ca, Mg, and P-i (inorganic phosphate), Fe, FFA (free fatty acid) and ss-HB (hydroxybutyrate) and the plasma for the trace elements Cu, Zn, and Mn. After calving the milk yield (FCM) and the milk composition (fat, protein, lactose and urea) were analysed. Feed intake of group B, amounting to 6,2 1,3 kg DM/d was around 48% lower as compared to 12,0 1,4 kg DM/d for group A. The zeolite addition into the TMR showed a stabilizing effect on the average Ca concentration in the serum around calving. This effect led to a significantly lower Mg concentration on the day of calving and 1 day post partum. The Pi concentration was significantly lower already after the 1(st) week of zeolite supplementation and on the day of calving as compared to group A. There was no essential effect of zeolite A on the trace element concentration. The depression of feed intake for group B led to a significant increase of FFA one week after beginning zeolite supplementation and of ss-HB around calving. The feed intake post partum as well as the milk yield were not affected by zeolite supplementation. Because decreased feed intake of group B after zeolite supplementation and the occurred hypophosphatemia, it is not acceptable to use zeolite A in the proved dose for preventing milk fever