Clinical Chemistry Investigations in Recumbent and Healthy German Holstein Cows After the Fifth Day in Milk.

INTRODUCTION: Recumbency is a frequent symptom occurring throughout lactation. Its cause can be related to the energy or mineral metabolism, or to trauma or infectious diseases. We compared various clinical chemistry parameters between healthy and recumbent cows and between cows with different causes of recumbency and determined if hypocalcaemia manifests in later lactation. MATERIAL AND METHODS: Recumbent (n = 32) and healthy (n = 32) German Holstein cows were studied. After clinical examination, a serum sample was taken to measure the concentrations of Mg, Ca, Fe, Na, K, Pi, ß-hydroxybutyrate, total bilirubin, non-esterified fatty acids (NEFA), urea, and creatinine as well as activities of alkaline phosphatase, aspartate aminotransferase (AST), creatine kinase (CK), and γ-glutamyl transferase in recumbent cows > 5 d in milk and control cows matched for age, lactation number, and pregnancy stage. RESULTS: In recumbent cows, mean serum concentrations of NEFA, bilirubin, and CK were statistically higher, while those of Fe, K, and Pi were significantly lower. Parameters compared between different recumbency diagnoses showed some descriptive Fe, K, urea, and AST differences, but these were not statistically significant. CONCLUSION: The results show that only a limited number of parameters have diagnostic besides therapeutic value. Although of minor importance in our study, hypocalcaemia should be considered a cause of recumbency, even outside the typical risk period of parturient paresis.

Claw disorders in dairy cattle - an unexpected association between energy metabolism and sole haemorrhages.

The present study investigated whether changes of energy metabolism post-partum (pp) are associated with claw health. For this purpose, back-fat-thickness (BFT) was measured and blood samples were taken from 146 cows at four examination times. The serum levels of free fatty acids (FFA), ß-hydroxybutyrate (BHB) and glucose were measured. Furthermore, in the first week postpartum (pp) and at 8 weeks pp, a claw trimming was done and the presence and extent of sole haemorrhages (SH) was recorded. Animals with high BFT at calving and therefore high fat mobilisation and whose FFA and BHB levels in the first week pp exceeded the reference values had fewer pathological changes of the claws than thinner animals whose FFA and BHB levels stayed within reference ranges. The body condition before calving, represented in this study by BFT, plays an important role in non-infectious claw disorders. Poorer body condition was found to be associated with the SH that develop in the first 2 months of lactation.

[Testing for BTV, BVDV and BHV-1 in blood samples of new world camelids kept in middle Germany]. / Untersuchungen von Blutproben im mitteldeutschen Raum gehaltener Neuweltkameliden auf BTV-, BVDV- und BHV-1.

The susceptibility of camelids for infectious agents which may result in severe economic losses or which are strictly regulated for epidemiological reasons in farm animals potentially causes a mutual risk of transmission. This study aimed to investigate the presence of antibodies against bovine herpesvirus 1 (BHV-1), bluetongue virus (BTV) and bovine viral diarrhoea virus (BVDV) as well as the presence of pestivirus antigen in new world camelids in Central Germany. Therefore 107 serum samples from 93 alpacas and lamas from this region which had been obtained from 2007 to 2009 were examined using ELISA, serum neutralisation test, RT-PCR and a pestivirus specific gene probe. All sample were negative for BHV-1 antibodies. Antibodies against BVDV-1 could be detected in four animals, titres reaching from 1:64 to > 1:256. One animal was positive for BTV antibodies in the year 2008. This animal had been tested negative for BTV antibodies in 2007. It can be concluded that up to now, these viruses seem to be of minor importance as pathogens in new world camelids in Central Germany. Therefore the risk of infection originating from new world camelids for production animals could be considered to be rather low in this region at the moment. However, it must be taken into consideration that these animals due to lack of antibodies are fully susceptible in case of occurrence of one of these viruses. For maintenance and improvement of the present status, general hygienic precautions should be applied; direct and indirect contact between animals from different herds must be avoided and virological diagnostic and quarantine should be required trading these animals.

Application of strong ion difference theory to urine and the relationship between urine pH and net acid excretion in cattle.

OBJECTIVE: To develop an equation expressing urine pH in terms of independent variables, derive an equation relating urine pH to net acid excretion (NAE), and apply this new knowledge to determine the role that monitoring urine pH should play when diets with low cationanion difference are fed to dairy cattle. ANIMALS: 11 Holstein-Friesian cows. PROCEDURES: A physicochemical strong ion approach was used to develop a general electroneutrality equation for urine that involved urine pH and strong ion difference (SID [difference between strong cation and strong anion concentrations]), PCO(2), the concentration of ammonium ([NH(4)(+)]) and phosphate ([PO(4)]), and 3 constants. The general electroneutrality equation was simplified for use in bovine urine and applied to 321 data points from 11 cows fed different diets. RESULTS: Urine pH was dependent on 4 independent variables (urine SID, [NH(4)(+)], PCO(2), and [PO(4)]) and 3 constants. The simplified electroneutrality equation for bovine urine was pH approximately {pK(1)' - log(10)(S PCO(2))} + log(10)([K(+)] + [Na(+)] + [Mg(2+)] + [Ca(2+)] + [NH(4)(+)] - [Cl(-)] - [SO(4)(2-)]). The relationship between urine pH and NAE (in mEq/L) for cattle fed different diets was pH = 6.12 + log(10)(-NAE + [NH(4)(+)] + 2.6). CONCLUSIONS AND CLINICAL RELEVANCE: A change in urine SID, [NH(4)(+)], PCO(2), or [PO(4)] independently and directly led to a change in urine pH. Urinary [K(+)] had the greatest effect on urine pH in cattle, with high urine [K(+)] resulting in alkaline urine and low urine [K(+)] resulting in acidic urine. Urine pH provided an accurate assessment of NAE in cattle when pH was > 6.3.

Percutaneous intragastric catheter (PIC) for administration of an unpalatable substance to large animals.

We studied an easy and reliable technique for administration of an unpalatable substance to large animals. There were three groups of pigs: group I (n = 6) received 1 g ethanol/kg body weight per day orally with water for 24 days, group II (n = 6) received 2 g ethanol/kg orally with water for 24 days and 4 g ethanol/kg via percutaneous intragastric catheter (PIC) for the next 24 days, group III (n = 6) received 6 g ethanol/kg via PIC for 72 days. The catheter was placed after insufflation of the stomach using an orogastric tube. PIC was successfully placed in each pig. No complications occurred during placement. The total amount of the administrated dose was assimilated each time. PIC is a safe, effective, well tolerated, and precise method of administering ethanol that is inexpensive and easy to perform. Ethanol administration via PIC is a convenient and effective mean of exposing animals to high levels of alcohol on a long-term basis.

Effect of zeolite A on rumen fermentation and phosphorus metabolism in dairy cows.

The aim of the present study was to determine the effect of zeolite A on several physiological parameters and on mineral metabolism in the rumino-intestinal-tract of cows. Eight double fistulated (rumen and proximal duodenum) cows were fed maize silage, grass silage and concentrate. Zeolite A was added to the ration over a period of three weeks at 0, 10 and 20 g/kg dry matter (DM). The daily feed amounts were adjusted to the current performance and varied between 3.9 and 15.5 kg/d. Rumen fluid, duodenal chyme and faeces were sampled to characterise the nutrient digestibility. Blood samples were taken to analyse the concentration of inorganic phosphate. Zeolite A supplementation led to a significantly reduced ruminal DM digestibility and fermentation of organic matter. The molar proportion of acetate in the rumen increased, and propionate as well as valerate decreased significantly after zeolite A supplementation. The concentration of the total fatty acids and ruminal pH were not affected. No effect on faecal digestion of DM, organic matter nor on calcium and magnesium digestion was observed. Otherwise the phosphorus (P) concentration in rumen fluid correlated negatively with the mean zeolite A intake (r (2) = 0.75; p = 0.0003). Further, the faecal excretion of P increased significantly for cows with the highest zeolite A dosage (36.9 g P/d) compared to the control group (29.9 g P/d). The lower digestibility of P resulted in a significantly decreased concentration of inorganic P in serum from a basal value of 2.05-1.16 mmol/l six days after starting zeolite A supplementation. The zeolite A treated cows showed a significantly higher Al concentration already in rumen fluid (14.31 and 13.84 mmol/l) compared to the control cows (6.33 mmol/l). The Al flow in the duodenum was also higher for zeolite A treated cows.

[Investigations on the antioxidative metabolism during the periparturient period in dairy goats with special regard to seasonal differences in feeding and management]. / Untersuchungen zum antioxidativen Stoffwechsel bei Milchziegen im peri- partalen Zeitraum unter Berücksichtigung jahreszeitlich assoziierter Veränderungen in Fütterung und Management.

In a herd of 1400 dairy goats with an average milk yield of 840 kg/year, 40 "Weisse Deutsche Edelziegen" (October-January: n = 19; April-July: n = 21) were examined. Venous blood samples were collected 6-8, 3-4 and < 2 weeks (wks) ante partum (a. p.) and 2-4 days (d), 3-4 and 6-8 wks post partum (p. p.). Antioxidative Capacity of Water soluble substances (ACW) and Trolox Equivalent Antioxidative Capacity (TEAC) were measured in serum; activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) were measured in an erythrocyte pellet and in whole blood. ACW and TEAC increased significantly 3-4 wks p. p. In summer these two parameters showed significantly higher concentrations than in winter. The SOD had a significantly higher activitiy < 2 wks a. p. and 6-8 wks p. p. GPX-activity showed a constant increase from the beginning of investigations and from 3-4 wks p. p. up to the end of investigations activities were significantly higher than 6-8 wks a. p. The samples ante partum and the first sample taken post partum showed significantly higher activities in summer than in winter. The present study shows, that the metabolic challenge associated to the periparturient period in combination with changing capacity of food intake, influences the antioxidative metabolism in dairy goats. Seasonal depending changes on feeding quality and climate (barn temperature, quality of feeding components) also influence this system.

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.

[Influence of zeolite A supplementation during the dry period of dairy cows on feed intake, on the macro and trace element metabolism around calving and milk yield in the following lactation]. / 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 Pi (inorganic phosphate), Fe, FFA (free fatty acid) and beta-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 1st 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 beta-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.

Effect of preoperative erythromycin or dexamethasone/vitamin C on postoperative abomasal emptying rate in dairy cows undergoing surgical correction of abomasal volvulus.

OBJECTIVE: To determine the effects of preoperative erythromycin or combined dexamethasone/vitamin C treatment on postoperative abomasal emptying rate in cows undergoing surgical correction of abomasal volvulus (AV). STUDY DESIGN: Prospective, controlled, clinical study using a convenience sample. ANIMALS: Lactating Holstein-Friesian cows (n=45) with AV were alternately assigned to 3 groups (n=15): group C: untreated (control); group E: erythromycin (10 mg/kg intramuscularly [IM]); group D: dexamethasone (0.02 mg/kg intravenously [IV]) and vitamin C (10 mg/kg IV). METHODS: Drugs were administered 1 hour before surgical correction of AV. D-xylose solution (50%, 0.5 g/kg body weight) was injected into the abomasal lumen during surgery. Jugular venous blood samples for determination of serum d-xylose concentration were periodically obtained. Time to maximal serum D-xylose concentration (T(max-model)) was pharmacokinetically determined. RESULTS: Abomasal emptying rate was significantly (P<0.05) faster in group E (T(max-model)=182+/-69 min; mean+/-SD) than in group C cows (T(max-model)=237+/-64 min). Abomasal emptying rate was similar in group D (T(max-model)=196+/-47 min) and group C. Both treatments improved postoperative milk yield within 1 day after surgery. CONCLUSION: Preoperative injection of erythromycin (10 mg/kg IM) is an effective method for ameliorating postoperative abomasal hypomotility in cows with AV. CLINICAL RELEVANCE: Parenteral erythromycin can be recommended for preoperative treatment of cows with AV.

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.

[Effects of glucocorticoids on parameters of lipid metabolism, hepatic metabolism, haematological parameters and milk yield in high-yielding cows in early lactation]. / Glucocorticoideinflüsse auf Parameter des Fett- und Leberstoffwechsels, auf hämatologische Parameter sowie auf die Milchleistung bei Hochleistungskühen in der Frühlaktation.

Effects of glucocorticoids on lipid metabolism, hepatic metabolism, haematological parameters and milk yield in high-yielding cows in the early stages of lactation. The assumption is widespread that glucocorticoids promote lipolysis and fatty liver in ruminants. But there are contrary experimental results. Therefore we investigated the effects of dexamethasone (in the form of Voren suspension) in cows with very high milk yields (herd average 10.000 kg/year) between 7 and 15 days post partum, when high levels of lipolysis occur. Nine cows were given Voren 7 and 11 days post partum at doses of 0.02 mg/kg body weight. Glucose and insulin concentrations rose whilst FFA concentrations fell. Hepatic lipid levels were unchanged compared to a control group (n=8). There were also no changes in the various liver function parameters tested (beta-hydroxybutyrate, bilirubin, cholesterol, albumin, aspartat-amino-transferase, glutamat-dehydrogenase), which suggests that liver damage did not occur. Each of the two doses of Voren resulted in typical glucocorticoid-related changes in the differential leukocyte count. There was only a very slight reduction in daily milk yield. This studies show that, in ruminants, glucocorticoids have an indirect antilipolytic effect in vivo and do not aggravate or accelerate fatty degeneration of the liver.

[Effects of a single dose of dexamethasone-21-isonicotinate on the phagocytosis performance of neutrophilic granulocytes and monocytes in periparturient dairy cows]. / Auswirkungen einer einmaligen Gabe von Dexamethason-21-isonicotinat auf die Phagozytoseleistung von neutrophilen Granulozyten und Monozyten bei Kühen im Frühpuerperium.

The objective of the study was to describe the effects of a short acting glucocorticoid which was administered immediately after parturition in dairy cows on haematological, immunologic and metabolic parameters. The study was performed on 104 cows, 52 cows received an intramuscular injection of 2 mg/100 kg BW dexamethasone within 12 hours after parturition. The numbers and the phagocytic activity of granulocytes and monocytes were measured on day 1 and day 3 post partum in 17 randomly chosen cows from each group. From day 1 to day 3 the percentage of phagocytic granulocytes increased in the dexamethasone group from 73.2 +/- 6.1% to 79.6 +/- 6.6% (P < 0.05); in the control group the percentage remained unchanged (74.7 +/- 6.3% and 76.2 +/- 5.8%). The cellular phagocytic activity of granulocytes did not change significantly between day 1 and 3. In both groups the phagocytic activity of monocytes also remained unchanged. The concentrations of endotoxin, haptoglobin and the anti-lipid-A-IgG-antibody-titer did not show significant differences between the groups. Between both groups differences were not observed in the clinical parameters, milk yield or in the incidence of diseases in the peripartal period. The effects of the glucocorticoid on the metabolic parameters were especially seen in bilirubin and free fatty acid concentration. The present study shows that a single injection of glucocorticoids within 12 hours after parturition did not influence the phagocytic activity of neutrophils and monocytes negatively and did not have an effect on the measured parameters of acute-phase-response. Therefore, it seems possible to benefit from the positive effects of glucocorticoids on metabolism in this critical early postpartal period in high yielding cows.

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.

Comparison of abomasal luminal gas pressure and volume and perfusion of the abomasum in dairy cows with left displaced abomasum or abomasal volvulus.

OBJECTIVE: To compare abomasal luminal gas pressure and volume and perfusion of the abomasum in dairy cows with a left displaced abomasum (LDA) or abomasal volvulus (AV). ANIMALS: 40 lactating dairy cows (25 with an LDA and 15 with an AV). PROCEDURE: Abomasal luminal gas pressure and volume and pulse oximetry values for the caudal portion of the dorsal ruminal sac and abomasal wall were measured during laparotomy. Abomasal perfusion was assessed on the basis of abomasal O2 saturation (pulse oximetry) before correction of the LDA or AV. Abomasal perfusion was also assessed after correction of the LDA or AV by measuring venous O2 saturation in the right gastroepiploic vein and calculating the abomasal oxygen-extraction ratio. RESULTS: Abomasal luminal gas pressure and volume were higher in cattle with an AV than in cattle with an LDA. Abomasal O2 saturation was lower and abomasal oxygen-extraction ratio higher in cattle with an AV, compared with values in cattle with an LDA. In cows with an AV, lactate concentration in the gastroepiploic vein was greater than that in a jugular vein, whereas no difference in lactate concentrations was detected in cows with an LDA. Abomasal luminal gas pressure was positively correlated (r, 0.51) with plasma lactate concentration in the gastroepiploic vein and negatively correlated (r, -0.32) with abomasal O2 saturation determined by use of pulse oximetry. CONCLUSIONS AND CLINICAL RELEVANCE: Abomasal perfusion decreases as luminal pressure increases in cattle with an AV or LDA.

[Concentrations of carnitine and further biochemical parameters in the blood serum of healthy dairy cows and cows with abomasal displacement (dislocatio abomasi) and puerperal disorders]. / Carnitinkonzentrationen und weitere biochemische Parameter im Blutserum von gesunden Milchkühen und Kühen mit Dislocatio abomasi sowie Puerperalstörungen.

It was the aim of this study to compare the concentrations of total (TC) and free L-carnitine (FC) in blood serum of different groups of lactating cows. The animals were allotted into three groups, a) control animals (N = 11), b) cows with abomasal displacement (AD) (N = 5) and c) cows with puerperal disorders (PD) (N = 5). TC and FC were measured with an radioenzymatic assay. Blood samples were collected from 5 to 0 d before parturition (a. p.) and from 0 to 28 d after parturition (p. p.). It was of interest to examine whether L-carnitine might be limiting under certain conditions of metabolic stress which are typical for high yielding lactating cows. Concentrations of TC and FC (mumol/l) in control cows before and after parturition were 10.0* and 8.6* and 6.0-8.9 and 3.7-4.9, respectively. The corresponding TC and FC values for cows with AD were 19.6* and 8.9* and 10.5-20.7 and 4.8-6.9, respectively. Cows with PD showed TC and FC concentrations a. p. and p. p. of 15.7* and 9.2* and 10.3-13.0 and 4.8-6.3, h other puerperal disorders PD respectively (* only one value). TC and FC concentrations in serum of normal cows were higher before than after parturition. Cows, which developed post partal puerperal disorders had a higher prepartum concentrations of TC and CE, on the other hand, serum concentrations of FC was lower. Post partum cows with metabolic disorders showed higher CE levels than control animals. Cows which developed DA had significantly higher concentrations of TC and CE in serum only on d 7 p.p. than animals with other PD. It appeared that increased fat mobilization was regularly associated with responsive increases of CE concentrations in blood serum.