Abomasal infusion of essential fatty acids and conjugated linoleic acid during late pregnancy and early lactation affects immunohematological and oxidative stress markers in dairy cows.

Oxidative stress and inflammation, as natural parts of metabolic adaptations during the transition from late gestation to early lactation, are critical indicators of dairy cows' metabolic health. This study was designed to investigate the effects of abomasal infusion of essential fatty acids (EFA), particularly α-linolenic acid, and conjugated linoleic acid (CLA) on plasma, erythrocyte, and liver markers of oxidative stress in dairy cows during the transition period. Rumen-cannulated German Holstein cows (n = 38) in their second lactation (11,101 ± 1,118 kg milk/305 d, mean ± standard deviation) were abomasally infused with one of the following treatments from d -63 antepartum until d 63 postpartum (PP): CTRL (n = 9; 76 g/d coconut oil); EFA (n = 9; 78 g/d linseed plus 4 g/d safflower oil); CLA (n = 10; isomers cis-9,trans-11 and trans-10,cis-12 CLA; 38 g/d); and EFA+CLA (n = 10; 120 g/d). Hematological parameters as well as markers of oxidative status were measured in plasma, erythrocytes, and liver before and after calving. Immunohematological parameters, including erythrocyte number, hematocrit, hemoglobin, mean corpuscular hemoglobin, leukocytes, and basophils, were affected by time, and their peak levels were observed on the day after calving. The oxidative stress markers glutathione peroxidase 1 and reactive oxygen metabolites in plasma and erythrocytes were both affected by time, exhibiting the highest levels on d 1 PP, whereas ß-carotene, retinol, and tocopherol were at their lowest levels at the same time. Immunohematological parameters were only marginally affected by fatty acid treatment in a time-dependent manner. As such, lymphocyte and atypical lymphocyte counts were both significantly highest in the groups that received EFA at d 1 PP. Moreover, EFA supplementation increased the mean corpuscular volume and showed a trend for induction of mean corpuscular hemoglobin compared with the CLA group during the transition period. The PP mean thrombocyte volume was higher in the EFA than in the CLA group (except for d 28) and both EFA and CLA reduced number of thrombocytes and thrombocrit at distinct time points. Hepatic mRNA abundance of markers related to oxidative status, including glutathione peroxidase (GPX-1) and catalase (CAT), was lower (P < 0.05) in EFA-treated than non-EFA-treated cows at d 28 PP. Dairy cows at the onset of lactation were characterized by induced markers of both oxidative stress and inflammation. Supplementing EFA and CLA had minor and time-dependent effects on markers of oxidative stress in plasma, erythrocytes, and liver. A comparison of EFA supplementation with CLA or CTRL showed higher immunohematological response at d 1 PP and lower hepatic antioxidant levels by d 28 PP. Supplementation with EFA+CLA had only a minor effect on oxidative markers, which were more similar to those with the EFA treatment. Altogether, despite the time-dependent differences, the current findings show only minor effects of EFA and CLA supplementation in the prevention of early lactation-induced oxidative stress.

Aspects of transition cow metabolomics-Part I: Effects of a metaphylactic butaphosphan and cyanocobalamin treatment on the metabolome in liver, blood, and urine in cows with different liver metabotypes.

Dairy cows in modern production systems are at risk to develop metabolic disorders during the transition period. Reasons for individual differences in susceptibility, as well as the underlying pathomechanisms, are still only partially understood. The development of metaphylactic treatment protocols is needed. In this context, an on-farm prospective 3-fold blinded randomized study involving 80 German Holstein cows was performed throughout 1 yr. The trial involved a thorough recording of the production and clinical traits, clinical chemistry, and liver biopsies and blood and urine sampling at d 14 (mean: 12 d, range: 1-26 d) antepartum (AP), and d 7 (7, 4-13) and 28 (28, 23-34) postpartum (PP) for metabolomics analyses. Two groups received a treatment with butaphosphan and cyanocobalamin (BCC) at either the dosage recommended by the manufacturer or the double dosage (5 or 10 mL/100 kg of body weight 10% butaphosphan and 0.005% cyanocobalamin (Catosal, Bayer Animal Health), n = 20 in each group, parity: 4.2 ± 2.0 and 3.4 ± 1.3, respectively (mean ± SD)] and one group a placebo treatment (NaCl 0.9%, n = 40, parity: 4.0 ± 1.9). The animals were treated at 6 time points (7, 6, and 5 d AP, and 1, 2, and 3 d PP) via intravenous injection. Mass spectroscopy-based targeted metabolomics analysis of blood plasma and liver samples were performed using the AbsoluteIDQ p180 kit (Biocrates Life Sciences), whereas the urine samples were analyzed by nuclear magnetic resonance spectroscopy. Statistical analysis was performed using multivariate [partial least squares discriminant analysis (PLS-DA)] and univariate methods (linear mixed model). Multivariate data analysis (PLS-DA plots) of the liver metabolome revealed 3 different metabotypes (A = medium, B = minor, C = large alterations in liver metabolome profile between AP and PP status). Metabotype B animals were characterized by higher PP lipomobilization (stronger PP body condition decrease and higher blood bilirubin, fatty acids, gamma-glutamyltransferase, and triglyceride levels) and a higher occurrence of transition cow diseases, compared with the animals in metabotype C. Analysis of the feeding data showed that the period of metabotype B animals (calving in a distinct time frame) was characterized by a decreased grass silage quality. The PP liver metabolome of the metabotype C animals was characterized by higher concentrations of AA, acylcarnitines, lysoPC and sphingomyelins compared with metabotype B. For the metaphylactic treatment with BCC a dose-dependent effect was confirmed, differing between the metabotypes. In all matrices and metabotypes at various time points significant treatment effects were observed, with different profiles in clinical chemistry and as well in metabolomics data. The most clear-cut treatment effect was observed in metabotype B in the liver at 7 d PP, characterized by an increase in several acylcarnitines and phosphatidylcholines, indicating a more efficient influx and oxidation of fatty acids in mitochondria and thereby an increase in energy supply and more efficient triglyceride export in the liver. The results from the liver metabolomics analysis support the application of an indication-based metaphylactic treatment with BCC.

Aspects of transition cow metabolomics-Part II: Histomorphologic changes in the liver parenchyma throughout the transition period, in cows with different liver metabotypes and effects of a metaphylactic butaphosphan and cyanocobalamin treatment.

The aims of this study were to evaluate histopathologic changes during the transition period, describe the histopathological features of the metabotypes identified in Part I (Schären et al., 2021b), and investigate effects of a metaphylactic treatment with butaphosphan and cyanocobalamin (BCC) on the liver parenchyma. Eighty German Holstein cows (mean 305-d production: 10,957 kg, range: 6,480-15,193 kg; mean lactation number: 3.9, range: 2-9) from a commercial dairy farm in Saxony, Germany, were enrolled in a randomized, prospective, triple-blinded study. Two groups received a treatment with BCC (5 or 10 mL/100 kg of body weight 10% butaphosphan and 0.005% cyanocobalamin, Catosal, Bayer Animal Health, n = 20 each) and one group a placebo treatment (NaCl 0.9%, n = 40). Liver biopsy specimens were collected 14 d antepartum (AP) and 7, 28, and 42 d postpartum (PP), routinely processed for histologic examination, and stained with hematoxylin and eosin, Sudan III, periodic acid-Schiff, and picrosirius red stains. The sections were assessed for fat and glycogen content and degenerative, inflammatory, fibrotic, and proliferative changes. The statistical analysis included the effects of the sampling day, the lactation number, the treatment, and the metabotype (A = medium, B = minor, C = large alterations in the liver metabolome profile between AP and PP status). There was mild to moderate fat infiltration in the liver of 37% of cows in the last 2 wk AP, and moderate to severe fat infiltration in 66% of cows in the first days PP. The degree of fat infiltration increased from 2 wk AP until the end of the first week PP, and then decreased until the end of the study period, at which time about 25% of cows had moderate to severe fatty infiltration. Lipidosis was positively correlated with the severity of liver cell degeneration, and negatively correlated with the degree of glycogen deposits. Complete glycogen depletion of hepatocytes was not observed in cows, even in the presence of severe hepatic lipidosis. Moderate to severe lymphocytic hepatitis was seen in 39% of cows throughout the study period, and cows with lactation numbers 5 or greater had perisinusoidal fibrosis more often than younger cows. Severe fibrosis and cirrhosis of the liver did not occur. Metabotype B animals exhibited a higher chance of fatty infiltration, lower glycogen storage, and perisinusoidal fibrosis and for this metabotype positive correlations were calculated between increased fat deposition in the liver and marked glycogen depletion, and increased degenerative, inflammatory, fibrotic, and proliferative changes of hepatic tissue. For the treatment with BCC, no significant effect was observed. In summary, during the transition period, the liver of dairy cows is characterized by fat accumulation and glycogen depletion and histologic signs of hepatitis and hepatocyte degeneration. These histomorphologic changes were accentuated in animals exhibiting little alterations in their liver metabolome profile across the transition period (metabotype B) and support the assumption of a decreased grass silage quality as a causative factor.

Aspects of transition cow metabolomics-Part III: Alterations in the metabolome of liver and blood throughout the transition period in cows with different liver metabotypes.

The liver plays a central role in the postpartum (PP) energy metabolism of the transition dairy cow; however, studies describing the liver metabolome during this period were lacking. The aim of the presented study was therefore to compare the alterations in the liver and blood metabolome of transition dairy cows. For this purpose, an on-farm trial with 80 German Holstein cows (mean lactation number: 3.9; range: 2-9) was performed, with thorough documentation of clinical traits and clinical chemistry, as well as production data. Liver biopsies and blood samples were collected at d 14 (mean: 12 d, range: 1-26 d) antepartum (AP), d 7 (7, 4-13) and 28 (28, 23-34; mean, earliest-latest) PP for targeted mass spectroscopy-based metabolomics analysis using the AbsoluteIDQ p180 kit (Biocrates Life Sciences). Statistical analysis was performed using multivariate (partial least squares discriminant analysis) as well as univariate methods (linear mixed model). Multivariate data analysis of the liver metabolome revealed 3 different metabotypes (A = medium, B = minor, C = large alterations in the liver metabolome profile between AP and PP). In metabotype C, an increase of almost all acylcarnitines, lysophosphatidylcholines (lysoPC), sphingomyelins, and some phosphatidylcholines (PC, mainly at 7 d PP) was observed after calving. In contrast to metabotype C, the clinical data of the metabotype B animals indicated a higher PP lipomobilization and occurrence of transition cow diseases. The liver metabolome profile of these animals most likely mirrors a failure of adaptation to the PP state. This strong occurrence of metabotypes was much less pronounced in the blood metabolome. Additionally, differences in metabolic patterns were observed across the transition period when comparing liver and blood matrices (e.g., in different biogenic amines, acylcarnitines and sphingolipids). In summary, the blood samples at 7 d PP showed lower acylcarnitines and PC, with minor alterations and a heterogeneous pattern in AA, biogenic amines, and sphingomyelins compared with 14 d AP. In contrast to 7 d PP, the blood samples at 28 PP revealed an increase in several AA, lysoPC, PC, and sphingomyelins in comparison to the AP state, irrespective of the metabotype. In the liver biopsies metabotype B differed from metabotype C animals ante partum by following metabolites: higher α aminoadipic acid, lower AA, serotonin, taurine, and symmetric dimethylarginine levels, lower or higher concentrations of certain acylcarnitines (higher: C2, C3, C5, C4:1; lower: C12:1, C14:1-OH, C16:2), and lower lysoPC (a C16:0, C18:0, C20:3, C20:4) and hexose levels. In blood samples, fewer differences were observed, with lower serotonin, acylcarnitine C16:2, lysoPC (a C16:0, C17:0, C18:0 and C18:1), PC aa C38:0, and PC ae C42:2. The results show that the use of only the blood metabolome to assess liver metabolism may be hampered by the fact that blood profiles are influenced by the metabolism of many organs, and metabolomics analysis from liver biopsies is a more suitable method to identify distinct metabotypes. Future studies should investigate the stability and reproducibility of the metabotype and phenotypes observed, and the possible predictive value of the metabolites already differing AP between metabotype B and C.

Glucose metabolism and the somatotropic axis in dairy cows after abomasal infusion of essential fatty acids together with conjugated linoleic acid during late gestation and early lactation.

Sufficient glucose availability is crucial for exploiting the genetic potential of milk production during early lactation, and endocrine changes are mainly related to repartitioning of nutrient supplies toward the mammary gland. Long-chain fatty acids, such as essential fatty acids (EFA) and conjugated linoleic acid (CLA), have the potential to improve negative energy balance and modify endocrine changes. In the present study, the hypothesis that combined CLA and EFA treatment supports glucose metabolism around the time of calving and stimulates insulin action and the somatotropic axis in cows in an additive manner was tested. Rumen-cannulated German Holstein cows (n = 40) were investigated from wk 9 antepartum (AP) until wk 9 postpartum (PP). The cows were abomasally supplemented with coconut oil (CTRL, 76 g/d); 78 g/d of linseed and 4 g/d of safflower oil (EFA); Lutalin (CLA, isomers cis-9,trans-11 and trans-10,cis-12 CLA, each 10 g/d); or the combination of EFA+CLA. Blood samples were collected several times AP and PP to determine the concentrations of plasma metabolites and hormones related to glucose metabolism and the somatotropic axis. Liver tissue samples were collected several days AP and PP to measure glycogen concentration and the mRNA abundance of genes related to gluconeogenesis and the somatotropic axis. On d 28 AP and 21 PP, endogenous glucose production (eGP) and glucose oxidation (GOx) were measured via tracer technique. The concentration of plasma glucose was higher in CLA than in non-CLA-treated cows, and the plasma ß-hydroxybutyrate concentration was higher in EFA than in non-EFA cows on d 21 PP. The eGP increased from AP to PP with elevated eGP in EFA and decreased eGP in CLA-treated cows; GOx was lower in CLA than in CTRL on d 21 PP. The plasma insulin concentration decreased after calving in all groups and was higher in CLA than in non-CLA cows at several time points. Plasma glucagon and cortisol concentrations on d 21 PP were lower in CLA than non-CLA groups. The glucagon/insulin and glucose/insulin ratios were higher in CTRL than in CLA group during the transition period. Plasma IGF-I concentration was lower in EFA than non-EFA cows on d 42 AP and was higher during the dry period and early lactation in CLA than in non-CLA cows. The IGF binding protein (IGFBP)-3/-2 ratio in blood plasma was higher in CLA than in non-CLA cows. Hepatic glycogen concentration on d 28 PP was higher, but the mRNA abundance of PC and IGFBP2 was lower in CLA than non-CLA cows on d 1 PP. The EFA treatment decreased the mRNA abundance of IGFBP3 AP and PCK1, PCK2, G6PC, PCCA, HMGCS2, IGFBP2, and INSR at several time points PP. Results indicated elevated concentrations of plasma glucose and insulin along with the stimulation of the somatotropic axis in cows treated with CLA, whereas EFA treatment stimulated eGP but not mRNA abundance related to eGP PP. The systemic effects of the combined EFA+CLA treatment were very similar to those of CLA treatment, but the effects on hepatic gene expression partially corresponded to those of EFA treatment.

[Right upper abdominal pain, vomiting, weight loss and icterus in a 20-year-old male refugee]. / Rechtsseitiger Oberbauchschmerz, Erbrechen, Gewichtsverlust und Ikterus bei einem 20-jährigen Flüchtling.

Tuberculosis (TB) is one of the most common infectious diseases worldwide. The case of a 20-year old male refugee from Somalia, who initially presented with right-sided upper abdominal pain, vomiting, weight loss and jaundice with suspected cholecystitis is reported. In the course of further diagnostics, pyloric stenosis surprisingly appeared, which, like the cholestasis, was caused by compressing peripancreatic lymph nodes. Lymph node cytology finally showed evidence of caseating necrosis with evidence of TB pathogens.

Effects of abomasal infusion of essential fatty acids and conjugated linoleic acid on performance and fatty acid, antioxidative, and inflammatory status in dairy cows.

The objective of this study was to test the effects of essential fatty acids (EFA), particularly α-linolenic acid, and conjugated linoleic acid (CLA) supplementation on fatty acid (FA) composition, performance, and systemic and hepatic antioxidative and inflammatory responses in dairy cows. Four cows (126 ± 4 d in milk) were investigated in a 4 × 4 Latin square and were abomasally infused with 1 of the following for 6 wk: (1) coconut oil (control treatment, CTRL; 38.3 g/d; providing saturated FA), (2) linseed and safflower oil (EFA treatment; 39.1 and 1.6 g/d, respectively; providing mainly α-linolenic acid), (3) Lutalin (BASF, Ludwigshafen, Germany; CLA treatment; cis-9,trans-11 and trans-10,cis-12 CLA, 4.6 g/d each), (4) or EFA+CLA. The initial dosage was doubled every 2 wk, resulting in 3 dosages (dosage 1, 2, and 3). Cows were fed a corn silage-based total mixed ration with a high n-6/n-3 FA ratio. Dry matter intake and milk yield were recorded daily, and milk composition was measured weekly. The FA compositions of milk fat and blood plasma were analyzed at wk 0, 2, 4, and 6. The plasma concentration and hepatic mRNA abundance of parameters linked to the antioxidative and inflammatory response were analyzed at wk 0 and 6 of each treatment period. Infused FA increased in blood plasma and milk of the respective treatment groups in a dose-dependent manner. The n-6/n-3 FA ratio in milk fat was higher in CTRL and CLA than in EFA and EFA+CLA. The sum of FA

Effects of a combined essential fatty acid and conjugated linoleic acid abomasal infusion on metabolic and endocrine traits, including the somatotropic axis, in dairy cows.

The objective of this study was to test the effects of essential fatty acids (EFA), particularly α-linolenic acid (ALA), and conjugated linoleic acid (CLA) supplementation on metabolic and endocrine traits related to energy metabolism, including the somatotropic axis, in mid-lactation dairy cows. Four cows (126 ± 4 d in milk) were used in a dose-escalation study design and were abomasally infused with coconut oil (CTRL; 38.3 g/d; providing saturated fatty acids), linseed and safflower oils (EFA; 39.1 and 1.6 g/d; n-6:n-3 FA ratio = 1:3), Lutalin (CLA; cis-9,trans-11 and trans-10,cis-12 CLA, 4.6 g/d of each), or EFA and CLA (EFA+CLA) for 6 wk. The initial dosage was doubled twice after 2 wk, resulting in 3 dosages (dosages 1, 2, and 3). Each cow received each fat treatment at different times. Cows were fed with a corn silage-based total mixed ration providing a low-fat content and a high n-6:n-3 fatty acid ratio. Plasma concentrations of metabolites and hormones (insulin-like growth factor-binding proteins only on wk 0 and 6) were analyzed at wk 0, 2, 4, and 6 of each treatment period. Liver biopsies were taken before starting the trial and at wk 6 of each treatment period to measure hepatic mRNA abundance of genes linked to glucose, cholesterol and lipid metabolism, and the somatotropic axis. The changes in the milk and blood fatty acid patterns and lactation performance of these cows have already been published in a companion paper. The plasma concentration of total cholesterol increased with dosage in all groups, except CLA, reaching the highest levels in EFA+CLA and CTRL compared with CLA. The high-density lipoprotein cholesterol plasma concentration increased in CTRL and was higher than that in EFA and CLA, whereas the concentration of low-density lipoprotein cholesterol increased in a dose-dependent manner in EFA and EFA+CLA, and was higher than that in CLA. Hepatic mRNA expression of 3-hydroxy-3-methyl-glutaryl-CoA synthase 1 was upregulated in all groups but was highest in EFA+CLA. Expression of sterol regulatory element-binding factor 1 tended to be lowest due to EFA treatment, whereas expression of long chain acyl-CoA-synthetase was lower in EFA than in CTRL. Hepatic mRNA expression of GHR1A tended to be higher in EFA+CLA than in CTRL. The plasma concentration of insulin-like growth factor I increased in CLA, and the plasma IGFBP-2 concentration was lower in EFA+CLA than in CTRL at wk 6. The plasma concentration of adiponectin decreased in EFA+CLA up to dosage 2. Plasma concentrations of albumin and urea were lower in CLA than in CTRL throughout the experimental period. Supplementation with EFA and CLA affected cholesterol and lipid metabolism and their regulation differently, indicating distinct stimulation after the combined EFA and CLA treatment. The decreased IGFBP-2 plasma concentration and upregulated hepatic mRNA abundance of GHR1A in EFA+CLA-supplemented cows indicated the beneficial effect of the combined EFA and CLA treatment on the somatotropic axis in mid-lactation dairy cows. Moreover, supplementation with CLA might affect protein metabolism in dairy cows.

Changes in fatty acids in plasma and association with the inflammatory response in dairy cows abomasally infused with essential fatty acids and conjugated linoleic acid during late and early lactation.

Dairy cows are exposed to increased inflammatory processes in the transition period from late pregnancy to early lactation. Essential fatty acids (EFA) and conjugated linoleic acid (CLA) are thought to modulate the inflammatory response in dairy cows. The present study investigated the effects of a combined EFA and CLA infusion on the fatty acid (FA) status in plasma lipids, and whether changes in the FA pattern were associated with the acute phase and inflammatory response during late pregnancy and early lactation. Rumen-cannulated Holstein cows (n = 40) were assigned from wk 9 antepartum to wk 9 postpartum to 1 of 4 treatment groups. Cows were abomasally supplemented with coconut oil (CTRL, 76 g/d), linseed and safflower oil (EFA, 78 g/d of linseed oil and 4 g/d of safflower oil; ratio of oils = 19.5:1; n-6:n-3 FA ratio = 1:3), Lutalin (CLA, 38 g/d; isomers cis-9,trans-11 and trans-10,cis-12; each 10 g/d), or both (EFA+CLA). Blood samples were taken to measure changes in FA in blood plasma on d -63, -42, 1, 28, and 56, and in plasma lipid fractions (cholesterol esters, free fatty acids, phospholipids, and triglycerides) on d -42, 1, and 56 relative to calving, and in erythrocyte membrane (EM) on d 56 after calving. Traits related to the acute phase response and inflammation were measured in blood throughout the study. Liver samples were obtained for biopsy on d -63, -21, 1, 28, and 63 relative to calving to measure the mRNA abundance of genes related to the inflammatory response. The concentrations of α-linolenic acid and n-3 FA metabolites increased in lipid fractions (especially phospholipids) and EM due to EFA supplementation with higher α-linolenic acid but lower n-3 metabolite concentrations in EFA+CLA than in EFA treatment only. Concentration of linoleic acid decreased in plasma fat toward calving and increased during early lactation in all groups. Concentration of plasma arachidonic acid was lower in EFA- than in non-EFA-treated groups in lipid fractions and EM. The cis-9,trans-11 CLA increased in all lipid fractions and EM after both CLA treatments. Plasma haptoglobin was lowered by EFA treatment before calving. Plasma bilirubin was lower in EFA and CLA than in CTRL at calving. Plasma concentration of IL-1ß was higher in EFA than in CTRL and EFA+CLA at certain time points before and after calving. Plasma fibrinogen dropped faster in CLA than in EFA and EFA+CLA on d 14 postpartum. Plasma paraoxonase tended to be elevated by EFA treatment, and was higher in EFA+CLA than in CTRL on d 49. Hepatic mRNA abundance revealed time changes but no treatment effects with respect to the inflammatory response. Our data confirmed the enrichment of n-3 FA in EM by EFA treatment and the inhibition of n-3 FA desaturation by CLA treatment. The elevated n-3 FA status and reduced n-6:n-3 ratio by EFA treatment indicated a more distinct effect on the inflammatory response during the transition period than the single CLA treatment, and the combined EFA+CLA treatment caused minor additional changes on the anti-inflammatory response.

Effects of abomasal infusion of essential fatty acids together with conjugated linoleic acid in late and early lactation on performance, milk and body composition, and plasma metabolites in dairy cows.

Rations including high amounts of corn silage are currently very common in dairy production. Diets with corn silage as forage source result in a low supply of essential fatty acids, such as α-linolenic acid, and may lead to low conjugated linoleic acid (CLA) production. The present study investigated the effects of abomasal infusion of essential fatty acids, especially α-linolenic acid, and CLA in dairy cows fed a corn silage-based diet on performance, milk composition, including fatty acid (FA) pattern, and lipid metabolism from late to early lactation. Rumen-cannulated Holstein cows (n = 40) were studied from wk 9 antepartum to wk 9 postpartum and dried off 6 wk before calving. The cows were assigned to 1 of 4 treatment groups. Cows were abomasally supplemented with coconut oil (CTRL, 76 g/d), linseed and safflower oil (EFA, 78 and 4 g/d; linseed/safflower oil ratio = 19.5:1; n-6/n-3 FA ratio = 1:3), Lutalin (CLA, 38 g/d; BASF SE, Ludwigshafen, Germany; isomers cis-9,trans-11 and trans-10,cis-12 each 10 g/d) or EFA+CLA. Milk composition was analyzed weekly, and blood samples were taken several times before and after parturition to determine plasma concentrations of metabolites related to lipid metabolism. Liver samples were obtained by biopsy on d 63 and 21 antepartum and on d 1, 28, and 63 postpartum to measure triglyceride concentration. Body composition was determined after slaughter. Supplementation of CLA reduced milk fat concentration, increased body fat mass, and improved energy balance (EB) in late and early lactation, but EB was lowest during late lactation in the EFA group. Cows with CLA treatment alone showed an elevated milk citrate concentration in early lactation, whereas EFA+CLA did not reveal higher milk citrate but did have increased acetone. Milk protein was increased in late lactation but was decreased in wk 1 postpartum in CLA and EFA+CLA. Milk urea was reduced by CLA treatment during the whole period. After calving, the increase of nonesterified fatty acids in plasma was less in CLA groups; liver triglycerides were raised lowest at d 28 in CLA groups. Our data confirm an improved metabolic status with CLA but not with exclusive EFA supplementation during early lactation. Increased milk citrate concentration in CLA cows points to reduced de novo FA synthesis in the mammary gland, but milk citrate was less affected in EFA+CLA cows, indicating that EFA supplementation may influence changes in mammary gland FA metabolism achieved by CLA.

Evaluation of arterial digital blood flow in dairy cows with claw horn disruption lesions using Doppler ultrasonography.

Vascular changes play an important role in the pathogenesis of claw horn disruption lesions in cattle. The aim of the study was to measure arterial blood flow in the hind limbs of German Holstein cows with claw horn disruption lesions. A 10-MHz linear transducer was used to assess blood flow in the interdigital artery in the dorsal pastern region in the hind limbs of 11 non-lame and 33 lame German Holstein cows in which lameness was scored clinically. Qualitative and quantitative blood flow parameters were compared in affected limbs and unaffected contralateral hind limbs in lame cows and in the hind limbs of lame cows and non-lame cows. A pulsed-wave Doppler signal suitable for analysis was obtained in 78 of 88 limbs (33 affected and contralateral limbs, 22 limbs of control cows). Blood flow curve types 1 and 2 were predominant in the hind limbs of lame cows. Vessel diameter, end-diastolic velocity, and blood flow rate were significantly greater in lame cows than in non-lame cows and were numerically greater in moderately lame cows than in mildly lame cows. The differences in the qualitative and quantitative parameters between lame and non-lame cows were most likely caused by inflammation of the pododerm. The role of weight distribution between the paired hind limbs and the existence of claw horn disruption appeared to have an effect on the differences in local circulation in the affected and unaffected contralateral hind limbs in lame cows.

Evaluation of arterial digital blood flow using Doppler ultrasonography in healthy dairy cows.

BACKGROUND: Local circulatory disturbances have been implicated in the development of foot disorders in cattle. The goals of this study were to evaluate the suitability of the interdigital artery in the pastern region in both hind limbs using pulsed-wave (PW) Doppler ultrasonography and to investigate quantitative arterial blood flow variables at that site in dairy cows. An Esaote MyLabOne ultrasound machine with a 10-MHz linear transducer was used to assess blood flow in the interdigital artery in the pastern region in both hind limbs of 22 healthy German Holstein cows. The cows originated from three commercial farms and were restrained in a standing hoof trimming chute without sedation. RESULTS: A PW Doppler signal suitable for analysis was obtained in 17 of 22 cows. The blood flow profiles were categorised into four curve types, and the following quantitative variables were measured in three uniform cardiac cycles: vessel diameter, pulse rate, maximum systolic velocity, maximum diastolic velocity, end-diastolic velocity, reverse velocity, maximum time-averaged mean velocity, blood flow rate, resistance index and persistence index. The measurements did not differ among cows from the three farms. Maximum systolic velocity, vessel diameter and pulse rate did not differ but other variables differed significantly among blood flow profiles. CONCLUSIONS: Differences in weight-bearing are thought to be responsible for the normal variability of blood flow profiles in healthy cows. The scanning technique used in this report for evaluation of blood flow in the interdigital artery appears suitable for further investigations in healthy and in lame cows.

Evaluation of intravenous regional anaesthesia and four-point nerve block efficacy in the distal hind limb of dairy cows.

BACKGROUND: Intravenous regional anaesthesia (IVRA) and hindfoot four-point nerve block anaesthesia (NBA) are recommended for local anaesthesia (LA) in the distal limb of dairy cows. Two studies were conducted to compare the efficacy, time until onset and stress responses to IVRA and NBA in dairy cows. In the first cross-over designed study, eight healthy unsedated German Holstein cows, restrained in lateral recumbency (LR) on a surgical tipping table, were treated with IVRA and NBA using procaine 2% as a local anaesthetic. Distal limb desensitization was tested by electrical (e-), mechanical (m-) and thermal (t-) nociceptive stimulation 10 min before and 15 and 30 min after LA. Hormonal-metabolic (blood concentrations of cortisol, lactate, non-esterified fatty acids, and glucose) and cardio-respiratory (heart and respiratory rate, mean arterial blood pressure) stress responses to treatment were assessed at predetermined intervals. In the second study, six healthy, unsedated German Holstein cows in LR were treated (crossover design) with IVRA and NBA. Short-interval e-stimulation was measured by the time until complete distal limb desensitization. RESULTS: In the first study, four of eight cows responded to e-stimulation 15 min after IVRA, while none of the cows treated with NBA responded until the safety cut-off level was reached. E-stimulation revealed complete desensitization of the distal limb 30 min after LA in all cows. Half of the cows did not respond to m- and t-stimulation before LA, so no further evaluation was performed. Stress reactions to IVRA and NBA treatment were similar, but differences may have been masked by stress response to LR restraint. In the second study, complete desensitization was achieved 12.5 min after NBA, while one of the six cows still responded to e-stimulation 20 min after IVRA. CONCLUSION: Hindfoot nerve block anaesthesia and intravenous regional anaesthesia induced complete desensitization of the distal hind limb in dairy cows. However, the anaesthesia onset after NBA was significantly faster than that of IVRA, which may be clinically relevant in the field, particularly when distal limb anaesthesia is required for major claw surgeries under time constraints.

Analysis of behavioral changes in dairy cows associated with claw horn lesions.

Detecting lame cows is important in improving animal welfare. Automated tools are potentially useful to enable identification and monitoring of lame cows. The goals of this study were to evaluate the suitability of various physiological and behavioral parameters to automatically detect lameness in dairy cows housed in a cubicle barn. Lame cows suffering from a claw horn lesion (sole ulcer or white line disease) of one claw of the same hind limb (n=32; group L) and 10 nonlame healthy cows (group C) were included in this study. Lying and standing behavior at night by tridimensional accelerometers, weight distribution between hind limbs by the 4-scale weighing platform, feeding behavior at night by the nose band sensor, and heart activity by the Polar device (Polar Electro Oy, Kempele, Finland) were assessed. Either the entire data set or parts of the data collected over a 48-h period were used for statistical analysis, depending upon the parameter in question. The standing time at night over 12 h and the limb weight ratio (LWR) were significantly higher in group C as compared with group L, whereas the lying time at night over 12 h, the mean limb difference (△weight), and the standard deviation (SD) of the weight applied on the limb taking less weight were significantly lower in group C as compared with group L. No significant difference was noted between the groups for the parameters of heart activity and feeding behavior at night. The locomotion score of cows in group L was positively correlated with the lying time and △weight, whereas it was negatively correlated with LWR and SD. The highest sensitivity (0.97) for lameness detection was found for the parameter SD [specificity of 0.80 and an area under the curve (AUC) of 0.84]. The highest specificity (0.90) for lameness detection was present for Δweight (sensitivity=0.78; AUC=0.88) and LWR (sensitivity=0.81; AUC=0.87). The model considering the data of SD together with lying time at night was the best predictor of cows being lame, accounting for 40% of the variation in the likelihood of a cow being lame (sensitivity=0.94; specificity=0.80; AUC=0.86). In conclusion, the data derived from the 4-scale-weighing platform, either alone or combined with the lying time at night over 12 h, represent the most valuable parameters for automated identification of lame cows suffering from a claw horn lesion of one individual hind limb.

Short communication: Pilot study on hormonal, metabolic, and behavioral stress response to treatment of claw horn lesions in acutely lame dairy cows.

Short-term effects of therapeutic claw trimming in acutely lame cows (n=21) with nonadvanced claw horn lesions on the endocrine, metabolic, and behavioral stress responses were investigated in comparison to regular claw trimming in nonlame control cows (n=21). Controls were matched to lame cows by parity and stage of lactation. Lame cows suffering from typical sole ulcers or white line disease were blinded and randomly assigned to 2 treatments, receiving 15 min before interventions either ketoprofen (n=11; 3mg/kg of BW intramuscularly; Romefen, Merial, Lyon, France) or placebo (n=10; saline in equivalent amount and route of administration). All cows underwent functional claw trimming in lateral recumbency on a surgical tipping table, and claw horn lesions in lame cows were conventionally treated (removal of loose horn, block on opposing claw, bandaging of affected claw). Blood samples collected 15 min before, at the end, and 24h after claw trimming were analyzed for concentrations of cortisol, fatty acids, lactate, and glucose, and fecal samples (collected before treatment and after 24 h) for cortisol metabolites. Behavioral stress responses during functional and therapeutic claw trimming were recorded. Concentrations of blood cortisol, fatty acids, glucose, and fecal cortisol metabolites were higher in lame than in nonlame cows after treatment. During claw treatment, more leg movements were recorded for lame cows than nonlame cows. Pre-emptive administration of ketoprofen had no obvious effects on stress responses to therapeutic claw trimming. Treatments of claw horn lesions caused a significant stress and pain reaction in acutely lame cows, demonstrating the necessity of adequate pain management protocols for such interventions.

Effects of Fusarium mycotoxins in rations with different concentrate proportions on serum haptoglobin and hepatocellular integrity in lactating dairy cows.

It was hypothesized that long-term intake of a diet contaminated with deoxynivalenol (DON) and differing in the proportion of concentrate might affect hepatocellular integrity and function as well as biomarkers of systemic inflammation in lactating dairy cows. In Period 1 (11 weeks), 26 lactating German Holstein cows (13 primiparous and 13 pluriparous, 31 days in milk, 522 kg body weight, on average) were divided into two groups and fed diets (50% concentrate) with (MYC, n = 12; on average 5.3 mg DON/kg DM) or without (CON, n = 14) DON contaminations. In Period 2 (16 weeks), each group was further divided into two groups to test whether elevated concentrate proportion as additional burden might enhance the toxicity of DON. The cows in MYC60 (n = 6; 4.6 mg DON/kg DM) and CON60 (n = 7) received the diet with 60% concentrate, while cows in MYC30 (n = 6; 4.4 mg DON/kg DM) and CON30 (n = 7) received the diet with 30% concentrate. Blood samples were taken in biweekly intervals for activities of aspartate amino transferase (AST), glutamate dehydrogenase (GLDH) and gamma-glutamyl transferase as well as for concentration of total bilirubin and haptoglobin. Biopsies from liver were collected in week 27 for morphological analyses. No DON effect was found for the variables assessed in blood. The diet with 60% concentrate led to higher activities of AST and GLDH in Period 2. No morphological change was found by both light and electron microscopic analyses of liver samples. Results indicated that long-term intake of DON-contaminated diet over 27 weeks led to neither relevant damages of hepatocytes nor systemic inflammatory responses in lactating dairy cows, even if the dietary concentrate proportion was increased to 60%.

Bioavailability of quercetin from its aglycone and its glucorhamnoside rutin in lactating dairy cows after intraduodenal administration.

Because of their health-promoting properties, flavonoids are used in feed supplements for ruminants, although scientific evidence for their efficacy in vivo is limited. It has been shown recently that bioavailability of quercetin is low after ruminal administration in cows because of degradation by the ruminal microbiota. It is unknown whether quercetin could be absorbed from the small intestine in ruminants if degradation is prevented; therefore, we investigated the bioavailability of quercetin after duodenal administration in 6 German Holstein cows. On 88 ± 3 d in milk, each cow received equivalent doses of quercetin [9, 18, or 27 mg of quercetin equivalents (QE)/kg of body weight] either as quercetin aglycone (QA) or as its glucorhamnoside rutin (RU). In addition, 2 control studies with duodenal administration of NaCl solution (0.9%) were conducted per cow to examine concentrations of flavonoids in plasma during regular feeding. Blood samples were collected at defined time intervals over a period of 24h before and after administration of the test compounds. A washout period of 2d was applied between the runs to avoid possible carryover effects. Concentrations of plasma quercetin aglycone and its metabolites isorhamnetin, tamarixetin, and kaempferol were measured after treatment with glucuronidase/sulfatase by HPLC with fluorescence detection. After administration of RU, levels of plasma quercetin did not increase above baseline, irrespective of dose administered. After duodenal administration of QA, the plasma concentration of QA and its methylated metabolites clearly increased above baseline. The maximal plasma concentrations of total flavonols (about 2h after application) increased in a dose-dependent manner but showed high interindividual variability (range 368.8 to 983.3 nmol/L at 27 mg of QE/kg of body weight) but peak time did not differ. Preadministration baseline values of total flavonols were reached again 3 to 4h after QA administration. The bioavailability of quercetin and its metabolites, as measured by the area under the concentration-time curve, was affected by the quercetin source applied, whereby quercetin from RU was unavailable. Taken together, duodenal administration enhanced bioavailability of QA almost to values previously reported in pigs after oral administration of QA. In contrast to findings in monogastrics or after oral administration in cows, quercetin from RU seems to be unavailable when administered duodenally.

Influence of 4-week intraduodenal supplementation of quercetin on performance, glucose metabolism, and mRNA abundance of genes related to glucose metabolism and antioxidative status in dairy cows.

Quercetin has been shown to be a potent antioxidant, acts hepatoprotectively, and affects glucose and lipid metabolism in monogastrics. If this is also true in ruminants, quercetin could be beneficial in periparturient high-yielding dairy cows by ameliorating the negative effects of free radical formation and reducing the severity of liver lipidosis and ketosis. In a first attempt to evaluate effects of a long-term quercetin treatment, we intraduodenally administered twice daily 18 mg of quercetin (Q)/kg of body weight to 5 late-lactation (215d in milk) dairy cows over a period of 28 d. Frequent blood samples were taken before and during administration to determine plasma concentrations of flavonols and metabolites. Before and after 1 and 4 wk of Q administration, glycogen and fat content as well as mRNA expression of selected genes were measured in liver biopsies. Furthermore, euglycemic, hyperinsulinemic, and hyperglycemic clamp studies were conducted before and after 2 wk of Q administration. During the experiment, dry matter intake and most other zootechnical data remained unchanged. Milk protein content was increased in wk 2 and 4 of Q administration compared with basal values, whereas fat and lactose contents of milk remained unchanged. Plasma nonesterified fatty acids, γ-glutamyl transferase, cholesterol, glutamate dehydrogenase, triglyceride, and albumin concentrations, as well as liver fat and glycogen concentrations, were not affected by Q supplementation. Plasma glucose and ß-hydroxybutyrate concentrations in plasma decreased and increased, respectively, under the influence of quercetin. During hyperglycemic clamp conditions, the relative increase of plasma insulin was higher after 2 wk of Q administration, and a tendency for an increased rQUICKI (revised quantitative insulin sensitivity check index) was observed. The relative mRNA expression levels of selected genes related to glucose metabolism, fat metabolism, and antioxidative status were not altered after 1 or 4 wk of Q supplementation. In conclusion, the effects on insulin release and sensitivity support the assumption that administration of Q could have positive effects on the metabolic adaption of high-yielding cows to early lactation. The increase of milk protein content in response to Q supplementation needs to be verified.

Postoperative analgesic efficacy of meloxicam in lame dairy cows undergoing resection of the distal interphalangeal joint.

The objective was to evaluate the analgesic efficacy of pre- and postoperative administration of meloxicam on the postsurgical convalescence period of lame dairy cows undergoing resection of the coffin joint. In a blinded, placebo-controlled, explorative clinical trial, 19 lame German Holstein-Friesian cows weighing 536 ± 98 kg (mean ± SD) and aged 5.7 ± 2.8 yr were included. All cows suffered from unilateral lameness due to septic arthritis of the coffin joint. Lame cows were randomly allocated to either the meloxicam group (n=9) or the control group (n=10) and received an intravenous injection of meloxicam (0.5mg/kg of BW) or an equal volume of saline immediately before surgery (d 0) and once daily from d 1 to 4. All cows received a retrograde intravenous local anesthesia (20 mL of procaine 2%) before the surgical intervention. Heart rate, respiratory rate, body temperature, plasma concentrations of cortisol, as well as production parameters (milk yield and feed intake) were evaluated from d 0 to 7. The gait of the animals was assessed daily by lameness scores and by monitoring the cows' activity by means of pedometers attached to both hind legs. Possible adverse effects on abomasal mucosal integrity were monitored by fecal occult blood tests and blood cell counts from d 0 to 7 and on d 14. Under meloxicam treatment plasma cortisol levels, lameness scores, and body temperature were significantly reduced compared with controls. While being treated with meloxicam, the time cows were standing per day was significantly longer compared with controls. In the healthy limb significantly more steps were registered in meloxicam-treated cows than in controls. Feed intake and milk yield were not significantly affected by meloxicam. No group differences were found in number of positive tests for fecal occult blood or blood cell counts. In conclusion, repeated meloxicam application demonstrated effective analgesia in the postsurgical period after resection of septically infected coffin joints in dairy cows without indications of evoking adverse effects on abomasal integrity.

[Risk factors for infectious foot -disorders on two Swiss cattle -mountain pastures]. / Risikofaktoren für infektiöse Zehen­erkrankungen auf zwei Schweizer ­Rinderalpen.

INTRODUCTION: In the present study, risk groups for infectious foot disorders were identified on two large Swiss cattle mountain pastures by analyzing animal and treatment data of a total of 3256 animals of the bovine species. Both mountain pastures were part of the Federal Office for Agriculture (FOAG) consultancy project «Healthy animals, attractive herdsmen positions and less medication on large cattle mountain pastures¼. The project was launched in 2020 following the increased incidence of lameness on these mountain pastures. Bacteriological and histological analyses were to provide information as to whether the most common foot disorder was interdigital phlegmon (IP) or whether digital dermatitis also occurred. Further, the temporal distribution of cases over the mountain pasture season and the influence of mountain pasture and year were investigated and interpreted for the project years 2020 to 2022, and treatment incidences were compared between years. Multiple treatment cycles in the same individual were classified into persistent infections and new infections. Nineteen of 394 first-treated cattle were clinically examined, 12 of them were additionally sampled for bacteriological and histological analyses. All cases examined showed, both clinically and following laboratory analyses, typical characteristics for IP. In contrast, there was no specific evidence for the presence of digital dermatitis. No persistent infections occurred during treatment with benzylpenicillin. Multivariate logistic regression analyses identified > 365-730-day-old cattle (odds ratio OR 8,29), as well as inseminated (OR 5,30) and non-inseminated (OR 7,85) heifers as risk groups for the disease studied (p < 0,05). Association with the oestrus activity of non-inseminated heifers and a generally higher locomotor activity in heifers compared to cows - with a correspondingly increased risk of injury - is conceivable. Meat breeds had a reduced risk compared to dairy breeds (OR 0,29). Breed differences in behavior and/or the effectiveness of the local immune response might have an impact. Knowing about these risk groups can be put to use in the future when selecting animals to be taken to the mountain pastures and/or when planning pasture management in order to reduce the prevalence of infectious foot disorders and thereby the use of antibiotics.

INTRODUCTION: Dans la présente étude, nous avons identifié, grâce à l'analyse des données concernant les animaux et les traitements d'un total de 3256 animaux de l'espèce bovine, des groupes à risque pour les maladies infectieuses des onglons sur deux grands alpages bovins en Suisse. Les deux alpages faisaient partie du BLW-projet de conseil «Animaux sains, postes de bergers attractifs et moins de médicaments sur les grands alpages bovins¼. Le projet a débuté en 2020 suite à l'accumulation de problèmes de boiteries sur ces alpages. Des analyses bactériologiques et histologiques devaient fournir des indications afin de savoir si la maladie des onglons majoritaire était le phlegmon interdigité (PI) ou si la dermatite digitale était également présente. La répartition temporelle des cas de maladies durant la saison d'estivage et l'influence de l'alpage et de l'année pour les années de projet 2020 à 2022 ont été évaluées et interprétées, et les incidences des traitements comparées entre les années. Les cycles de traitement multiples chez le même individu ont été répartis en deux groupes: les infections persistantes et les nouvelles infections. Dix-neuf des 394 bovins primo-traités ont été évalués cliniquement. Douze de ces 19 animaux ont également été soumis à un échantillonnage bactériologique et histologique. Tous les cas étudiés présentaient, aussi bien cliniquement que suite à l'analyse technique en laboratoire, les caractéristiques typiques d'un PI. Par contre, il n'y a pas eu d'indication quant à la présence de dermatite digitale. Aucune infection persistante n'a été constatée après traitement avec de la Benzylpénicilline. Les bovins âgés > 365­730 jours (OR 8.29), ainsi que les génisses inséminées (odds ratio OR 5.30) et non inséminées (OR 7.85) ont été identifiés, suite à une analyse de régression logistique multivariée, comme faisant partie de groupes à risque pour la maladie étudiée (p < 0.05). Un lien avec l'activité en période de chaleurs des génisses non inséminées et une activité locomotrice généralement plus intensive des génisses par rapport aux vaches ­ avec par conséquent un risque accru de blessures ­ est concevable. Le risque était réduit pour les races à viande par rapport aux races laitières (OR 0.29). Des différences de comportement et/ou d'efficacité de l'immunité locale entre les races pourraient avoir une influence. Le fait de connaître ces groupes à risque pourrait être mis à profit à l'avenir lors de la sélection des animaux à monter à l'alpage et/ou lors de la planification de la gestion des prairies, afin de diminuer la prévalence des maladies infectieuses des onglons et ainsi l'utilisation d'antibiotiques.