Towards sustainable and humane dairy farming: A low-cost electrochemical sensor for on-site diagnosis of milk fever.

Milk fever is a metabolic disorder that predominantly affects dairy animals during the periparturient period and within four weeks of calving. Milk fever is primarily attributed to a decrease in the animal's serum Ca2+ levels. Clinical milk fever occurs when Ca2+ concentration drops below 1.5 mM (6 mg/dL). Without prompt intervention, clinical milk fever leads to noticeable physical symptoms and health complications including coma and fatality. Subclinical milk fever is characterized by Ca2+ levels between 1.5 and 2.12 mM (6-8.48 mg/dL). Approximately 50% of multiparous dairy cows suffer from subclinical milk fever during the transition to lactation. The economic impact of milk fever, both direct and indirect, is substantial, posing challenges for farmers. To address this issue, we developed a low-cost electrochemical sensor that can measure bovine serum calcium levels on-site, providing an opportunity for early detection of subclinical and clinical milk fever and early intervention. This calcium sensor is a scalable solid contact ion sensing platform that incorporates a polymeric calcium-selective membrane and ionic liquid-based reference membrane into laser-induced graphene (LIG) electrodes. Our sensing platform demonstrates a sensitivity close to the theoretical Nernstian value (29.6 mV/dec) with a limit of detection of 15.6 µM and selectivity against the species in bovine serum. Moreover, our sensor can detect Ca2+ in bovine serum with 91% recovery.

Can reticulorumen ph, temperature and cow activity registered before calving act as biomarkers of diseases after calving?

The aim of this study was to determine if reticulorumen ph, temperature and cow activity registered before calving can serve as indicators of diseases after calving.The cows were selected according to those fitting the profile of having had two or more lactations (on average 2.9±0.13 lactations), from 60 to 0 days before and the first 30 days after calving, and being clinically healthy. The clinical examination (identification of diseases after calving) was performed from 60 days before calving to 60 days after calving. Diseases after calving were diagnosed based on clinical symptoms specific to these diseases. The pH and temperature of the contents of the cow reticulorumens and cow activity were measured using specific smaX-tec boluses manufactured for animal care.We found that the highest pH and temperature before calving can serve as biomarkers of healthy cows after calving. The lowest reticulum temperature before calving can serve as an indicator of MF after calving. A positive correlation of reticulum pH and temperature before calving can serve as biomarkers of PR. Decreasing cow activity before calving can serve as an indicator of diseases after calving. For calving prognosis, temperature of the reticulorumen can be used; it decreased 6-7 days before calving.

Evaluation of infrared thermography compared to rectal temperature to identify illness in early postpartum dairy cows.

This study evaluated and compared infrared thermography (IRT) and rectal temperature (RT) as screening tests to identify sick transition dairy cows. Holstein cows (n = 72; 42 primiparous) had RT and IRT temperatures taken daily from 1 to 12 days in milk (DIM). Health examinations were performed daily to diagnose retained fetal membrane, milk fever and metritis, and blood was analyzed for ß-hydroxybutyrate at 6 and 9 DIM to diagnose ketosis. Plasma concentrations of cortisol, interleukin-6, tumor necrosis factor α and serum amyloid A at 3, 6, 9 and 12 DIM were included as additional indicators of illness. Cows were categorized as true sick if clinically diagnosed with an illness, or if at least 2 blood parameters were above the normal range. Diagnostic test performances for RT and IRT variables were determined for each variable at a test referent value that provided the highest Youden's (J) index. The best performing screening test depended on the definition of true sickness. In general, the J index for RT was 0.15-0.17 whereas the highest J index for the IRT variables was 0.22 for the mean eye temperature and 0.19 for the mean cheek temperature. Infrared thermography was at least comparable to RT and some IRT variables performed better as a screening tests than RT. Future studies into the automation of IRT for surveillance of early postpartum diseases is warranted.

Mineral profile of crossbred F 1 Holstein x Gyr dairy cows during the transition period in summer and winter / Perfil mineral de vacas F1 Holandês x Gir durante o período de transição no verão e inverno

The transition period is often a great challenge for dairy cows and mineral imbalances are frequent. With the aim to better understand the mineral profile of F1 Holstein x Gyr dairy cows and their performances under the different conditions of summer and winter, we collected blood samples to measure calcium, magnesium and phosphorus. Samplings were performed during summer and winter, on 15 and 13 pluriparous F1 Holstein x Gyr dairy cows, respectively. Blood sampling started 4 weeks prior to the expected calving date until 30 days postpartum. The mean concentrations of all three minerals had a different pattern during the transition period in each season, representing the interaction time x season. Calcium concentration was lower in winter and more animals suffered from subclinical hypocalcemia (100%) then in summer (38.46%). Magnesium concentration was also lower in winter and 46.67% of animals had hypomagnesemia, contributing for the higher hypocalcemia frequency observed in the same season. A high proportion of animals had hyperphosphatemia what can represent an environmental problem and more attention should be given to it. The high frequency of animals with subclinical hypocalcemia is alarming once that can lead to greater consequences.(AU)

O período de transição é uma fase de grandes desafios para vacas leiteiras, e desequilíbrios minerais são frequentes. O objetivo ao desenvolver este trabalho foi de entender melhor o perfil mineral de vacas leiteiras F1 Holandês x Gir e suas performances sob as diferentes condições de verão e inverno. Para isso, foram mensurados cálcio, magnésio e fósforo sanguíneo. As coletas de sangue foram realizadas durante os períodos de verão e inverno, e utilizaram-se, respectivamente, 15 e 13 vacas leiteiras pluríparas, todas F1 Holandês x Gir. As coletas de sangue começaram quatro semanas antes da data prevista do parto até 30 dias pós-parto. As concentrações médias e o padrão de variação dos três minerais foram distintos em cada estação do ano, representando a interação tempo de coleta x estação do ano. A concentração de cálcio foi menor no inverno, período em que todos os animais apresentaram hipocalcemia subclínica, enquanto no verão 38,46% apresentaram essa condição. A concentração de magnésio foi maior no verão e nenhum animal teve hipomagnesemia, enquanto no inverno 46,67% dos animais apresentaram hipomagnesemia subclínica, contribuindo para a maior frequência de hipocalcemia observada no inverno. Uma alta proporção de animais teve hiperfosfatemia, o que pode representar um problema ambiental. A alta frequência de animais com hipocalcemia subclínica é alarmante principalmente devido às consequências geradas por essa condição.(AU)

[Diagnosis, therapy and prophylactic measures of parturient paresis in dairy cattle: results of an online survey for Swiss veterinarians]. / Diagnose, Therapie und prophylaktische Massnahmen der Gebärparese beim Rind: Ergebnisse der Online-Umfrage bei Schweizer Tierärzten.

INTRODUCTION: The aim of this study was to obtain the diagnostic, therapeutic and prophylactic approach among Swiss veterinary practitioners in cows with parturient hypocalcemia. All members of the Association for Ruminant Health were contacted per e-mail. The survey was completed by 108 (28%) of 393 that were contacted. According to the questionnaire responses, the typical presentation of a parturient paresis cow is a pluriparous middle-yielding dairy cow one day post-partum in sternal recumbency with normal consciousness. The diagnosis is usually based upon the medical history. Therapy of parturient paresis consists of mixed infusions (with calcium, phosphorus, magnesium or glucose) as well as oral preparations with calcium. The veterinarians estimate that 25-50% of the cows treated for parturient paresis need more than one treatment and that one case of parturient paresis costs CHF 200-300. Prophylactic treatments are usually used for cows, which have suffered from parturient paresis in the previous lactation, elder cows (≥ 3 lactations) as well as cows with a high body condition score (> 3.25). Prophylactic measures used by the veterinarians are vitamin D3 injections and oral preparations with calcium. They recommended a special diet, for example a low calcium diet ante-partum.

INTRODUCTION: Le but de la présente enquête en ligne était de relever les méthodes de diagnostic, de traitement et de prophylaxie utilisées en pratique en matière de parésie puerpérale hypocalcémique. Tous les membres de l'Association suisse pour la santé des ruminants ont été contactés par courriel. Sur les 393 questionnaires envoyés, 108 (28%) ont été remplis complètement et exploités. L'anamnèse typique est un animal pluripare avec une production de parésie puerpérale, il est mentionné des animaux pluripares avec une production laitière moyenne, incapables de se lever un jour après le vêlage et présentant un état de conscience normal. Le diagnostic est fréquemment posé sur la base de l'anamnèse. Les vaches laitières concernées sont traitées avec des perfusions mixtes (produits à base de calcium et de phosphore, parfois avec du magnésium et du glucose) et des préparations de calcium orales. Les vétérinaires estiment que 25 à 50% des vaches nécessitent plusieurs traitements et que les coûts totaux par animal de l'ordre de CHF 200 à 300. Du point de vue prophylactique, ce sont principalement les animaux ayant déjà souffert d'une parésie lors de la lactation précédente ainsi que les vaches plus âgées (3ème lactation et plus) et celles présentant un indice de condition élevé (> 3.25) qui sont traitées. Les vétérinaires utilisent pour cette prophylaxie des injections de vitamine D3 ainsi que des préparations orales de calcium et/ou conseillent aux propriétaires une alimentation pauvre en calcium ante partum.

The monitoring, prevention, and treatment of milk fever and subclinical hypocalcemia in dairy cows.

The periparturient cow undergoes a transition from non-lactating to lactating at calving. The animal is tremendously challenged to maintain calcium homeostasis. Those that fail can develop milk fever, a clinical disorder that is life threatening to the cow and predisposes the animal to a variety of other disorders. Guidelines for monitoring the incidence of hypocalcemia and methods for treating milk fever are reviewed. The physiological factors that cause milk fever and strategies for prevention of milk fever are discussed, focusing on the effects diet cation-anion difference can have on tissue sensitivity to parathyroid hormone. Another major risk factor for milk fever is hypomagnesemia, which is observed when animals are fed inadequate amounts of magnesium, or some factor is present in the diet that prevents adequate absorption of magnesium. Moderate hypomagnesemia impairs the ability of the cow to maintain calcium homeostasis and hypocalcemia occurs.

Using activity and milk yield as predictors of fresh cow disorders.

The objective was to determine whether daily walking activity and milk yields could be used as predictors of metabolic and digestive disorders early in lactation. Data were collected from 1996 through 1999 from 1445 dairy cows in 3 Florida herds. Walking activity, milk yield, and other measures were collected from a computerized dairy management system. Mixed models analysis was used for data on cows before their first detected estrus, as identified by difference in activity. Healthy cows were defined as those without any metabolic or digestive disorder during the prebreeding stage, whereas a sick cow had an occurrence of those disorders at any time during the prebreeding stage. Metabolic disorders were ketosis, retained placenta, and milk fever. Digestive disorders included displaced abomasum, indigestion, reduced feed intake, traumatic gastritis, acidosis, and bloat. Data from cows with known cases of ketosis, left displaced abomasum, and digestive disorders were analyzed to determine changes in activity and milk yield before those specific disorders were clinically diagnosed. Although walking activity was generally lower among sick cows, cows with ketosis, left displaced abomasum, and digestive disorders had higher than average activity 8, 9, and 8 d, respectively, before each diagnosed disorder. Daily milk yields of sick cows were approximately 15 kg/d less than milk yields of healthy cows. Milk yields were lower by 6, 7, and 5 d, respectively, before diagnoses of ketosis, left displaced abomasum, and digestive disorders. Cows with ketosis, left displaced abomasum, and general digestive disorders could possibly be detected about 5 to 6 d earlier than clinical diagnoses based on changes in daily walking activity and milk yield.

Serum activities of tartrate-resistant acid phosphatase and bone specific alkaline phosphatase as indices of bone metabolism in the cow.

The correlation between the serum hydroxyproline concentration and serum activity levels of TRAP and BALP was examined in 41 cows. The correlated coefficient (r) was 0.6391 for TRAP and 0.3147 for BALP, respectively. Judging from the significant correlation to the serum hydroxyproline concentration, serum TRAP activity is an index for bone metabolism in cows. Serum TRAP activity was therefore measured in 205 healthy cows (2-9 years old) in order to observe the changes in bone resorption with aging and milk production. TRAP levels differed slightly between group A (< or =4 yrs) and B (5 yrs< or =) at the same stage of lactation. The activity levels rose slightly at the height of lactation stage and during the dry stage.

Milk fever and subclinical hypocalcaemia--an evaluation of parameters on incidence risk, diagnosis, risk factors and biological effects as input for a decision support system for disease control.

The present review analyses the documentation on incidence, diagnosis, risk factors and effects of milk fever and subclinical hypocalcaemia. It is hereby evaluated whether the existing documentation seems sufficient for further modelling in a decision support system for selection of a control strategy. Several studies have been carried out revealing an incidence of milk fever most often in the level of 5-10%. Few studies indicate that the incidence of subclinical hypocalcaemia is several times higher than milk fever. The diagnosis based on clinical or laboratory methods or based on presence of risk factors is outlined. The clinical symptoms of milk fever are highly specific and the disease level may thus be determined from recording of treatments. Diagnosis of subclinical hypocalcaemia needs to include laboratory examinations or it may be determined by multiplying the incidence of milk fever by a certain factor. From the documentation on risk factors, it is very complex to predict the incidence from the exposure level of the risk factors. Due to uncertainty, sensitivity analyses over a wide range of values for each parameter are needed. The documentation of cow characteristics, nutrition, environment and management as risk factors are described. Among cow characteristics, parity or age, body condition and production level were found to be important. Risk factors associated with nutrition included most importantly dietary cation-anion difference and calcium level whereas the importance of general feeding related factors like type of feed stuff and feeding level were less clear. Environment and management included season, climate, housing, pasturing, exercise, length of dry period and prepartum milking. Several of the parameters on environment and management were confounded among each other and therefore firm conclusions on the importance were difficult. The documentation of the effect of milk fever includes the downer cows, reproductive disorders, occurrence of other diseases and the effect on milk production, body weight and culling. The reproductive disorders included most importantly dystocia, uterine prolapse, retained placenta, metritis and repeat breeding, and occurrence of other diseases included ketosis, displaced abomasum and mastitis. The documentation was substantial and often quantifiable within certain limits. Overall it is concluded that the present documentation on milk fever concerning incidence, diagnosis, risk factors and effects seems sufficient for a systematic inclusion in a decision support system. A model on milk fever should take into consideration the variation in biological data and individual herd characteristics. The inclusion of subclinical hypocalcaemia would be more uncertain and probably should await further documentation on possibilities of determining the herd level incidence and also the effect of this condition on production.

Concentrations of apolipoprotein C-III in healthy cows during the peripartum period and cows with milk fever.

Apolipoprotein (apo) C-III is a low-molecular-mass protein mainly distributed in the high-density lipoprotein fraction in cattle serum. We have recently shown that the apoC-III concentration is decreased in cows with fatty liver, ketosis, left displacement of the abomasum, retained placenta and milk fever. The decrease was most distinct in milk fever, thereby suggesting that apoC-III is particularly relevant to the development of milk fever and also that apoC-III is a candidate diagnostic marker for this disease. The purpose of the present study was to examine whether the apoC-III concentration in healthy cows is altered during the peripartum period, to assess the usefulness of apoC-III as a marker for milk fever. ApoC-III concentrations in 17 cows were monitored during the peripartum period (-48 to +12 days from parturition). Of the 17 cows, 14 were apparently healthy during the period. The apoC-III concentrations in the 14 healthy cows were unaltered during the period from -48 to -21 days, but thereafter showed individual variations. Compared with values during the period from -48 to -21 days, the apoC-III concentration was increased (137%) in 5 cows during the period from +1 to +12 days, whereas it decreased (60.7%) in 9 cows. Three cows suffered from milk fever at -3 to +10 days. Decreased apoC-III concentrations in diseased cows (15 to 37% of controls) were more distinct than in the 9 healthy cows. The apoC-III concentration was correlated with lecithin:cholesterol acyltransferase activity in cows with milk fever, but not in healthy cows. Correlation analysis also indicated that apoC-III and apoB-100 concentrations were negatively correlated in 5 healthy cows with increased apoC-III concentrations, but positively in 9 healthy cows with decreased concentrations and cows with milk fever. Determination of the apoC-III concentration during the peripartum period is suggested to be helpful in diagnosing milk fever. The possible relevance of apoC-III and apoB-100 in the development of milk fever is also implied.

[Determination of bone markers in dairy cows with parturient paresis]. / Bestimmung von Knochenmarkern bei Milchkühen mit Gebärparese.

The collagen metabolites hydroxyproline (HYP), deoxypyridinoline (DPD) and pyridinoline (PYD) are suitable markers for bone resorption in humans and several animal species. In a field trial cows with symptoms of periparturient paresis (group A) and healthy control cows without symptoms (group B) were compared and urine and blood samples were collected on day 1, 2, 3, 4, 5, 9 and 14 after parturition. In group A the mean +/- SE serum Ca concentration on day 1 was 1.4 +/- 0.1 mmol/l whereas those of group B were 2.0 +/- 0.1 mmol/l. A significant increase of the corrected urinary HYP concentration was observed from parturition to day 14 (from 2.8 to 8.8 mumol/mmol creatinine) and the concentrations at the different times were higher in group A than in group B. The mean corrected total and free DPD and total PYD concentration in urine increased after parturition to reach a peak at day 9. For DPD and PYD the mean concentrations between the two groups did not differ significantly. The DPD and PYD are useful tools to follow bone resorption in dairy cows, although in our study no difference between the two groups could be found which means that both groups were able to mobilize Ca from bone.

Aspectos clínicos, epidemiológicos e terapêuticos da hipocalcemia de vacas leiteiras / Hipocalcemia in a Brazilian dairy cattle herd: some epidemiological, clinical and therapeutical considerations

No decorrer de 1987 e 1988 acompanhou-se o aparecimento de casos clínicos de hipocalcemia, durante o puerpério, em vacas leiteiras da raça Holandesa ou mestiças Gir-Holando, de uma propriedade do Vale do Paraíba, Estado de Säo Paulo. A incidência de hipocalcemia foi de 4,25 por cento. Näo se observou influência do grupo genético e da época do ano (seca ou chuva) no aparecimento da afecçäo. Quanto maior a ordem de lactaçäo maior a incidência de hipocalcemia, näo ocorrendo a enfermidade em vacas com menos de três lactaçöes. A hipocalcemia foi mais frequente no decorrer do primeiro dia pós-parto, 64,10 por cento, que no segundo 30,80 por cento, e após, 5,10 por cento. A maioria dos casos, 84,10 por cento, foi detectada em animais que apresentavam o segundo estádio clínico da afecçäo (depressäo, paralisia flácida etc.), mais do que no terceiro (comatose, depressäo da consciência etc) ou no primeiro (tetanias, hiperexcitabilidade etc) estádios. Todas as vacas acometidas foram tratadas com doses crescentes de cálcio injetável, num máximo de nove gramas, até a recuperaçäo do animal. Quanto maior a dose de cálcio empregada maior o sucesso acumulado no tratamento. O exame laboratorial do soro sanguíneo revelou que vacas com afecçäo apresentaram hipocalcemia, hipofosfatemia e hipermagnesemia quando comparadas com vacas parturientes hígidas

Bovine haptoglobin response in clinically defined field conditions.

In order to assess the usefulness of haptoglobin as a measure of the acute phase response in cattle, the concentration of serum haptoglobin was estimated in the non-infectious conditions of milk fever and ketosis, and in the infectious conditions of severe mastitis, acute severe metritis, retained placenta and chronic endometritis. Mean haptoglobin concentrations were normal in cattle with non-infectious conditions and chronic endometritis but significantly increased in cattle with infectious conditions.

Definition of a non-alert downer cow syndrome and some case histories.

The clinical, blood biochemical and autopsy findings on a cow affected by a 'non-alert downer cow syndrome' are described in detail and compared with brief clinical and biochemical details from six similar cases attended elsewhere. The significance of the biochemical observations is discussed in relation to the observations from many other clinical milk fever cases in a dairy practice in Victoria. This syndrome developed in 1.9 per cent of 584 cases of milk fever. The essential findings in the syndrome were that all cows had an initial clinical episode suggestive of milk fever but showed an unsatisfactory clinical response to calcium borogluconate therapy. After a day or two all cows became laterally recumbent, some exhibited expiratory moaning and all developed mucoid faeces which, in many cases contained spots of blood. All cases had significantly lower erythrocyte and plasma potassium concentrations than those in milk fever cases which responded to treatment.

Fat cow syndrome in a British dairy herd.

The fat cow syndrome developed over a two year period in a 100 cow dairy herd following overfeeding in late lactation and the dry period. It was characterised clinically by a high incidence of parturient paresis and chronic unresponsive ketosis in early lactation. The reproductive performance of the herd was poor throughout this period, with extended calving indices confirming a suggested link between fatty liver and infertility.

Hypocalcaemia and Q-oTc interval in cows with parturient paresis.

The degree of hypocalcaemia was determined from serum total, and serum ionized calcium concentrations in 27 cows with parturient paresis. Electrocardiographic recordings were made just before the start of the intravenous calcium treatment. The T-oTc interval was determined, but could only be adequately measured in 16 cases because of inherent difficulties in recording from paretic animals. No significant correlation was found between the degree of hypocalcaemia and Q-oTc interval, whether the hypocalcemia was determined from serum total or serum ionized calcium concentrations. This study indicated that measurement of the Q-oTc interval was of very little value as a clinical test for detection of hypocalcaemia and indication of the degree of hypocalcaemia in parturient paresis.

[Follow-up studies on the behavior of mineral metabolic parameters with particular reference to the degree of skeletal minearlization in the milch cow in the period 4 weeks ante- to 16 weeks postpartum]. / Verlaufsuntersuchungen zum Verhalten einiger Parameter des Minearlstoffwechsels unter besonderer Berücksichtigung des mineralisationsgrades des Skeletts der Milchkuh im Zeitbereich 4 wochen ante bis 16 Wochen post partum.

The following parameters were tested in clinically intact dairy cows and those afflicted with parturitional paresis, over a period from four weeks before to 16 weeks after parturition: calcium, inorganic phosphate (PA), magnesium, alkaline phosphatase (AP), glucose, total protein, mineral mass/fat-free dry matter (A/FFT), mineral mass/volume of fresh skeletal bioptate (A/V). Literature data regarding the behaviour patterns of Ca, PA, Mg, AP, and glucose were confirmed. The dynamics of physiological mineral catabolism and mineral anabolism were expressed by the A/V changes more clearly than they had been reflected in A/FFT. The criterion A/V should be included as a function of age in the spectrum of parameters of metabolic monitoring.