Exploring the impact of high-energy diets on cattle: Insights into subacute rumen acidosis, insulin resistance, and hoof health.

Cattle lameness remains a significant concern, causing economic losses and compromising animal welfare. Claw horn lesions have been identified as a major cause of lameness in dairy cows, but their correlation with high-energy diets and ruminal acidosis remains unclear. Hence, the primary objective of this study was to assess the effects of a high-starch diet and a conventional diet on the rumen environment, acute-phase proteins, and metabolic alterations, with a particular focus on insulin resistance and the consequent implications for the histology of the hooves in Holstein steers. A total of 16 animals were divided into the high-starch (HS; 37% starch) and conventional (CON; 16.8% starch) groups. Glucose tolerance tests (GTT), blood analyses, rumen fluid analyses, and histological evaluations of the hoof tissue were conducted over a 102-d experimental period. The HS group showed a lower ruminal pH than the CON group, and with values indicating SARA. The plasma glucose and IGF-1 concentrations were higher in the HS group, suggesting an anabolic state. Both groups exhibited an increase in the insulin area under the curve (AUC) after the GTT on d 102. Histological analysis of the hooves showed a reduction in the length and width of the epidermal lamella in both groups. We found a significant negative correlation between the insulin AUC and the length and width of the epidermal lamella. Because both groups were similarly affected, the hypothesis that histological alterations were caused by the experimental diets still needs confirmation. Additionally, the development of SARA was not essential for the observed histological changes in the hoof. Further studies are warranted to thoroughly investigate the role of insulin and IGF-1 imbalances in claw health.

Comparison of one novel and four established diagnostic tests for insulin dysregulation in ponies.

Several tests have been advocated for diagnosis of insulin dysregulation (ID). Tests using simple sugars may not reflect the response to naturally ingested carbohydrates. This study aimed to evaluate agreement between the oral glucose test (OGT), the oral sugar test (OST), a novel oral test using a proprietary cereal (WEET), the IV combined glucose-insulin tolerance test (CGIT) and fasted basal insulin (FI) for diagnosis of ID. Each of the five tests above was performed on a group of six normal and six insulin dysregulated mixed-breed ponies in a randomised crossover study. Area under the curve (AUC) and maximum concentration of insulin from OGT, OST and WEET showed strong to very strong bivariate correlations (r = 0.85-0.94, and r = 0.87-0.92, respectively; P ≤ 0.001) and were significantly different between tests (associated with dose of carbohydrate) and between CGIT-positive and -negative ponies. Dichotomous results showed substantial agreement between OST and both WEET (κ = 0.65; P = 0.02) and OGT (κ = 0.67; P = 0.01) and between CGIT and both OST (κ = 0.63; P = 0.03) and OGT (κ = 0.67; P = 0.01), and no agreement between FI, which had low sensitivity, and all other tests (κ = 0.15 - 0.31; P > 0. 05). Palatability of WEET was variable, resulting in one pony being excluded for analysis of WEET data. Further work on development of an oral test using a more palatable feedstuff and appropriate cut-offs or diagnostic thresholds for tests of ID is warranted.

Effect of phenylbutazone on insulin secretion in horses with insulin dysregulation.

BACKGROUND: Phenylbutazone is often prescribed to manage pain caused by hyperinsulinemia-associated laminitis, but in diabetic people nonsteroidal anti-inflammatory drugs increase insulin secretion and pancreatic activity. HYPOTHESIS/OBJECTIVES: Investigate the effect of phenylbutazone administration on insulin secretion in horses. It was hypothesized that phenylbutazone will increase insulin secretion in horses with insulin dysregulation (ID). ANIMALS: Sixteen light breed horses, including 7 with ID. METHODS: Randomized cross-over study design. Horses underwent an oral glucose test (OGT) after 9 days of treatment with phenylbutazone (4.4 mg/kg IV q24h) or placebo (5 mL 0.9% saline). After a 10-day washout period, horses received the alternative treatment, and a second OGT was performed. Insulin and glucose responses were compared between groups (ID or controls) and treatments using paired t test and analyses of variance with P < .05 considered significant. RESULTS: In horses with ID, phenylbutazone treatment significantly decreased glucose concentration (P = .02), glucose area under the curve (2429 ± 501.5 vs 2847 ± 486.1 mmol/L × min, P = .02), insulin concentration (P = .03) and insulin area under the curve (17 710 ± 6676 vs 22 930 ± 8788 µIU/mL × min, P = .03) in response to an OGT. No significant effect was detected in control horses. CONCLUSION AND CLINICAL IMPORTANCE: Phenylbutazone administration in horses with ID decreases glucose and insulin concentrations in response to an OGT warranting further investigation of a therapeutic potential of phenylbutazone in the management of hyperinsulinemia-associated laminitis beyond analgesia.

Investigation of glucagon-like peptide-1 response to six oral carbohydrates in ponies.

Glucagon-like peptide-1 (GLP-1), the principal incretin in horses, may play a role in the pathophysiology of insulin dysregulation (ID). This study aimed to describe its concentration in response to three preserved forages and four dynamic tests for ID in ponies. Twelve adult ponies of mixed ID status were given a meal of hay, soaked hay or haylage, an in-feed oral glucose test (OGT), oral sugar test (OST), an oral test using a proprietary breakfast cereal (WEET) or a combined glucose-insulin tolerance test (CGIT) weekly in a randomised cross-over study. Glucose, insulin and GLP-1 concentrations were measured before and following each intervention. Ponies were designated ID or non-ID and insulin resistant (IR) or non-IR according to OGT and CGIT results, respectively. All interventions apart from the CGIT provoked a GLP-1 response within 30 min. The OGT and WEET interventions, (containing the greatest dose of non-structural carbohydrate, 1.06 and 1 g/kg BW, respectively), resulted in a greater area under the curve (AUC) for GLP-1 compared to all other interventions (P < 0.001). No difference in GLP-1 response was detected according to ID or IR status, despite there being strong positive correlations (rs [95 % CI]) between GLP-1 and insulin concentrations measured at individual time points (0.67 [0.62 - 0.71]; P < 0.001) and as AUC (0.66 [0.49-0.79], P < 0.001). These data do not support of the use of GLP-1 as an adjunctive diagnostic test for ID or IR, as defined by conventional intravenous or oral dynamic tests.

Comparación de los valores de glucosa en caninos obtenidos con glucómetros portátiles y la prueba estándar de laboratorio / Comparação dos valores de glicose em caninos obtidos com glicômetros portáteis e o teste laboratorial padrão / Comparison of glucose values in dogs obtained with portable glucometers and the standard laboratory test

La medición de glucosa en caninos es un procedimiento habitual en la clínica diaria, actualmente este valor se puede obtener mediante dispositivos portátiles y pruebas laboratoriales. Se realizó esta investigación con el fin de aportar mayor conocimiento sobre la importancia de la medición de glucosa, ya que en los últimos años ha perdido valor entre las pruebas hematológicas a considerar debido a que solo se relaciona con determinadas patologías como la diabetes u otras enfermedades metabólicas. El presente trabajo tiene como objetivo comparar los valores de glucosa en caninos obtenidos mediante un glucómetro portátil de uso humano (Accu-chek® Active, Roche Diagnostic, Mannheim, Alemania); veterinario (aLcose® Vet Glu, jjPlus Corporation, New Taipei, Taiwán) y la prueba estándar de laboratorio, esto nos indicará la fiabilidad de los resultados obtenidos mediante estos métodos. Se realizó la toma de muestras de sangre de 50 caninos clínicamente sanos, de los cuales se obtuvo el resultado de glucemia mediante estos tres métodos. Los resultados de nuestra investigación evidenciaron que las tres formas de evaluación de la glucosa sanguínea en perros brindaban resultados estadísticamente diferentes (p < 0.05). Se obtuvo valores de glucosa diferentes entre los tres métodos de medición, teniendo como promedios finales 84.14 mg/dL, 101.12 mg/dL y 91.12 mg/dL correspondientes al glucómetro portátil de uso humano, veterinario y a la prueba estándar de laboratorio respectivamente. En conclusión, los glucómetros portátiles de uso humano subestiman los valores reales de glucosa, mientras que los de uso veterinario lo sobreestiman, comparados con la prueba estándar de laboratorio.

A medição de glicose nos cães é um procedimento habitual realizado no atendimento clínico. Atualmente este valor pode ser obtido por meio de dispositivos portáteis e testes laboratoriais. Esta pesquisa foi realizada com a finalidade de destacar a importância da medição de glicose, visto que nos últimos anos esta avaliação não tem sido muito valorada entre os testes hematológicos, sendo considerada relevante apenas em relação a patologias como a diabetes e outras doenças metabólicas. O presente estudo teve como objetivo comparar os valores de glicose em cães obtidos com glicômetro portátil de uso humano; veterinário e o teste padrão de laboratório. Esta comparação poderá indicar a confiabilidade dos resultados obtidos mediante os métodos avaliados. Foi realizada a amostragem do sangue de 50 caninos clinicamente sadios os quais foram submetidos a avaliação de glicose mediante os três métodos. Os resultados de nossa investigação evidenciaram que as três formas de avaliação da glicose sanguínea têm resultados estatisticamente diferentes (p < 0,05). Os valores de glicose tiveram medias finais de 84,14 mg/dL, 101,12 mg/dL e 91,12 mg/dL para o glicômetro portátil de uso humano (Accu-chek® Active, Roche Diagnostic, Mannheim, Alemanha), veterinário (aLcose® Vet Glu, jjPlus Corporation, Nova Taipei, Taiwan) e o teste padrão de laboratório, respectivamente. Ao concluir, os glicômetros portáteis de uso humano subestimam os valores reais de glicose e os de uso veterinário os superestimam quando comparados com o teste padrão de laboratório.

The measurement of glucose in canines is a common procedure in daily clinical practice. Currently this value can be obtained by use of portable devices and laboratory tests. This research was carried out in order to provide more knowledge about the importance of glucose measurement, since in recent years it has lost value among the hematological tests to be considered because it is only related to certain pathologies such as diabetes or other metabolic diseases. The present study aimed to compare the glucose values in dogs obtained with a portable glucometer for human use, veterinarian use, and the standard laboratory test. This comparison may indicate the reliability of the results obtained through the evaluated methods. A blood sampling of 50 clinically healthy canines was taken and submitted to glucose evaluation using the three methods. Our investigation showed that the three ways of assessing blood glucose have statistically different results (p < 0.05). Glucose values had final averages of 84.14 mg/dL, 101.12 mg/dL, and 91.12 mg/dL for the portable glucometer for human use (Accu-chek® Active, Roche Diagnostic, Mannheim, Germany), veterinary (aLcose® Vet Glu, jjPlus Corporation, New Taipei, Taiwan) and the standard laboratory test, respectively. In conclusion, portable glucometers for human use underestimate the glucose values, and those for veterinary use overestimate them compared to the standard laboratory test.

Correlação entre cálcio e insulina durante o teste de tolerância à glicose em ovelhas gestantes e não gestantes / Calcium and insulin correlation during the glucose tolerance test in pregnant non-pregnant ewes

Compararam-se as concentrações de cálcio, glicose e insulina em ovelhas gestantes e não gestantes submetidas ao teste de tolerância à glicose (TTG). Oito ovelhas gestantes (GG) e oito não gestantes (NG) foram submetidas ao TTG por meio da administração endovenosa de uma solução de glicose, na dose de 500mg/kg de peso vivo. Amostras de sangue foram coletadas nos tempos de -15, zero, 15, 30, 45, 60, 90, 120, 150 e 180 minutos, sendo zero min o momento da infusão, para avaliação da concentração sanguínea de glicose, cálcio e insulina. Foi avaliada a taxa de metabolização de glicose e insulina, por meio do cálculo da área sob a curva (ASC). As concentrações de glicose, cálcio, insulina e a ASC da insulina não diferiram entre os grupos (P>0,05), entretanto as três últimas ASCs da glicose foram mais elevados nas gestantes (P<0,05), que correspondem ao período entre 90 e 180min. O teste de correlação de Pearson revelou correlação negativa entre concentração de cálcio e insulina nas gestantes (P<0,05). Estes resultados indicam menor taxa de metabolização de glicose em ovelhas gestantes e uma possível relação de cálcio e insulina no terço final de gestação.

The aim of this study was to investigate glucose, insulin and calcium metabolism during the Glucose Tolerance Test (GTT) in pregnant or nonpregnant ewes. Eight pregnant (PG) and nonpregnant (NPG) ewes per group received a glucose endovenosus bolus containning 500mg/kg in one minute. Blood samples were collected on -15, 0, 15, 30, 45, 60, 90, 120, 150 and 180 minutes interval (0 min - injection). These samples were used to evaluate glucose, calcium, insulin concentration, as well as insulin and glucose metabolization rate, which were determined by calculating the Area Under the Curve (AUC). The calcium, glucose and insulin concentrations were not different between groups. However, the three last glucose ASCs were higher in the pregnant group and in this group calcium and insulin blood concentrations were negatively correlated .These results showed lower glucose tolerance in pregnant ewes and suggest a link between insulin and calcium in the late pregnancy.

Influence of acute and chronic administration of benzylamine on glucose tolerance in diabetic and obese mice fed on very high-fat diet

The combination of vanadate plus benzylamine has been reported to stimulateglucose transport in rodent adipocytes and to mimic other insulin actions in diversestudies. However, benzylamine alone activates glucose uptake in human fat cells andincreases glucose tolerance in rabbits. The aim of this work was to unravel the benzylamineantihyperglycemic action and to test whether its chronic oral administrationcould restore the defective glucose handling of mice rendered slightly obese anddiabetic by very high-fat diet (VHFD). When VHFD mice were i.p. injected withbenzylamine at 0.7 to 700 ìmol/kg before glucose tolerance test, they exhibitedreduced hyperglycemic response without alteration of insulin secretion. Whole bodyglucose turnover, as assessed by the glucose isotopic dilution technique, wasunchanged in mice perfused with benzylamine (total dose of 75 ìmol/kg). However,their in vivo glycogen synthesis rate was increased. Benzylamine appeared thereforeto directly facilitate glucose utilisation in peripheral tissues. When given chronicallyat 2000 or 4000 ìmol/kg/d in drinking water, benzylamine elicited a slightreduction of water consumption but did not change body weight or adiposity anddid not modify oxidative stress markers. Benzylamine treatment improved glucosa tolerance but failed to normalize the elevated glucose fasting plasma levels of VHFDmice. There was no influence of benzylamine ingestion on lipolytic activity, basal andinsulin-stimulated glucose uptake, and on inflammatory adipokine expression inadipocytes. The improvement of glucose tolerance and the lack of adverse effects onadipocyte metabolism, reported here in VHFD mice allow to consider orally givenbenzylamine as a potential antidiabetic strategy which deserves to be further studied in other diabetic models (AU)

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