Serum muscle-derived enzymes response during show jumping competition in horse.

AIM: The effect of two jumping competitions, performed in two consecutive weekends, on serum creatine phosphokinase (CPK), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH), urea, creatinine (CREA) concentrations were evaluated in 12 healthy jumper horses. MATERIALS AND METHODS: Blood sampling was performed before the 1(st) day of competition (T0), at the end of each show (J1, J2), on the day after the competition (T1); the same sampling plan was followed during the second weekend (J3, J4 and T2). RESULTS: One-way repeated measures analysis of variance showed an increase in CPK at J1 and J2 respect to T0 and at J3 and J4 respect to all other time points (p<0.05). LDH activity showed an increase at J2 respect to T0, at J3 respect to T0, J1, J2 and at J4 respect to all other time points (p<0.05). AST values increased at J1 and J2 respect to T0 (p<0.05). A significant increase of CREA was found at J3 respect to T0, T1 and J1 and at J4 respect to all other time points (p<0.05). A decrease in serum urea levels was found at J1 respect to T0, at J2 and J4 respect to T0 and T1; at T2 respect to T0 (p<0.05). A positive correlation between urea/CPK (p=0.0042, r(2)=0.030), LDH/CPK (p<0.0001, r(2)=0.535), CREA/LDH (p<0.0001, r(2)=0.263), CREA/CPK (p<0.0001, r(2)=0.496) was observed. CONCLUSION: Our results suggest that 5 days recovery period between the two consecutive competition weekends is insufficient to allow muscle recovery and avoid potential additional stress. The findings obtained in this study improve the knowledge about metabolic changes occurring in athlete horse during the competition to identify muscle alterations following show jumping competitions.

Training-induced changes in clotting parameters of athletic horses.

The purpose of this study was to investigate the effects of training on prothrombin time, activated partial thromboplastin time, and fibrinogen (Fb) concentrations in horses to assess potential adaptive response to training. Fifteen clinically healthy horses were enrolled in the present study and equally divided into three groups. Group A completed an intense training program, group B participated in a light training program, and group C included sedentary horses. After 5 weeks, group B was subjected to the same training program completed by group A and renamed group B1. Blood samples were collected by jugular venipuncture from each animal at rest and analyzed within 2 h after sampling. A two-way ANOVA for repeated measures showed a significant effect of training (p < 0.05) on Fb concentrations in group B1 alone during the first week after changing the training program. Our findings demonstrated that Fb is a parameter susceptible to training. Fb plasma levels increase with a more intense training program. However, Fb plasma levels decreased after the first week and returned to basel levels, suggesting that the horses had adapted to the new training program.

Effect of storage time and temperature on the total protein concentration and electrophoretic fractions in equine serum.

Serum protein electrophoresis (SPE) is a technique that could be considered one of the most useful diagnostic aids available to the clinician. The effect of storage time and temperature on the total proteins and electrophoretic fractions (albumin, α1-, α2-, ß1-, ß2-, and γ-globulins) was assessed in 24 healthy horses. All samples, collected by jugular vein puncture, were centrifuged and divided into 4 aliquots. The 1st aliquot was analyzed within 3 h from collection (time 0), the 2nd was refrigerated at +4°C for 24 h, the 3rd was refrigerated at +4°C for 48 h, and the last was frozen at -20°C for 48 h. One-way repeated-measures analysis of variance (ANOVA) showed a significant effect (P < 0.05) of the different storage conditions on the concentrations of all the parameters studied and significant variations in the percentages of albumin, α1-globulins, α2-globulins, and γ-globulins. Compared with time 0 the total protein concentration increased significantly after 48 h at -20°C, the albumin percentage decreased after 48 h at -20°C, the α1-globulin percentage increased after 24 h at +4°C, the α2-globulin percentage increased after 48 h at +4°C and at -20°C, and the γ-globulin percentage increased after 48 h at -20°C. The results should help veterinary practitioners handle and store equine serum samples appropriately. Further investigations at different storage times and temperatures could be useful.

L'électrophorèse des protéines sériques (SPE) est une technique qui pourrait être considérée comme un des outils diagnostiques les plus utiles au clinicien. L'effet du temps et de la température d'entreposage sur les protéines totales et les fractions électrophorétiques (albumine, α1-, α2-, ß1-, ß2-, et γ-globulines) a été évalué chez 24 chevaux en santé. Tous les échantillons ont été prélevés par ponction de la veine jugulaire, centrifugés et divisés en quatre aliquots. Le premier aliquot a été analysé en dedans de trois heures du moment de la collecte (temps 0), le deuxième a été réfrigéré à 4 °C pour 24 h, le troisième a été réfrigéré à 4 °C pour 48, et le dernier a été congelé à −20 °C pendant 48 h. Une analyse de variance unidirectionnelle sur des mesures répétées (ANOVA) a montré un effet significatif (P < 0,05) des différentes conditions d'entreposage sur les concentrations de tous les paramètres étudiés et des variations significatives dans les pourcentages d'albumine, d'α1-globuline, d'α2-globuline, et de γ-globuline. Comparativement au temps 0, la concentration de protéines totales a augmenté significativement après 48 h à −20 °C, le pourcentage d'albumine a diminué après 48 h à −20 °C, le pourcentage d'α1-globuline a augmenté après 24 h à 4 °C, le pourcentage d'a2-globuline a augmenté après 48 h à 4 °C et à −20 °C, et le pourcentage de γ-globuline a augmenté après 48 h à −20 °C. Ces résultats devraient aider les vétérinaires praticiens à manipuler et entreposer de manière appropriée les échantillons de sérum équin. Des études ultérieures sur différents temps et températures d'entreposage seraient utiles.(Traduit par Docteur Serge Messier).

Effects of hydrocortisone and aminophylline on the aggregation of equine platelets in vitro.

The purpose of this study was to evaluate in vitro the effects of hydrocortisone and aminophylline on adenosine diphosphate (ADP)-induced platelet aggregation in horses. Blood samples from 30 healthy Thoroughbred horses were collected by via jugular venipuncture to assess platelet aggregation. Platelet-rich and platelet-poor plasma were prepared from all samples by centrifugation and divided into three different aliquots. In the first aliquot, platelet aggregation was measured after platelet activation with 1 µM and 0.5 µM ADP (Group A). In the other two aliquots, the effect of a 10 min preincubation with hydrocortisone (Group B) or aminophylline (Group C) on ADP-induced aggregation at final ADP concentrations of 1 µM and 0.5 µM was observed. Platelet aggregation, recorded by an aggregometer, was evaluated by measuring the maximum degree of platelet aggregation and the initial velocities of platelet aggregation were obtained. Our results demonstrated the inhibitory effect of hydrocortisone and the induction effect of aminophylline on equine platelet responses in vitro.

Acute phase protein response during road transportation and lairage at a slaughterhouse in feedlot beef cattle.

The effects of transport for 5 hr by road and lairage for 48 hr on acute phase protein in Limousine feedlot beef cattle (n = 10, 14-16 months old, body weight 620 ± 70 kg) were examined. Blood was collected at before loading, immediately after unloading and 12, 24 and 48 hr after the initiation of transportation. Serum was collected for assay of haptoglobin (Hp) and serum amyloid A (SAA), plasma was obtained for assay fibrinogen (Fb) and the white blood cell count (WBC) was determined in whole blood at each time point. A significant effect of experimental conditions on Hp, SAA and WBC was observed. In particular, this effect was found 24 hr after transport for Hp and SAA and after 48 hr for WBC. Application of a linear regression model showed a high correlation between WBC and Hp and SAA. Lairage in a slaughterhouse represents a stressful condition that can compromise animal welfare and meat quality. Monitoring of SAA with the highest sensitivity and specificity could be a useful marker of welfare condition in this period.