Season’s Effects on Some Clinical,Hematological Parameters and Blood Cortisol Level in Sedated Arabian Horses With Xylazine

Influence of heat or cold stress in sedated animals is unclear and requires further investigations. The present study aimed to evaluate the season’s effects on some clinical, hematological parameters and blood cortisol level in sedated Arabian horses with xylazine. Therefore, seven Arabian horses were used to investigate heart and respiratory rates, and capillary refill time and serum cortisol level were recorded before (0) and at 5, 15, 60, and 180 minutes postsedation. Heparinized venous samples were collected before (0) and 3 hours postsedation for analysis of hematological analysis. Arterial blood samples were collected before and 1 hour postsedation for arterial blood gases and electrolytes analysis. Repeated analysis of variance was performed (P < .05). Significant decreases have been observed in heart and respiratory rates at 5, 15, and 60 minutes postsedation in summer and only at 5 minutes postsedation in winter. Arterial oxygen pressure and arterial carbon dioxide pressure showed a significant decrease and increase, respectively at 1 hour postsedation in summer and winter. The serum cortisol levels were significantly higher in summer than in winter at 5, 15, and 60 minutes postsedation. In summer, the postsedation concentrations of cortisol did not change significantly than its values before sedation. However, in winter, the cortisol concentration decreased significantly at 5, 15, and 60 minutes postsedation compared with their value before sedation. The present study suggests that these season’s effects on the sedated Arabian horses could take into consideration in xylazine-sedated Arabian horses.     

The Effect of Different Physical Exercise on Plasma Leptin,Cortisol, and Some Energetic Parameters Concentrations in Purebred Arabian Horses

Leptin is a hormone that coordinates food intake, energy expenditure, and metabolic rate; it is, however, unknown how exercise influences plasma leptin concentration in horses. The aim of the study was to evaluate the exercise-induced changes in plasma leptin concentration in purebred Arabian horses competing in races and endurance rides. A total number of 26 horses (12 purebred Arabian racehorses aged 3–5 years and 14 endurance horses aged 7–14 years) were studied during performing routine physical exercise. From each horse, blood samples were collected at rest and immediately after the exercise session. Concentrations of plasma leptin, cortisol, lactic acid, uric acid, triacylglycerols, glycerol and free fatty acids were determined. Exercise-induced increase in cortisol and free fatty acid values were higher in endurance horses than in racehorses. Neither endurance nor race exercises influenced the plasma leptin concentration. Further research is needed to elucidate the effects of different types of exercise on leptin synthesis and secretion in horses.     

Plasma Coenzyme Q10 and Tocopherols in Thoroughbred Race Horses: Effect of Coenzyme Q10 Supplementation and Exercise

The fundamental role of coenzyme Q10 (CoQ10) in cellular bioenergetics is well established in humans and several other species, yet there is no information about its role in horses. In continuation of our study of serum CoQ10 in Thoroughbred race horses, we examined the effect of CoQ10 supplementation and exercise on changes in plasma CoQ10 and α- and γ-tocopherol concentrations. Two groups of horses, five per group, were used. One group received 1.9 g of CoQ10 daily and the second group 3.4 g as a dietary supplement. Both groups were subjected to graduated training sessions that involved low-intensity exercise (gallop) followed by high-intensity exercise (breeze). CoQ10 supplementation resulted in a significant increase in plasma CoQ10 during low-intensity exercise, whereas the increase following high-intensity exercise was markedly attenuated in both groups (P < .05). There were no changes in plasma α- and γ-tocopherol concentrations following the two exercise sessions. γ-Tocopherol constituted approximately 5% of α-tocopherol; this is the first report of plasma γ-tocopherol in horses. The attenuated response of plasma CoQ10 in horses receiving CoQ10 supplementation following high-intensity exercise may be attributed to its consumption during severe oxidative stress. This finding indicates that in horses not receiving any CoQ10 supplementation, high-intensity exercise would result in a marked depletion of endogenous CoQ10 in plasma, which could compromise their health and physical performance. This documents the importance of CoQ10 in horses. The study also establishes the safety and tolerability of high-dose CoQ10 in Thoroughbred race horses.     

Effect of Marcha Exercise on Serum Electrolytes and Acid–Base Balance in Mangalarga Marchador Horses

The marcha competition is a functional evaluation, without similar in the world. In this competition, the animals perform marcha at average speed between 9 and 12 km/hr for 50 minutes, covering roughly 6 to 7 km with no rest. The aim of this study was to evaluate and compare the effect of batida gait competition on acid–base balance in Mangalarga Marchador horses during an official marcha competition. The study was conducted on 24 Mangalarga Marchador horses, 12 stallions, and 12 mares (aged 4–6 years and 399 ± 45 kg of body weight). Venous blood samples were collected before and after competition. Blood samples were analyzed for acid–base balance, as well as biochemical and electrolyte parameters. In stallions, a significant (P < .05) postexercise increase in pH, partial pressure of oxygen, bicarbonate concentration, base excess, and glucose was noted. Decrease (P < .05) in pCO₂ (partial pressure of carbon dioxide), chloride and ionized calcium were observed after exercise only in stallions. No changes (P > .05) in hematocrit, hemoglobin, sodium, and potassium were observed after exercise in all animals. The changes in the acid–base balance and electrolyte profile of the Mangalarga Marchador stallions after marcha competition resulted in hypochloremic metabolic alkalosis. Marcha competition did not cause acid–base disturbance in mares. This study enables an evaluation and comparison of physical effort caused by the marcha exercise on acid–base balance in Mangalarga Marchador horses and provides further evidence of the existence of gender differences in sports horses.     

Effect of Sward Height on Pasture Nonstructural Carbohydrate Concentrations and Blood Glucose/Insulin Profiles in Grazing Horses

Six mature stock-type geldings with maintenance only requirements were used in a randomized cross-over design to determine the effect of sward height on pasture plant nonstructural carbohydrate (NSC) concentrations and blood glucose and insulin concentrations. Horses were randomly assigned to one of two tall fescue (Lolium arundinaceum Schreb cv Max-Q, Pennington Seed, Madison, GA) grazing cells (0.37 ha) having two different sward heights for a period of 7 days: (1) short (approximately 15 cm; n = 3) or tall (between 30 and 40 cm; n = 3). After the first 7-day period, treatment groups were reversed by moving horses to ungrazed cells having similar characteristics to those used in the first 7 days, so that all horses receive all treatments resulting in six observations per treatment. Both short and tall grazing cells were mowed to a height of approximately 15 cm 32 days before the experiment starts. The short grazing cells were removed to approximately 15 cm at 11 days before the start of the first 7-day period and again 1 day before the start of each 7-day period. All horses had access to pasture for 10 h/d beginning at 8 AM and ending at 6 PM. Although not at pasture, all horses were individually housed in 3.7 × 12.2 m partially covered pens containing automatic water troughs and a crushed stone surface. Herbage mass (kg DM/ha) was determined by use of a falling plate meter for each pasture to ensure that both groups of horses had adequate dry matter to provide grazing for at least 7 days. On day 7 of each period, jugular venous blood samples were collected from each horse before being turned out to pasture, and then at 2, 4, 6, and 8 hours after turn-out. Pasture samples were also collected from each grazing cell at the same time blood samples were taken. Serum and plasma from blood samples were harvested and analyzed for insulin and glucose concentrations, respectively. Pasture samples were analyzed for water soluble carbohydrate (WSC), ethanol soluble carbohydrate (ESC), and starch. The sum of WSC and starch were used as an estimate of NSC. Area under the curve (AUC) and peak concentration were calculated for both plasma glucose (PPG) and serum insulin (PSI) concentration and were analyzed using analysis of variance for randomized cross-over designs. Pasture WSC, ESC, starch, and NSC concentrations were analyzed using analysis of variance for randomized complete block design. A P value of < .05 was considered significant. Mean pasture plant NSC, WSC, and ESC concentrations were lower (P < .001) in short as compared with tall. Pasture plant starch concentration was not different between treatments. Mean pregrazing plasma glucose concentrations, PPG concentrations, and plasma glucose AUC were not affected by treatment. Mean pregrazing serum insulin concentrations were not affected by treatment. Mean PSI and insulin AUC were greater (P < .01) when horses grazed tall, as compared with short. In conclusion, decreasing the sward height by mowing pasture decreased NSC, WSC, and ESC concentrations and subsequently decreased the postprandial insulin response of horses grazing the pasture. These findings may be important in developing strategies aimed at preventing insulin resistance in grazing horses.     

Effects of a Novel Dietary Supplement on Indices of Muscle Injury and Articular GAG Release in Horses

This study determined the ability of an oral nutraceutical supplement to attenuate the oxidative stress and inflammation that occurs in muscles and joints with repeated bouts of high-intensity exercise in horses. The supplement, fed daily, was comprised of whole dried mushrooms, golden flaxseed, omega-3 fatty acids, plant-based enzymes, a melon-concentrate powder, and Saccharomyces cerevisiae boulardii. Ten horses participated in a partial cross-over design, with 7 horses completing the Control trial and 7 horses completing the supplement trial. Blood and synovial fluid samples (from the intercarpal joint) were taken before, and at 1 and 24 hours after a standardized, repeated high-intensity exercise test that was performed before supplementation and on the 22nd day of supplementation. At the end of the supplement trial exercise resulted in reduced concentrations of plasma markers of oxidative stress (decreased thiobarbituric acid reactive substances, with increased total antioxidant status and increased superoxide dismutase activity); there was no effect on plasma markers of muscle injury (creatine, creatine kinase, and aspartate aminotransferase) or inflammation (PGE₂, nitric oxide). Within synovial fluid, there was a tendency for increased superoxide dismutase activity, and decreased concentration of glycosaminoglycans. It is concluded that the supplement, when fed to horses as part of the normal diet for 23 days, was associated with reduced concentrations of markers of oxidative stress and inflammation in muscle and synovial fluid.     

A Proton-Pump Inhibitor Modifies the Concentration of Digestion Biomarkers in Healthy Horses

To determine the concentration of various blood biomarkers associated with digestion in healthy horses treated with different doses of omeprazole (OMPZ), four Arabian horses without gastric ulcers were selected and distributed in one factorial with four oral treatments (Control; OMPZ^BOLUS; OMPZ^4mg/kg; OMPZ^1mg/kg). Control did not receive any treatment. OMPZ^BOLUS were given 4 mg/kg of omeprazole in a single dose on the day before blood sampling. In the OMPZ^4mg/kg and OMPZ^1mg/kg treatments, horses were treated over 11 days. All treatments were performed 16 hours before morning feeding. The “washout” period was 21 days between rounds. After an overnight fasting period, blood samples were collected from all animals (T1), after which the animals received supplementation, and blood samples were collected after 30 minutes (T2), 1.0 hours (T3), 1.5 hours (T4), 2.0 hours (T5), 3.0 hours (T6), 4.0 hours (T7), 5.0 hours (T8), 6.0 hours (T9), and 7.0 hours (T10). Blood samples were analyzed for total plasma protein (TPP), glucose, urea, creatinine, uric acid, cholesterol, triglycerides, calcium, phosphorus, and magnesium. The results showed differences between treatments for urea, cholesterol, uric acid; between phases for glucose; and between phase and treatment for creatinine, triglycerides, phosphorus, and magnesium; however, there was no difference for TPP and calcium between treatment and between phases. Oral administration of OMPZ in healthy equines interfered with the metabolism of digestion biomarkers of lipid, mineral, and protein metabolism, although the animals were treated for a maximum of 11 days. Horses treated with a proton-pump inhibitor need to be evaluated regularly to avoid significant modification in their metabolic parameters.     

Effect of Age and Performance on Physical,Hematological, and Biochemical Parameters in Endurance Horses

Endurance horses are subjected to heightened stress even after several conditioning protocols. Hence, the goal of this study was to examine the effect of age and performance on the hematology, biochemistry, and physical parameters after an endurance race. Eighteen horses aged 6-15 years were grouped into 80-km race category. All the horses were physically examined, and blood samples were collected postrace. After physical examination, the poor (n = 9) and good (n = 9) performance horses were identified. Potassium concentration was significantly higher (P < .05) in the good performance horses; chloride concentration was significantly higher (P < .05) in the poor performance horses. The mean blood glucose concentration of the poor performance horses in all the age-groups was significantly higher (P < .05). The mean blood lactate concentration was significantly lower (P < .05) in the poor performance horses. There was significant effect of performance on heart rate (P < .031), capillary refill time (P < .013), and gut motility (P < .05). Univariate Fisher exact test results were significantly higher for skin recoil (P < .03), mucous membrane (P < .03), and gait (P < .04) in the performance categories. In conclusion, the influence of age was seen in the poor performance category in relation to lactate, but age did not influence other physical, hematological, and biochemical parameters of the endurance horses. Thus, further studies are required to determine whether physical, hematological, and biochemical parameters during training could be used to estimate performance in endurance horses based on age.     

Feeding practice and influence on selected blood parameters in show jumping horses competing in Switzerland

The aim of this study was to compare the nutritional management of show jumping horses in practice with recommendations from the literature. Additionally, the effects of these feeding practices on several blood metabolic parameters before and after exercise were studied. Blood samples were collected in the field from 27 different horses at 71 trials on the level M1 to S2 show jumping competitions in Switzerland and questionnaires on feeding practice of the studied horses were evaluated. The questionnaires revealed that during training and on tournament days horses received on average 3.1 kg of concentrate per day (min. 2.0 kg, max. 6.6 kg) divided into two to three meals. The horses were fed on average 6.9 kg of roughage per day (min. 4.0 kg, max. 13.0 kg). Additionally, it was observed that the horses received the last meal on average 6 h 10 min (min. 1 h 50 min, max. 12 h 30 min) before the start of the first show jumping turn, respectively, 7 h 30 min (min 1 h 50 min, max. 13 h 0 min) before the second turn. Seven horses (35%) had access to hay waiting in the trailer between two turns. The statistical analysis revealed no significant influence of the concentrate feeding time point on lactate, triglyceride and insulin levels, but a significant influence on free fatty acids (FFA) and blood glucose concentrations. Roughage feeding of the show jumping horses 2–4 h prior to exercise revealed the most remarkable changes in blood parameters during the show jumping course. These results received under field conditions should be approved in future under standardized conditions.     

Antioxidant and haematological biomarkers in different groups of horses supplemented with polyunsaturated oil and vitamin E

Oxidative stress has been correlated with pathologies that impair the performance of athlete horses. The aim of this study was to assess the effects of supplementation with a mixture of polyunsaturated oil and vitamin E on the antioxidant and haematological biomarkers of horses. Horses under maintenance care (n = 6) and horses in training (n = 10) received 100 and 300 ml of the oil mixture respectively. Supplementation was provided for a period of 8 weeks, together with isocaloric inclusion. Blood samples were collected at three time periods (pretest, after 4 weeks and after 8 weeks) to analyse the following: the red blood cell count (RBCc); haemoglobin (Hb); haematocrit (HT); leucocytes; lymphocytes; platelets; the mean corpuscular volume (MCV); the mean corpuscular haemoglobin concentration (MCHC); the standard deviation of the red blood cell distribution width (RDW‐SD); the coefficient of variation of the red blood cell distribution width (RDW‐CV); glutathione peroxidase (GPx); superoxide dismutase (SOD); uric acid (UrAc); total plasma proteins (TPP); and creatine kinase (CK). After the 8 weeks of supplementation, animals under maintenance care exhibited significant increases in SOD, UrAc, the white blood cell count (WBCc), the RDW‐SD and the RDW‐CV (p < 0.05). The animals in training exhibited increases in GPx, SOD and UrAc (p < 0.05). In conclusion, supplementation with polyunsaturated oil and vitamin E increases blood antioxidants among animals under maintenance and in training, with different trends, while contributing to the fight against oxidative stress in each group analysed.     

Effect of different levels of bee pollen on performance and blood profile of New Zealand White bucks and growth performance of their offspring during summer and winter months

The effect of bee pollen on productive and reproductive performances of adult buck rabbits and their offspring was studied during winter and summer seasons. Forty New Zealand White bucks were equally divided among four groups feeding the same commercial diet and receiving a water solution containing, respectively, 0 (control), 100, 200 and 300 mg bee pollen/kg body weight, twice per week along two experimental periods. The experimental periods were listed for ten weeks both during winter (30–40 weeks of age) and summer seasons (56–66 weeks of age). During the trials body weight, body weight gain, total feed intake, semen quality, fertility and blood constituents were determined. Fertility was determined after natural mating with no treated females. For each season, 80 weaned rabbits obtained from the bucks of the control group were equally divided (20 per group) among 4 levels (0, 100, 200 and 300 mg/kg BW) of bee pollen, given as a water solution twice per week. The offspring sired by bucks given 100, 200 and 300 mg (20 for each group and season) were not administrated bee pollen. The effect of bee pollen on growth performance of rabbits was studied from 4 to 12 weeks of age. Bee pollen at 200 mg/kg BW significantly (p < 0.01) improved semen quality, increased fertility percentage, improved biochemical profiles of blood and helps outstanding of bucks during both seasons. The same concentration of bee pollen increased body weight gain and survival rate and reduced feed intake and feed conversion ratio of offspring up to 12 weeks of age.     

Pharmacokinetic and pharmacodynamic properties of pergolide mesylate following long‐term administration to horses with pituitary pars intermedia dysfunction

The objective of this study was to gain an understanding of the pharmacokinetic and pharmacodynamic properties of pergolide in horses with PPID after of long‐term oral administration. Six horses with confirmed PPID were treated with pergolide (Prascend^®) at 1 mg/horse po q24 h for 2 months, followed by 2 mg/horse po q24 h for 4 months. Following the last dose, plasma samples were collected for measurement of pergolide using an LC/MS/MS method and ACTH measurement using a chemiluminescent immunoassay. Noncompartmental and compartmental pharmacokinetic analyses were performed, as well as pharmacodynamic assessment of the effect of plasma pergolide concentrations on plasma ACTH concentrations. Pergolide effectively decreased plasma ACTH concentration in aged horses with PPID, with similar pharmacokinetic properties as reported in young horses, including an approximate terminal half‐life of 24 h. Plasma ACTH concentration increased by 50% in 3/6 horses at 2 days and 6/6 horses 10 days after discontinuing drug administration. Pergolide was quantified in all horses at 2 days and in none at 10 days after last dose. In summary, after discontinuing pergolide treatment, plasma ACTH concentration increased while pergolide was still quantifiable in some horses. Once‐daily dosing of pergolide is likely appropriate in most horses with PPID for regulating the plasma ACTH concentration.     

Erythrocyte Osmotic Fragility and Hematological Responses of Horses Administered Ascorbic Acid and Exposed to Road Transportation

The experiment was performed to evaluate the ameliorative effect of ascorbic acid (AA) on some hematological parameters and erythrocyte osmotic fragility (EOF) in horses transported by road. A total of 14 horses, consisting of seven experimental and seven control horses, were used for the experiment. Before the transportation, blood samples were obtained by jugular venipuncture from all the horses. Experimental horses were administered with AA (200 mg/kg dissolved in 20 mL of distilled water per os), whereas the control horses were given 20 mL of distilled water per os. Thereafter, the animals were transported for 6 hours and blood samples collected after transportation. Packed cell volume and hemoglobin concentration were higher (P < .05) in experimental than the control group, whereas total leukocytes reduced significantly (P < .05) in experimental in comparison with the control horses. Lymphocyte, neutrophil counts, neutrophil/lymphocyte ratio, and total protein decreased in experimental horses in comparison with control, but they were not significant (P > .05). Erythrocyte osmotic fragility was lower in experimental than the control at 0.3% NaCl concentration (P < .05). The result of the present study revealed that AA ameliorated changes in hematological parameters and EOF induced by road transport stress, partly because of its antioxidant properties.     

Growth performance,carcass quality,biochemical and haematological traits and immune response of growing rabbits as affected by different growth promoters

The aim of the article was to study the effect of different growth promoters on growth performance, carcass quality, biochemical and haematological traits and immune response of growing rabbits. A total number of 105 male growing NZW rabbits during 35–91 days of age were randomly distributed among 7 groups fed the same basal diet and submitted to different dietary treatments: the first group was unsupplemented and used as control; the other groups were supplemented respectively with bee pollen and/or propolis at 200 mg/kg BW of each and inulin and/or mannanoligosaccharides (MOS) at 35 mg/kg BW of each. Body weight gain, daily feed intake, feed conversion ratio (FCR), biochemical and haematological blood parameters, carcass characteristics, histological studies of ileum and spleen and economical efficiency were measured. Bee pollen administered alone or with propolis significantly (p < 0.01) the body weight gain and improved FCR in respect of the control group. Inulin with MOS significantly improved just FCR than the control group. Bee pollen with propolis and MOS supplemented‐groups resulted in significantly higher (7.96 and 8.41% respectively) white blood cells compared to the control group. Plasma total cholesterol was significantly higher for the MOS group in respect of the control, bee pollen, inulin and inulin with MOS supplemented‐groups. Propolis resulted in significantly higher dressed carcass percentage than the control group and higher carcass index than only bee pollen with propolis supplemented‐group. Bee pollen, in particular if in combination with propolis, could be used as a supplement in the growing rabbits during days 35–91 of age with positive effects on growth rate and feed conversion ratio.     

Validation of the Lactate Plus Lactate Meter in the Horse and Its Use in a Conditioning Program

The equine industry has a need for a convenient, rapid, and reliable method of measuring blood lactate concentrations ([LA]). We hypothesized that the handheld Lactate Plus lactate meter (LPlus), developed and tested for use in humans, would provide dependable results when used in horses undergoing an exercise conditioning program and that horse's fitness would improve following individualized conditioning based on each horse's velocity at which [LA] = 4 mmol/L (V_LA4) was reached. Five adult horses underwent a 4-week training program that consisted of 3 exercise bouts/wk. Horses were subjected to an incremental step standardized exercise test (SET) before starting (SET-1) and after the completion of the program (SET-2). Blood samples were collected before each increase in speed until [LA] reached ≥4 mmol/L, and then the SET was terminated. The [LA] sample range in our study was 0–8 mmol/L. Blood was analyzed at the time of collection using a calibrated LPlus, and plasma was collected for [LA] determination using the lactate dehydrogenase–based enzymatic colorimetric method. Although the LPlus tended to significantly underestimate [LA] by 0.39 mmol/L (P < .001), the LPlus proved to be a dependable device for use in horses based on good correlation with the biochemical analysis (r = 0.978) and Bland–Altman limits of agreement and 95% confidence intervals. All horses showed an increase in V_LA4 from SET-1 to SET-2, consistent with improved fitness following our 3 exercise bout/wk training protocol. The LPlus can reliably be used in horses to determine [LA] ranging from 0–8 mmol/L. When determining serial [LA], analytical techniques should not be used interchangeably.     

Effect of bee pollen levels on productive, reproductive and blood traits of NZW rabbits

Forty New Zealand White (NZW) rabbit does were equally divided among four groups feeding the same commercial diet and receiving a water solution containing, respectively, 0 (control), 100, 200 and 300 mg bee pollen/kg body weight (BW), 1 week before and after mating during moderate (October-February) and hot seasons (May-September) for three consecutive mating in each season. Does were mated with non-treated adult NZW male rabbits 11 days after kindling. Body weight of does, number of service per conception, conception rate, feed intake, litter size, milk production, blood constituents, weight of kits from birth up to weaning and survival rate were determined. For each season, 80 weaned rabbits originated from the does of the control group (untreated does) were equally divided into four groups (0, 100, 200 and 300 mg/kg BW) of bee pollen, given as a water solution twice per week from 4 to 12 weeks of age. The kit of the does given 100, 200 and 300 mg/kg BW did not receive bee pollen during the growing period (4-12 weeks of age). The effect of bee pollen on growing rabbit's performance was studied from 4 to 12 week of age. Bee pollen at 200 mg significantly (p < 0.01) increased body weight of does, conception rate, milk yield, litter size; improved biochemical profiles of blood and helps outstanding of does during both seasons. The same dose of bee pollen significantly increased kit growth and their survival rate until weaning. Growth and feed conversion ratio (FCR) of kits from the treated does during 4-8 weeks of age were significantly better than growth of kits from the untreated does that administrated bee pollen during 4-12 weeks of age. Meanwhile, during the following period (8-12 weeks of age) growth and FCR of kits given bee pollen from the untreated does were significantly better than that of treated does.     

Whole-Blood Validation of a New Point-of-care Equine Serum Amyloid A Assay

Serum amyloid A (SAA) is considered a major acute phase protein (APP) in horses. Serum amyloid A stall-side assays are commercially available to assess the inflammatory response of patients with various infectious and noninfectious conditions. The objective of this study was to determine the analytical performance of a new point-of-care (POC) assay for the measurement of SAA in whole blood and plasma of horses. One hundred and sixty blood samples were collected from 60 horses at various time points after immunization with an equine core vaccine. Analytical validation of the SAA POC assay included the measurement of SAA in whole blood and plasma, assessment of linearity and precision, and comparison of the SAA POC results with those obtained with a validated turbidimetric immunoassay (TIA). The SAA POC assay yielded similar results in whole blood and plasma (P > .05), and the results were positively correlated with the TIA (R² = 0.964). The assay displayed solid linearity throughout the detection range of ≤ 20 to 3,000 μg/mL (R² = 0.984) with inter-assay and intra-assay coefficients of variation ranging from 7.8% to 13.3% and 5.7% to 12.0%, respectively. The new SAA POC assay was able to reliably measure SAA in both whole blood and plasma. Similar to previously validated assays, the new SAA POC assay is a valuable tool to investigate the inflammatory response in various clinical diseases of horses.     

Effects of dietary amino acid supplementation on measures of whole‐body and muscle protein metabolism in aged horses

The objective of this study was to examine markers of whole‐body and muscle protein metabolism in aged horses fed a diet typical for North American aged horses, supplemented with amino acids. In a replicated Latin square design, six aged horses (20 ± 1.1 years) were studied while receiving each of three isocaloric, isonitrogenous diets, a control treatment concentrate (CON; 100 mg/kg^?1 BW day^?1 lysine, 84 mg kg^?1 day^?1 threonine, 51 mg kg^?1 day^?1 methionine), LYS/THR (134 mg kg^?1 BW day^?1 lysine, 110 mg kg^?1 BW day^?1 threonine, 52 mg kg^?1 BW day^?1 methionine) and LYS/THR/MET (132 mg kg^?1 BW day^?1 lysine, 112 mg kg^?1 BW day^?1 threonine, 62 mg kg^?1 BW day^?1 methionine). In each 15‐days period, urine and faeces were collected for assessment of nitrogen balance. Blood samples were collected before and after feeding for analysis of plasma urea nitrogen (PUN), glucose, insulin and plasma amino acid concentrations. Skeletal muscle samples were collected for measurement of proteins associated with muscle protein synthesis and degradation, and horses underwent stable isotope infusion procedures for comparison of differences in whole‐body rates of protein synthesis and degradation. There was no effect of treatment on relative abundance of proteins involved in protein synthesis, nitrogen retention or phenylalanine kinetics. PUN concentrations tended to be higher for LYS/THR (p = 0.054) and were higher for LYS/THR/MET (p = 0.0056) than for CON. Atrogin‐1 abundance tended to be higher in the post‐absorptive state for the CON treatment (p = 0.07), indicating that amino acid supplementation resulted in less muscle protein degradation when horses were in the post‐absorptive state. However, lack of differences in nitrogen retention and phenylalanine kinetics indicated that whole‐body protein metabolism was not improved, and higher PUN concentrations in the supplemented diets suggest that the supplemented amino acids may have been catabolized. Amino acid availability was not limiting protein synthesis in the sedentary aged horses in this study when fed the CON diet.     

The Effect of Season on Spermatozoa Motility,Plasma Membrane and Acrosome Integrity in Fresh and Frozen–Thawed Semen from Xinong Saanen Bucks

The aim of this study was to evaluate whether the season of ejaculate collection influences seminal quality parameters of pre‐ and post‐freeze–thawing in Xinong Saanen bucks. Ejaculates were collected from eight bucks throughout the four seasons (spring, summer, autumn and winter) in a 12 months’ time period, identified in the Northern Hemisphere. Semen samples were evaluated by the combinations of conventional and Computer‐Assisted Sperm Analysis (CASA) when fresh and after frozen–thawed, respectively. The results clearly demonstrated that season of ejaculate collection influenced (p < 0.05) fresh semen quality. Highest semen quality was observed during autumn. On the contrary, undesirable indices (significantly lower, p < 0.05) were observed in winter as compared with the other remaining seasons. CASA has clearly shown the influences of seasonal variations on semen motility parameters. Furthermore, season of ejaculate collection was also found to influence sperm freezability. Semen characteristics after frozen–thawed followed a similar pattern with that of fresh ejaculate except in spring. The results revealed that sperm quality was higher (p < 0.01) in summer and autumn than in spring and winter. In conclusion, seasonal variation influences semen quality in Xinong Saanen bucks. In addition to summer and autumn, fresh ejaculates in spring can also be successfully used for AI. Sperm from ejaculates collected during summer and autumn are more suitable for cryopreservation. Hence, it is possible to increase the efficiency of goat breeding by manipulating the seasonal variations of semen quality for immediate AI and/or cryopreservation.     

Effects of β-Hydroxy-β-Methylbutyrate and γ-Oryzanol on Blood Biochemical Markers in Exercising Thoroughbred Race Horses

In both the horse and the man, nutritional ergogenic aids have been used to improve physical ability in conjunction with an appropriate training regimen. Although training increases physical condition, the ease of taking a nutritional additive to improve training results explains the demand for supplementation, which may increase mechanical energy of work, delay onset of fatigue, or improve neuromuscular coordination. The purpose of this study was to determine the effects of oral supplementation of β-hydroxy-β-methylbutyrate (HMB) and γ-oryzanol (GO) on indices of exercise-induced muscle damage in Thoroughbred race horses. In this 32-week study, the horses were assigned to either a placebo, GO (3.0 g/d), HMB (15 g/d), or GO and HMB treatment groups. The supplements were administered for the first 16 weeks of the study during the training period before the racing season began. Blood samples were taken at baseline, and then during training, before exercise, immediately after exercise, and 30 minutes after exercise. Heart rate and speed were monitored in each exercise session. Hematocrit, glucose, lactate (LA), creatine phosphokinase, and aspartate aminotransferase were measured before and after each exercise session. Analysis of variance showed a significantly greater increase in postexercise creatine kinase activity in placebo-supplemented group than in the other treatment groups, both in the training period and during the racing seasons (P < .05). Blood LA was higher immediately after exercise in the placebo group compared with the supplemented groups. In conclusion, supplementation with HMB and GO resulted in decreased creatine kinase and LA after exercise. These findings support the hypothesis that HMB and GO supplementation helps to prevent exercise-induced muscle damage.