Risposta corticosurrenalica nel cavallo quarter horse in corso di sedute di allenamento e di gara simulata di barrel racing

ABSTRACT - Cortisol changes of 12 Quarter horses utilized in both training and not competitive Barrel Racing sessions were examined before and after both activities. The subjects in the study were divided into 2 groups, group A (control) and group B (exercise). From the comparison between cortisol basal levels of both groups, the statistical analysis showed a significant training effect on cortisol (F=8.86; P=0.011) changes. In the comparison between the last training session (the 6th) and the race simulation, statistical analysis showed a significant effect of not competitive race on cortisol (F=10.91; P=0.02) levels. One-way RM-ANOVA showed a significant effect of exercise on cortisol changes during both all-training weeks and not competitive sessions, with significant (F=10.91; P=0.02) higher levels in the not competitive session compared to the last training session

Modificazioni endocrino-ematologiche in cavalli P.S.I. in corso di prove di cross-country a differente altitudine

The endocrine and hematological changes were studied in 24 healthy horses before and after cross-country sessions, performed at different altitudes. On the basis of different altitude and stabling, horses were distinguished in group I (200 m), group II (500 m), group III (800 m), group IV (control group: 1200 m). Compared to basal values, horses submitted to cross-country sessions showed higher cortisol levels post exercise, both at T1 (after the 1st hour) and T2 (after the 2nd hour), irrespective of different altitude, with significant effects of exercise on cortisol changes. Significant effects of different altitude were observed on the post-exercise cortisol changes in group I and III. Compared to basal values, Wbc, Rbc Hgb, Plt and Pct were higher after exercise, at T1, both in group I and group II, with higher Plt and Pct after exercise (T1) in group III. Basal Wbc, Rbc, Hgb, Hct and Plt values of groups III and IV were significantly higher than basal values of group I. Statistical analysis showed significant effects of exercise and altitude on the hematological variables

Modificazioni dell'assetto elettrolitico ed ematochimico nella cavalla nell’ultimo trimestre di gravidanza e nel primo mese di lattazione

ABSTRACT - The electrolyte and biochemical variables were evaluated in 8 healthy mares, aged 4-10 years. Blood samples were taken after the 8th month of gestation, and then, every 30 days, for 3 consecutive months. During the lactation, blood samples were taken in the day 7, 15, 30 post partum. Mares were bled from the jugular vein between 7:30-9:00 AM. The purpose of this study was to determine which physiological changes occur in serum clinical biochemical analytes in pregnant and lactating mares and to determine whether the changes between pregnancy and lactation conditions are significant. Two way RMANOVA showed significant effects of lactation on the changes of all electrolytes and hematochemical variables, with higher levels of Na+, Pi and urea, and lower levels of Na+, Ca++, K+, creatinine, bilirubin and triglycerides in lactation than in pregnancy

Release of β-endorphin, adrenocorticotropic hormone and cortisol in response to machine milking of dairy cows

Aim: The present study was undertaken with the objective to obtain insight into the dynamics of the release of β-endorphin, adrenocorticotrophic hormone (ACTH) and cortisol in response to machine milking in dairy cows. Materials and Methods: A total of 10 healthy multiparous lactating Italian Friesian dairy cows were used in the study. Animals were at the 4th-5th month of pregnancy and were submitted to machine milking 2 times daily. Blood samples were collected in the morning: In baseline conditions, immediately before milking and after milking; and in the early afternoon: In baseline conditions, before milking and after milking, for 2 consecutive days. Endocrine variables were measured in duplicate, using a commercial radioimmunoassay for circulating β-endorphin and ACTH concentrations and a competitive enzyme-linked immunoassay for cortisol concentration. Results: Data obtained showed a similar biphasic cortisol secretion of lactating dairy cows, with a significant increase of cortisol concentration after morning machine milking, at both the 1st and the 2nd day (p<0.05), and a decrease after afternoon machine milking at the 2nd day (p<0.01). One-way RM ANOVA showed significant effects of the machine milking on the cortisol changes, at both morning (f=22.96; p<0.001) and afternoon (f=15.10; p<0.01) milking, respectively. Two-way RM ANOVA showed a significant interaction between cortisol changes at the 1st and the 2nd day (f=7.94; p<0.0002), and between the sampling times (f=6.09; p<0.001). Conversely, no significant effects of the machine milking were observed on β-endorphin and ACTH changes, but only a moderate positive correlation (r=0.94; p<0.06) after milking stimuli. Conclusions: A wide range of cortisol concentrations reported in this study showed the complex dynamic patterns of the homeostatic mechanisms involved during machine milking in dairy cows, suggesting that β-endorphin and ACTH were not the main factors that caused the adrenocortical response to milking stimuli

Pituitary-adrenocortical adjustments to transport stress in horses with previous different handling and transport conditions

Aim: The changes of the hypothalamic pituitary adrenal (HPA) axis response to a long distance transportation results in increase of adrenocorticotropic hormone (ACTH) and cortisol levels. The purpose of the study was to quantify the level of short-term road transport stress on circulating ACTH and cortisol concentrations, related to the effect of previous handling and transport experience of horses. Materials and Methods: The study was performed on 56 healthy horses after short-term road transport of 30 km. The horses were divided into four groups, Groups A, B, C, and D, with respect to the handling quality: Good (Groups A and B), bad (Group D), and minimal handling (Group C) conditions. According to the previous transport, experience horses were divided as follows: Horses of Groups A and D had been experienced long-distance transportation before; horses of Groups B and C had been limited experience of transportation. Results: One-way RM-ANOVA showed significant effects of transport on ACTH changes in Groups B and C and on cortisol changes in both Groups A and B. Groups A and B showed lower baseline ACTH and cortisol values than Groups C and D; Groups A and B showed lower post-transport ACTH values than Groups C and D. Groups A, B, and C showed lower post-transport cortisol values than Group D. Only Groups A and B horses have shown an adequate capacity of stress response to transportation. Conclusion: The previous transport experience and quality of handling could influence the HPA axis physiological responses of horses after short-term road transport

Thyroid evaluation in suspicious hypothyroid adult dogs before and after treatment

The purpose of this study was to measure circulating TSH, T4 and fT4 concentrations in dogs submitted to a clinical visit for general symptoms (weight gain, polyuria and polydipsia, changes in hair coat). Twenty-eight dogs, 14 cross-breed and 14 purebreds (Golden Retriever, Labrador, Doberman), of both sexes (14 males and 14 females), aged 8 to 14 years, were assessed. No significant differences of circulating TSH, T4, fT4 concentrations between the baseline and after therapeutic treatment nor between intact and neutered females were observed. Compared to baseline values, intact males showed higher TSH concentrations (p&lt;0.01), and castrated males lower TSH concentrations (p&lt;0.01) after therapeutic treatment. Compared to intact males, castrated males showed baseline TSH concentrations higher (p&lt;0.01), but lower (p&lt;0.01) after therapeutic treatment. No significant differences of T4 and fT4 concentrations between baseline conditions and after therapeutic treatment, nor between intact and castrated males, were observed. The experimental sample considered in this study falls within that casuistry involving elevated TSH concentrations but low serum T4 and fT4 concentrations or close to the minimum physiological cut-off, in which the common clinical signs suggestive of hypothyroidism was, essentially, overweight and neglected appearance of the hair

Effects of dietary protein and fat concentrations on hormonal and oxidative blood stress biomarkers in guide dogs during training

We compared the effects of different feeding strategies on hormonal and oxidative stress biomarkers in guide dogs during specialized training programs. Eight neutered adult dogs belonging to the Labrador retriever breed were divided during the training work into two homogeneous groups for sex (2 males, 2 females), age (17 months ± 1), initial body weight (26.3 kg ± 1), and BCS (4.5 of 9 ± 0.11) and fed two commercial diets with different concentration of energetic nutrients. One diet was a performance diet (HPF) characterized by low-carbohydrate/high-protein and fat content (29:39:19% as-fed) and the other a normal maintenance diet (LPF), characterized by high-carbohydrate/low-protein and fat content (50:24:12% as-fed). The trial lasted 84 days. At days 0, 28, 56, and 84, 180 min before the training work (T0) and immediately after (T1) and after 120 min (T2), blood adrenocorticotrophic hormone (ACTH), cortisol, d-ROMS (reactive oxygen metabolites–derived compounds), and BAP (biological antioxidant potential) were evaluated. Lactate was measured at T0 and T1. The statistical model included the effects of diet (HPF vs. LPF), time (from day 0 to day 84, end of the trial), and exercise (T0, T1, and T2) and their interaction. ACTH (P = 0.002) and cortisol (P = 0.013) showed higher values in the HPF than in the LPF group; there were no significant differences observed for lactate. Time showed no significant difference for any hormones or blood lactate. Exercise significantly (P < 0.001) influenced ACTH and cortisol concentrations, showing higher values at T1 than T0 and T2, and with lactate higher (P < 0.0001) at T1 than T0. Diet did not influence biomarkers of oxidative stress. Time did significantly (P < 0.05) influence BAP results but not d-ROMs. Exercise had no effect on BAP results, but d-ROMs were higher at T0 than T2 (P = 0.001). There was no interaction effect. The pituitary-adrenal (HPA) axis response and the oxidative stress indices could represent an objective method to identify optimal dietary protocols for creating a successful guide dog during the early training period