Effect of housing system on reproductive behaviour and on some endocrinological and seminal parameters of donkey stallions.

Reproductive management of male donkeys employed for artificial breeding has been poorly studied. The aim of this study was to evaluate the effect of housing system, with the animals grouped together in a paddock or kept in individual boxes, on sexual behaviour, cortisol and testosterone concentration and seminal characteristics of adult male donkeys. The study included four Amiata donkey jacks (stallions) from which ejaculates, saliva and blood were collected during two distinct 3 weeks periods, one in the group and one in the box housing system. Time needed for semen collection was shorter when donkeys were kept in paddocks compared to when they were kept in single boxes (14:57 ± 07:27 and 20:52 ± 09:31 min, p < .05). Native semen characteristics were not influenced by housing system, while cooled preservation in an Equitainer® showed that sperm motility parameters were significantly higher during the paddock period compared to the box period. Salivary cortisol was influenced by housing system, both before and 60 min after ejaculation, being statistically higher when donkeys were housed in paddocks. On the contrary, overall and basal testosterone concentrations were significantly higher when animals were kept in boxes. In conclusion, in the present study, good quality semen could be successfully collected from donkeys irrespective of the housing system despite some differences in hormone concentrations.

Dynamic pulmonary hyperinflation and low grade systemic inflammation in stable COPD patients.

BACKGROUND AND OBJECTIVES: It is increasingly recognized that a low grade of systemic inflammation occurs in patients with advanced chronic obstructive pulmonary disease (COPD). C-reactive protein (CRP), a marker of systemic chronic inflammatory response, has been related with decreased survival in large cohorts of COPD patients. The aim of the study was to assess if resting dynamic pulmonary hyperinflation (DH) is linked to the presence of systemic inflammation in COPD. MATERIALS AND METHODS: In a 12-month retrospective study involving 55 out-patients with COPD (FEV1 59+/- 23% pred.) examined in stable conditions, inspiratory capacity (IC) was measured at rest and considered as index of DH when lower than 80% predicted. Simultaneously, CRP (by immuno-turbidometry) and white blood cells (WBC), uric acid and alpha-1 globulins were measured in the venous blood in the morning before eating. RESULTS: CRP was significantly increased in the COPD patients with IC < 80% pred. (n = 35; IC = 61 + 14% pred.) as compared with that measured in COPD patients with IC > 80% pred. (n = 20; IC = 97 + 13% pred.), amounting to 0.70 +/- 0.59 vs 0.29 +/- 0.28 mg/dl, respectively (p < 0.01). CRP was inversely related to IC (% pred.) (r = 0.45, p < 0.01). WBC, serum uric acid (an endogenous danger signal), and albumin and alfa-1 globulins were not different between the two groups. DISCUSSION: These results show that the IC reduction is associated with higher serum levels of CRP in stable COPD patients, suggesting a potential role of dynamic pulmonary hyperinflation on development and maintenance of low grade systemic inflammation in COPD.

Application of a constant blood withdrawal method in equine exercise physiology studies.

The aim of the present study was to test a constant blood withdrawal method (CBWM) to collect blood samples from horses during treadmill exercise. CBWM was performed in 4 Standardbreds and 5 Haflinger horses. A peristaltic pump was used to control blood aspiration from an i.v. catheter via an extension line. Blood was collected using an automatic fractions collector, with a constant delay time between the drawing of blood and sample collection. Blood withdrawal using CBWM was made during a treadmill standardised exercise test (SET). A blood flow of 12 m/min was used and samples collected every 60 s during the entire period of exercise. The volume of blood collected in each sample tube was 12.1+/-0.2 ml, with a delay time of mean +/- s.d. 25.3+/-0.8 s. Plasma lactate kinetics based on measurement of lactate in each fraction showed an exponential increase during the first 13 min of exercise (10.5 min of SET and 2.5 min recovery). The peak plasma lactate concentration was observed between 2.5 and 5.5 min after the end of SET. CBWM permits the kinetics of lactate and other blood-borne variables to be studied over time. This method could be a valuable aid for use in studying equine exercise physiology.

Daily fluctuations of haematology and blood biochemistry in horses fed varying levels of protein.

Changes in the plasma biochemistry of 12 stallions were studied over seven 24 h periods. Twelve healthy male horses of 4 different breeds (Thoroughbred [TB], Anglo-Arabo-Sardo [AAS], Avelignese [Av] and Maremmano [M]) were divided into 3 experimental groups and fed with an isoenergetic maintenance ration with different protein levels. The same amount of food was given daily at 0730 and 1930 h. After 20 days of pretrial, a series of 6 blood samples were collected daily from the jugular vein every 4 h for 7 days. The samples were analysed for packed cell volume (PCV), haemoglobin, plasma glucose, free fatty acids, cholesterol, total plasma protein, urea, creatinine, calcium, phosphorus and enzymatic activities: aspartate aminotransferase (AST), alanine aminotrasferase (ALT), creatine kinase (CK) and lactate dehydrogenase (LDH). The data were analysed following the armonic analysis (Fourier) in order to define the pattern of biorhythm. Many parameters showed a biorhythmical pattern. Protein levels of the diet failed to influence haematology, blood biochemistry and biorhythm. Thoroughbreds showed the highest values of PCV, haemoglobin and creatinine and the lowest total protein, phosphorus and enzymatic activities.

Influence of training on plasma adrenaline and noradrenaline kinetics in untrained standardbreds.

REASONS FOR PERFORMING STUDY: Catecholamines (CAT) play an important role in modulating the response to exercise. But the kinetics of CAT changes during exercise are difficult to study due to their short biological half-life. OBJECTIVES: Learning about variations in plasma CAT levels during training could furnish new information regarding sweating, redistribution of blood flow and energy metabolism. METHODS: Four untrained Standardbreds, adapted to treadmill work, were used to determine the influence of training on plasma adrenaline (A) and noradrenaline (NA) kinetics. Horses underwent a standardised exercise test (SET) on treadmill before (SET1), and 1 (SET2) and 2 months after (SET3) the start of a moderate training period on treadmill. The SET procedure was: warm-up and a single step of 2 min at 200 beats/min heart rate (SS). The automatic blood collection system (that has been carried out during SS) and the preparation of the horses have been described previously. The system was programmed to obtain a blood sample every 15 sec (8 blood samples per SS). Analyses were performed by HPLC. Training progress was monitored by means of anaerobic threshold velocity (V4) and the velocity during SS (V200). Wilcoxon's test was used for statistical analysis. RESULTS: Decreased levels of A and NA with significant differences between SET1/SET2 and SET1/SET3 for A (P = 0.007) and NA (P = 0.007) were found. There were no differences between SET2 and SET3 for A (P = 0.195) and NA (P = 0.054). CONCLUSIONS: Training appears to influence the level of plasma CAT and this influence is greater during the first training period in untrained Standardbreds. POTENTIAL RELEVANCE: It may prove interesting to associate the study of training-induced modifications of the concentration of plasma CAT with thermoregulation, which is under catecholaminergic control and undergoes important adaptations during training.