Anna Assenza

Impact of an acoustic stimulus on the motility and blood parameters of European sea bass (Dicentrarchus labrax L.) and gilthead sea bream (Sparus aurata L.)

The physiological responses of fish to underwater noise are poorly understood and further information is needed to evaluate any possible negative effects of sound exposure. We exposed European sea bass and gilthead sea bream to a 0.1-1 kHz linear sweep (150 dB(rms) re 1 microPa). This band frequency is perceptible by many species of fish and is mainly produced by vessel traffic. We assessed the noise-induced motility reaction (analysing the movements) and the haematological responses (measuring blood glucose and lactate, and haematocrit levels). The noise exposure produced a significant increase in motility as well as an increase in lactate and haematocrit levels in sea bream and sea bass. A significant decrease of glucose was only observed in sea bream. A linear correlation between blood parameters and motility in fish exposed to the noise was observed. The acoustic stimulus produced intense muscle activity.

Modifications of some acute phase proteins and the white blood cell count in thoroughbreds during training

The concentrations of plasma fibrinogen and serum haptoglobin and the white blood cell count (WBC) were assessed in 17 thoroughbreds. All horses were trained for 80 days, six days a week, with one day of rest per week. Blood samples were collected from each animal by jugular venepuncture, at 06.00, every 20 days for a period of 80 days, and the fibrinogen and haptoglobin concentrations and WBC were determined. One-way repeated measures analysis of variance, followed by the Bonferroni test, was used to determine significant differences. Training was associated with a significant increase in the concentrations of plasma fibrinogen (Plt;0.01) and serum haptoglobin (Plt;0.0005), but had no significant effect on the WBC count.

Automatic analysis to assess haematological parameters in farmed gilthead sea bream (Sparus aurata Linnaeus, 1758)

The haematological parameters (RBC, Hb, PCV, WBC, TC, MCV, MCH, and MCHC) in farmed gilthead sea bream (Sparus aurata) were measured using an automatic method. We then compared the outcomes using the traditional manual method. After blood collection (T0), all samples were immediately analyzed using both the manual and automatic methods. The samples were successively divided into five different aliquots and stored at +4°C to evaluate the effect of the storage time on haematological parameters, measured with the automatic method, at 6, 24, 48, 72, and 96 h after collection. Paired t-tests were applied between the values obtained at T0 with the manual and automatic methods and no statistical difference was observed. One-way repeated measures analysis of variance (ANOVA) showed that parameters measured with the automatic system were significantly affected by the storage time (p < 0.0001). These results provide an innovative automatic method for the determination of haematological parameters in sea bream and suggest that the haematological profile can be accurately assessed within 6 h from blood collection.

Central fatigue and nycthemeral change of serum tryptophan and serotonin in the athletic horse

Background The serotonergic system is associated with numerous brain functions, including the resetting of the mammalian circadian clock. The synthesis and metabolism of 5-HT in the brain increases in response to exercise and is correlated with high levels of blood-borne tryptophan (TRP). The present investigation was aimed at testing the existence of a daily rhythm of TRP and 5-HT in the blood of athletic horses. Methods Blood samples from 5 Thoroughbred mares were collected at 4-hour intervals for 48 hours (starting at 08:00 hours on day 1 and finishing at 4:00 on day 2) via an intravenous cannula inserted into the jugular vein. Tryptophan and serotonin concentrations were assessed by HPLC. Data analysis was conducted by one-way repeated measures analysis of variance (ANOVA) and by the single cosinor method. Results ANOVA showed a highly significant influence of time both on tryptophan and on serotonin, in all horses, on either day, with p values < 0.0001. Cosinor analysis identified the periodic parameters and their acrophases (expressed in hours) during the 2 days of monitoring. Both parameters studied showed evening acrophases. Conclusion The results showed that serotonin and tryptophan blood levels undergo nycthemeral variation with typical evening acrophases. These results enhance the understanding of the athlete horses chronoperformance and facilitate the establishment of training programs that take into account the nycthemeral pattern of aminoacids deeply involved in the onset of central fatigue.

Influence of different schedules of feeding on daily rhythms of blood urea and ammonia concentration in cows

Abstract Many physiological processes of domestic animals exhibit daily rhythmicity. The goal of the present study was to investigate, in cows, the influence of different schedules of feeding on daily rhythms of blood urea and ammonia concentrations. Fifteen Italian Brown cows, from the same farm, clinically healthy and placed at the same environmental temperature and photoperiod, were used for this study. Thirty days before the experiment, all the subjects were divided into three homogeneous groups of five cows: A group was fed at 08.00, B group was fed at 16.00, both having access to food for two hours (A group 08.00 – 10.00; B group 16.00 – 18.00) and C group was fed ad libitum. Blood samples were collected at four hour intervals for 72 consecutive hours starting at 08.00 of the first day and finishing at 04.00 of the third day via intravenous cannula inserted into the jugular vein. On each serum, blood urea and ammonia concentrations were assayed. Data analysis was conducted by one-way repeated measures analysis of variance (ANOVA) and by the single cosinor method. ANOVA showed a significant effect of time on all parameters studied, in either day, with P < 0.0002 for ammonia in A group and P < 0.0001 for ammonia and P < 0.0005 for urea in B group. Cosinor analysis identified the periodic parameters and their acrophases (expressed in hours) during the three days of monitoring: urea showed nocturnal acrophases in B group, ammonia showed diurnal acrophases both in A and B groups. Our results suggest the influence of external stimuli, such as feeding time, on the rhythmic pattern of the metabolites involved in liver function and the hypothetic interaction between circadian clocks placed in the liver and the mean circadian system.

Electrophoretic Serum Protein Fraction Profile During the Different Physiological Phases in Comisana Ewes

The aim of this study was to evaluate the influence of different physiological phases on serum total proteins and their fractions of ten Comisana ewes housed in Mediterranean area. From each animal, blood samples were collected at different physiological phases: late pregnancy, post-partum, early, mid-, end lactation and dry period. On all samples serum total proteins were determined by the biuret method, and albumin, α-globulins, β(1) -globulins, β(2) -globulins and γ-globulins concentrations were assessed using an automated system. One-way repeated measures analysis of variance was applied to determine the significant effect of different physiological phases on the parameters studied. During the late pregnancy and post-partum, total proteins, β1- and β2-globulins and γ-globulins showed the highest values. Starting from post-partum, α-globulins increased to reach their peaks in mid-lactation. Early lactation was characterized by low γ-globulins values. The increase in serum albumin concentration and the drop in some globulin fractions determined the significant increase in albumin/globulin ratio. The obtained results contributed to improve the knowledge on electrophoretic profile during the different physiological phases in ewes, confirming that pregnancy and lactation periods affect the protein metabolism. Particularly, serum protein fractions pattern could give information about dehydration, plasma volume expansion and hepatic function, which occur during the different physiological phases. Dynamics of the protein profile - from pregnancy to dry period - which are provided by our results, could be considered as guidelines for the management strategies to guarantee the nutritional needs of these animals during the different physiological phases and to avoid a decline of productive performance and consequently an economic loss.

Daily rhythm of tear production in normal dog maintained under different Light/Dark cycles

This study was conduced to assess the daily rhythm of tear production in clinically healthy dog. For our study eight female purebred Beagles were subjected to three different Light/Dark schedules: 12/12L/D, 24/0L/D and 0/24L/D cycles. In all subjects Schirmer tear test I was performed at 4h intervals over a 24h period. A statistical significant effect of photoperiod was observed comparing the three different L/D schedules, and a statistical significant difference was observed comparing left and right eye during the 12/12L/D schedule. We demonstrated daily variation of tear production in dogs maintained under an L/D cycle. We also provided strong evidence that the rhythm of tear production is endogenously generated because it persisted in constant darkness. Although the range of excursion of the daily/circadian oscillation in STT I (about 2mm/min) is likely too narrow to be of clinical significance, it is statistically significant and may have physiological implications not yet appreciated.

Electrocardiographic changes induced by physical exercise in the jumper horse

Realizou-se uma investigacao eletrocardiografica em oito cavalos saltadores de raca Sella Italiana para avaliar as modificacoes cardiovasculares associadas com competicoes desportivas especificas. O registro eletrocardiografico foi realizado com eletrocardiografo digital de multiplos canais com calibracao de 10 mm/mV e velocidade de 25 mm/s. Registros foram obtidos nas seguintes condicoes: em repouso, durante o aquecimento, apos uma sessao de saltos e 15 e 30 minutos apos a sessao de saltos. Reducoes significativas foram observadas na duracao da onda P, do intervalo P-Q e dos intervalos R-R imediatamente apos o teste. Elevacoes significativas foram observadas nos limites de variacao das ondas T e P e da frequencia cardiaca. Essas modificacoes podem ser atribuidas primariamente a elevacao da atividade simpatica ligada a elevacao da frequencia cardiaca necessaria para o aumento do debito cardiaco. Estes resultados podem ser extremamente uteis no planejamento e monitoria de programas especificos de treinamento.

Influence of time of day on body temperature, heart rate, arterial pressure, and other biological variables in horses during incremental exercise.

We examined the response to exercise of selected physiological variables in horses performing the identical routine for eight days, in the morning (a.m.) or in the afternoon (p.m.). Heart rate (HR), systolic and diastolic blood pressure (BP), and body temperature (BT) were all consistently greater in the p.m. For BP and BT, the absolute increase above the a.m. values was the same at rest and during exercise. For HR, the absolute increase was greater during exercise, but the percent increase was the same as during rest. During exercise, blood glucose decreased, while blood lactate and skin temperature increased; these changes were the same during the a.m. and p.m. sessions. We conclude that there is no indication in horses of a difference in the responses of HR, BP, and BT to exercise between the a.m. and p.m. The circadian oscillations, however, alter the absolute values of these variables both at rest and during exercise, raising the possibility that the safety margins against hyperthermia and hypertension may decrease during p.m. exercise.

Daily pattern of some fatty acids in the athletic horse

In the sport field, non-esterified fatty acids (NEFA) are important for the physical performance during the aerobic exercise of short intensity and long duration. In man, rat, goat and in the sedentary horse studies on the chronometabolism showed the presence of a circadian rhythm of the plasmatic concentration of NEFA while data for the athletic horse are lacking. To define a chronogram helpful for a specific planning and the differentiation of the training programmme in the athletic horse, the circadian pattern of some fatty acids (NEFA, palmitic, stearic, oleic, linoleic and linolenic acids) was studied in five Sella Italiana horses. These horses trained following a daily model of activity consisting of walk, trot, gallop and jump of obstacles of different heights. Blood samples were collected from the jugular vein every 4 h, starting at 08:00 hours, for 2 days to assess the concentrations of total NEFA (by spectrophotometry), palmitic, stearic, oleic, linoleic and linolenic acids (by gas chromatography). anova for repeated measures showed a statistical significant effect of the time of the day in NEFA, oleic and linolenic acids. The application of the periodic model showed the periodic pattern of NEFA, oleic, linoleic and linolenic acids. Acrophases were in the afternoon for all parameters. The results obtained showed a different trend of the circadian pattern of the studied parameters in the athletic horse than in the sedentary one because the physical activity and the post-prandial metabolism acted as zeitgebers.