BACKGROUND: Many physiological processes of mammalian species exhibit daily rhythmicity. An intrinsic relationship exists between fat soluble vitamins (A, D, E and K) and several body functions. Few ...investigations on the rhythmic pattern of vitamins in domestic animals have been carried out. The present study evaluated the circadian rhythmicity of fat soluble vitamins in the horse. METHODS: Blood samples from 5 Thoroughbred mares were collected at four-hour intervals over a 48-hour period (starting at 8:00 hours on day 1 and finishing at 4:00 on day 2) via an intravenous cannula inserted into the jugular vein. Fat soluble vitamin concentration in the serum (A, D, E and K) was measured by HPLC. One-way repeated measures analysis of variance (ANOVA) was used to determine significant differences. p values < 0.05 were considered statistically significant. RESULTS: ANOVA showed a highly significant effect of time in all the horses for the vitamins studied (p < 0.0001). The application of the periodic model and the statistical analysis of the "Cosinor" enabled us to define the periodic parameters and their acrophases (expressed in hours) during the 2 days of monitoring: all the studied vitamins showed diurnal acrophases with values between 15:16 and 18:08 hours. CONCLUSION: Fat soluble vitamins exhibit daily rhythmicity with diurnal peak. Further investigations could help optimize the use of these substances according to their circadian (or other) rhythms.
The goal of this study was to investigate the influence of physical activity on the daily rhythm of platelet aggregation and body temperature in horses. Blood samples from 12 Thoroughbred horses, six ...sedentary animals and six athletes (studied both before and after a period of inactivity) were collected at 4
h intervals for 48
h via an intravenous cannula inserted into the jugular vein. Body temperature was recorded every 4
h for 48
h with a rectal probe. Platelet aggregation was measured with an aggregometer. Collagen was used to test the aggregation of the plasma samples. Statistical analysis of the data was performed by one-way repeated-measures analysis of variance (ANOVA) and by single cosinor method. Cosinor analysis identified the periodic parameters and their acrophases (expressed in hours) during the 2 days of monitoring. On each single day, there was a highly significant effect of time in all the horses, with
P values <0.05. Temperature rhythms were unaffected by exercise. Platelet aggregation in exercising horses differed from the sedentary horses, and this difference disappeared after a 2-week period of rest. The results could be interpreted as indicating that physical exercise has an influence on the daily rhythm of platelet aggregation in horses.
Effects of physiological variables (age, body weight and sex) on lipemia (total lipids, phospholipids, triglycerides and NEFA), fecal fat and chymotrypsin excretion were examined in dogs. On ...comparing various ages and body weights, they found statistically significant differences, while only total lipids showed a statistically significant difference between the two sexes. Moreover, there was a significant correlation between body weight and fecal fat and chymotrypsin excretion. The results obtained contribute to the evaluation of small intestine functionality, especially in relation to some diseases, as malabsorption, maldigestion and steatorrhea in the dog.
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.
Background: The effect of storage temperature and time on blood gas and acid‐base values has been investigated intensively in cattle and dogs; however, data are lacking in other species. Objective: ...The aim of our study was to evaluate changes in gas composition and acid‐base values in venous blood stored at different temperatures and for different times in 4 domestic species in Italy. Methods: Blood samples from Comisana sheep (n=10), Maltese goats (n=10), Ragusana donkeys (n=10), and Thoroughbred horses (n=10) were analyzed after storage at 23°C (room temperature) for 15 minutes (group I), 23°C for 1 hour (group II), 37°C for 8 hours (group III), and 4°C for 24 hours (group IV). Results were analyzed using a 1‐way repeated measures ANOVA. Results: In all species no statistically significant differences in pH values were present in samples stored at 4°C for 24 hours. This also was true for Pco2 in all species except the horse. Except for HCO3− concentration in the horse, significant changes in Po2, HCO3− concentration, base excess, and the standard bicarbonate concentration were observed for all species in samples stored at 4°C. In samples stored for only 1 hour at room temperature, significant changes in most analytes were detected. Conclusions: The results of this study underline the need for rapid assessment of acid‐base samples, because any delay, even for 1 hour, may affect the results.
Leptin je hormon koji uglavnom proizvode adipociti. Utjecaj tjelesne vježbe na razinu serumskog leptina u konja dosada nije istražen. U ovom istraživanju cilj je bio utvrditi razlike u koncentraciji ...leptina i glukoze u tijeku preskakanja prepona. Osim toga, određivana je i koncentracija laktata u krvi radi procjene jačine opterećenja. U istraživanje je bilo uključeno 8 talijanskih Sella konja. Vježba je uključivala 6 preskakivanja različitih visina (između 100 i 140 cm). Uzorci krvi uzeti su iz jugularne vene u sljedećim vremenskim razmacima: u tijeku odmora, neposredno nakon vježbe, 30 min nakon vježbe i 24 sata nakon vježbe. Koncentracija laktata u krvi utvrđena je terenskim instrumentom (Accusport Boehringer Mannheim, Monza, Italy), koncentracija glukoze pomoću enzimske kolorimetrijske metode GOD-PAP, a koncentracija serumskog leptina pomoću ELISA kitova. Primjenom analize ponovljenih mjerenja ANOVA, utvrđene su statistički značajne vrijednosti za laktat F(7,21) = 34.35 (P<0.0001) i za glukozu F(7,21) = 8.706 (P<0.0003). Razlike u vrijednostima za koncentraciju serumskog leptina nisu bile statistički značajne. Polučeni rezultati pokazuju da kratkotrajna vježba, poput preskakanja prepona ne utječe na koncentraciju serumskog leptina.
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