Biological Rhythm in Livestock

n/

Daily and estrous rhythmicity of body temperature in domestic cattle

BACKGROUND: Rhythmicity in core body temperature has been extensively studied in humans and laboratory animals but much less in farm animals. Extending the study of rhythmicity of body temperature to farm animals is important not only from a comparative perspective but also from an economic perspective, as greater knowledge of this process can lead to improvements in livestock production practices. In this study in cattle, we investigated the maturation of the daily rhythm of body temperature in newborn calves, characterized the parameters of the daily rhythm in young cows, and studied the oscillation in body temperature associated with the estrous cycle in adult cows. RESULTS: We found that the daily rhythm of body temperature is absent at birth but matures fully during the first two months of life. The mature rhythm had a mean level of 38.3°C, a range of excursion of 1.4°C, and was more robust than that of any mammalian species previously studied (90% of maximal robustness). Sexually mature cows also exhibited a robust estrous rhythm of body temperature. An elevation of about 1.3°C was observed every 21 days on the day of estrus. Small seasonal variations in this pattern were observed. CONCLUSION: In conclusion, calves exhibit a very robust daily rhythm of body temperature, although this rhythm is absent at birth and develops during the first two months of life. Adult cows exhibit also 21-day rhythmicity in body temperature reflecting the duration of the estrous cycle

Daily rhythms of liver-function indicators in rabbits.

Serum concentrations of urea and cholesterol were used as indicators of liver function in rabbits in an investigation of the responsiveness of the daily rhythm of liver function to phase shifts in the environmental light-dark cycle. Locomotor activity was simultaneously monitored by actigraphy. Serum urea and cholesterol concentrations exhibited robust daily rhythmicity with opposite phases. Both indicators of liver function phase shifted in response to phase shifts of the light-dark cycle. The phase shifts in liver function appeared to be parallel to phase shifts in locomotor activity, but the data were not sufficiently strong to confirm that the liver relies on the secondary effect of photic phase shift on ingestive behavior in order to be phase-shifted by light as previously indicated by gene expression studies in laboratory rodents

Energetski kronometabolizam u novozelandskog bijelog kunića.

The temporal organization of some physiological parameters in rabbits by evaluating the circatrigintan rhythms of some haematochemical and haematological parameters, and of rectal temperature, in New Zealand white rabbits was studied. For 30 days before the study the animals all followed the same pattern of daily activity with the natural photoperiod for that season, and were fed on hay ad libitum. Subsequently, the same animals followed another pattern of daily activity for a further 30-day period with a natural photoperiod and were fed on commercial pellets. At the end of each experimental period, blood samples were taken and rectal temperature was measured every 5 days for 30 days. Spectrophotometry in UV was used to calculate the concentration in each sample of: glucose, NEFA, triglycerides, total cholesterol, total proteins, uric acid, urea, albumin, creatinine, calcium, phosphorus and magnesium. The following values were measured on samples rendered unclottable: haematocrit, haemoglobin, RBC, MCV, WBC and VES. A periodic statistical model was used to elaborate the data, on average values of the two sets of samples. Intra-group variance was not significant. Glucose, triglycerides, RBC, Hb, PCV and rectal temperature showed a circatrigintan rhythm in both the experimental periods, but with different acrophases; creatinine, magnesium and phosphorus showed periodicity only when the subjects were fed on hay, while total proteins, urea, albumin and calcium were periodic only when they were fed with commercial pellets. The results obtained showed that the type of ration synchronizes the circatrigintan rhythm of some haematochemical and haematological parameters in the rabbit.Istražena je pojavnost određenih fizioloških osobina na osnovi prosudbe mjesečnog ritma nekih biokemijskih i hematoloških pokazatelja i rektalne temperature u novozelandskog bijelog kunića. Trideset dana su životinje bile držane pod jednakim uvjetima trajanja prirodne svjetlosti i hranjene sijenom ad libitum. U drugom tridesetdnevnom razdoblju držane su pod drugim načinom dnevnih aktivnosti s prirodnim trajanjem dnevne svjetlosti te hranjene komercijalnom peletiranom hranom. Na kraju svakog pokusnog razdoblja uzimani su uzorci krvi i mjerena temperatura svakog petog dana u tijeku 30 dana. UV-spektrofotometrijom određena je u svakom uzetom uzorku koncentracija glukoze, NEFA, triglicerida, ukupnog kolesterola, ukupnih bjelančevina, mokraćne kiseline, mokraćevine, albumina, kreatinina, kalcija, fosfora i magnezija. Određivan je hematokrit, hemoglobin, broj eritrocita, leukocita i VES. Podaci su obrađeni periodičkim statističkim modelom na razini prosječnih vrijednosti dvije skupine uzoraka. Varijanca između skupina nije bila značajna. Vrijednosti glukoze, triglicerida, hemoglobina, PVC te broj eritrocita i vrijednost rektalne temperature pokazivale su tridesetdnevni ritam u oba pokusna razdoblja, ali s različitim najvišim fazama. Vrijednosti kreatinina, magnezija i fosfora pokazivale su periodičnost samo kad su životinje bile hranjene sijenom dok su vrijednosti ukupnih bjelančevina, mokraćevine, albumina i kalcija pokazivale periodičnost kad su životinje bile hranjene peletiranom komercijalnom hranom. Dobiveni rezultati su pokazali da vrst obroka usklađuje tridesetdnevni ritam određenih biokemijskih i hematoloških pokazatelja u kunića

Daily rhythm of circulating fat soluble vitamin concentration (A, D, E and K) in the horse

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

Daily rhythm of salivary and serum urea concentration in sheep

BACKGROUND: In domestic animals many biochemical and physiological processes exhibit daily rhythmicity. The aim of the present study was to investigate the rhythmic pattern of salivary and serum urea concentrations in sheep. METHODS: Six 3-year-old female sheep kept in the same environmental conditions were used. Sheep were sampled at 4 hour intervals for 48 consecutive hours starting at 08:00 of the first day and finishing at 04:00 of the second day. Blood samples were collected via intravenous cannulae inserted into the jugular vein; saliva samples were collected through a specific tube, the "Salivette". Salivary and serum urea concentrations were assayed by means of UV spectrophotometer. ANOVA was used to determine significant differences. The single Cosinor procedure was applied to the results showing significant differences over time. RESULTS: ANOVA showed a significant effect of time on salivary and serum urea concentrations. Serum and salivary urea peaked during the light phase. In the dark phase serum and salivary urea concentrations decreased, and the diurnal trough occurred at midnight. Cosinor analysis showed diurnal acrophases for salivary and serum urea concentrations. Daily mean levels were significantly higher in the serum than in the saliva. CONCLUSION: In sheep both salivary and serum urea concentrations showed daily fluctuations. Urea is synthesized in the liver and its production is strongly influenced by food intake. Future investigation should clarify whether daily urea rhythms in sheep are endogenous or are simply the result of the temporal administration of food

Thirty-day rhythmicity in electrocardiographic and electrolytic parameters in the athletic horse

This paper describes circatrigintan progress of some electrocardiographic parameters and of the serum electrolytes in the jumper horse during a period of pre-competitive training performed in order to define the temporal organization of some parameters employed to evaluate the athletic performance of the horse. Five Sella Italiana horses, clinically healthy and specifically trained have been utilized for the study. All the subjects have undergone electrocardiographic recordings and blood sample takings by means of jugular venopuncture, at rest and always at the same hour, every five days for a period of one month. The following electrocardiographic parameters have been measured on individual ECG-recordings: P wave duration and amplitude, P-Q interval duration, QRS complex duration, R wave amplitude, T wave duration, S-T segment duration, Q-T interval duration, the longest and shortest R-R intervals; besides, mean R-R interval and D R-R, the highest, lowest and mean heart rate, have been calculated. The concentrations of magnesium, calcium, phosphorus and chlorine and of sodium and potassium have been determined on the blood samples, respectively by UV spectrophotometry and by flaming. The application of a statistic trigonometric model has permitted to point out the circatrigintan periodicity of the following electrocardiographic parameters: P wave duration, T wave duration, R wave amplitude, mean R-R interval and mean heart rate, and of the following serum electrolytes: sodium and magnesium. Based on these results, it is hypothesized that the cardiovascular system follows a “deterministic” progress with a “linear” variability systematically predictable within the temporal period considered

Utjecaj kratkotrajne vježbe na koncentraciju serumskog leptina u konja.

Leptin is a protein hormone produced predominantly by adipocytes. The influence of physical exercise on serum leptin levels was not studied in the horse. The aim of our research is to evaluate, in this species, the variations of leptin and glucose concentration during show jumping. Moreover, blood lactate concentration was determined in order to evaluate the intensity of the effort. Eight Sella Italiana horses were used for this study. The test consisted of six jumping trials at different heights (between 100 and 140 cm). Blood samples were collected through jugular venipuncture on the following experimental conditions: at rest, immediately after the trial, 30 min after the trial and 24 h after the trial. Blood lactate concentration was immediately analyzed with a field meter (Accusport Boehringer Mannheim, Monza, Italy). Glucose concentration was determined by the enzymatic colorimetric method GOD-PAP, while serum leptin concentration was quantified by using ELISA kits. From analysis of obtained results, applying repeated measures ANOVA, P value for lactate was P<0.0001, with a F(7,21)= 34.35 and for glucose was P<0.0003, with a F(7, 21)= 8.706, while no statistical significance was observed for serum leptin concentration. Obtained results showed that short duration exercise, as show jumping, does not affect serum leptin levels.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