Erythrocyte Osmotic Fragility and Hematological Responses of Horses Administered Ascorbic Acid and Exposed to Road Transportation

Thermoregulatory, oxidative stress and lipid responses in prepartum ewes administered with L-carnosine during the hot-dry season

The aim of the study was to investigate the effects of L-carnosine administration to prepartum ewes on oxidative status, lipid profile and thermoregulatory responses in the tropics during the hot-dry season. Twenty pregnant ewes were allotted each into two groups of treated and untreated ewes. The untreated ewes received orally 10 mL of water, while treated ewes were administered orally with L-carnosine (100 mg/kg) daily during the last 3 weeks of gestation. Blood samples were obtained during pre-gestation on day 0, gestation days 136 and 143 and after lambing. Dry-bulb temperatures (DBTs) of the pen were measured once per week at 06:00, 14:00 and 18:00 h as well as the thermoregulatory responses of the ewes. Birth weights of the lambs were determined 2-3 h postpartum. The DBT (37.33 ± 1.20 °C) and temperature-humidity index (85.24 ± 1.91) were above the thermoneutral zone. The results revealed no significant effect of L-carnosine on thermoregulatory responses of ewes and on the live-birth weight of their lambs. Malondialdehyde, 8-isoprostane and triglyceride concentrations were lower (P < 0.05) in treated ewes than in untreated ewes, but superoxide dismutase, catalase and glutathione peroxidase activities were higher (P < 0.05) in treated ewes compared to untreated ewes. In conclusion, L-carnosine reduced lipo-peroxidative products and augmented antioxidant enzyme activities in prepartum ewes under hot-dry conditions.

Daytime Evaluation of Oxidative Stress and Behavioural Parameters of Donkeys (Equus asinus) During The Hot-Dry and Cold-Dry (Harmattan) Season in a Tropical Savannah

The aim of the study was to evaluate oxidative stress and behavioural responses of donkeys during the cold-dry and hot-dry seasons. Thirty donkeys divided into three groups of ten donkeys each according to their age served as experimental subjects. During each season, behavioural and blood parameters of the donkeys were evaluated three times with an interval of one week at 06:00 h, 12:00 h and 18:00 h (GMT+1). During the hot-dry season, the peak dry-bulb temperature (DBT) value of 36.00 ± 1.00°C was recorded at 12:00 h, indicating that the season induced heat stress. The time spent feeding demonstrated diurnal fluctuations in adult, yearling and foal donkeys, with the highest time occurring at 12:00 h in both seasons. The malondialdehyde (MDA) concentrations in adults (2.34 ± 0.14 nMol/L), yearlings (2.28 ± 0.19 nMol/L) and foals (3.48 ± 0.17 nMol/L) during the hot-dry season were significantly (P < 0.05) higher, when compared to the corresponding values (0.96 ± 0.09, 1.18 ± 0.10 and 1.82 ± 0.10 nMol/L, respectively) recorded during the cold-dry season. At 0.3% NaCl-concentration, the percentage haemolysis obtained during the hot-dry season in adult (90.33 ± 0.49%), yearling (91.24 ± 0.88%) and foal (97.44 ± 0.24%) donkeys were significantly (P < 0.05) higher than the corresponding values (78.53 ± 0.98, 78.67 ± 0.58 and 88.23 ± 0.47%, respectively), recorded during the cold-dry season. In conclusion, the hot-dry season induced heat stress in the donkeys, resulting in a decrease in time spent on feeding and oxidative stress, as evidenced by high erythrocyte MDA concentration and percentage haemolysis.

Farming systems in sheep rearing: Impact on growth and reproductive performance, nutrient digestibility, disease incidence and heat stress indices

The experiment was conducted with an intent to know the effect of different farming systems on the growth performance, nutrient digestibility coefficients, reproductive traits, disease incidence, heat stress indices, and cost economics of Nellore sheep. The study includes two parallel trials to prevent the influence of age on heat stress indices (panting score and erythrocyte osmotic fragility (EOF)). One hundred and twenty lambs (60 ram-lambs and 60 ewe-lambs) were allotted in a randomized block design under extensive, semi-intensive, and intensive systems for trial I, whereas trial II include eighteen rams assigned to the three respective farming systems in a completely randomised design. Both, season (summer) and grazing practice increased the panting score and EOF. The heat stress indices were positively correlated (P<0.01) with dry-bulb temperature and temperature-humidity index (THI) and inversely correlated (P<0.01) to relative humidity. Allotting the sheep to intensive system increased (P<0.001) weight gain and average daily gain with higher effect in males compared to females. The parameters of asymptotic weight (A), integration constant (B), and maturation rate were higher for intensive males. The male Nellore lambs had higher asymptotic weight and lower maturity rate than females, irrespective of the rearing system. Intensive sheep revealed a higher dry matter intake, digestibility coefficients, feed conversion ratio. The instantaneous bite mass (IBM) was higher for Commelina benghalensis, while instantaneous bite frequency (IBF), instantaneous intake rate (IIR) were higher for Cyanodon dactylon and amaranthus viridis, respectively. The proportion of intakes were highest for Stylo hemata followed by Cynodon dactylon and Tridax procumbens species. No differences were observed for the weight at puberty, oestrus cycle length, oestrus duration, conception percent, gestation period, and lambing percent in three rearing systems; however, the age at puberty was lower (P<0.001) and the birth weight was higher (P<0.001) for sheep reared under intensive farming system. Highest disease incidence was observed in rainy and winter seasons, particularly in sheep reared under extensive system. The capital expenditure was same for the three rearing systems, while the recurring expenditure was higher for Intensive farming system. The gross income and net income were higher for intensive system on account of higher weight gains. However, the higher returns per rupee of expenditure project the extensive farming as an ideal rearing system for small farmers and entrepreneurs with a low initial capital.

Cobalt accumulation in horses following repeated administration of cobalt chloride

OBJECTIVE

To monitor cobalt concentrations in urine, red blood cells and plasma after chronic parenteral administration of cobalt chloride evaluate these results against the current International Federation of Horseracing Authorities thresholds for detecting cobalt misuse.

DESIGN

Eight mares were randomly assigned to four treatment groups, with two mares in each group: Group 1 - control group, Group 2 - 25 milligrams cobalt intravenously as CoCl₂ weekly, Group 3 - 50 milligrams cobalt intravenously as CoCl₂ weekly, and Group 4 - 25 milligrams cobalt intravenously mid-week and at the end of the week. Urine and blood samples were collected before each weekly administration so that trough levels were assessed. In the group receiving two doses per week, urine and blood were collected prior to the dose given at the end of each week. Samples were initially collected at time zero then weekly for 10 weeks. Three further collections of urine and blood were made at days 81, 106 and 127.

METHODS

Urine creatinine measurements to assess horse hydration status were performed by the Jaffe reaction method. Cobalt determinations in plasma, blood and urine were by inductively coupled plasma-mass spectrometry. Haematocrit concentrations, used to calculate red cell cobalt levels, were performed using a microhematocrit centrifuge. Statistical analyses were conducted in Genstat (v17, VSNi).

RESULTS

Marked cobalt accumulation was evident with increasing cobalt concentrations for all sample matrices in specimens collected immediately prior to cobalt administration. Correlation between the sample matrices improved when urine cobalt concentration was adjusted for creatinine level. Red cell cobalt levels remained elevated for at least 12 weeks after cessation of administration, consistent with the lifespan of the red cell. There was no significant change in haematocrit concentrations for the duration of the study.

CONCLUSION

The current urine cobalt threshold was only effective at detecting acute cobalt exposure while the plasma cobalt threshold was able to consistently identify chronic high-level cobalt exposure and potential cobalt misuse. The threshold values legislated for urine cobalt do not correlate with those set for plasma. The acute nature of urinary cobalt excretion provides a relatively small window through which cobalt administration is detected. Plasma and red cell cobalt concentrations can provide a clearer picture of potential cobalt misuse.

Effects of L-glutamine on rectal temperature and some markers of oxidative stress in Red Sokoto goats during the hot-dry season

The experiment investigated the ameliorative effects of L-glutamine administration on rectal temperature (RT), erythrocyte osmotic fragility (EOF), serum antioxidant enzyme activities and malondialdehyde (MDA) concentration in Red Sokoto goats during the hot-dry season. Twenty eight healthy Red Sokoto goats, comprising 14 experimental (administered 0.2 g/kg of L-glutamine dissolved in 10 mL of distilled water, once daily for 21 days) and 14 control (administered equivalent of distilled water) goats served as subjects. Rectal temperature (measured at 6:00, 13:00 and 18:00 h) and blood samples (taken at 8:00 h) were obtained from all subjects weekly, before, during and after L-glutamine administration. Data obtained were compared using one-way repeated-measures ANOVA, followed by Tukey's post-hoc test. The dry-bulb temperature, relative humidity and temperature-humidity index for the study period ranged between 24.0 and 37.5 °C, 26.0 and 84.0% and 73.0 and 86.3, respectively. L-glutamine administration decreased (P < 0.05) RT, EOF and MDA and increased superoxide dismutase (SOD) activity in experimental group, compared to controls during weeks 1, 2 and 3. Glutathione peroxidase (GPx) and catalase activities were higher (P < 0.05) in the experimental group than in the controls only during week 1 of L-glutamine administration. In conclusion, L-glutamine administration mitigated increases in RT, EOF and serum MDA concentration and enhanced serum SOD, GPx and catalase activities and may be beneficial in heat-stressed goats during the hot-dry season.