EFFECTS OF ASCORBIC ACID ON SOME PHYSIOLOGICAL PARAMETERS AND BIOMARKERS OF OXIDATIVE STRESS IN PACK DONKEYS (Equus asinus) TRANSPORTED BY ROAD DURING THE HARMATTAN SEASON

Abstract
The aim of the study was to determine the physiological responses of pack donkeys, administered with ascorbic acid (AA) and transported by road for 4 h during the harmattan season in the Northern Guinea Savannah zone of Nigeria. During the study period the thermal environmental parameters, values of rectal temperature (RT), respiratory rate (RR), heart rate (HR), haematological parameters, erythrocyte osmotic fragility (EOF), malondialdehyde and electrolyte concentrations were determined before, during and after the transportation using standard methods. The minimum and maximum values of dry-bulb temperature (DBT) were 13oC and 32 oC, respectively, and the corresponding relative humidity (RH) values of 10 % and 37% were recorded during the study period. The temperature humidity index (THI) fluctuated between 11 oC and 29 oC. The values of thermal environmental parameters were outside the thermoneutral zone, established for the donkey, which indicated that the season was thermally stressful. The overall value of RT (36.6 ± 0.3 oC) obtained in test donkeys and that recorded in the control donkeys (36.3 ± 0.3 oC) did not differ significantly. The RT values recorded in test and control donkeys (35.8 ± 0.2 oC and 35.4 ± 0.2 oC, respectively) for three consecutive days after transportation were not significantly different, but the values were lower (P < 0.05) than the corresponding pre-transportation values of 37.0 ± 0.1 o C and 37.0 ± 0.2 oC, respectively. Handling, loading and transportation did not increase the RT above the pre-transportation values and the normal range in the donkey. The RR values of 17.5 ± 1.8 and 17.2 ± 0.9 breaths/min, recorded in tested and control donkeys, respectively after loading were not higher than the corresponding pre-loading values of 16.6 ± 0.8 and 16.1 ± 0.8 breaths/min, respectively. The HR values in test (45.3 ± 2.1 beats/min) and control donkeys (43.8 ± 1.8 beats/min), recorded after the transportation were not significantly different, and they did not differ from the corresponding pre-transportation values of 48.4 ± 1.6 oC and 49.0 ± 1.2 oC, respectively. The values of N:L ratio obtained in test and control donkeys before transportation were 1.6 ± 0.3 and 1.4 ± 0.5, respectively; but after transportation, the values decreased to 0.8 ± 0.1 and 1.0 ± 0.1, respectively. The post-transportation value of N:L ratio was higher (P < 0.05) in controls than that of the test donkeys. EOF decreased after loading (P < 0.05) at 0.3 % NaCl in the test donkeys compared to that of the control donkeys, and the values obtained were 30.5 ± 0.6 % and 49.5 ± 0.4 %, respectively. At 0.1 % NaCl, the post-transportation EOF value in test donkeys was lower than that of the controls, and the values obtained immediately after the journey and 3 days posttransportation. Malondialdehyde concentration decreased in the test compared to that of the control donkeys after the transportation. Na+ concentration of 132.8 ± 2.2 mMol/L recorded after transportation in test donkeys was not significantly different from that of 135.6 ± 0.7 mMol/L obtained in control donkeys. There were no significant differences in K + , Cl- , HCO₃ - and urea concentrations obtained pre- and post-transportation in between the control and test donkeys, and the concentrations recorded in both the test and control donkeys after the transportation. In conclusion, AA administration prior to 4 h of road transportation in pack donkeys decreased the adverse effects of the transportation on RT, EOF and N/L ratio, and the ameliorative effect of AA was particularly significant after loading and immediately after the transportation.
Description
A THESIS SUBMITTED TO SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA
Keywords
EFFECTS OF ASCORBIC ACID,, SOME PHYSIOLOGICAL PARAMETERS,, BIOMARKERS OF OXIDATIVE,, STRESS IN PACK DONKEYS,, TRANSPORTED BY ROAD,, DURING THE HARMATTAN SEASON.
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