ISRAEL JOURNAL OF
VETERINARY MEDICINE
THE INFLUENCE OF LATE PREGNANCY AND
EXCITEMENT ON BLOOD PARAMETERS OF ISSA TYPE
DROMEDARIES IN EASTERN ETHIOPIA
Getnet1, A.M. and Abebe, W.2
1. Utrecht University, Faculty of Veterinary Medicine, 80.3505 TD Utrecht, The
Netherlands
Vol. 60 (4) 2005 1. National Animal Health Research Center, P.O.Box 04, Sebeta, Ethiopia.
2. Addis Ababa University, Faculty of Veterinary Medicine, P.O.Box 34, Debre
Zeit, Ethiopia
* Address: For Correspondence Yalelaan 1, P.O. Box 80.158, 3508 TD, Utrecht,
The Netherlands. E mail- getabmek@yahoo.com
Summary
The study was conducted in eastern Ethiopia, in and around Dire Dawa
administrative council, in an attempt to see the influence of late pregnancy
and excitement on blood values of Issa type dromedaries.
Blood values were determined using standard hematological methods. An
Improved Neubauer Haemoctytometer was used to determine RBC and
WBC counts. Sahli Helling's and Microhematocrit methods were used to
determine Hb and PCV values respectively.
Mean blood values found for camels at the stage of late pregnancy include:
RBC- 7.38±0.36 mil/µl, PCV- 26.46±1.02 %, Hb- 12.6±0.48 g% and WBC14.7±1.66 x 103/µl. RBC, PCV, Hb and total WBC were higher as compared
with not pregnant animals.
An increase in the values of RBC-1.88 mil/µl, total WBC-1.4 x 10 3/µl, PCV2.15 % and Hb- 1 g% were seen for excited camels compared to those that
were in non-destabilized state.
The Wintrobe indices of erythrocytes and the differential counts of leukocytes
were also calculated and the influences due to these physiological
phenomena are discussed. From this study it is noted that late pregnancy
and excitement are found to affect the blood values, thus care has to be
taken during interpretation of blood values for disease diagnosis.
Key words: blood values, Ethiopia, excitement, Issa type dromedaries, late
pregnancy
Abbreviations: RBC- red blood cells, WBC- white blood cells, PCV- packed
cell volume, Hb- hemoglobin concentration, MCHC- mean corpuscular
hemoglobin concentration, MCV- mean corpuscular volume, MHC- mean
hemoglobin concentration
Introduction
The dromedarian camel is distributed in Africa, Middle East and the Indian
sub-continent (Lensch, 1999). It is far superior to the two-humped camel in
number and over 75% are found in Africa (Wilson, 1984). Ethiopia possesses
over one million camels mainly distributed in the southern, eastern and
northeast arid and semi-arid regions of Borana, Ogaden and Afar
(Alemayehu, 1998).
The camel plays a significant role in the socio-economic affairs of the nomadic
people in providing meat, milk and draught power (Abebe, 1991 and Tegegne,
1991). The love, affection and admiration the nomadic people have for the
camel are very deep. It is the standard of measurement for them against
which every thing is weighed. Wealth, status and subsistence of the nomadic
people are based on it. Camels are also used as bride price and for sacrifice
in nomadic culture (Tegegne, 1991). Despite its significant contribution to the
livelihood of pastoral societies, the camel is one of the neglected and least
exploited animals in Ethiopia (Zeleke et al., 2000). There have been very few
systematic researches and expertise on camels. The available information is
based mainly on milk production indices and reproductive parameters. Very
few attempts have been made so far to characterize the physiological
parameters of a healthy camel. Studies directed towards gathering baseline
data on such parameters have paramount importance for professionals and
researchers interested in camels for clear understanding and interpretations
of physiological and pathological abnormalities. Parameters such as blood
values, biochemical and electrolytic substances in the body are known to be
affected as the result of pregnancy and stresses to maintain the normal
physiologic state. The camel has many physiologically unique features as
compared to other species of animals so that it is capable of adapting to the
desert climate.
This study was designed to see the influence of late pregnancy and
mechanically induced excitation on blood values of Issa camels in eastern
Ethiopia. Issa type camels are reported to have good meat producing
potential next to the Borana and Ogaden type camels of Ethiopia (Mekonnen,
2004).
Materials and Methods
Study Areas
The study was conducted in and around Dire Dawa Administrative Council,
eastern Ethiopia. Physiographically it is amongst the most broken and
mountainous regions of Ethiopia and it is composed of diversified topographic
features. The main climatic divisions of the area are low land and midhighland. The annual rainfall varies from 440mm to 760mm, the rainfall
pattern being bimodal. The mean maximum and minimum temperatures range
between 22.7-34.6oC and 11.5-29oC respectively.
Study Animals and Study Design
People of Issa clan dwelling in the study area owned the study animals and
the production system of camels was traditional. The common feeds for
camels in the area include bushes (mainly Atriplex and Cacia species) and
shrubs (Acacia and Kochia species). The frequency of watering was usually
2-5 days; however, during rainy seasons as bushes and shrubs become very
green and contain much water; camels stay up to 20 days without drinking.
Supplementary feeding was not practiced in the area. During the night,
camels were kept in kraals fenced by branches of acacia trees. Young
suckling calves were kept and nursed in separate kraals beside the adults.
For the study of the influence of late pregnancy on blood values, 26 healthy
camels, 13 at the stage of late pregnancy (8-12 months) and 13 non-pregnant
females of similar body weight and age were selected from breeder camel
herds. The health status of camels was assumed healthy based on the
following criteria: parasitic burden less than 700 eggs per gram of faeces
(Graber, 1973), free from any visible signs of diseases and normal rectal
temperature, pulse and respiratory rates.
For the study of the influence of excitement on blood values, 39 camels of
similar age groups (>10 years of age, as determined by dentition pattern and
owners information according to Payne, 1990) were purposively selected
among camels to be slaughtered in the Dire Dawa municipal abattoir and
blood samples were taken two times from each camel. Once during the antemortem examinations while the animal was in an insignificantly destabilized
state and the other after the animal was introduced to the slaughterhouse,
and the calcaneus communis tendons were severed prior to slaughter (the
system adopted by the local butchers for slaughter). Camels were neither fed
nor watered between first and second sampling (interval of 4-5 hours) and
they showed no signs that can directly or indirectly affect the blood values
such as diarrhea and vomiting.
Blood samples were taken from the jugular vein using double pointed needles
and heparinized vacutainer tubes and were kept at +40C until analysis.
Laboratory Techniques
Blood values were determined based on the standard hematological
techniques (Jain, 1986). An Improved Neubauer Haemoctytometer was used
to determine the values of RBC and WBC counts. Sahli Helling's and
Microhematocrit methods were used to determine Hb and PCV values
respectively. The MCV, MCHC and MCH of erythrocytes were calculated
using the following formula:
MCV (fl)=(PCV/RBC Count) x 10
MCHC (%)=Hb/PCV) x 100
MCH (pg)=(Hb/RBC Count) x 10
The neutrophil, lymphocyte, eosinophil, monocyte and basophil counts were
determined using the differentials and the total WBC. Proportion of every
leukocytic cell type multiplied by the WBC was assumed to give the absolute
count of each white cell type.
Data analysis
Microsoft Excel program was used to store data and carry out preliminary
statistical analysis. Using statistical computer package, mean values of the
measured parameters were determined. Non-parametric test (Mann-Whitney
U-test) was used to determine the mean differences between groups.
Results
The influence of late pregnancy
The range of blood values in the stage of late pregnancy include: RBC- 5.5910.16 mil/ µl, PCV- 21-25%, Hb-10.2-14.8g% and total WBC-7.8-27.5x 103/µl
while that of non-pregnant ones were RBC-5.85-9.92 mil/µl, PCV-20-32%, Hb10-16.6 g% and total WBC-7.15-26.55 x 103/µl. Camels at late pregnant
showed higher mean values of RBC count, PCV, Hb, MCV, WBC and
neutrophil counts and lower in other parameters (Table I). Statistical tests for
mean differences between the values of pregnant and non-pregnant camels,
however, showed significance (P<0.05) only for MCHC and monocyte counts.
The neutrophil to lymphocyte ratios for pregnant and non-pregnant camels
were 1.23:1 and 1.05:1 respectively
The influence of excitement on blood values
The values of RBC count, PCV, Hb and WBC count for camels in
physiologically excited state camels showed RBC- 6.34-12.23 mil/µl, PCV- 2340%, Hb-11.3-20 g% and total WBC-6.35-28.15 x/10 3/µl. Before the animals
were exposed for excitation, these values were RBC- 4.93-10.15 mil/µl, PCV20-38%, Hb- 8.2-21.6g% and total WBC- 10.65-32.2 x/10 3/µl.
However, deviations were statistically significant (P<0.05) for RBC count,
PCV, MCV and MCH (Table II). The neutrophil to lymphocyte ratios before
and after excitation were 1.11:1 and 1.23:1 respectively.
Discussion
The influence of late pregnancy
Variations in blood values due to late pregnancy were observed. Erythrocyte
values: RBC count, PCV, MCV and Hb were slightly higher (P>0.05) for late
pregnant camels compared with the values obtained for non-pregnant ones.
Similar findings were seen in cattle (Jain, 1986). An increase in the leukocyte
picture was observed for pregnant camels comparable with the results
reported by Coles (1986) for cattle. This could be due to the physiological
increase of neutrophil count at late stage of pregnancy. Increased WBC count
particularly neutrophil count was noted at the period near to parturition day in
cattle (Doxey, 1977), which was in agreement with the present study.
Statistical tests for mean differences were not significant except only for
monocyte count (p<0.05). Camels at later stage of pregnancy showed marked
difference on the ratio of neutrophil to lymphocyte number than non-pregnant
ones as lymphocytes decrease while neutrophils increase in number during
the late stage of pregnancy.
The influence of excitement on blood values
The blood count of camels depended on to a large extent on its physical
condition. Camels in non-excited state showed an average 7.55±0.22 mil/ µl
RBC and 12.90x103/µl WBC counts. Abrupt increases of the counts were
seen after excitation was induced. The most influenced parameters were
erythrocyte and leukocyte counts although higher values were also recorded
for PCV, and Hb concentration. Doxey (1977) showed the increase of all
cellular values irrespective of species, age and breed in animals that are
unduly stressed during blood sampling. Jeffcott (1977) also mentioned the
increase of PCV after a horse was exposed to exertion.
The increase of cellular counts can be associated with the contraction of
spleen, which forces the stored blood cells into the circulation. The increased
rate and force of the heart flushing sequestered WBC into the peripheral
blood vessels also favor the increase.
Statistical tests showed significance (p< 0.05) for the mean difference of the
RBC count, PCV, MCV and MCH. Compared with other species exposed to
excitement, the increased blood values for excited camels were not
exaggerated. For instance, 10% and 25% increase in PCV were noted for
cattle and sheep (Jain, 1993 and Jain, 1986) while only 2.15% increase of the
same parameter were recorded for excited camels in the present study. This
signifies the presence of only lower reserve RBC in the normal camels than
cattle and sheep. Camels show lower PCV as a general finding (Getnet, et al.,
2005) that can be associated with higher plasma and extra cellular water
content as an evolutionary adapted water conservation mechanism of camels
and/or the inherently low basal metabolic rate (need of low oxygen transport)
as a thermo-regulatory mechanism (Farid, 1989). Despite the plasma content,
camel red blood cells naturally have higher osmotically unresponsive water
fraction but lower erythrocyte water content (Péter et al., 1998).
The MCV, MCHC and MCH obtained for excited camels were lower than that
of non-excited camels. However, different finding was noted for horse (Smith,
1989) suggesting the existence of species variation in the physiological
response for excitation. The neutrophil: lymphocyte ratio for excited camels
was higher than that of non-excited ones. This is in agreement with that of
Jain (1993) reported for horses. The increased value for excited camels could
be due to the influence of hormones secreted as the result of stress.
LINKS TO OTHER ARTICLES IN THIS ISSUE
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