Small Ruminant Research 38 (2000) 45±49
The relationship between semen quality and mineral
composition of semen in various ram breeds
H.A. Abdel-Rahman, M.S. El-Belely*, A.A. Al-Qarawi, S.A. El-Mougy
Department of Veterinary Medicine, Faculty of Agriculture and Veterinary Medicine,
King Saud University, P. O. Box 1284, Bureidah, Al-Qassim, Saudi Arabia
Received 18 October 1999; accepted 18 February 2000
Abstract
Semen was collected during the breeding season from rams by electroejaculation from two native (13 Najdi and 8 Naemi)
and three imported (6 Merino, 7 Somalian and 9 Sudanese) sheep breeds. There was a marked reduction in sperm
concentration and the percentage live spermatozoa (p<0.01) produced by the Somalian (Barbari) and Sudanese (Sawakni)
breeds. On the other hand, these two breeds showed the highest percentage of spermatozoal individual motility (p<0.05) and
the highest concentrations of sodium (Na) chloride (Cl) and inorganic phosphorus (P) in the whole semen, seminal plasma and
spermatozoa. Superior sperm density, percentage live spermatozoa and seminal concentrations of potassium (K) and calcium
(Ca) were evidenced in the Najdi, Naemi and to a lesser extent, in the Merino rams. The biological effects of these inorganic
constituents, together with magnesium (Mg), in the semen on semen quality should be considered in the interpretation of the
results obtained in the fertility evaluation of the various ram breeds. # 2000 Published by Elsevier Science B.V.
Keywords: Minerals; Spermatozoa; Breeds; Ram
1. Introduction
Genetic improvements of farm animals rely on the
intensive use of a few superior males either for natural
mating, or in arti®cial insemination programs. The
production of meat and milk may be increased through
selective breeding of ewes with rams exhibiting desirable genetic combinations. However, sperm density,
viability and activity as well as other sexual characteristics of the different breeds may limit the extent to
which rams can be used for breeding. The in¯uence of
the major biologically active inorganic components on
these sperm parameters has been extensively studied
in various breeds of rams (Scott et al., 1963; Dott and
White, 1964; Wallace and Wales, 1964; Quinn et al.,
*
Corresponding author.
1965;QuinnandWhite,1966;Stechell,1974;Hamamah
and Gatti, 1998). However, these investigations were
con®ned to one speci®c breed and came to no conclusion
regarding the effect of breed on the interaction between
the chemical composition of semen and semen quality.
The present attempt was, therefore, conducted to
identify the breed-related variations in inorganic elements including Na, Cl, K, Ca, P and Mg of the different seminal fractions and their concentration effects
on semen quality of native and imported sheep breeds.
2. Materials and methods
Twenty one native (13 Najdi and 8 Naemi), 6
Australian (Merino), 7 Somalian (Barbari) and 9
Sudanese (Sawakni) rams were selected at the
0921-4488/00/$ ± see front matter # 2000 Published by Elsevier Science B.V.
PII: S 0 9 2 1 - 4 4 8 8 ( 0 0 ) 0 0 1 3 7 - 1
46
H.A. Abdel-Rahman et al. / Small Ruminant Research 38 (2000) 45±49
expected time of greatest output of spermatozoa
(October to February 1998) from the farm of the
Faculty of Agriculture and Veterinary Medicine, King
Saud University, together with a private farm nearby to
Bureidah. Animals were clinically healthy and ranging in age from 2 to 5 years. When the ®ve breeds are
combined, they produce an age pro®le (2.90.3 years)
typical of a single breed.
Semen collection by electroejaculation from the 43
rams was undertaken using a bipolar electrode with a
4-s stimulation period and an 8-s rest period. Immediately after collection, each sample was placed into a
portable, temperature controlled waterbath (378C) to
prevent cold shock and only samples of good initial
motility (not <70%) were evaluated. Each ejaculate
was evaluated for the following criteria:
1. Individual spermatozoa motility percent, semen
was diluted with 2.9% sodium citrate dihydrate
solution was recorded on a subjective scale of
(0±100%) to the nearest 5% after viewing several
microscopic ®elds.
2. Sperm cell concentration was quanti®ed by direct
cell count using the improved Neubauer haemocytometer (Sorenson, 1979).
3. Percentage live sperm was recorded as described
by Campbell et al. (1956). Duplicate smears from
each freshly collected ejaculate were stained with
eosin-nigrosin stain. A total of 200 spermatozoa
were examined randomly (100 in each of the two
smears).
Following evaluation, approximately two-thirds of the
collected sample was processed as follows:
1. Semen was drawn off into a capillary blood tube
and centrifuged at 4000g for 5 min to obtain the
packed sperm volume (PSV) according to the
equation:
PSV …%† ˆ
Length of packed sperm column …mm†
Length of total semen column …mm†
100
2. 50ml of semen was drawn into a tube containing
1 ml deionized water (dilution rateˆ1:21) to
provide a lysed sperm sample (LSS)
3. The remaining semen sample was centrifuged as
previously mentioned for harvesting of the
seminal plasma sample (SPS).
Concentrations of the electrolyte in spermatozoa were
determined according to the formula reported by
Mulei and Daniel (1988) with certain modi®cations:
Inter-spermatic mineral content
100 21 A ÿ …100 ÿ PSV† B
ˆ
PSV
where A and B are concentrations (mg/100 ml) of the
mineral in LSS and SPS, respectively.
Na and K were determined in the whole semen,
seminal plasma and spermatozoa by emission ¯ame
photometry, Ca by atomic absorption spectrophotometry, whereas Cl, P and Mg were assessed using
commercial diagnostic kits (bio-Merieux, France).
The statistical signi®cance of the results was evaluated by the least-squares analysis of variance using
the general linear models (GLM) procedures of the
Statistical Analysis System (SAS, 1996).
3. Results
As shown in Table 1, the overall mean values (SE)
of sperm count (1943.4132.3106/ml), percentage
of motile spermatozoa (80.56.4%) and percentage
of live spermatozoa (75.25.8%) were signi®cantly
affected by breed. Spermatozoa of the native (p<0.01)
and Merino (p<0.05) rams were higher in concentrations
and percentage live than Barbari and Sawakni rams
(Table 1) displaying the highest (p<0.01) percentage
of motile spermatozoa than the former breeds.
In all of the breeds studied, concentrations of Na, Cl
and P in the seminal plasma always exceeded those in
the spermatozoa, while concentrations of K, Ca and
Mg was greater in the spermatozoa. Despite this general
agreement between breeds, the Barbari and Sawakni
rams showed the highest (p<0.01) concentrations of
Na, Cl, and P whereas the other breeds displayed the
highest (p<0.05) concentrations of K and Ca in the
whole semen, seminal plasma and spermatozoa. There
was no de®nite trend in the distribution of Mg in the
different semen fractions amongst breeds.
Correlation coef®cients of spermatozoal counts, the
percentage of motile spermatozoa and the percentage
live sperm with mineral levels of the ram semen;
seminal plasma and spermatozoa are set out in Table 2.
As might be expected from the distribution of
chemical components between the sperm and plasma,
H.A. Abdel-Rahman et al. / Small Ruminant Research 38 (2000) 45±49
47
Table 1
Semen quality and concentrations of the major inorganic components in the semen of various ram breedsa
Breed
Semen quality
Material
Na
(mg/100 ml)
Cl
(mg/100 ml)
K
(mg/100 ml)
Ca
P
Mg
(mg/100 ml) (mg/100 ml) (mg/100 ml)
Najdi (nˆ13)
S.C.b 2251.6227.4**
%Mc 74.87.5
%Ld 76.46.9*
Semen
Plasma
Sperm
192.318.1
194.619.2
86.69.3
183.518.6
236.424.1
130.213.3
87.58.8*
31.43.2*
145.614.9*
20.92.8
16.82.0
25.63.3*
10.61.8
13.21.4
8.01.0
9.30.8
8.00.7
9.91.1
Naemi (nˆ8)
%S.C. 2468.4239.6** Semen
%M 77.26.8
Plasma
%L 79.98.1**
Sperm
129.213.1
158.116.3
91.910.4
141914.4
163.417.2
118.811.1
118.312.1** 26.92.8*
8.91.4
75.27.8** 20.22.4
10.31.8
161.616.4** 32.43.5** 5.81.1
9.71.0
8.40.8
10.31.2
Merino (nˆ6)
%S.C. 2036.5201.3*
%M 81.38.5*
%L 74.17.6*
Semen
Plasma
Sperm
156.315.9
202.621.4
114.311.5
174.217.6
216.322.8
133.714.0
109.111.2** 24.32.9*
66.36.8** 19.12.0
153.715.2** 28.82.8*
9.21.3
11.71.5
6.61.0
11.61.3
9.80.9
13.41.5
Barbari (nˆ7)
%S.C. 1644.8206.2
%M 84.28.2**
%L 70.97.3
Semen
Plasma
Sperm
231.623.4** 250.124.9** 78.38.1
244.225.1** 276.328.1** 34.43.5
217.719.8** 223.921.7** 122.212.3
22.22.3
21.62.5
22.32.2
11.11.2
13.41.3
7.90.8
10.81.2
9.11.0
12.31.3
Sawakni (nˆ9) %S.C. 1318.2115.6
%M 86.68.5
%L 68.26.9
Semen
Plasma
Sperm
263.226.0** 279.628.6** 66.46.8
308.131.9** 300.329.9** 28.53.1
219.822.5** 257.825.2** 104.310.5
19.62.0
18.21.9
20.72.1
12.41.2*
16.51.2*
8.40.6
11.11.2
7.90.6
14.21.4*
Overall (nˆ43) %S.C. 1943.4132.2
%M 80.56.4
%L 75.25.8
Semen
Plasma
Sperm
194.214.3
221.418.8
145.511.4
22.81.6
19.21.3
26.32.3
10.41.3
13.41.8
7.30.6
10.51.2
8.60.6
12.10.9
205.417.1
238.221.4
172.615.3
51.44.6
47.23.7
137.011.5
a
All values are MeanSE.
Represents spermatozoal count106/ml.
c
Percentage of motile spermatozoa.
d
Percentage of live spermatozoa.
* p<0.05; **p<0.01.
b
the Na, Cl and P concentrations of the whole semen
decreases and the K, Ca and Mg increases as the
ejaculate becomes more dense. The percentage of
motile spermatozoa decreases as the K and Ca levels
increase and the Na, Cl, P and Mg decrease. The
percentage live (unstained) spermatozoa were correlated positively with K and Ca and negatively with P in
the different semen fractions (Table 2).
Table 2
Correlation between major inorganic constituents of ram semen and semen quality
Na
Cl
K
Ca
P
Mg
S.C.a: semen constituent
S.C.: plasma constituent
S.C.: sperm constituent
ÿ0.581**
ÿ0.663**
ÿ0.355*
ÿ0.611**
ÿ0.725**
ÿ0.299*
‡0.736**
‡0.169
‡0.386**
‡0.290*
‡0.283*
‡0.316*
ÿ0.301*
ÿ0.425**
ÿ0.511**
‡0.292*
‡0.336*
‡0.343*
%Mb: semen constituent
%M: plasma constituent
%M: sperm constituent
‡0.215
‡0.421**
‡0.379**
‡0.191
‡0.285*
‡0.314*
ÿ0.224
ÿ0.236
ÿ0.574**
ÿ0.096
ÿ0.133
ÿ0.306*
‡0.242
‡0.327*
‡0.284 *
‡0.188
‡0.213
‡0.468**
%Lc: semen constituent
%L: plasma constituent
%L: sperm constituent
ÿ0.268
ÿ0.236
ÿ0.270
ÿ0.139
ÿ0.088
ÿ0.104
‡0.363*
‡0.446**
‡0.618**
‡0.294*
‡0.325*
‡0.303*
ÿ0.292*
ÿ0.308*
ÿ0.276*
ÿ0.081
‡0.194
ÿ0.076
a
Represents spermatozoal count106/ml.
Percentage of motile spermatozoa.
c
Percentage of live spermatozoa.
* p<0.05; **p<0.01.
b
48
H.A. Abdel-Rahman et al. / Small Ruminant Research 38 (2000) 45±49
4. Discussion
Extensive studies on evaluating semen parameters
were conducted in rams of different breeds. The higher
sperm density and percentage live sperm shown by the
native breeds (Najdi and Naemi) agreed with those
reported for the British (Suffolk) rams (Jennings,
1976; Jennings and McWeeney, 1976) and the Egyptian (Awassi and Ossimi) rams (Amir, 1966; AbdelHakeam et al., 1978; Abou-Ahmed et al., 1986; Seida
et al., 1986). While no data are available in the
literature concerning results of semen characteristics
in the Barbari and Sawakni rams, results of sperm
density and viability estimates reported by Salamon
(1964), Dott and Foster (1972) and Lino and Braden
(1972) in Merino rams at Australia so far exceeded our
results. The discrepancy might be related, in part, to
environmental factors such as high ambient temperature and low humidity in the relevancy current study,
which has been shown to affect semen characteristics
in the ram (El-Wishy et al., 1976; Loubser and Van
Niekerk, 1983; Abou-Ahmed et al., 1986).
In this study, the overall mean (Table 1) of ion
concentrations found in the whole semen is in agreement with that recorded in the ram by Scott et al.
(1963), Wallace and Wales (1964) and Stechell
(1974), but Na, Cl and K values were about twice
the level reported by Quinn et al. (1965) and Quinn
and White (1966).
The correlations set out in Table 2 might explain the
encountered variations in semen quality of the various
ram breeds studied. As might be expected from the
distribution of the ions between the sperm and plasma,
higher concentrations of K, Ca and Mg in the whole
semen of the native breeds may be due to the more
dense ejaculates. The positive correlation (Table 2)
between all, except K and Ca, ions in plasma and
spermatozoa and the percentage motility could
explain the higher motility evidenced by the Barbari
and Sawakni spermatozoa. Moreover, the higher spermatozoal K and Ca levels notably caused some reduction in spermatozoal activity in the native and Merino
breeds. These results support the reports of earlier
work that K was detrimental to metabolism at high
concentrations (Cragle and Salisbury, 1959) for bull
spermatozoa and that Ca depressed the metabolism of
bull and ram spermatozoa and exaggerated the detrimental effects of K (Blackshaw, 1953). The data
suggest a reciprocal relationship between intracellular
contents of K, Ca and P with respect to percentage live
sperm (unstained); a high percentage of live cells
being associated with high K and Ca and low P levels.
These results were true for the native (Najdi and
Naemi breed) and Merino spermatozoa and this meant
that the K, Ca and P are concerned with the permeability of ram spermatozoa as reported by Mikulecky
and Tobias (1964).
In conclusion, the distribution of major ions studied
between sperm fraction and seminal plasma could
provide the basis for variation of semen quality
between ram breeds and should be considered in
the interpretation of the results obtained in the evaluation of the fertility of rams.
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