Reproduction in the male dromedary (Camelus dromedarius )

THERIOGENOLOGY

REPRODUCTIONIN THE HALE DROMEDARY (Camelus droniedarius) S.T. Taha Ismail Department of ‘lheriogenology, Faculty of Veterinary Medicine, Cairo University, Egypt

Received

for

publication: Accepted:

Nouember

25,

1986

March 21, 1988

The testes of one-humped camels are oval and are located, as in the dog in the scrotun in an oblique perineal position (1). Ihe anterior border is nearly straight and is connected to the epididymis. ‘Ihe posterior border is free and convex, and the proximal and distal poles are rounded (2). The testis is small (7.6 to 8.0 x 4.1 to 4.3 x 3.4 to 3.8 cm) and light (59.1 to Differences in size and weight between the right and left testis 91.7 g). Testicular weight and dimensions are not statistically significant (3-7). increase with age and reach their maximm values at 10 to 15) yr of age, then they decrease slightly after 15 yr of age (6-8). During the rutting season, the testis increased greatly in weight and size (3,7,9) due to the extensive development of interstitial tissues at this time (7,10,11). The tunica albuginea of the camel testis is very thick; on average, it constitutes 17 to 20.6% of the testis weight (5-7). The epididymis runs along the anterior border of the testis, extending frcun the ventral pole to a point slightly ‘Ihe caput is attached to the ventral above the level of the proximal pole. pole of the testis, while the cauda is attached to the proximal pole (2). The epididymis is COMeCted to the testis by strong fibrous connective tissue which increases in density with age (12). The three regions of the camel epididymis are more difficult to distinguish from each other than those of cattle- (4). The average weight of the camel epididymis is 14.4 to 15.7 g, of which the caput, corpus and cauda conprise 35.1 to 37%, 41.8 to 49.7% and 15 to 17.9% of the total epididymal weight, respectively (4,6,7). The penis of the camel has been described as ah intermediate between the fibroelastic and cavernous types. The total length of the penis is 59.6 cm and it contains a sigmoid flexure (13). It closely resembles the penis of the bull except for the position of s&mid flexure, which is prescrotal in the camel and postscrotal in the bull, and the shape of the glans penis, which is hook-shaped in the cams1 (12). lMDreover, in the cam1 semen deposition is intracervical (14). The prepuce is pendulous and contains three groups of nuscles which change the direction of the preputial orifice from caudal during urination to cranial during erection (12,13). .~CknO\Yl edgemen t s I wish manuscript.

to express

my deep

gratitude

JUNE 1988 VOL. 29 NO. 6

to Dr.

M. Drost

for

reviewing

this

1407

THERIOGENOLOGY

The accessory sex glands of the camel do not include the vesicular glands. However, the prostate gland is well developed and it consists of external and internal parts. ‘lhe external part is in the form of an irregular pyriform disc, ovoid, elliptical, or irregularly rounded. Average weight of this part of the prostate gland is 19.6 g. ‘lbe bulbo-urethral glands are almond shaped, with an average weight of 2.62 and 2.64 g for the right and left glands, respectively. The average diameters of the right and left aapullae of the deferent ducts are equal (0.42 cm), but the average length is 13.93 and 14.06 cm, respectively (15). FUNCTIONAL HIIYIOKXXOF THE‘IESIW The histological structure of the camel testes res&les that of other animals. There are some differences that are characteristic of this species (7). ‘lhe cycle of the seminiferous epithelitnn of the camel has been divided into eight stages (7,16). This classification is based on the morphology and cytology of the germ cells and their related positions within the seminiferous tubules (17.18). ‘lhe frequency of these stages, from Stages 1 through 8 are 21.9 to 25.3%, 11.1 to 14.38, 11.9 to 13.4%, 8.1 to 8.2%, 8.8 to 10.3%. 9.3 to 10.8%, 8.5 to 9.3%, and 12.2 to 16.48, respectively (7,161. While timan et al. reported that the frequency of these stages was not affected by the season, Ismail found a seasonal influence on the frequency of the different stages of the cycle. The duration of each stage of the cycle is 3.42, 1.93, 1.6, 1.10, 1.19, 1.46, 1.15 and 1.64 d, respectively (71. The percentage of the seminiferous tubules is 68.30% of the whole testicular ‘lhe estimated length of these seminiferous tubules is parenchyma in camels. when the animals are classified according to the percentage of 1138 (7). their Leydig cells in the testis volume (191, the camel can be included in the third category with the boar, zebra and opossun, which have abundant Leydig cells (20 to 60% of the testis volume). In the camel, Leydig cells The average diameter of the make up 28.2% of the testis volume (7). seminiferous tubules is 177 to 224 um (7,20). ‘lhe diameter increases with and reaches its maximm in camels at 10 to 15 yr of age (71. tireover, increases more than during the breeding season, the number of germ cells during any other season, while the ntz&er of spermatozoa decreases during the This finding indicates that spermatogenesis in the cams1 nonbreeding period. is partially affected by season (7,9,10,21). However, sane authors (8.22) shown by the various stages of have reported that active spermatogenesis, cell division, may be found during all seasons. The interstitial tissues of the camel testes are conposed of vascularized groups of interstitial cells. These cells increase in voltaae and nun&r during the rutting season and are distorted and reduced in volume during the nonrutting period (7.10.21-23).

The male camel is able to breed when he is 3 yr old, but full By that time he reproductive capacity is not developed until 6 yr of age. can service up to 50 females in a season, and if he is very well fed and cared for he can service up to 70 females (24). The male camel may continue mating until 20 yr of age (25).

1408

JUNE 1988 VOL. 29 NO. 6

It is well known that mature male camels show seasonal sexual activity, referred to as “the rut .)I During the rutting season the male camel shows a strong and aggressive libido. For the remainder of the year, it is generally thought that the male is sexually quiescent. However, some authors (26) believe that a stud male is capable of mating and fertilizing an estrous female at any time of year. I agree with this finding, because although nest studies reported a higher spermatogenic activity in the camel during the breeding season, none of thean found carplete arrest of spermatogenesis during the nonrutting period (4,6-10,16,20,22). The rutting season is frcm Novea-ber to July in Saudi Arabia (26), October to March in Smtmliland (2?), December to March in Pakistan f25), winter through spring in Novocco (28), Novesber to February in India (29) and January to March in Israel (30). In Egypt, spring is the reported breeding season for camels. Morphological and histological data reveal maxim values for testicular size (3,4,7,9), dianmter of the seminiferous tubules (7,20), and nmtber and size of the interstitial cells (7,lO) during spring; studies on sperm production likewise show a significant increase during the spring season (4.20). Moreover, plasma testosterone levels as measured by radioi~~ssay in 4- to %O-yr-old camels reached their peak concentration (2.27 r&ml) during spring, while the lowest concentrations (0.7 rig/ml) occurred during sumner. The overall average annual concentration was 1.43 rig/ml (7). Accordingly, studies on the pituitary gland of the Egyptian male camel throughout the year revealed high concentrations of gonadotropins during spring (31). SPEZFM PIVBIJCTION SATES Testicular and epididymal sperm reserves were measured by counting spennatids in the tissue homogenate using the sams technique as in the bull (32). Across all ages and seasons, the average gonadal sperm resefive and sperm production per ggram of parenchynnl tissue are 1.7 to 3.4 x 10 and 30.0 to 60.99 x 10 , respectively (4-7). Daily sperm product ion was determined in the camel by the sasm fomula used for the bull and was based on histological data (33). Average daily sperm production by 8- to lg-yr-old camels during the different seasons was calculated to be 0.751 x 10 (7). The low sperm production rates by camel testes ccmpared with other farm animals may be due to a> smaller testes size, b) lower contribution of the parenchyma to the testes weight because of the thick tunica albuginea, c) lower contribution of the seminiferous tubules to the parenchymal weight due to the abundant interstititsn. and d) shorter seminiferous tubules. Generally, gonadal sperm reserves increase with age and reach peak values in camels 10 to 15 yr of age, then they decrease slightly until 20 yr of age (7,19). Noticeably low sperm production occurs in camels over 20 yr of age (6). However, sperm production per gram of testis tissue reaches its highest values in camels 6 to 8 yr of age, coinciding with peak plasma testosterone concentrations (2.16 nglml). This represents the optimal age for camels to Season has a profound effect on sperm begin their reproductive life (7). production rates. Maximm values are usually reached during the winter and spring breeding season, while the lowest values are found in the sumner (4,6,7,9,20).

JUNE 1988 VOL. 29 NO. 6

1409

I’HERIOGENOLOGY

Epididymal sperm reserves of the camel averaged 2.3 to 6.1 x 10’. ‘Ihe percentage of contribution of the three segments of the epididymis to the total epididymal sperm reserve revealed that the corpus epididymidis contains the highest values (51 to 59) and acts as a sperm depot. ‘Ihe percentage of contribution of the caput and the cauda are 5.2 to 12.3 and 21 to 36%, respectively (4,6,7). The rate of sperm transport through the camel epididymis is 4.26 d. which is short conpared with other farm animals. The estimated transit time of sperm through the caput, corpus and cauda epididymidis is 0.22, 2.5 and 1.49 d, respectively (7). However, the shorter transit time in a given species may mean that spermatozoa leave the testis in a more mature state, that they mature mDre rapidly in the epididymis or that they are ejaculated in a less mature state (34). Because the time required for maturation of spermatozoa within the epididymis various species is 2.0 to 5.5 d (35). During this passage,spennatozoa acquire the ability to fertilize while in the distal corpus or proximal cauda epididymidis (35.36). Camel spermatozoa require 2.9 d to transit through the caput and corpus epididymidis, and they apparently acquire their fertilizing capacity at this time (7). SEXUALBEN4VloR Seasonality in the sexual behavior of the male camel is well known and characterized by high sexual excitation during a specific period of the year (known as the “rut”). the rutting cams1 is “Hej,” in India In Arabia, “Musth” and in ScmaIiland Waghagh” (24). During the rutting season, the tenperamsnt of the male canrel changes from compliant to aggressive. The camel may attack other males as well as people at this time (26). Male camels also lose considerable weight and become weak and emaciated. ‘Ibis occurs because they do not eat their normal amount of feed as they are continuously sexually active (37). A praninent feature of the rutting behavior is frothing at the muth and loud vocal gurgling acccnpanied by the protrusion of the markedly edematous and mobile soft palate. Additional peculiarities are profuse secretion of fetid fluid from the poll glands, intermittent micturation. and mvement of the tail to stirmlate the genitalia (14,26,37). Male camels detect the estrous female by the scent of her external genitalia. Smelling may be accompanied by biting the female. The usual or the place for biting is the vulvar lips, the posterior part of the hw, hock region. Sometimes this biting is so forceful that it causes bleeding. After courtship, the male tries to force the female to the ground for copulation by pressing his neck on the neck of the female. If the female fails to oblige, he bites her on the stifle joint to keep her from walking; she then sits down in sternal recurbency. ‘Ihe male cams1 stands over the sitting female by positioning his forelitis on each side of her shoulder and his hind litis on each side of her pelvis. The male then sits down on the female so that he places his full weight on the female with his chest pad, In this position, while his which rests on the rear portion of her hunp. front quarters are raised up, the male is actually sitting on the ground with his hind quarters. After mounting, the male starts pelvic thrusting to

1410

JUNE 1988 VOL. 29 NO. 6

locate the vulva with his penis, after which he begins copulation. Total copulation time ranges from 10 to 22 min (average 13 min); during this the bull camal ejaculates three to four times. period, After each ejaculation, the penis is withdrawn; the male rests for a few mxnents and then resumes copulation. The male camel either falls to one side or stands up after copulation, depending on the degree of exhaustion after each period of copulation (37,381. SEMENOF?HECXEL Semen can be collected from the male camel using an artificial boar vagina (AV), which has a pulsat&on device. ‘Ihe internal temperature of the AV is maintained at 38 to 38.5 C, the vaginal temperature of the female CsnEl. Otherwise, the male camel will refuse to serve the AV. Inaccurate pulsation during collection results in an ejaculate devoid of spermatozoa. Total copulation time is reduced by 50% with the use of the AV in comparison with natural service (38.39). The characteristics of camei semen are shown below (Table 1; 39,401. Volume of the ejaculate is considered large when carpared with other ruminants possessing a complete set of the accessory glands. The camel lacks vesicular glands, so the well-developed prostate gland may be responsible for this large ejaculate (as in the dog). Inmediately after collection, the ejaculate exhibits a viscous, jelly-like consistency. It subsequently liquifies in 7 to 8 min. The high concentration of fructose in camel semen in the absence of vesicular glands raises a question about the source of the fructose. Table 1.

Average semen characteristics

Volume (ml) Color Liquefaction time (min) PH Cone/ml (10’) Live sperm percentage Fructose concentration (mg %) Citric acid concentration (mg %)

of the one-hua-ped camel

light

8.49 grey to milk-white 7.68 8.60 0.396 55.36 706.03 105.79

REPlUXKKTIVE PA’EKUXY An abbatoir survey (41) of 155 male camels (a total of 310 testes) revealed testicular degeneration in 105 testes (33.9%) and other testicular abnormalities in 43 testes (33.9%). Other testicular abnormalities (Table 2) include hypoplasia (1.6%), cryptorchidism (0.7%), orchitis (2.3%), necrosis hydrocele (0.7%) and seminfma (0.3%). Pi larial orohitis and (0.7%). funiculitis due to Dipetalonema evansi is the mDst canmn abnontlality Another study (42) reported a higher incidence (10%) of filarial (7.7%).

JUNE 1988 VOL. 29 NO. 6

1411

THERIOGENOLOGY

orchitis in slaughtered camels. Camel filariasis is a serious disease caused by the fairly large filarial Dipetalonema evansi living in pulmonary and spennatic arteries and lynph nodes (24,. Infected camels suffer arteriosclerosis, cardiac insufficiency and parasitic orchitis. In man, the larvae transmitted by mosquitoes develop into hair-like adult nematodes that migrate to and obstruct the lynphatics of the groin and lower abdanen, causing acute funiculitis, epididymo-orchitis and/or hydrocele. Chronic funiculitis, lyaphvarices in the spennatic cord, and scrotal elephantiasis are late manifestations in man (44). Examination of the infected camel testis reveals very prominent, markedly thickened and corded vessels of the spennatic cord and the attached border of the testes as well as the presence of hard nodules along the spentntic cord. On cross section, the blood vessels are occluded by nodules of thread-like, fairly long, white filarial Wrms. Microscopically, the presence of the microfilaria inside the blood vessels evokes an acute inflamnation in which the endothelial lining proliferates, the womxs become surrounded by eosinophils. and occlusion of the vascular lumen is completed by exudation of fibrin. ‘Bble

2.

Effect of age on the incidence abnormalities in the one-hwed

Age (year)

No. of

testes Hypoplasia Cryptorchidism Crchitis Filariasis Necrosis Hydrocele Tumor Total Incidence (%I

4-6

64 1 1 1

3 4.7

and types of testicular camel

‘7-8

9-10

11-15

16-20

> 20

88 2 2 2 5 1

92 2

40

20

6

2 10

1 3

1 3

11 12.5

14 15.2

2 1 7 17.5

1 2 1

4 20.0

4 66.7

Total

310 5 2 I 24 2 2 1 43 13.9

Incidence (%)

1.6 0.7 2.3 7.7 0.7 0.7 0.3

Dead worms and degenerated residues becane calcified and surrounded by Varying nmnbers of leading to fonaation of hard nodules. fibrosis, the testicular interstitial tissues. eosinophils are seen infiltrating Infested testes also show marked degenerative changes of the seminiferous tubules (41). Filarial orchitis is most ccmnon among camels grazing in the Other testicular river zone and is absent in sandy desert zones (43). lesions (Table 2) are similar to those reported in other farm animals. the incidence of testicular abnomnlities (Table 2) shows a Generally, progressive increase from 4.7% in young camels (4 to 6 yr old) to 20% in 15to 20-yr-old camels and 66.7% in camels over 20 yr of age (411. Testicular degeneration (33.9%) is classified according to histopathological criteria which were given earlier for the bull (45.46) and the boar (47) according to three grades: mild (19%). moderate (8.4%). and advanced (6.5%).

1412

JUNE 1988 VOL. 29 NO. 6

Table 3.

Effects of testicular degeneration on the mrphanetry of the testis epididymis and the sperm production rates (mean -+ SD) in the one-htzqx?d camel Degeneration

Normal MiId

No.

of testes

Testes

162

length (an)

Testes breadth (an) Testes

thickness

Testis

weight (g)

fom)

and

Moderate

Advanced

26

59

20

-+

8.11 0.91

-+

7.90 1.06

-+

7.68 1.33

-+

-+

4.29 0.63

+

4.29 0.81

-+

4.15 0.84

+

8.42 0.94 ** 4.84 0.88

-+

3.86 0.55

-+

3.82 0.66

-+

3.68 0.79

-+

4.13 0.71

70.98 -+ 23.69

66.12 -+ 22.66

66.18 + 32.59

78.61 -+ 16.02

Parenchyma weight (g)

57.72 -+ 18.44

51.96 -+ 18.06

50.90 -+ 26.02

Snica albuginea weight (g)

+

12.94 4.89

-+

17.72 3.56

13.15 6.12 * 19.54 -+ 5.07

Epididymis weight (g)

-+

15.84 4.39

-+

Gonadal sperm reserve (x 109)

-+

4.465 1.805

-+

Sperm productiorilfC parenchym (x 10 >

78.664 -+ 23.008

-+

Epididymal spep reserve (x 10’ )

-+

4.378 2.681

-+

57.05 -+ 13.55 *** 20.51 + 7.09 *** 26.22 -+ 7.19 ** 17.11 -+ 3.98 *** 0.341 + 0.458 *** 7.690 -+ 10.262 *** 0.195 + 0.212

Tunica albuginea

(%)

- T-test between each degree of testicular * P < 0.05. ** PC 0.01. *** P < 0.001.

JUNE 1988 VOL. 29 NO. 6

-+

15.50 5.26 *** 3.026 1.537 *** 60.495 26.990 *** 2.577 1.171

degeneration

14.26 7.75 *** 21.64 -+ 5.16

-+

-+ -+ -+ -+

14.61 4.16 *** 2.533 2.149 *** 43.324 25.963 *** 1.974 1.453

and the normal values.

1413

THERIOGENOLOGY

Table

4.

Effects of age and season on the incidence degenerative changes of dranedary testes

of moderate

to advanced

-----___---~________~~~~__~~~~__~~~~____~~_____~____~~_______________________ Season

No. of

Degenerated testes ___________________

AgeCyear) ______-__________________-_____-___

testes 4-6 7-8 9-10 11-15 16-20 -----------_________~~~~~~~~~~~~~~~~~_~~~~_~~~~~__~~~~___

20

No. Incidence ___________________

2 Spring 86 Stunner 2 4 68 8 3 3 Autumn 12 4 3 2 2 1 Winter 1 4 2 84 1 1 ____________________~~~~~~~~~~~~~~~~_~~~~~_~~~~~___~~~___

2 1

4.7% 4 21 30.9% 12 18.1% 9 9.5% ___________________

Degenerated testes Total testes Incidence(%)

7 64 10.9

13 88 14.8

12 92 13.0

6 40 15.0

5 20 25.0

__---____--_________~~-~-__~~~____~~_____~_______________ Testicular criteria according

3 6 50.0

46 310 14.8

___________________

degeneration (33.9%) is classified according to histopathological which were given earlier for the bull (45,461 and the boar (47) to three grades: mild (19%), moderate (8.4%) and advanced (6.5%).

The relationship between these grades and the morphonmtry of the testis and epididymis as well as the sperm production rates are shown in Table 3. The most profound influence of the testicular degeneration is exerted on the sperm production rates. When gonadal sperm reserve values are expressed as a percentage of normal sperm, they account for 67.8% in mild, 55.7% in moderate and 7.6% in advanced degeneration. The respective values of the epididymal sperm reserves are 58.9, 45.1, and 4.5% (48). As mild degenerative changes in the form of vacuolizat ion of the germinal epithelitnn occur normally in fertile animals (49,501. the pathobiological effect of age and season was focused only on the pathological degeneration, i.e. moderate to advanced degeneration (51). ‘Ihe incidence of testicular degeneration increased from 10.9 to 15.0% in camels 4 to 15 yr of age to 25% in old (15 to 20 yr) and 50% This may explain the decreased in senile (over 20) camels (Table 4). capacity of sperm production per unit volume of testes with increasing age that was noted (6,7,9,20) for this species. In the Bos taurus aging is characterized by progressive intertubular fibrosis, azpmbular changes and reduction of seminiferous surface to testis volume ratio (52). The minirrwn incidence of testicular degeneration in the camel occurred during spring (4.7%) and winter (9.5%). the breeding seasons, whereas the The high highest incidence (30.9%) was reached in smtmer (‘Iable 4). incidence of testicular degeneration during Sumner could be due to the fact is subjected to desert teqeratures that are that the camel, a desert animal, much higher than his body temperature. Moreover, the camel testes, because thev are located in the oerineal region. are exoosed to direct sunlight during the hot Sumner months. Signifi-cantcorrelations were reported in The cams 1 between testicular degeneration and the plasma the degree of concentrations of thyroxine, vitamin A and beta-carotene: the lower the concentrations of these products, the greater the incidence of degenerative lesions in the testes (51).

JUNE 1988 VOL. 29 NO. 6

Arch. 1903.

Fwls. Nat.

1.

Lesbre, M.F. Research on the anatomy of the caml. VIII. Cairo. Imp. Bureau of Animal Breeding and Genetics

2.

Tayeb, M.A.F. The Anatany of the Genital Organs of the Camal, Male and Female. M.V. SC. Thesis, Fouad I University, Cairo, Egypt, 1945.

3.

IV. Abdel-Raouf, M. and *ida. M.M. Studies on reproduction in camels. Gross changes in the morphology of the testis in relation to age and Assuit Vet. Med. J. 1 and 2 1974. season.

4.

Gsnm, A.M. ancI El-Azab, E.A. Gonadal and epididymal sperm reserve cams1 (Camelus dromedarius). J. Reprod. Fertil. =:425-430 1974.

5.

El-Wishy, A.B. and Gnar, A.A. & the relation between testes size and sperm reserve in the one-humped camel (Camelus dromedarius) Beitrage Veterinanned. -133391-398 1975. Trop * Iandwirtsch.

6.

Factors Affecting Sperm Production in the tie-Burped Camel Ismail, S.T. (Camelus dromsdarius). M.V. SC. Thesis. Veterinary Medical College, Cairo University, Egypt, 1979.

7.

Studies on the Testis and Epididymis of the One-I-hqxd Camel Ismail, S.T. (Camelus drcmedarius). Ph.D. thesis. Veterinary &Medical College, Cairo University, Egypt, 1982.

8.

Singh, M.B. and Uharadwaj. M.B. Mxphological epididymis of camels (Camelus dranedarius). 1978.

9.

&aida, M.M.A. Study of the Seasonal Changes in the Morphology of the Testes of the Camel (Camelus dranedarius) with reference to the changes in relation to age. M.V. SC. Thesis, Assuit University Egypt, 1973.

in the

changes in the testis Acta Anat. -101:275-279

and

10. Hussein, I .A. Micrcxnxphological and Histochemical Studies on the Seasonal Changes of the Testis of the Adult I)ne-HLnped Camel (Camelus dromedariusl . M.V. SC. Thesis, Cairo University,Egypt 1980. 11. Charnot, Y. Endocrinologie et sexualite a deshydratation dromadaire male, C.R. Seance, Sot. Biol. -159:1103-1105 1965. Reproduction 12. Novoa, C. -22:3-20 1970.

in Camelidae:

A review.

13. Mobarak, A.M., El Wishy, A.B. and Samira, M.F. the one-hwped camel (Camelus drcmedarius). -19:787-795 1972.

J.

le

Fertil.

The penis and prepuce of Zbl. Vet. Med. A.

14. Arthur, G.H., Noake, D.E. and Pearson, H. Veterinary C&stetrics. Bailliere Tindall, London, 1982.

JUNE 1988 VOL. 29 NO. 6

Reprod.

chez

Reproduction

and

1415

THERIOGENOLOGY

15.

El-Wishy, A.B., Mobarak, organs of the one-hqed Bd. 131:s. l-12 1972.

16.

Osman, D., Monies, K. and Tingari, M. Histological observations on the testis of the camel with special etnohasis on soennetogenesis. Acta Anat. 1979. -104:164-1’71

17.

Roosen-Range, spermatogenesis

18.

Grtavant , R. Spermatogenesis and morphology of Cole, H.H. and Cupps, P.T. (eds.). Reproduction Vol. II Academic Press, NY, 1959, pp. 203-224.

19.

Fawcett, D.W., Neaves, intertubular lynphatics of the maamalian testis.

20.

Fateh El-Bab, M. and @aida, M.M. Studies Alxlel-Raouf, M., reproduction in the camel (Csmelus drcmedarius). V. Morphology of testis in relation to age and season. J. Reprod. Fertil. s:109-116 1975.

21.

Volcani, R. Seasonal activity Agriculture Department Bulletin 1978. Acta Anat. -101:280-288.

22.

Histological Singh, M.B. and Bharadwaj, M.B. on the testis of camel (Camelus dromedarius) and ages. Acta Anat. -101:280-288 1978.

23.

Rathore, Msnlnals.

24.

Leese, A. A Treatise on the tie-HuqXd Stamford, Lines, 1927.

25.

Yasin. S.A. and Wahid, A. Agriculture Pakist . !:289-298

26.

Arthur, G.H., Rahim A.T. Reproduction disease: 7. J. 1985. -141:650-659

27.

Mares, R.G. Protestorate,

28.

Charnot, Y. Synchronization of testis during the sexual cycle Phys. Maroc. -43:49-54 1963.

1416

M.S. M.S.

A.M. and male camel

E.C. Gissel, and in the albino rat.

Fouad, S.M. The accessory genital (Camelus dromedarius). Anat. Anz.

L.O. Quantitative studies Am. J. Anat. E:l-30 1950. the spermatozoa. In: in Domestic AnimXs.

W. and Flores, M.N. Comparative observations on and the organization of the interstitial tissue Biol. Reprod. 2:500-532 1973.

shown in Cited 1957.

male camels. by Singh, M.B.

Histology and Histochemistry Thesis, University of Rajasthsn,

Animal Br. Vet.

on

husbandry, J. -100:114

animal 1954.

studies seasons

of Testis in India, 1960.

Sane

Haynes

Maidenlene,

camels:

and Al-Hindi, A.S. and genital diseases

Israel State and Bharadwaj

and histochemical during the various

Camel.

Pakistan 1957.

on the

a

& Sons,

preliminary

The camel in of the camel.

industry

and

growth of the palatal in the dromedary bull.

animal

&anon

survey.

hecrltFeyd . . disease.

expansion and the Sot. Sci. Nat.

JUNE 1988 VOL. 29 NO. 6

THERIOGENOLOGY

29. Singh. V. and Prakash, -41~475-477 1964.

A.

Mating

behaviour

30. Bodenheimer, F.S. Biology of Deserts. Institute of Biology, London, 1954.

in

J.

L.

camel.

Claudsly

Indian

(ed).

Vet.

J.

‘Ibcnpson

31. Hemeida, N.A., Ismail, S.T., Shahien, Y.M., El-Wishy, A.B. and Kandil, M.H. Seasonal changes in the histology and histochemistry of the adenohypophysis of the one-huaped male camel (Csmelus dranedarius). J. Vet. Med. Ass. -45:139-148 1985. EgyDt. 32. Amann, R.P. and Almquist, J.O. Reproductive capacity Detection of testicular deficiencies and requirements evaluating testis function from semen characteristics. -44:2283 1961.

of dairy bulls. V. for experimentally 6. Dairv Sci.

33. Amann, R.P. and Alaquist, J.O. Reproductive capacity of dairy bulls. VIII. Direct and indirect measurements of testicular sperm production. J. Dairy Sci. -45:774-781 1962. 34. Cebauer. M.R., Pickett, of the stallion. III. Anim. Sci. -39:737-742.

B.W. and Swierstra, Extragonadal transit

E.E. Reproductive physiology time and sperm reserves. J.

Daily 35. Amann, R.P., Johnson, I,., ‘Ihcnpson, D.L. and Pickett, B.W. spermatozoa1 production, epididymal spermatozoa1 reserves and transit time of spemratozoa through the epididymis of rhesus monkey. Biol. Reprod. 3:586-592 1976. 36. Dyson, A.L.M. and Orgebin-Crist, M.C. Effect of castration and androgen replacement upon the fertilizing spermatozoa. Endocrinology -93:391-401 1973. 37. Khan, A.A. and Kohli, (Camelus drcmedarius).

hypophysectomy, ability of rat

I.S. A note on the sexual behaviour of Indian J. Anim. Sci. -43:1092-94 1973.

38. Alxlel-Raouf, M. and El-Naggar, M.A. Studies (Camelus dronedarius). I. Mating technique J. Vet. Sci. Egypt -1:113-119 1964. 39. Khan, A.A. and Kohli, I.S. the help of an artificial 1973.

on reproduction and collection

A note on collection vagina. Indian d.

JUNE

1988 VOL. 29 NO. 6

camel

in camels of semen.

of semen from camel with .Anim. Sci . -43:454-55

40. Abdel-Raouf, M. and El-Naggar, M.A. Studies on reproduction (Camelus dranedarius). VI. Properties and constituents of semen. Congr Anim. Reprod. and AI. Krakow 1976. 41. Hemeida, N.A., El-Wishy, A.B. and Ismail, S.T. in the one-burped camel (Camelus drcmedarius). Appl. Sci. Zagazig Univ. Egypt -111:438-49 1985.

male

in camels ejaculated

Testicular abnormalities First Int. Conf. of

1417

THERIOGENOLOGY

42. Youssef, A.H. Orchidectcuny in camel filariasis. -35:147-157 19’76.

Egypt J. Vet. Med.

Ass.

43. Kornieko, H., Koneva, Z.P. and Orekker, M.D. La prophylaxie de quelques maladies parasitavies des chemeaux dans la R.S.S. de1 Taurkmenie. Bull. Intern. Epiz. -49:305-312 1958. 44. Chatteri jee, Wltterworth’s

K.D. Calcutta

Parasitology, 1964.

Protozoology

and

Helminthology.

N. Morphologische Untersuchungen uber Veranderungen in 45. Lagerlof, Spermabild und in den Hoden bei Bullen mit venainderter oder aufgehobener Fertilitat. Acta. Patho. Microbial. Stand., (Suppl. 19) 1934. 46. Rao, A.R. Changes in the Morphology of Sperm During Iheir Passage Through the Genital Tract in Bulls With Normal and Inpaired Spennatogenesis. Ph.D. Thesis, Royal Veterinary College,Stockholm, 1971. 47. Holst, 1949.

S.J.

Sterility

in Boars.

Ph.D. Thesis.

Nord. Vet. Med.L:87-120

Studies on testicular S.T. and El-Wishy, A.B. 48. Hemeida, N.A., Ismail, degeneration in the one-hqed camel (Camelus dromedarius). First Int. Ccnf. of Appl. Sci. Zagazig Univ., Egypt. -111:450-58 1985. Reproductive capacity of 49. Amann, R.P. and testicular germ cell degeneration.

dairy bulls. Am. J. Anat.

IV. Spermatogenesis -110:69-78 1962.

50. Courot, M., Hochereau, M.T. and Ortavant, R. Spermatogenesis. Testis. Vol. 1 Johnson, A. D. and Vat&n-ark, N.L. (eds.). Press, NY, 1970.

In: ‘Ihe xcademic

effects of 51. Hemeida, N.A., Ismail, S.T. and El-Wishy, A.B. Pathobiological age and season on testes of the one-harped camel (Csmelus drcmedarius). First Int. Conf. of Appl. Sci. Zagazig Univ., Egypt. -111:426-37 1985. 52. Mvrphrey, epididymis Sci. Vet.

1418

J.D. and associated -19:135-141

testis and Changes in the bovine Ladds. P.W. histological study. Res. with age: a quantitative 1975.

JUNE 1988 VOL. 29 NO. 6