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Semen characteristics of Ile-de-France rams of different age and physical condition
Theriogenology
42:321-326,
1994
SEMEN CHARACTERISTICS OF ILE-DE-FRANCE RAMS OF DIFFERENT AGE AND PHYSICAL CONDITION F. Toe?
A. Lahlou-Kassi’
and E. Mukasa-Mugerwa’
‘Institute
of Agronomy and Veterinary Science Hassan II B.P. 6202 Rabat-Instituts, Rabat, Morocco 2Animal Reproduction and Health Section, International Livestock Centre for Africa PO Box 5986, Addis Ababa, Ethiopia Received
for publication: Accepted:
March 2, 1993 June ISZ, 1994
ABSTRACT A breeding soundness examination (BSE) involving animal physical examination, scrotal circumference (SC) and semen evaluation was undertaken on 80 Ile-de-France rams at a government breeding farm, 32 km south-west of Casablanca (Morocco) from March to May 1988. A large percentage of rams (21.4%) was found to be unfit for breeding due to physical and genital abnormalities; 11 and 5% had disorders of the feet and respiratory system;upon genital palpation, 17.5, 13.8 and 7.5% of animals had orchitis, epididymitis and posthitis, respectively. The SC increased with age from 28.8 f 3.2 cm at <2 yr to 35.4 f 3.5 cm at 4 yr or more (P< 0.001). The quality of semen was significantly (PcO.01) depressed by orchitis and epididymitis (PcO.01) but not by ram age. Semen volume decreased from l.lkO.6 ml in rams with normal genitalia to 0.5 $0.4 and 0.25kO.2 ml in animals with orchitis and epididymitis, respectively. Similarly, sperm cell concentration declined from 2.52 1.2 to 1.120.7 and 1.6+ 1.2 billion per ml, while sperm motility dropped from 81.5+12.3% to 58.3? 14.3 and 61.3+26.5%. The percentage of abnormal spermatozoa was also higher among rams with orchitis (24.3+ 17.5%) and epididymitis (20.7+24.3%) than among rams with normal genitalia (6.4? 6.2%). We concluded that older rams need better health care to improve their semen production properties that may be influencing fertility. Key words: ram semen quality, physical condition,
Be-de-France,
Morocco
INTRODUCTION The total number of sheep in Morocco is about 16 million with a productivity level calculated as 0.6 to 0.7 lambs raised to slaughter per ewe per year. Production is partly
Acknowledgments The authors thank the SNDE staff in Rabat and Had Soualem for permission to collect data and Dr. A. Tibary for helpful advice. This study was partially funded by the Small Ruminants Collaborative Research Support Program (SR-CRSP), IAV Hassan II. ‘To whom correspondence should be addressed: ILCA, Animal Reproduction and Health Section, PO Box 5689, Addis Ababa, Ethiopia.
Copyright
0 1994 Butterworth-Heinemann
Theriogenology
322
limited by low ewe fertility (78 to 83%), minimal twining rate except for the D’Man breed, and high lamb mortality (18 to 31%), (3). The low rate of productivity coupled with a relatively low carcass weight leads to insufficient sheep meat production, rising prices and thus lowering consumption. To increase production, rams of European breeds, especially the Ile-de-France, are being used for crossing with ewes of the local breeds by small-scale farmers. Information on the reproductive traits of Moroccan rams are limited (19) and not available for European breeds introduced into North Africa. This study was undertaken in the spring season at sea level altitude in the mediterranean climate. In Western Europe, this season is considered to be the most unfavorable for Be-de-France ram fertility, being associated with a decrease in testicular size and spermatogenesis efficiency (513). The aim of this study was to assess the prevalence of physical and genital disorders and their relationship to the semen properties of Ile-de-France rams raised in Morocco. MATERIALS AND METHODS Data were collected from a government farm located at sea level in the Chaouia agricultural plain, about 32 km south-west of Casablanca (33.39”N and 7.3S’W). The annual rainfall for the area averages 432 mm and the minimum and maximum temperatures are, respectively, 11.7”C (January) and 28.8”C (August). Day length increases from December 21 to June 21, including the spring season (March to April), and decreases from June 21 to December 21. A breeding soundness examination (BSE) was conducted during the Spring of 1988, on 80 Ile-de-France rams (born and raised in Morocco) used for mating Timahdite ewes 3 times a year. Each mating season lasted for 40 d when 1 ram was mated with 20 to 25 ewes in a pen overnight. The rams ranged in age from 1 to 7 yr. Except during mating season, rams were separated from the ewes. Each ram was clinically examined with emphasis on the integrity of its genital tract. After scrotal circumference measurement, a semen sample was collected by electroejaculation. The volume was read from transparent graduated glass collection tubes ( f 0.1 ml), while the percentage of individual sperm motility was assessed by examining 1 drop of semen and 1 drop of physiological saline solution under a warm stage microscope at low magnification (x 40). A diluted semen sample was preserved with formalin and kept for subsequent determination of sperm cell concentration using a photospectrometer. Further, a semen smear was stained with eosine-nigrosine for determining the percentage of abnormal spermatozoa. The data were analyzed by analysis of variance procedures using the SAS computer package (6), and the results are reported as simple statistics (frequencies, means and standard deviations), as well as mean comparisons. Data on SC were analyzed according to ram age excluding data from rams with genital tract disorders except posthitis. Data on semen quality were analyzed using the genital tract integrity and age as the independent variables.
323
Theriogenology
RESULTS Problems associated with the feet, especially foot rot and lameness, were the most common pathological conditions encountered. They affected 11.3% of the rams, followed by respiratory disorders in 5%; both conditions occurred exclusively in older rams (Table 1). Other ailments consisted of abscesses (2 cases), digestive tract disorders (1 case), and poor conformation (1 case), and, as a result, we estimated that 21.4% of the rams were unfit for mating. This was particularly the case in animals older than 4 yr of age (28.1%) in contrast with the younger animals (4.4%). Almost one half (42.5%) of the rams were afflicted by a genital tract abnormality, including that of orchitis (17.5%), epididymitis (13.8%), and posthitis (7.5%). In addition, there were 2 cases of testicular abscesses and 1 case of complete hypoplasia (Table 1). Half of the cases of orchitis cases were also associated with epididymitis (8.8%). After clinical examination, we estimated that 42 of the 80 rams were physically and sexually unfit for mating.
Table 1. Frequency of physical and sexual disorders in Ile-de-France rams Disorder
Locomotion Respiratory Abscesses Digestive Conformation Orchitis Epididymitis Orchitis + epididymitis Posthitis Testicular abscesses Testicular hypoplasia
Young ramsa
Old rams”
Overall
Sick
Healthy
Sick
Healthy
Sick
Healthy
0 0
23 23 22 23 23 23 22 22 22 22 22
9 4 1 1 1 14 10 6 5 1 0
48 53 56 56 56 43 47 51 52 56 57
9 4 2 1 1 14 11 7 6 2 1
71 76 78 79 79 66 69 73 74 78 79
1 0 0 0 1 1 1 1 1
‘Young rams: 1 to 4 years. bOld rams: 5 to 7 years. Mean (2 SD) SC increased from 28.8 + 3.2 cm in rams of less than 2 yr of age to 35.4 2 3.5 cm in animals older than 4 yr of age. This parameter was influenced by ram age (P c 0.001; Table 2).
324
Theriogenology
Table 2. Scrotal circumference
(SC) of Ile-de-France
Age of rams (years)
n
1 to 2 2 to 3 3 to 4 14
11 2 3 28
Means with different
superscripts
rams examined
MinimumMaximum SC SC
25 26 28 28
34 31 33 41
are statistically
in the spring
Mean
SD
28.aa 28.5’ 30.7b 35.4c
3.19 3.54 2.52 3.49
different
(P
Mean ejaculate volume, sperm cell motility, percentage of abnormal spermatozoa and sperm cell concentration were, respectively, 1.12 0.6 ml, 81.5 2 12.3%, 6.4 2 6.2% and 2.5 f 1.2 lo9 spermatozoa per ml in rams with normal genitalia (Table 3). Semen characteristics were significantly influenced by the presence or absence of testicular lesions (P < 0.01) but not by ram age (P>O.O5). Altogether, SC was well correlated with semen volume (r =0.51; P < 0.025).
Table 3.
Effect of the status of the genital tract on semen characteristics rams examined in the spring (MeankSD)
Variables
Normal genital tract Orchitis Epididymitis Posthitis
n
38 10 6 3
Ejaculated volume (ml)
1.15 0.50 0.25 1.20
+ + + +
0.6’ 0.4b 0.2’ o.ga
Motile spermatozoa (%)
81.5 58.3 61.3 81.6
+ + k +
Means in columns with the same superscript
Concentration (109 spz/ml)
12.3’ 14.3b 26.5b 18.9’
2.5 1.1 1.6 3.1
r + f r
1.2’ 0.7’ 1.2b 0.8’
are not statistically
in Ile-de-France
Abnormal spermatozoa (%)
6.4 24.3 20.7 7.1
2 6.2’ -+ 17.5b + 24.3b + 6.01a
different
(PcO.01).
DISCUSSION We attributed the feet problems in this study to improper hoof care, while the respiratory ailments were largely ascribed to area proximity to the sea whose high humidity also
Theriogenology
325
encourages the prevalence of lungworm. The higher incidence of both conditions among the older rams strongly suggested that rams over 4 yr of age need to be culled more aggressively, particularly since both conditions may influence ram mating capability (9). Alternatively, more preventive health measures could be performed, but this would entail additional expense. The fact that almost one-third (28.1%) of the 4-yr-old rams were not fit for mating due to poor physical condition was consistent with previous findings that the ram fertility rate is generally better at a younger age (7,15). The fact that 52.6% of the older rams (more than 4 yr) had a genital disorder vs 17.4% of the young ones strongly pointed to a relationship between testicular disturbance and ram age. The present incidence of 17.5 and 13.8% for orchitis and epididymitis, respectively, were higher than the values of 7.6 and 3.2 to 10.6% previously reported in local Moroccan rams (18.19). Local animals commonly graze extensively and mate continuously throughout the year. In contrast, the Ile-de-France rams were maintained indoors and were used for intensive mating only over a 40-d period 3 times a year which, we suspect, might have contributed to their testicular dysfunction and foot problems. Moreover, an abattoir study on extensively grazing Merino rams in Australia also found the frequency of orchitis and epididymitis to be only 0.6 and 3.6%, respectively (4). The close association between orchitis and epididymitis in this study is similar to previous data showing that such an association is more frequent than a single testicular disorder (12). Bruce& M and &tinobacilluS spp. are the most common pathogens isolated from epididymitis conditions (2,8). Further, many micro-organisms found in the preputial mucosa can induce posthitis and then epididymitis and orchitis (8). The relationship between SC and semen production was also similar to those of other investigators (10). In ruminants, semen quality increases from puberty to adult age with concomitant increase of fertility (11) but only up to a certain level, as we also found, when semen quality in very old animals decreased despite the greater scrotal circumference (16). Additionally, body and testicular development and semen production characteristics in Ilede-France ram lambs are also affected by season (18) through photoperiodism (13,14). Testicular weight and size and the efficiency of spermatogenesis in the breed decrease during the spring (5,6). However, the semen characteristics of rams with normal genitalia in this study were better than values previously reported in the spring season by researchers in France (1,5,6). We concluded, first, that the high percentage of physical and reproductive disorders in rams was strongly attributable to inadequate management and culling practices, since rams older than 5 yr constituted 71.2% of the male flock. Second, little attention was being given to ram genital tract and general health management, as shown by improper endo- and ectoparasite control and hoof management. We suggest that the high prevalence of orchitis, epididymitis and posthitis necessitates further large-scale study of their causes in both the imported and local Moroccan breeds. Finally, although the study was limited to the spring season (the lowest period of fertility), the good semen traits we recorded in the rams with normal genitalia suggests that with proper management Ile-de-France rams could be used successfully in breeding programs in North Africa.
326
Theriogenology
REFERENCES 1. Alberio R. Role de la photoperiode dans le developpement de la fonction de reproduction chez l’agneau Ile-de-France, de la naissance a 21 mois. These de doctorat, Universite de Paris VI, Paris, France, 1976. 2. Baynes I D, and Simmons G C. Ovine epididymitis caused by Actinobacillus seminis. Aust Vet J 1960;36:454-459. 3. Berger Y M, Kabbali A, Bradford G E. The physical and human environment of sheep in Morocco Is: Berger Y M, Kabbali A, Bradford G. E. (Eds), Sheep Production and Management in the Mediterranean Climate. The agropastoral system of Morocco. 1989. 4. Burgess G W. An abattoir survey of lesions in the scrotal contents of rams. Aust Vet J 1983;60:85-86. 5. Colas G. Variations saisonieres de la qualite du sperme chez le belier Ile-de-France. II. Fecondance: relation avec les critbres qualitatifs observes in vitro. Repr Nutr Dh 1981;21:399-407. 6. Colas G, Lefevre J, Guerin Y. Etude de la transmission pbre fils des variations saisonieres du diamttre testiculaire et du pourcentage de spermatozoides anormaux chez le belier Ile-de-France. 1: Fils nts en Fevrier. Repr Nutr Dev 1990;30:589-603. 7. Craplet C, Thibier M. Anatomie et physiologie du belier. k: Le mouton. Tome IV, Ed. Vigot, Paris, 1980;143-159. 8. De Long W J, Waldham D G, Hall D F. Bacterial isolates associated with epididymitis in rams from Idaho and Eastern Oregon flocks. Am J Vet Res 1979;40:101-102. 9. Hulet C V. Prediction of fertility in rams: factors affecting fertility and collection, testing and evaluation of semen. Vet Med/Small Anim Clin 1977;8:1363-1367. 10. Lino B P. Relationship to scrotal circumference, testis weight, and the number of spermatozoa in different parts of the urogenital tract: Relationship with testicular output of spermatozoa and the effect of ejaculation. Aust J Biol Sci 1972;25:351-358. 11. Osinowo 0 A, Hamed M S, Ekpe G A. Semen quality and sperm output of Yankasa rams at different ages. Theriogenology 1988;29:381-386. 12. Ott R S, Memon M A. Breeding soundness examinations of rams and bucks, a review. Theriogenology 1980;2(13):155-164. 13. Pelletier J. Contribution of increasing and decreasing day length to the photoperiodic control of LH secretion in the Be-de-France ram. J Repr Fert 1971;77:505-512. 14. Pelletier J, Almeida G. Short light cycles induce persistent reproductive activity in Ilede-France rams. J Repr Fert Suppl 1987;34:215-226. 15. Ruttle J L, Southward G M. Influence of age and scrotal circumference on breeding soundness examination of range rams. Theriogenology 1988;29:945-949. 16. Robert S J. Fertility in the male. b: Robert S J (ed) Veterinary Obstetrics and Genital Diseases. Brothers, Inc. Ann. Arbor, MI, 1956;426-513. 17. SAS, SAS/STAT Guide to Personal Computers. SAS Institute Inc. Cary, NC, 1985. 18. Tibary A, Boukhliq R, Adnani M, Toe F. Importance de l’examen du belier en gestion de la reproduction ovine: Variations physiologiques de la qualite du sperme et dominantes pathologiques. XVIIItme Joumdes de I’Association Nationale pour la Production Animale (ANPA) 1988, Institut Agronomique et V&&inaire Hassan II, Rabat, Morocco, 1988. 19. ToC F. Vulgarisation de I’examen des beliers: causes d’elimination des btliers de la lutte. D.V.M. Thesis, Institut Agronomique et Veterinaire Hassan II, Rabat, Morocco 1989;1-136.
42:321-326,
1994
SEMEN CHARACTERISTICS OF ILE-DE-FRANCE RAMS OF DIFFERENT AGE AND PHYSICAL CONDITION F. Toe?
A. Lahlou-Kassi’
and E. Mukasa-Mugerwa’
‘Institute
of Agronomy and Veterinary Science Hassan II B.P. 6202 Rabat-Instituts, Rabat, Morocco 2Animal Reproduction and Health Section, International Livestock Centre for Africa PO Box 5986, Addis Ababa, Ethiopia Received
for publication: Accepted:
March 2, 1993 June ISZ, 1994
ABSTRACT A breeding soundness examination (BSE) involving animal physical examination, scrotal circumference (SC) and semen evaluation was undertaken on 80 Ile-de-France rams at a government breeding farm, 32 km south-west of Casablanca (Morocco) from March to May 1988. A large percentage of rams (21.4%) was found to be unfit for breeding due to physical and genital abnormalities; 11 and 5% had disorders of the feet and respiratory system;upon genital palpation, 17.5, 13.8 and 7.5% of animals had orchitis, epididymitis and posthitis, respectively. The SC increased with age from 28.8 f 3.2 cm at <2 yr to 35.4 f 3.5 cm at 4 yr or more (P< 0.001). The quality of semen was significantly (PcO.01) depressed by orchitis and epididymitis (PcO.01) but not by ram age. Semen volume decreased from l.lkO.6 ml in rams with normal genitalia to 0.5 $0.4 and 0.25kO.2 ml in animals with orchitis and epididymitis, respectively. Similarly, sperm cell concentration declined from 2.52 1.2 to 1.120.7 and 1.6+ 1.2 billion per ml, while sperm motility dropped from 81.5+12.3% to 58.3? 14.3 and 61.3+26.5%. The percentage of abnormal spermatozoa was also higher among rams with orchitis (24.3+ 17.5%) and epididymitis (20.7+24.3%) than among rams with normal genitalia (6.4? 6.2%). We concluded that older rams need better health care to improve their semen production properties that may be influencing fertility. Key words: ram semen quality, physical condition,
Be-de-France,
Morocco
INTRODUCTION The total number of sheep in Morocco is about 16 million with a productivity level calculated as 0.6 to 0.7 lambs raised to slaughter per ewe per year. Production is partly
Acknowledgments The authors thank the SNDE staff in Rabat and Had Soualem for permission to collect data and Dr. A. Tibary for helpful advice. This study was partially funded by the Small Ruminants Collaborative Research Support Program (SR-CRSP), IAV Hassan II. ‘To whom correspondence should be addressed: ILCA, Animal Reproduction and Health Section, PO Box 5689, Addis Ababa, Ethiopia.
Copyright
0 1994 Butterworth-Heinemann
Theriogenology
322
limited by low ewe fertility (78 to 83%), minimal twining rate except for the D’Man breed, and high lamb mortality (18 to 31%), (3). The low rate of productivity coupled with a relatively low carcass weight leads to insufficient sheep meat production, rising prices and thus lowering consumption. To increase production, rams of European breeds, especially the Ile-de-France, are being used for crossing with ewes of the local breeds by small-scale farmers. Information on the reproductive traits of Moroccan rams are limited (19) and not available for European breeds introduced into North Africa. This study was undertaken in the spring season at sea level altitude in the mediterranean climate. In Western Europe, this season is considered to be the most unfavorable for Be-de-France ram fertility, being associated with a decrease in testicular size and spermatogenesis efficiency (513). The aim of this study was to assess the prevalence of physical and genital disorders and their relationship to the semen properties of Ile-de-France rams raised in Morocco. MATERIALS AND METHODS Data were collected from a government farm located at sea level in the Chaouia agricultural plain, about 32 km south-west of Casablanca (33.39”N and 7.3S’W). The annual rainfall for the area averages 432 mm and the minimum and maximum temperatures are, respectively, 11.7”C (January) and 28.8”C (August). Day length increases from December 21 to June 21, including the spring season (March to April), and decreases from June 21 to December 21. A breeding soundness examination (BSE) was conducted during the Spring of 1988, on 80 Ile-de-France rams (born and raised in Morocco) used for mating Timahdite ewes 3 times a year. Each mating season lasted for 40 d when 1 ram was mated with 20 to 25 ewes in a pen overnight. The rams ranged in age from 1 to 7 yr. Except during mating season, rams were separated from the ewes. Each ram was clinically examined with emphasis on the integrity of its genital tract. After scrotal circumference measurement, a semen sample was collected by electroejaculation. The volume was read from transparent graduated glass collection tubes ( f 0.1 ml), while the percentage of individual sperm motility was assessed by examining 1 drop of semen and 1 drop of physiological saline solution under a warm stage microscope at low magnification (x 40). A diluted semen sample was preserved with formalin and kept for subsequent determination of sperm cell concentration using a photospectrometer. Further, a semen smear was stained with eosine-nigrosine for determining the percentage of abnormal spermatozoa. The data were analyzed by analysis of variance procedures using the SAS computer package (6), and the results are reported as simple statistics (frequencies, means and standard deviations), as well as mean comparisons. Data on SC were analyzed according to ram age excluding data from rams with genital tract disorders except posthitis. Data on semen quality were analyzed using the genital tract integrity and age as the independent variables.
323
Theriogenology
RESULTS Problems associated with the feet, especially foot rot and lameness, were the most common pathological conditions encountered. They affected 11.3% of the rams, followed by respiratory disorders in 5%; both conditions occurred exclusively in older rams (Table 1). Other ailments consisted of abscesses (2 cases), digestive tract disorders (1 case), and poor conformation (1 case), and, as a result, we estimated that 21.4% of the rams were unfit for mating. This was particularly the case in animals older than 4 yr of age (28.1%) in contrast with the younger animals (4.4%). Almost one half (42.5%) of the rams were afflicted by a genital tract abnormality, including that of orchitis (17.5%), epididymitis (13.8%), and posthitis (7.5%). In addition, there were 2 cases of testicular abscesses and 1 case of complete hypoplasia (Table 1). Half of the cases of orchitis cases were also associated with epididymitis (8.8%). After clinical examination, we estimated that 42 of the 80 rams were physically and sexually unfit for mating.
Table 1. Frequency of physical and sexual disorders in Ile-de-France rams Disorder
Locomotion Respiratory Abscesses Digestive Conformation Orchitis Epididymitis Orchitis + epididymitis Posthitis Testicular abscesses Testicular hypoplasia
Young ramsa
Old rams”
Overall
Sick
Healthy
Sick
Healthy
Sick
Healthy
0 0
23 23 22 23 23 23 22 22 22 22 22
9 4 1 1 1 14 10 6 5 1 0
48 53 56 56 56 43 47 51 52 56 57
9 4 2 1 1 14 11 7 6 2 1
71 76 78 79 79 66 69 73 74 78 79
1 0 0 0 1 1 1 1 1
‘Young rams: 1 to 4 years. bOld rams: 5 to 7 years. Mean (2 SD) SC increased from 28.8 + 3.2 cm in rams of less than 2 yr of age to 35.4 2 3.5 cm in animals older than 4 yr of age. This parameter was influenced by ram age (P c 0.001; Table 2).
324
Theriogenology
Table 2. Scrotal circumference
(SC) of Ile-de-France
Age of rams (years)
n
1 to 2 2 to 3 3 to 4 14
11 2 3 28
Means with different
superscripts
rams examined
MinimumMaximum SC SC
25 26 28 28
34 31 33 41
are statistically
in the spring
Mean
SD
28.aa 28.5’ 30.7b 35.4c
3.19 3.54 2.52 3.49
different
(P
Mean ejaculate volume, sperm cell motility, percentage of abnormal spermatozoa and sperm cell concentration were, respectively, 1.12 0.6 ml, 81.5 2 12.3%, 6.4 2 6.2% and 2.5 f 1.2 lo9 spermatozoa per ml in rams with normal genitalia (Table 3). Semen characteristics were significantly influenced by the presence or absence of testicular lesions (P < 0.01) but not by ram age (P>O.O5). Altogether, SC was well correlated with semen volume (r =0.51; P < 0.025).
Table 3.
Effect of the status of the genital tract on semen characteristics rams examined in the spring (MeankSD)
Variables
Normal genital tract Orchitis Epididymitis Posthitis
n
38 10 6 3
Ejaculated volume (ml)
1.15 0.50 0.25 1.20
+ + + +
0.6’ 0.4b 0.2’ o.ga
Motile spermatozoa (%)
81.5 58.3 61.3 81.6
+ + k +
Means in columns with the same superscript
Concentration (109 spz/ml)
12.3’ 14.3b 26.5b 18.9’
2.5 1.1 1.6 3.1
r + f r
1.2’ 0.7’ 1.2b 0.8’
are not statistically
in Ile-de-France
Abnormal spermatozoa (%)
6.4 24.3 20.7 7.1
2 6.2’ -+ 17.5b + 24.3b + 6.01a
different
(PcO.01).
DISCUSSION We attributed the feet problems in this study to improper hoof care, while the respiratory ailments were largely ascribed to area proximity to the sea whose high humidity also
Theriogenology
325
encourages the prevalence of lungworm. The higher incidence of both conditions among the older rams strongly suggested that rams over 4 yr of age need to be culled more aggressively, particularly since both conditions may influence ram mating capability (9). Alternatively, more preventive health measures could be performed, but this would entail additional expense. The fact that almost one-third (28.1%) of the 4-yr-old rams were not fit for mating due to poor physical condition was consistent with previous findings that the ram fertility rate is generally better at a younger age (7,15). The fact that 52.6% of the older rams (more than 4 yr) had a genital disorder vs 17.4% of the young ones strongly pointed to a relationship between testicular disturbance and ram age. The present incidence of 17.5 and 13.8% for orchitis and epididymitis, respectively, were higher than the values of 7.6 and 3.2 to 10.6% previously reported in local Moroccan rams (18.19). Local animals commonly graze extensively and mate continuously throughout the year. In contrast, the Ile-de-France rams were maintained indoors and were used for intensive mating only over a 40-d period 3 times a year which, we suspect, might have contributed to their testicular dysfunction and foot problems. Moreover, an abattoir study on extensively grazing Merino rams in Australia also found the frequency of orchitis and epididymitis to be only 0.6 and 3.6%, respectively (4). The close association between orchitis and epididymitis in this study is similar to previous data showing that such an association is more frequent than a single testicular disorder (12). Bruce& M and &tinobacilluS spp. are the most common pathogens isolated from epididymitis conditions (2,8). Further, many micro-organisms found in the preputial mucosa can induce posthitis and then epididymitis and orchitis (8). The relationship between SC and semen production was also similar to those of other investigators (10). In ruminants, semen quality increases from puberty to adult age with concomitant increase of fertility (11) but only up to a certain level, as we also found, when semen quality in very old animals decreased despite the greater scrotal circumference (16). Additionally, body and testicular development and semen production characteristics in Ilede-France ram lambs are also affected by season (18) through photoperiodism (13,14). Testicular weight and size and the efficiency of spermatogenesis in the breed decrease during the spring (5,6). However, the semen characteristics of rams with normal genitalia in this study were better than values previously reported in the spring season by researchers in France (1,5,6). We concluded, first, that the high percentage of physical and reproductive disorders in rams was strongly attributable to inadequate management and culling practices, since rams older than 5 yr constituted 71.2% of the male flock. Second, little attention was being given to ram genital tract and general health management, as shown by improper endo- and ectoparasite control and hoof management. We suggest that the high prevalence of orchitis, epididymitis and posthitis necessitates further large-scale study of their causes in both the imported and local Moroccan breeds. Finally, although the study was limited to the spring season (the lowest period of fertility), the good semen traits we recorded in the rams with normal genitalia suggests that with proper management Ile-de-France rams could be used successfully in breeding programs in North Africa.
326
Theriogenology
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