Semen characteristics, scrotal circumference and bacterial isolates of fine wool range rams

During 1983, 887 fine wool rams were subjected to breeding soundness evaluation to determine effects of age and scrotal circumference on semen characteristics. Of rams evaluated, 94.4, 84.8, and 81.9% of young (6 yr), respectively, were rated as satis-factory. Old rams had fewer (P < 0.05) motile cells and more (P < 0.05) abnormal cells than young rams. Among older rams there was a higher percentage (P < 0.05) with testicular lesions than among young or mature rams. Scrotal circumference was positively correlated (P < 0.01) with semen volume and percentage of motile normal cells. Motility was negatively correlated (P < 0.01) with percentage of abnormal cells. Mature and old rams with large (>/=36.7 cm) testis had more (P < 0.10) abnormal cells than those in the same age groups with smaller testis. Scrotal circumference was positively correlated (P < 0.10) to volume and motility in mature and old rams, while motility was negatively correlated (P < 0.01) to percentage of abnormal cells in all age groups. Previous semen testing reduced (P < 0.05) the percentage of mature rams with leucocytes. Vaccination against epididymitis reduced (P < 0.05) the incidence of mature rams with leucocytes and testicular lesions. Brucella ovis was recovered from 54 (67.5%) of 80 ejaculates cultured. Among rams infected with B . ovis , only three (5.6%) were vaccinated against B . ovis and had their semen tested previously.     

Melatonin modifies scrotal circumference but not plasma testosterone concentrations and semen quality of rams during the seasonal anestrus at 43°S

The effect of melatonin implants on semen quality on semen samples at 43°S has been studied. Scrotal circumference and plasma testosterone levels have also been determined. Sixteen (experiment 1) and twelve rams (experiment 2) were used from September to December 2011 and 2012, respectively. Half of the rams were treated with melatonin (M groups), the remaining rams being the control group (C groups). M rams presented a higher scrotal circumference than C animals (p < 0.01) from 30 days after melatonin implantations up to the end of experiment 1 and from day 45 to day 75 in experiment 2. No differences between groups were detected for any of the seminal parameters under study and plasma testosterone levels. In conclusion, the use of melatonin implants during the seasonal anoestrus at 43°S produces a significant increment of the scrotal circumference of rams without changing seminal quality parameters of fresh and frozen/thawed semen.     

Scrotal dimensions and ejaculate characteristics of three breeds of sheep in tropical Nigeria

Scrotal circumference and semen characteristics of three breeds of sheep (Udda, Balami and Yankasa) indigenous to Nigeria and Southern Guinea Savannah zones of Africa were compared. The age, body weight, scrotal circumference and spermiogram of the rams were studied by standard techniques. The mean age, body weight, and scrotal circumference of the three breeds were not comparable with significant interbreed, but were with significant intrabreed differences. The mean ejaculate concentration of sperm cells (x 10 /ml) were: Udda, 3.8 +/- 0.050, Balami, 4.1 +/- 0.32, Yankasa, 4.5 +/- 0.11. The mean morphological sperm cell abnormalities for the Udda, Balami and Yankasa were; 7.5 +/- 2.1%, 4.5 +/- 0.58% and 6.0 +/- 0.87%, respectively, with significant inter- and intrabreed differences. There were significant intrabreed differences in the other semen traits, i.e., percent of live cells, percent of motility, mean volume and mean concentration. In all the breeds of sheep studied, the scrotal circumference and spermiogram were comparable to, and within the range reported for the exotic breed of rams.     

Preliminary implications of B-mode ultrasonography of the testicles of beef bulls with normal breeding soundness examinations

Four polled Hereford bulls were found to have satisfactory breeding soundness examinations. They were examined by B-mode ultrasonography, at which time the testicular diameter was measured by ultrasound. The testicles were removed, measured physically and this data was compared with the ultrasound measurements and correlated with other parameters of the breeding soundness examination. The testicles from bulls with normal breeding soundness examinations appeared ultrasonographically identical with the normal testicles from other species such as the pig and dog. Results indicated that the bull testicle diameter could be accurately measured by ultrasonography. Neither ultrasonographic nor physical testicular diameter measurements correlated statistically with scrotal circumference, but they did correlated well with testicular circumference, weight and volume.     

Relationship Between Testicular Measurements,Body Weight and Semen Quality in Young Dairy Bulls

Dairy bulls, 322 Ayrshires (Ay) and 85 Friesians (Fr), were studied at the age of 11 months. Of the bulls, 286 Ay-bulls and 80 Fr-bulls produced semen of acceptable quality for use in A.I. Scrotal circumference, tonometer measure, scrotal fold thickness, 1-year body weight and testicular palpation were used to predict unsuitable bulls for A.I. Non-return rate was used as a measure of fertility. Scrotal fold thickness and 1-year weight had no significant correlation with fertility or semen quality. Scrotal circumference had a significant positive correlation with fertility. Tonometer ratio had a significant negative correlation with fertility. Testicular palpation was the best basis for predicting bulls with poor semen quality in this study. Twelve bulls were recorded as having testicles of different sizes, 1 testicle being more than 20 % bigger than the other. Only 2 of these 12 bulls produced semen of acceptable quality. One of these 2 bulls was, after slaughter, diagnosed as having a hereditary testicle disease. Friesians were shown to have significantly higher fertility than Ayrshires.     

Testicular development, body weight changes, puberty and semen traits of growing guzerat and Nellore bulls

One hundred fifty-nine purebred Guzerat (8 to 110 months of age) and sixty Nellore bulls (8-30 months of age) were used in two trials to examine testicular development and consistency, body weight changes, puberty and semen traits. Scrotal circumference measurements and semen collections by electroejaculation were made every 28 d. At both trial locations, bulls were maintained under grazing conditions and fed commercial protein supplements (2 kg/head/day) during the dry season. Age and body weight affected (P<0.01) scrotal circumference in both breeds. Scrotal circumference increased (P<0.01) linearly with age and body weight. However, scrotal circumference tended to reach mature size more rapidly than did body weight in both Guzerat and Nellore bulls. Correlation coefficients between scrotal circumference and semen traits were positive (P<0.01) ranging from 0.49 to 0.73 in the two breeds, but were not significant for testicular consistency in either breed. Scrotal circumference and age at puberty of Guzerat and Nellore bulls averaged 25.6 +/- 2.2 cm at 18.0 +/- 2.0 mo and 23.6 +/- 0.2 cm at 18.5 +/- 2.7 mo, respectively. Nellore bulls were 42 kg lighter than Guzerat at puberty. Testicular consistency was not affected by either age of body weight (P>0.10) in these young bulls. The percentages of abnormal spermatozoa were higher (P<0.01) at 13 to 15 mo of age in Guzerat (11.1%) and Nellore (14.4%) bulls than at 22 to 24 mo (6.7 and 8.0%, respectively). These data indicate that scrotal circumference measurements can be a useful tool for selecting and improving semen traits of young Guzerat and Nellore bulls under tropical grazing conditions.     

Seasonal thyroidal activity and reproductive characteristics of Iranian fat-tailed rams

An experiment was conducted to study seasonal variations of thyroidal activity, serum testosterone concentration and seminal characteristics of two breeds of Iranian fat-tailed sheep. Eight 3 to 4-year-old rams of Ghezel and Mehraban breeds (4 rams/breed) were randomly selected from a flock of fertile rams. Semen was collected by using an artificial vagina, and blood samples were obtained via jugular vein. Seminal characteristics, scrotal length, width, and circumference, and blood parameters were measured at 3-week intervals. Time of the year significantly (P < 0.05) affected the volume of semen, sperm concentration, percent live sperm, percent normal sperm, total sperm number, seminal pH, seminal lactate dehydrogenase (LDH) concentration, scrotal circumference, scrotal width, and serum levels of testosterone, cholesterol, triiodothyronine (T(3)), tetraiodothyronine (T(4)), free T(4) index (FT(4)I), and TSH. Scrotal length was not affected by the time of sampling (P > 0.05). The effect of breed on the serum concentrations of hormones and cholesterol was not significant. Volume of semen, percent normal sperm, and total number of normal sperm were significantly (P < 0.05) higher in Mehraban but scrotal circumference, scrotal width and scrotal length were greater in Ghezel rams. Breedxtime interaction effect was significant for T(4), FT(4)I, sperm concentration, and total sperm number. The largest values for TSH, T(4), FT(4)I, testosterone, total sperm number, percent normal sperm, percent live sperm, sperm concentration, volume of semen and scrotal circumference were found from early summer to winter and the lowest values were recorded at the end of spring and in early summer. In both breeds, high and negative correlations (r = -0.7 to -0.8) were found between LDH levels in semen and percent live sperm, percent normal sperm and total sperm number (P < 0.01). It is unlikely that such variations in seminal quality would affect the fertility under natural mating.     

Breed-type effects on fertility traits of young bulls

Measures of fertility in young beef bulls (N=76) representative of divergent breeds and F₁ crosses were evaluated. Breed-types were straightbred Hereford and Red Poll, Hereford × Red Poll reciprocal crosses, Angus × Hereford, Angus × Charolais, Brahman × Hereford and Brahman × Angus.There was evidence of significant breed-type variation in scrotal circumference and total testicle weight, although differences were less pronounced when animal weight was taken into account. Scrotal circumference in Brahman × Hereford bulls was less (P<.05) than straightbred Hereford, Red Poll × Hereford and Angus × Hereford crosses at 8 months of age. However, at 13 months there was no difference in scrotal circumference measurements of Brahman × Hereford, Red Poll × Hereford and Angus × Hereford crosses, and all three crosses exceeded (P<.05) straightbred Herefords. Breed-type differences in semen score and presence of normal, mature sperm in the seminiferous tubules at 13 months of age approached significance at the .10 probability level. Heterosis effects on bull fertility characteristics were insignificant when body weight was included as a covariate in the analyses.     

The relationship between scrotal circumference and quantitative testicular traits in yearling beef bulls

A study was designed to investigate relationships between testicle size and histological, sperm production and endocrinological traits in yearling beef bulls at the end of performance test. Twenty-five beef bulls, (Hereford, n=16; Angus, n=4; and Charolais, n=5), with scrotal circumference (SC) measurements ranging from 28.5 to 36.0 cm, were used. Just prior to slaughter at 15 mo of age, SC measurements were taken, semen was collected, and a GnRH response test was conducted. Testicles were processed for daily sperm production (DSP), epididymal sperm reserves (ESR), seminiferous epithelial area (SEA), and degree of germinal epithelial loss (DGEL). There were significant positive correlations between SC and testicular weight (P<0.05), DSP/g (P<0.02), and DSP/bull (P<0.01) and ESR (P<0.01); however, the correlation between SC and SEA was not significant (P=0.4). Scrotal circumference was negatively correlated with DGEL (P<0.05). Degree of germinal epithelial loss was also negatively correlated with DSP/g, DSP/bull and ESR (P<0.01). Morphological characteristics of spermatozoa were diversely related to sperm production traits, and the percentage of normal spermatozoa was positively related to SC (P<0.02) and negatively related to DGEL (P<0.001). Gonadotropin releasing hormone stimulation did not reveal evidence of gonadotropin deficiency in any of the bulls. However, peak testosterone levels were lower in bulls with SC below 31 cm (P<0.05) than those with SC measurements above 31 cm.     

Scrotal circumference does not accurately predict degree of germinal epithelial loss or semen quality in yearling Hereford and Simmental bulls

The accuracy of scrotal circumference as a predictor of specific pathologic changes within testicular parenchyma was assessed by scoring 121 Hereford and Simmental bulls for scrotal circumference, degree of germinal epithelial loss and semen quality. Scrotal circumference was not linearly related to the degree of germinal epithelial loss or to the percentage of tubules (Grade 4+ or higher, no germinal epithelium) for either breed (P > 0.1). Thirty-two centimeters was the minimal acceptable scrotal circumference to ensure both a low prevalence of tubules with irreversible loss of germinal epithelium and acceptable semen quality. Scrotal circumference had a positive predictive value (the proportion of test-positive animals truly diseased) of 0.07 (95% confidence interval [CI] of 0 to 0.29) and a specificity (the proportion of test postive individuals that are diseased) of 0.89 (95% CI of 0.83 to 0.95) for 25% Grade 4 + tubules. For acceptable semen morphology (>/= 75% morphologically normal spermatozoa), scrotal circumference had a positive predictive value of 0.08 (95% CI of 0 to 0.34), a sensitivity (the proportion of diseased individuals testing positively) of 0.06 (95% CI of 0 to 0.24), and a specificity of 0.88 (95% CI of 0.80 to 0.95). For acceptable sperm motility (>/= 30% progressively motile spermatozoa) scrotal circumference had a positive predictive value of 0.0 (95% CI of 0 to 0.22), a sensitivity of 0.0 (95% CI of 0 to 0.15), and a specificity of 0.87 (95% CI of 0.80 to 0.94). Although scrotal circumference is widely accepted as a useful test, its accuracy should be recognized as low when 32 cm is used as the minimal acceptable scrotal circumference in predicting unacceptable testicular histology or unacceptable semen quality in a healthy population of yearling bulls.     

Genetic parameters of libido in Brazilian Nellore bulls

Genetic, environmental and phenotypic correlations between libido, testicular measurements, body weight and semen traits were estimated by multiple-trait-restricted maximum likelihood (MTDFREML) under animal models. Reproductive records, collected from 1992 to 1997, of 288 Nellore bulls were used. Estimates of heritability for libido unadjusted, adjusted for scrotal circumference and adjusted for body weight, were 0.34 +/- 0.10, 0.31 +/- 0.10, and 0.19 +/- 0.11, respectively. Genetic correlations between libido and body weight, scrotal circumference, testis length, testis width, testis volume and testis consistency were, respectively, 0.69, -0.43, -0.31, -0.16, 0.10, 0.87, and between libido and semen volume, sperm motility, vigor, gross motility, major, minor and total defects were, respectively, 0.71, 0.51, 0.12, 0.16, 0.31, 0.26 and 0.43. Results suggested that selection for libido would be effective and that it would lead to desirable correlated response for scrotal circumference, physical and morphological semen traits and undesirable correlated response in body weight.     

Influence of age and scrotal circumference on breeding soundness examination of range rams

Breeding soundness examinations (BSE) were conducted on 3,167 range rams on New Mexico sheep ranches during 1982, 1983 and 1984. Age and scrotal circumference (SC) were recorded for each ram and based on SC, rams were further classified as small (<30.8 cm), medium (31-37 cm) or large (>37.8 cm). Scrotal circumference increased with age (P < 0.05) up to 7 yr of age. Rams rated as satisfactory by BSE had a large (P < 0.05) SC, averaging 34.4 cm for all ages combined. Most rams classed as small (P < 0.01) were also rated unsatisfactory. There was no difference (P > 0.10) in BSE rating of rams classified by SC as medium or large. Results of this study suggest that SC is influenced by age, and this trait should be considered within age groups. Rams with an SC of <30 cm are more likely (P < 0.05) to be rated unsatisfactory by BSE.     

The effect of scrotal circumference, sperm motility and morphology in the ram on conception rates and lambing percentage in the ewe

Ten Suffolk and ten Lincoln yearling rams were examined for breeding soundness. Semen was evaluated, and the scrotal circumference measured. They were single-sire mated to ten to twelve, whiteface ewe lambs during a 45-day breeding season (October 15 - December 1). First-service conception rates, total conception rate, lambing percentage and lambing percentage per ewe exposed were calculated for each ram and breed. The mean scrotal circumference was 36.5 cm (range 31 - 41.5 cm). The breeding data was then compared for eleven rams with a scrotal circumference of less than 36.5 cm and nine rams greater than 36.5 cm. No direct relationship was demonstrated between scrotal circumference, sperm motility or morphology with fertility in the rams used in this experiment. However, there was a tendency for rams with a high first-service conception rate to have sired more lambs per ewe exposed. The mean first-service conception rate was 63.2% (range 44.4 - 80.0%). When rams with greater than 63.2% first-service conception rate were compared to those with less than 63.2%. the lambs born per ewe exposed were 1.04 and .89, respectively, a significant difference (P<.05). There were no significant differences (P<.05) in performance between the two groups when rams with a scrotal circumference less than 36.5 cm and greater than 36.5 cm were compared, nor were there any differences between scrotal circumference, sperm motility, and morphology when rams with total conception rates greater than 80% were compared to those with conception rates less than 80%.     

Correlation of scrotal circumference and age in American Brahman bulls

Scrotal circumference (SC) measurements were taken of 921 American Brahman bulls located on two ranches in southcentral Texas. Measurements were taken at various seasons of the year over an 11-yr time span. Body condition scores, as reflected by fat cover, and a subjective estimate of overall nutritional status were 4 or better, based upon a 1 to 9 scoring system, with 5 representing an animal with an average amount of body fat. Associated body weights were not measured and semen evaluations were not performed. Ages were calculated from exact birthdates and rounded to the nearest whole month. Ages from 8 mo to more than 36 mo were reported. SC measurements ranged from 16.0 cm to 42.5 cm. The relationship of SC and age was positively correlated (r=0.74) (P<0.0001) and could be predicted using the equation y=0.525x + 18.702 where y=SC in centimeters and x=age in months. These data provide evidence that the relationship of scrotal circumference and age of American Brahman bulls is similar to that of other cattle breeds.     

Relationships between growth parameters and scrotal circumference in young beef bulls

Scrotal circumferences of 119 young bulls of four distinct breeding groups were measured at the end of a feedlot performance test and at the beginning of the breeding season when the bulls were approximately 14 months old, to study the relationships of weight and growth parameters with testes size. Scrotal circumference was positively correlated with body weight at the end of feedlot test in the four breeding groups. The association between scrotal circumference and body weight was much stronger in the breeding group which had been selected for low yeariing weight than in the other three breeding groups which had been selected for high growth rate. The relationships between scrotal circumference and preweaning and postweaning gain differed among the four breeding groups. Preweaning gain was the most important factor in the association between body weight and scrotal circumference among the three beef breeding groups. The results indicated that the preweaning stage was a critical period for testicular development and that the probability of finding beef bulls with smaller than average testes among the bulls selected for weaning weight would be relatively small. Scrotal circumference was reduced $\text{(2.5–11\%)}$ from the end of feedlot test until the beginning of the breeding season.     

Correlation of in vivo testicle and seminal vesicle size with post mortem dimensions in bulls

This study was conducted to quantify the relationships between in vivo measurements of testicular and seminal vesicle size and post mortem size of these organs in 30 Santa Gertrudis bulls. The in vivo measurements of testicles were obtained by transrectal ultrasonography and palpation per rectum, while scrotal circumference was measured by scrotal tape. Linear post mortem dimensions were obtained by direct measurements of the excised organs. Volume was assessed by water displacement while the testicles were weighed. Seminal vesicle length, determined by palpation, had the highest correlation with post mortem measurements (r = 0.70; P = 0.0001). Accurate estimation of the thickness of the vesicles (1.47 vs 1.55 cm for in vivo and post mortem, respectively) was performed by ultrasonograph. Of all seminal vesicle linear measurements, width had the highest correlations with volume measured by water displacement (r = 0.67; P = 0.0001 and r = 0.38; P = 0.04 for post mortem and in vivo, respectively). Testicular diameter was accurately measured by ultrasonography (5.54 vs 4.58 cm in vivo and post mortem, respectively) and was highly correlated (range r = 0.84 to 0.89; P = 0.0001) with post mortem measurements of testicular volume, weight and circumference. The correlation between scrotal circumference and diameter of the testicle was 0.75 (P = 0.0001). The correlations of testicular diameter measured by ultrasound with the post mortem measurements of testicular weight and circumference were similar to the correlations between scrotal circumference and those 2 post mortem measurements. We conclude that palpation of vesicle length is highly correlated with volume of the seminal vesicle in situ. Individual linear measurements do not seem to be an accurate predictor of the relativ size of the seminal vesicle. Furthermore, ultrasonography does not seem to be a more accurate measure of testicular size than scrotal circumference for evaluation of breeding soundness.     

Postpubertal sexual development in merino rams after differential feeding through puberty

Spring-born Merino ram lambs were reared on 130%, 165% or 200% of recommended maintenance energy requirements from 7 to 12 mo of age and were then placed on a common plane of nutrition from 12 to 25 mo of age. During the latter 13 mo, the 24 rams were studied for changes in live-weight and testicle characteristics. Semen characteristics and sexual activity were observed from 12 to 19 mo of age. At the beginning of the study, groups coming from low (L), medium (M), and high (H) nutrition had liveweights of 38.9, 46.8, and 53.6 kg (P < 0.05) and scrotal circumferences of 24.6, 28.9, and 32.1 cm (P < 0.05), respectively. When the rams were given common feed conditions, the differences between groups in both liveweight and scrotal circumference quickly decreased and were not significant by the sixth month. No significant differences existed between groups in ejaculate characteristics during semen collection, except in sperm density which, at the end of semen collection, was significantly (P < 0.05) higher in Group M (3.98 x 10(9)/ml) than in Group L (2.55 x 10(9)/ml). However, in analyses of pooled data, there were significant differences between months of collection in sperm density, total number of sperm per ejaculate, and percentages of live and abnormal sperm. The data indicate that differential nutrition during the first year of life will affect some reproductive characters contemporaneously, but with restored feeding, reproductive differences are resolved more quickly than those in liveweight and the changes proceed despite countervailing photoperiodic influences.     

Ram scrotal circumference measurements

A preliminary study was performed to determine the normal scrotal circumference (SC) measurements of rams, the results of which may become useful in the evaluation of rams for breeding soundness. Body weights (BW) and SC measurements were obtained from 717 rams of 9 different breeds. Analysis of the data showed that rams of the larger maturing breeds had larger SC measurements and that there was a significant correlation between SC and BW in all breeds.     

Effects of administration of ergotamine tartrate on fertility of yearling beef bulls

Sixteen yearling bulls were utilized to investigate administration of ergotamine tartrate on semen parameters, fertilization, and endocrinology. Bulls were allotted to a control diet of cracked corn, corn silage, and soybean meal (CON, n = 8) or a diet supplemented daily with 40 microg/kg body weight of ergotamine tartrate (ET, n = 8). Blood samples, average daily gain, scrotal circumference and rectal temperatures were collected every 14 day. Semen samples were obtained every 60 day and evaluated for motility and morphology. Scrotal temperatures were obtained by thermography immediately before electroejaculation. Semen from a subset of bulls from each treatment was also evaluated for in vitro fertilization. Administration of ET increased rectal temperature and resulted in lower scrotal temperatures compared to CON bulls (P < 0.05). However, prolactin, scrotal circumference, testosterone, and semen motility and morphology did not differ between groups throughout the experimental period (224 day). Cleavage rates of embryos derived from in vitro fertilization (IVF) with semen of bulls, fed with ET, were reduced compared to CON (P < 0.05); however, development of cleaved embryos to blastocyst did not differ between treatments. In conclusion, extended exposure of bulls to ET appeared to reduce fertilization potential of sperm.     

Semen characteristics of Ile-de-France rams of different age and physical condition

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+/-3.2 cm at 相似文献