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.     

Testicular shape and its relationship to sperm production in mature Holstein bulls

This study was conducted to determine the relationship between testicular shape, scrotal circumference (SC) and sperm production. Twenty-seven mature Holstein bulls were evaluated subjectively and objectively for testicular shape as indicated by testicular length and width, then placed in 1 of 3 groups. Group 1 contained 17 bulls with a normal ovoid testicular shape and a length to width ratio of 1.61:1 +/- 0.01 (SEM). Group 2 was composed of 4 bulls with a long, slender testicular shape and a length to width ratio of 1.95:1 +/- 0.06 (SEM). Group 3 was comprised of 6 bulls with spheroid-shaped testicles and a length to width ratio of 1.3:1 +/- 0.03 (SEM). All the groups were statistically different for length to width ratios (P < 0.05). Length measurements from cranial to caudal pole of the testis proper were also different between groups (P < 0.05). Width or testicular diameter was different between Group 2 and Group 3 at P < 0.05; however, there was no difference between Group 1 and Group 2 or between Group 1 and Group 3. Predicted volumes and weights of testicles were not significantly different between groups. Scrotal circumference measurements were significantly different between groups (P < 0.05). Group 1 had an average SC of 43.07 +/- 0.36 cm (SEM), Group 2 of 39.33 +/- 1.18 cm (SEM) and Group 3 of 46.22 +/- 0.69 cm (SEM). Sperm production for a twice daily, 2-day-per-week collection schedule revealed a statistically significant difference for sperm output. A total of 2742 ejaculates was evaluated. A total of 1818 ejaculates was evaluated in Group 1, 440 ejaculates in Group 2 and 484 ejaculates in Group 3. The mean spermatozoal harvest per day for Group 1 bulls was 13.62 +/- 0.09 x 10(9) (SEM). Group 2 bulls with the longer-shaped testicles produced 14.82 +/- 0.18 x 10(9) (SEM) spermatozoa per day, and Group 3 bulls, with the more rounded testicle shape and the significantly larger SC produced 11.72 +/- 0.64 x 10(9)(SEM) sperm cells per day. All 3 groups were statistically different at the P = 0.05 level. The results suggest that prediction of sperm production may be dependent on factors other than SC, testicular volume, or weight. Testicular shape may influence sperm output in mature Holstein bulls.     

Testicular measurements and reproductive characteristics in stallions.

Factors affecting testicular measurements in situ and the relationships among the measurements and various reproductive characteristics were studied using data from 48 stallions. Mean values during the breeding season are provided for scrotal width, widths and lengths of individual testes, combined weight of testicular parenchyma, daily sperm production and daily sperm output. Testicular measurements were highly repeatable from day to day and for repeated measurements on a given day; technician provided the largest source of variation in the measurements of a given stallion. Age significantly affected all testicular measurements; testicular size for 2- to 3-year-old stallions did not differ (P greater than 0.05) from that for 4- to 6-year-olds, but was smaller (P less than 0.05) than testicular size of stallions greater than or equal to 7 years old. Scrotal width was correlated (P less than 0.01) with daily sperm production (r = 0.75) and daily sperm output (r = 0.55) and was generally the most repeatable measurement.     

Computer analysis of video and ultrasonographic images for evaluation of bull testes

The objectives of this study were to determine relationships between scrotal size (SC; estimated from a video image) and testicular size, and between ultrasonographic echotexture of the testis and seminiferous tubule area in bulls. Video images of the scrotum of 49 Holstein-Friesian (H-F) bulls were recorded and digitized. Scrotal width and length were measured with custom software. After slaughter, scrotums (containing testes) were excised, SC and testicular height, width and volume were measured, and the testes were examined ultrasonographically. Correlations between SC and testicular width or volume (r = 0.86, P < 0.001 and r = 0.84, P < 0.001, respectively) were much higher than those between scrotal width and testicular width or volume (r = 0.23, P < 0.11 and r = 0.28, P < 0.06). Histological examination of the testes was performed in 31 of the bulls. Ultrasonographic echotexture of the testes (determined with custom software) was highly correlated (r = -0.5, P < 0.005) with seminiferous tubule area. Although SC was superior to video imaging for estimating testicular size, ultrasonographic imaging of the testes has considerable potential for the evaluation of testicular function in bulls.     

Ultrasonic measurement of canine testes

The goals of the present study were to determine if ultrasonic measurement of testicular dimensions (length, width, and height) would provide an accurate assessment of canine testicular size (weight) and to determine the relationship of these measurements to animal body weight. The bodies of 30 intact male dogs of unknown health, breed or breeding history were obtained after the dogs were humanely killed at the local animal shelter. Total scrotal width (TSW) was measured by calipers and the length, width and height of each scrotal testis, excluding the epididymis, were measured by sonography. The testes were then excised and weighed, again excluding the epididymis. Multiple regression was used to predict total testicular weight from 1) only sonographic measurements (Model 1), 2) all testicular measurements (Model 2), 3) only total scrotal width (Model 3), and 4) only body weight (Model 4). In addition, stepwise multiple regression was used to identify models (Models 5 and 6) using external measurements of the testes which seemed most useful in predicting total testicular weight. Models 1, 2, 3, 4, and 6 yielded r(2) values 0.90, 0.94, 0.88, 0.48 and 0.95 respectively. Model 5 yielded an r(2) of 0.90, but the additional accuracy achieved by using the testicular height was minimal. Although sonographic testicular measurement accurately predicted testicular weight, the small degree of additional accuracy achieved over TSW measurement by calipers does not justify the use of sonography in each case. However, if a testicular ultrasound scan is being performed, the ultrasonic measurements could be used to predict testicular weight.     

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.     

Measurement of dimeric inhibins and effects of active immunization against inhibin alpha-subunit on plasma hormones and testis morphology in the developing cockerel

Inhibins and activins are implicated as endocrine regulators of follicle-stimulating hormone production and of testicular steroidogenesis and spermatogenesis in mammals. The potential involvement of these proteins in cockerels was investigated by measurement of circulating inhibin A, inhibin B, total inhibin alpha-subunit immunoreactivity (ir-alpha), activin A, LH, FSH, and testosterone from the juvenile state through to sexual maturity. Plasma inhibin A remained low between 6 to 12 wk of age and increased approximately threefold (P < 0.05) to a prepubertal peak between Weeks 14 to 18, followed by a gradual decline to the end of the study (Week 24). Although plasma FSH levels were not correlated to inhibin A before Week 16 (r = -0.17), they were negatively correlated from Week 18 (r = -0.49; P < 0.005). Inhibin B levels were below the assay detection limit until 16 wk of age but thereafter rose steadily in parallel with FSH (r = 0.27; P < 0.02) and testosterone (r = 0.35; P < 0.005). Thus, inhibins A and B showed divergent profiles during sexual maturation. Plasma ir-alpha levels were much higher than dimeric inhibin levels throughout, although the relative difference varied with age. Plasma activin A levels were below the assay detection at all times. Juvenile cockerels were actively immunized against a synthetic chicken inhibin alpha-subunit peptide conjugate to determine effects on plasma hormones and on testicular weight, morphology, and activin A content. Immunization generated circulating antibodies that bound (125)I-bovine 32-kDa inhibin but did not affect plasma FSH or testosterone levels at any stage of development. However, immunization reduced postpubertal plasma LH levels (P < 0.05) and promoted increased testicular weight (24%; P < 0.01) and total testicular activin A content (42%; P < 0.001) at 24 wk. Testis weight of immunized birds was positively correlated with inhibin antibody titer (r = 0.61; P < 0.05). Live weight gain was not affected by immunization. Morphometric analysis of testis sections showed that inhibin immunization had no effect on the fractional volume of the seminiferous tubule wall, seminiferous tubule lumen, or interstitial tissue area. Likewise, seminiferous tubule surface area and surface area:volume ratios were not different from controls. These findings support differential roles for inhibins A and B in regulating the pituitary-testicular axis during sexual maturation in the cockerel but highlight the need for more detailed studies to distinguish between potential endocrine and local intragonadal roles of inhibin-related peptides and to elucidate the mechanism by which immunization against inhibin alpha-subunit promotes testis enlargement without raising plasma FSH.     

Testicular and epididymal function during the peripuberal period in Brahman bulls receiving various amounts of protein degradable in the rumen

Thirty-nine Brahman bulls with an initial age and weight of 301.7 +/- 4.1 d and 202.7 +/- 4.7 kg, respectively, were randomly allocated to 1 of 2 dietary treatment groups within age, weight and sire in order to study the influence of source of protein and stage of peripuberal period on testicular and epididymal function. In the soybean meal treatment the amount of protein undegradable in the rumen averaged 47%, while it was 72% in the fish meal treatment. The supplements were isocaloric and isonitrogenous. Bulls were electroejaculated, and castrations were performed randomly in a predetermined order when the first ejaculate with the first motile sperm cells (Stage 1), 10 to 25 million (Stage 2), and 50 million or more sperm cells (Stage 3 - puberty) was obtained. Testicular and epididymal traits were analyzed for a single testicle and epididymis. Daily sperm production, daily sperm production per gram of testicular parenchyma, testicular weight and testicular parenchyma weight were not affected by treatment. Bulls receiving fish meal had heavier (P < 0.01) epididymis than soybean meal-fed bulls (6.6 +/- 1.0 vs 3.9 +/- 0.6 g) but similar (P > 0.05) epididymal sperm reserves. Daily sperm production (1 testicle) was 115.2 +/- 0.1, 447.4 +/- 0.1, 792.7 +/- 0.1 million sperm cells, and daily sperm production per gram of testicular parenchyma was 1.5 +/- 0.5, 3.2 +/- 0.6 and 6.4 +/- 0.6 million sperm cells for bulls at Stage 1, 2 and 3, respectively. Sire and amount of undegradable intake protein had significant (P < 0.05) affects on the distribution of epididymal sperm reserves, with soybean meal-fed bulls having the higher proportions of epididymal sperm reserves in the cauda epididymis.     

Fascicle length of gastrocnemius muscles in monozygous twins

A large inter-individual variation is seen in muscle fascicle length of the athletes but the reasons for this phenomenon are unclear. The purpose of this study was to determine whether genetic factors contribute to the variances in muscle architectural characteristics. Nine monozygous twin pairs (3 males and 6 females), mean age 23 years (range 17-40) were studied. Fascicle length, pennation angle, and muscle thickness of the medial (MG) and lateral (LG) gastrocnemius muscles were measured in vivo by B-mode ultrasound. In the LG muscle intrapair resemblance (P < 0.01) for fascicle length (r = 0.98), pennation angle (r = 0.94) and muscle thickness (r = 0.86) were observed. In MG muscle, however, there was no intrapair resemblance for fascicle length (r = 0.66, P > 0.05), although pennation angle (r = 0.73, P < 0.05) and muscle thickness (r = 0.86, P < 0.01) were significant. Mean percent intrapair difference in LG and MG muscles were 1.8% and 5.1% for fascicle length, 11.3% and 12.3% for pennation angle and 12.4% and 9.9% for muscle thickness, respectively. There is intrapair difference between muscle thickness and pennation angle in both MG (r = 0.69, P < 0.05) and LG (r = 0.70, P < 0.05) muscles. However, no significant correlation was observed for intrapair difference between muscle thickness and fascicle length in both muscles (MG, r = 0.46; LG, r = 0.40). It appears that genetic predisposition is the predominant factor for the determination of muscle fascicle length. However, a lack of intrapair resemblance in MG fascicle length raises the possibility that fascicle length may be further influenced by external environmental factors such as physical training.     

Studies on the size of human male gonad in biomorphosis, alcohol intoxication, and cirrhosis--a review and own findings

The size of the testicle (absolute weight, relative weight as the index X, length, and width was measured in 142 late patients aged 17 to 87 a (mean age = 54 a) serving as controls, in 193 deceased patients aged 20 to 81 a (mean age = 47 a) with a history of alcoholism, and in 136 defunct patients aged 30 to 92 a (mean age = 59 a) with cirrhosis. A significant difference in the mean size of the testicles was demonstrated between the cirrhosis group and both the control and alcoholism groups. No statistically significant differences was observed between the control group and the alcoholism group. The degree of acute alcoholic intoxication has no significant effect on the degree of testicular atrophy. Chronic alcoholism exerted a more significant effect on the degree of testicular atrophy than acute alcoholism. Coexistent cirrhosis increased this difference even more. The type of cirrhosis and the degree of its inflammatory activity had no significant influence on the testicular size. Such effect was demonstrated, however, if diffuse fatty infiltration of the cirrhotic liver was present. In the biomorphosis, the greatest mean testicular size was observed in the 4th and 5th decade of life. From the 6th decade on, the testicular size decreased statistically significantly. The curve of the values of the mean testicular size in alcoholism was more flat than in the control group and was situated below it. No statistically significant differences among the values of the testicular size in this curve were found. The testicular size curve in cirrhosis was below both these curves, and a statistically significant difference was found between the 7th and the 9th decades. The mean weight of the testicules in controls, alcoholics, and patients with cirrhosis was 17.58, 16.49, and 13.25 g, respectively, the mean volume was 16.37, 15.34, and 12.21 ml, respectively, the value of the index X was 2.47, 2.52, and 1.97, respectively, the testicular length was 5.05, 4.08, and 3.61 cm, respectively, the width was 2.93, 2.87, and 2.70 cm, respectively.     

Effect of age and genetic group on characteristics of the scrotum,testes and testicular vascular cones,and on sperm production and semen quality in AI bulls in Brazil

The objectives were to determine the effects of age and genetic group on characteristics of the scrotum, testes and testicular vascular cones (TVC), and on sperm production and semen quality in 107 Bos indicus, B. taurus and cross-bred bulls at three artificial insemination (AI) centers in Brazil. In addition, predictors of sperm production and semen quality were identified. In general, scrotal circumference (SC), scrotal shape score, scrotal neck perimeter, and testicular size (length, width and volume) increased (P < 0.05) with age. Although there were no significant differences among genetic groups for SC or testicular size, B. indicus bulls had the least pendulous scrotal shape, the shortest scrotal neck length, and the greatest scrotal neck perimeter (P < 0.05). Fat covering the TVC was thinner (P < 0.05) in bulls < or = 36 months of age and in B. taurus bulls than in older bulls and B. indicus bulls, respectively. Age and genetic group did not affect testicular ultrasonic echotexture. B. indicus bulls tended (P < 0.1) to have the lowest average scrotal surface temperature (SST). In general, ejaculate volume, total number of spermatozoa and number of viable spermatozoa increased (P < 0.05) with age. However, there was no significant effect of age on sperm concentration, motility, major and total defects. The proportion of spermatozoa with minor defects was highest (P < 0.05) in bulls 37-60 months of age. B. indicus bulls had higher (P < 0.01) sperm concentration, total number of spermatozoa and number of viable spermatozoa than B. taurus bulls, with intermediate values for cross-bred bulls. Increased sperm production was associated with increased testicular volume, SC, TVC fat cover, and SST top-to-bottom gradient. Decreased semen quality was associated with increased SC and bottom SST, and decreased scrotal shape, scrotal neck perimeter and vascular cone diameter. In summary, age and genetic group affected the characteristics of the scrotum, testes, and TVC, sperm production and semen quality. In addition, characteristics of the scrotum, testes and TVC were associated with sperm production and semen quality in bulls and could be assessed for breeding soundness evaluation.     

Effect of age and number of parturitions on uterine and ovarian variables in owl monkeys

Background We aimed to evaluate the uterine and ovarian volumes of owl monkeys in different age groups with different numbers of live births and to analyze the interaction between both. Methods We performed pelvic ultrasound exams to compare the uterine measurements with weight, age (infant, juvenile, subadult, young adults, and adults) and the number of live births (nulliparous, primiparous, and multiparous) and to compare the ovarian measurements with weight and age. Results and Conclusions The uterine volume (UV) was directly proportional to the number of parturitions, which was the most important factor in the uterine growth of adult females (P < 0.05). The body weight and age of the animals showed a high positive correlation with UV (r = 0.5354, r = 0.6489, P < 0.01), respectively. The volume of the ovaries grew in proportion to the age of the females (P < 0.05). Puberty was the period of greatest uterine and ovarian growth.     

Acoustic stiffness and change in plug cartilage over time after autologous osteochondral grafting: correlation between ultrasound signal intensity and histological score in a rabbit model

We investigated quantitative changes over time in ultrasound signal intensity (an index of stiffness), signal duration (an index of surface irregularity), and interval between signals (an index of thickness) of plug cartilage in an animal model of autologous osteochondral grafting. A full-thickness osteochondral plug was surgically removed and replaced in male Japanese white rabbits (n = 22). Specimens obtained at day 0 and weeks 2, 4, 8, 12 and 24 postoperatively were assessed using an ultrasound system and by macroscopic and histological evaluation (modified Mankin's score). Histology revealed that the plug sank until 2 weeks postoperatively, and that newly formed cartilage-like tissue covered the plug, but at 24 weeks the tissue detached. The plug itself survived well throughout the period of observation. Although the signal intensity at the plug site was same as that in the sham operated contralateral knee at day 0, from 2 to 24 weeks postoperatively it was less than that in the sham knee. At 8 weeks, this difference was significant (P < 0.05). Modified Mankin's score revealed early degenerative changes at the site, but macroscopic examination did not. Signal intensity correlated significantly with score (both at day 0 and at the five postoperative time points [P < 0.05, r = -0.91] and as a whole [P < 0.05, r = -0.36]). Signal intensity also significantly correlated with the individual subscores for 'cartilage structure' (P < 0.05, r = -0.32) and 'cartilage cells' (P < 0.05, r = -0.30) from the modified Mankin's score, but not significantly with subscores for 'staining' and 'tidemark'. Signal duration correlated significantly with total score (as a whole [P < 0.05, r = 0.34]), but not significantly with the score for cartilage structure (P = 0.0557, r = 0.29). The interval between signals reflected well the actual thickness of the plug site. The significant relationships between ultrasound signal intensity and scores suggest that early degenerative changes in plug cartilage and cartilage-like tissue, especially in the superficial layer, are detectable by high-frequency ultrasound assessment.     

Effects of ultrasonography on the bovine testis and semen quality

Ten yearling beef bulls were assigned to control (n = 5) or ultrasound treatment (n = 5) groups. Treatment consisted of a single 3-min exposure per testis to ultrasonic radiation at a frequency of 5 MHz and at low acoustical intensity (spatial peak temporal averages at 10 and 18 mm, focal points of 0.14 and 0.59 mW/cm(2) and spatial peak pulse averages of 1.1 and 3.4 W/cm(2) at corresponding focal points). Ultrasonic treatment had no effect (P > 0.05) on the percentage of progressively motile spermatozoa, primary sperm defects, secondary sperm defects or normal acrosomes over a 10-wk posttreatment evaluation period. Similarly, scrotal circumference, testicular consistency, paired testes weight, paired epididymal weight, daily sperm production per gram of testicular parenchuma, and epididymal sperm reserves were not affected (P > 0.05) at 69 d following ultrasound treatment. Ultrasonography of bovine scrotal contents did not affect reproductive capacity over the interval studied.     

Seasonal variation in serum testosterone, testicular volume, and semen characteristics in the coyote (Canis latrans)

The coyote is a seasonally breeding mammal, with most copulations occurring between December and April (depending on location). The objective of this study was to characterize seasonal changes in serum testosterone concentrations, testicular volume, and ejaculate quantity and quality in captive male coyotes. There were seasonal differences in testicular volume, with the greatest volume (20.2+/-5.4cm2), mean+/-S.E.M.) in February, corresponding with peak breeding season. Circulating serum testosterone concentrations peaked (3.31+/-0.9 ng/mL) during January and were positively correlated (P< or =0.001, r=0.413) with testicular volume. Ejaculate volume (1.67+/-0.4 mL) and sperm concentration (549.2 x 10(6)+/-297.7 spermatozoa/mL) both peaked during January and February, consistent with the height of the breeding season. Ejaculate volume and sperm concentrations were positively correlated with testicular size (r=0.679, P< or =0.001 and r=0.499, P< or =0.001, respectively) and with serum testosterone concentrations (r=0.368, P< or =0.01 and r=0.208, P< or =0.05). Progressively motile, viable, and morphologically normal spermatozoa fluctuated seasonally, peaked (90.4+/-4.5, 84.8+/-4.1, and 87.9+/-2.9%) during the breeding season, and then subsequently declined (period of aspermatogenesis). All three of these end points were positively correlated with testicular size (r=0.589, P< or =0.001; r=0.586, P< or =0.001; and r=0.469; P< or =0.001) and serum testosterone (r=0.167, P< or =0.05; r=0.190, P< or =0.05; and r=0.221, P< or =0.01). In conclusion, there were intricate relationships among testosterone concentrations, testicular volume, and the production of both functionally intact and morphologically normal spermatozoa.     

Seasonal variation in testicular volume and sexual behavior of Chios and Serres rams

The seasonality of testicular volume and sexual behavior in two Greek breeds of sheep, Chios and Serres, was studied using 10 mature rams of each breed. The rams were kept out of breeding during 2 consecutive years. Live weight was recorded at monthly intervals. Testicular volume was measured at 2-week intervals using an orchidometer. Sexual behavior was recorded at 4-week intervals by exposing rams to oestradiol-treated ovariectomized ewes. The total number of mounts and matings, and the reaction time to first mount and mating were recorded. Chios rams were heavier than Serres rams (87.4 +/- 2.0 kg versus 76.4 +/- 1.9 kg, respectively). All traits varied significantly with month but only testicular volume exhibited a clear seasonal trend in both breeds, with a maximum volume in July-August and a minimum in February-April. Number of mounts showed clear seasonal trend in the Chios breed, with maximum in November. Number of mounts was significantly correlated with length of daylight (-0.18 and -0.21 for Chios and Serres, respectively; P < 0.01) and relative humidity (0.14 and 0.17 for Chios and Serres, respectively; P < 0.05). Testicular volume was positively correlated with air temperature (0.28; P < 0.01) and relative humidity (-0.23; P < 0.01) in the Serres breed only. Results of this study suggest that the testicular volume and number of mounts exhibit seasonal variation in the Chios and Serres rams.     

The testicular vascular cone, scrotal thermoregulation, and their relationship to sperm production and seminal quality in beef bulls

The objectives of the present study were to determine changes with age and relationships among characteristics of the testicular artery, scrotal surface temperature, scrotal circumference, testicular consistency, seminal quality and sperm production. Beef bulls aged 6 mo (n=12), 1 yr (n=12), 2 yr (n=11), and 3 yr (n=12) were used in this study. The mean length of the testicular artery as well as the length, width, and surface area of a latex cast of the testicular artery all increased between 6 mo and 1 yr of age (P<0.01). Wall thickness of the testicular artery and testicular arterial-venous distance in the spermatic cord decreased with age and with proximity to the testicle (P<0.01). Distance from the testicular vascular cone to the inner surface of the skin at the top of the scrotal neck (primarily fat) increased between 1 and 3 yr of age (P<0.01), and was associated with an increased top scrotal surface temperature (P<0.09). Increased epididymal sperm reserves were associated with an increase in testicular consistency, scrotal circumference and scrotal surface temperature gradient, and with a decrease in testicular arterial wall thickness and testicular vascular cone to skin distance. A decrease in sperm defects was associated with an increase in testicular consistency and with a decrease in the average scrotal surface temperature. Increased sperm motility was associated with increased scrotal circumference and a decreased top testicular vascular cone to skin distance. These findings emphasize the importance of thermoregulation to sperm production and seminal quality.     

Noninvasive fluorescent imaging reliably estimates biomass in vivo

Whole-body optical imaging of small animals has emerged as a powerful, user friendly, and high-throughput tool for assaying molecular and cellular processes as they occur in vivo. As with any imaging method, the utility of such technology relies on its ability to provide quantitative, biologically meaningful information about the physiologic or pathologic process of interest. Here we used an animal tumor model to evaluate the extent of correlation between noninvasively measured fluorescence and more traditional measurements of biomass (tumor volume and tumor weight). C57/BL6 mice were injected subcutaneously with murine colon adenocarcinoma cells that were engineered to express GFP. Serial measurements of fluorescence intensities were performed with a macroscopic in vivo fluorescence system. The progressive increases in intensity correlated strongly with growth in tumor volume, as determined by caliper measurements (R2 = 0.99). A more stringent correlation was found between fluorescence intensity and tumor weight (R2 = 0.97) than between volume and weight (R2 = 0.89). In a treatment experiment using tumor necrosis factor-alpha, fluorescence intensity (but not tumor volume) was able to differentiate between treated and control groups on day 1 post-treatment. These results validate the ability of noninvasive fluorescent imaging to quantify the number of viable, fluorescent cells in vivo.     

Spermatozoa output, testicular sperm reserve and epididymal storage capacity of the Red Sokoto goats indigenous to northern Nigeria

Fifteen Red Sokoto goats (bucks) aged 2 to 2 1 2 years with a mean body weight of 17.80+/-1.24 kg were used for studying daily spermatozea output, testicular and epididymal sperm reserves. Semen ejaculates were obtained from each buck and evaluated daily for six weeks. Semen characteristics were as follows: volume, 0.72+/-0.91ml; colour, milky/creamy; sperm concentration/ml, 0.61+/-0.05 x 10(9); mass motility, 3.80+/-0.33; individual metility, 77.50+/-5.60; and normal sperm morphology, 80.00+/-10.50. Mean scretal circumference was 21.80+/-0.29. Mean testicular and spididymal (capita, corpora and caudas) weights (gm) were 83.74+/-5.33, 7.27+/-0.63, 2.22+/-0.23 and 6.13+/-0.73 respectively. Corresponding sperm reserves were 44.32+/-5.79, 8.82+/-1.95, 4.99+/-0.86 and 45.64+/-7.87 x 10(9). Scrotal circumference was positively correlated to testicular weight (r = 0.86), testicular spermatids (r = 0.77), and caudas spermatozoa (r = 0.83).     

Expression of FGF2 and TGFalpha and testis morphology during testicular hypertrophy subsequent to hemicastration in the neonatal boar

The objective was to ascertain fibroblast growth factor-2 (FGF2), epidermal growth factor (EGF), and transforming growth factor-alpha (TGFalpha) mRNA expression and testis morphology during accelerated testicular growth after hemicastration in the neonatal boar. On Day 10 after birth (Day 0), boars were assigned to control (n = 28), no treatment; hemicastrated (n = 28), left testis removed. The right testis in both groups (n = 7) was removed on Days 5, 10, 15, and 20. Expression of mRNA for FGF2, EGF, and TGFalpha was determined by qRT-PCR using TaqMan. Testicular morphology was determined on Day 15. On Day 10, hemicastrated boars had a greater (P = 0.01) testis weight (6.2 +/- 0.8 g; mean +/- SEM) than controls (4.3 +/- 0.4 g) and on Day 15 testis weight in hemicastrated boars (8.8 +/- 0.8 g) was twice (P < 0.01) that of control boars (4.2 +/- 0.3 g). Seminiferous tubule volume was approximately doubled in hemicastrated boars (P < 0.01) and was associated with an increase (P < 0.01) in Sertoli cell number. Interstitial compartment volume was greater (P < 0.01) in hemicastrated boars. Leydig cell numbers were similar (P = 0.14) but volume was greater (P < 0.01) for hemicastrates. There were no differences (P > 0.05) between control and hemicastrated boars in TGFalpha or FGF2 expression on Day 5 or Day 10, and EGF was not detected. It was concluded that upregulation of TGFalpha or FGF2 expression is not a pre-requisite for enhanced testicular growth and increased Sertoli cell proliferation that occurs subsequent to hemicastration in the neonatal boar.