Mature Rams Research Articles

EFFICACY OF DIFFERENT LEVELS OF DRIED DISTILLER'S GRAINSWITH SOLUBLES AS A REPLACEMENT FOR SOYBEAN MEAL AND PORTION OF THE CORN IN A GROWING AND FINISHING BAFFALO CALVES DIET

Eighty growing buffalo calves, 14-16 months old, with an average weight of 202 kg, were divided, randomly, into four equal experimental groups, (20 calves each), and used to investigate the effect of replacing 0%, 10%, 20% and 30% of soybean and yellow corn by dried distiller's grains with soluble (DDGS) in total mixed rations (TMR) (1,2,3 and 4, respectively). The experimental diets were nearly similar in crude protein (CP) (iso-nitrogenous) and total digestible nutrients (TDN) (iso-caloric). All animals were fed daily 3% of live body weight and the trial lasted for 180 days. Metabolism trials were carried out on three mature rams for each TMR to estimate nutrient digestibilities, nutritive values and nitrogen balance. The economic efficiency was also calculated. Significantly lower values of live body weight and daily gain were recorded for calves fed the control diet (TMRI). Significantly best values were achieved by calves fed the 30% followed by 20% dietary DDGS instead of soybean meal and yellow corn. Results of digestibility trials indicated that rams fed the control diet (TMRI) had significantly (P<0.05) lower digestibility coefficients, nutritive values and nitrogen utilization compared with other diets. No significant differences were observed (P<0.05) among the experimental groups in ruminal pH and the obtained values were within the normal ranges (6.70-6.84). Ammonia–N concentration was greater in control diet but, there was a linear decrease in ammonia–N concentration as the level of DDGS increased in the diets. Supplemented rations with DDGS showed significant increase in the level of TVFA's. Increasing level of DDGS in diets of calves’ increased TP concentrations, being the lowest in TMRI (control), while albumin and globulin recorded insignificant differences among all diets. The values of AST were higher significantly (P<0.05) in rations containing DDGS than that of control. Values of serum- creatinine and cholesterol were not affected by dietary treatments. Blood parameters studied indicated normal physiological and healthy status of all experimental calves. Total body gain and daily gain were increased quadratically (P<0.05) with increasing DDGS replacement. Calves fed diets containing 20% or 30% DDGS recorded the best feed conversion values followed by 20% DDGS.It may be concluded that inclusion of DDGS with a rate of 30% from soybean meal and yellow corn in buffalo calves diet result in better net revenue, economical efficiency and feed cost per kg daily gain.

Sperm head phenotype and male fertility in ram semen

Although there is ample evidence for the effects of sperm head shape on sperm function, its impact on fertility has not been explored in detail at the intraspecific level in mammals. Here, we assess the relationship between sperm head shape and male fertility in a large-scale study in Manchega sheep (Ovis aries), which have not undergone any selection for fertility. Semen was collected from 83 mature rams, and before insemination, head shapes were measured for five parameters: area, perimeter, length, width, and p2a (perimeter2/2×π×area) using a computer-assisted sperm morphometric analysis. In addition, a cluster analysis using sperm head length and p2a factor was performed to determine sperm subpopulations (SPs) structure. Our results show the existence of four sperm SPs, which present different sperm head phenotype: SP1 (large and round), SP2 (short and elongated), SP3 (shortest and round), and SP4 (large and the most elongated). No relationships were found between males' fertility rates and average values of sperm head dimensions. However, differences in fertility rates between rams were strongly associated to the proportion of spermatozoa in an ejaculate SP with short and elongated heads (P < 0.001). These findings show how the heterogeneity in sperm head shape of the ejaculate has an effect on reproductive success, and highlight the important role of modulation of the ejaculate at the intraspecific level.

Effect of seminal plasma proteins on membrane cholesterol efflux of ram epididymal spermatozoa

This experiment was conducted to determine the effect of seminal plasma protein (SPP) on the membrane cholesterol efflux of ram epididymal spermatozoa. To obtain epididymal spermatozoa, testes of five healthy mature rams were collected from slaughterhouse in five times. Epididymal spermatozoa were split into three groups and it was added 0, 0.3 and 0.6mg/ml SPP and control group (containing 0.6mg/ml SPP without sperm) was included. Each group was split into three subgroups and incubated at 37°C. Sperm motility, viability and functional membrane integrity were evaluated after 0, 2 and 4h incubation. At 4h, a sample was centrifuged by 10,000×g at 4°C for 10min and the concentration of cholesterol was determined in supernatant by gas chromatography. The main effect of seminal plasma protein showed that sperm motility was highest at 0mg/ml SPP (66.33%; P<0.05) and there was no difference between 0.3 (56.70%) and 0.6mg/ml SPP (53.33%; P>0.05). The highest and lowest functional membrane integrity were observed at 0 (84.00%) and 0.6mg/ml SPP (77.13%), respectively (P<0.05). Sperm viability was higher at 0mg/ml SPP (87.27%) than 0.6mg/ml SPP (84.47%; P<0.05) and there was no difference between 0.3 (85.87%) and 0.6mg/ml SPP (P>0.05). The concentration of cholesterol was highest at 0.6mg/ml SPP (3.95μg/100×106 sperm) and lowest at 0mg/ml SPP (0.1mg/100×106 sperm) and control (0.0mg), respectively (P<0.05). Therefore, seminal plasma proteins induced cholesterol efflux from ram epididymal spermatozoa.

Effect of Vitamin D on basal and Luteinizing Hormone (LH) induced testosterone production and mitochondrial dehydrogenase activity in cultured Leydig cells from immature and mature rams

The objectives of this study were to investigate the potential effects of 1α,25-(OH)2VD3 (biologically active form of Vitamin D) on basal and LH-induced testosterone production and mitochondrial dehydrogenase activity in Leydig cells from immature and mature rams cultured in vitro. Leydig cells were isolated from testes of immature and mature rams, treated without (control) or with increasing concentrations of LH (1, 10, 100ng/ml) and/or 1α,25-(OH)2VD3 (1, 10, 100nM). After 24h, concentrations of testosterone in culture media were measured. After 96h, mitochondrial dehydrogenase activity in Leydig cells were measured. In immature and mature ram Leydig cells, treatment with 10 and 100ng/ml LH increased testosterone production and mitochondrial dehydrogenase activity. Treatment with 1α,25-(OH)2VD3 in the absence of LH did not increase testosterone production, but 10 and 100nM 1α,25-(OH)2VD3 increased LH induced testosterone production for both immature and mature ram Leydig cells. Treatment with all doses of 1α,25-(OH)2VD3 in the absence of LH and 10 and 100ng/ml LH in the absence of 1α,25-(OH)2VD3 increased mitochondrial dehydrogenase activity for cultured Leydig cells from immature and mature rams and 1 and 10nM 1α,25-(OH)2VD3 treatment enhanced the LH induced increase in mitochondrial dehydrogenase activity. Result demonstrate Vitamin D3 induced regulation of function of Leydig cells from immature and mature rams cultured in the presence or absence of LH and support a potential role for Vitamin D3 in regulation of gonadal function in rams.

Temporal concentrations of cortisol and LH in virgin ewes acutely exposed to rams during the transition into the breeding season

The objectives of this study were to determine if exposing seasonally anovular ewes to rams would alter patterns of cortisol concentrations, and if these changes are associated with changes in characteristics of LH concentrations. Seasonally anestrous ewes were assigned to be exposed to rams (RE; n=11) or wethers (NE; n=12). Blood samples were collected at 15-min intervals beginning 120min before introduction of males (time=0min), and continued for 360min after male exposure. Characteristics of cortisol and LH concentrations included: mean and baseline concentrations, pulse amplitude, duration, frequency, and time to first pulse. Mean and baseline cortisol concentrations, and cortisol pulse amplitude, frequency, and time to first pulse after male exposure did not differ between RE and NE ewes. Cortisol pulse duration was longer (P<0.05) in RE ewes than in NE ewes. Mean LH and LH pulse amplitude, duration, and time to first pulse after male exposure did not differ between RE and NE ewes. Baseline LH concentrations and LH pulse frequency were greater (P<0.05) in RE than in NE ewes. In RE ewes, but not NE ewes, LH pulse frequency tended to increase (P=0.06) as pulse frequency of cortisol decreased. In conclusion, exposing ewes to mature rams during the transition into the breeding season increased LH pulse frequency which hastened ovulatory activity. However, the results do not support the hypothesis that changes in cortisol concentrations plays a significant role in the ‘ram effect’.

Indirect ELISA for diagnosis of Brucella ovis infection in rams

Brucella ovis is a major cause of epididymitis in sexually mature rams, resulting in subfertility, infertility, and economic losses for the sheep industry worldwide. The aim of this study was to develop an indirect ELISA (iELISA) using recombinant proteins, namely rBoP59 and rBP26, as antigens for serological diagnosis of B. ovisinfection. The BoP59 and BP26 recombinant proteins were expressed in E. coli and purified by affinity chromatography. Antigenicity was tested by Western blot and iELISA. Standardization of iELISA was performed with 500ng and 1µg BoP59 and rBP26 per well, testing serum from uninfected and experimentally infected rams. rBP26 was effective in distinguishing positive from negative rams. The rBP26 iELISA developed in this study is the first to use a completely purified rBP26 as antigen resulting in high sensitivity (100%) and specificity (90.2%), and an overall accuracy equal to 1.0.

Supplementation of soybean lecithin-based semen extender by antioxidants: complementary flowcytometric study on post-thawed ram spermatozoa.

The purpose of the current study was to evaluate the effects of cysteine (C) and glutathione (G) on the post-thawed ram sperm quality. Collected semen samples from four mature rams were diluted with five soybean lecithin (SL)-based extenders containing: no antioxidant (SL-0), 5 mM cysteine (SL-C5), 10 mM cysteine (SL-C10), 5 mM glutathione (SL-G5) and 10 mM glutathione (SL-G10). After freeze-thawing process, motion and velocity parameters, plasma membrane integrity and functionality, morphological abnormality, lipid peroxidation, acrosomal status, mitochondria activity, and apoptosis status of post-thawed ram spermatozoa were assessed. The results showed that SL-C10 increased the total motility and plasma membrane integrity (p < 0.05) of post-thawed ram spermatozoa (55.86 ± 1.37 and 60.57 ± 1.34 %) compared to other extenders. Progressive motility was significantly higher in SL-C10 (24.71 ± 1.13 %) compared to SL-0 (20 ± 1.13 %) and SL-G10 (15 ± 1.13 %). Mitochondrial activity was significantly higher in SL-C10 (56.83 ± 2.29 %) compared to SL-G10 (38.75 ± 2.29 %). Capacitation and acrosomal status, lipid peroxidation, and the percentage of dead spermatozoa were not affected by different extenders. The percentage of live spermatozoa was higher in SL-C10 (56.33 ± 1.35 %) compared to other extenders. Also, SL-C10 resulted in a lower percentage of apoptotic spermatozoa (14.17 ± 0.53 %) compared to other extenders. The results of this study showed that supplementation of SL-based ram semen extender with 10 mM cysteine resulted in an improved quality of post-thawed ram spermatozoa.

Influence of season and reproductive management on the morphometry of ram sperm head

The aim of the present work was to study the morphometric characteristics of apparently normal ram sperm heads of an ovine insemination centre over a year, using a computer-assisted sperm morphometric assessment system (CASMA) which is commercially available. For this, 383 ejaculates from 9 mature rams kept in non-controlled environmental conditions were used. The morphometry was analyzed in fresh sperm and each spermatozoon was measured for four primary parameters (length, L; area, A; width, W and perimeter, P) and four derived parameters (ellipticity, L/W; rugosity, 4πA/P2; elongation, L−W/L+W and regularity, πLW/4A).A clear seasonal behaviour of both morphometric and derived parameters was observed, with sperm size being larger in autumn and winter. This behaviour was also observed for ellipticity and elongation.Due to organizational reasons in the insemination centre, the rams’ reproductive activity was suspended during the month of August; this fact was reflected, in the ejaculates collected in September, in the decrease of the sperm head size, as well as in the increase of ellipticity.The procedures used in the present study did not allow for natural separation in sperm subpopulations considering the size and shape of apparently normal sperm heads, but it was possible to divide the ejaculate into two subpopulations, taking rugosity into account. These subpopulations were present in all the rams – and had a clear seasonal distribution.

Sperms biometry of local Iraqi Awassi Rams

This study was designed to estimate of sperms biometry in local Iraqi Awassi rams. Five mature rams of 2.5-4 years old and 37-44 Kg live body weight were used in this study. Semen collection was performed by using an artificial vagina. Semen samples were evaluated immediately after collection of total 30 ejaculates. Semen volume and color, mass and individual sperms motility, live and abnormal sperms, as well as sperms concentration, were estimated. sperms biometry calculated by using phase contrast microscope and occulo-micrometer lens. Semen biometry means which estimated in this study were; sperms head length 9.62± 1.2 microns, sperms head width 5.32± 2.5 microns, acrosome length 6.10 ± 2.4 microns, head base width 2.54 ± 1.8 microns, midpiece length 11.92 ± 3.6, midpiece width 2.21 ± 0.8 microns, tail length 50. 62 ± 2.1 microns.

Subsequent influences of feeding intact green seaweed Ulva lactuca to growing lambs on the seminal and testicular characteristics in rams1

The present experiment was designed to investigate the subsequent influences of supplementing different levels of intact green seaweed Ulva lactuca (0%, 3%, and 5% DM) to growing sexually immature lambs during the growth period (74 d) on the seminal and testicular characteristics of sexually mature rams. Ulva lactuca was manually collected, adequately prepared, and then incorporated into lambs' diets. Eighteen male 3-mo-old lambs of the Awassi breed with a mean BW of 22.57 kg (SD = 1.08) were randomly assigned into treatments. The obtained results indicate that offering Ulva lactuca at the level of 3% or 5% DM to lambs during the growth period had no subsequent impacts (P > 0.05) on liver and kidney functions as well as blood water balance in rams, thereby suggesting that Ulva lactuca can be safely supplemented to lambs during growing. However, our findings point out that feeding a lamb diet supplemented with intact Ulva lactuca failed to demonstrate any subsequent benefit (P > 0.05) on the growth performance, thermoregulatory responses, and plasma oxidative status in rams. Above all, it was clearly evident that supplementing intact Ulva lactuca to lambs had demonstrated subsequent negative influences (P < 0.05) on seminal and testicular characteristics of rams, more noticeably observed at the 5% DM inclusion rate than at 3%. These results were manifested by the inferior (P < 0.05) seminal quality, reduced (P < 0.05) testicular morphometry, changes (P < 0.05) in testicular histopathology, defective (P < 0.05) endocrine signaling, and increased (P < 0.05) seminal oxidative stress in rams fed diets supplemented with Ulva lactuca during the growth period compared to control rams. The deleterious impacts of feeding intact Ulva lactuca on spermatogenesis and germ cell loss were proven to be attributed to the dysfunction of Sertoli cells. Collectively, these results provide novel insights on the subsequent influences of dietary supplementation of intact Ulva lactuca to lambs. The consistent evidence of profound negative impacts on seminal and testicular characteristics as well as the resulting data of no improvement of subsequent growth, thermoregulation, and plasma oxidative status in rams prompts us to tentatively recommend the avoidance of feeding intact Ulva lactuca to lambs.

The effect of dietary n-3 polyunsaturated fatty acids supplementation of rams on semen quality and subsequent quality of liquid stored semen

The objective of this study was to examine the effect of dietary n-3 polyunsaturated fatty acid (PUFA) supplementation of rams on semen quality and subsequent sperm function of liquid stored semen. Mature rams of proven fertility were individually housed and were blocked according to breed, body weight, and body condition score and randomly allocated within block to one of two dietary treatments (N = 7 per treatment). Rams were offered a base diet of hay and concentrate, with the concentrate enriched with either: (1) saturated palmitic acid (CON) or (2) high n-3 PUFA fish oil (FO) supplements. Both lipid supplements were added at 2% (wt/wt) of the total diet as fed and both were partially rumen-protected. The animals were fed their respective diets for a total of 9 weeks and blood samples were collected on weeks 0 (pre-experimental), 4, and 9, relative to initial allocation of diet (week 0), for measurement of plasma concentration of fatty acids, metabolites, insulin like growth factor 1 (IGF-1) and insulin. Semen was collected from each ram (on 1 day in each week) in weeks 4, 5, 7, 8, and 9, and each ejaculate was assessed for volume, wave motion, and concentration of sperm, after which it was diluted in a skim milk-based extender and stored at 4 °C. A second ejaculate was collected on weeks 4, 7, and 9, centrifuged, and the sperm frozen for subsequent lipid analysis. A sample of semen from each ram was assessed at 24, 48, and 72 hours after collection for sperm progressive linear motion, ability to penetrate artificial mucus, and the ability to resist lipid peroxidation (at 24 and 48 hours only) using the thiobarbituric acid reactive substances assay. There was no effect of diet on plasma insulin concentrations or on any of the metabolites measured, however, there was a diet by week interaction for plasma IGF-1 concentration (P < 0.05). This was manifested as the FO supplemented rams having higher IGF-1 concentrations on week 9 compared with the control treatment (P < 0.05), but not at the earlier sampling dates. Compared with the pre-experimental values, supplementation with FO increased plasma concentrations of total n-3 PUFAs by 3.1-fold and decreased n-6 PUFA concentrations by 1.84-fold. Consequently, the ratio of n-6 to n-3 PUFA was decreased in the FO-supplemented rams (P < 0.001). Dietary supplementation with FO increased the concentration of eicosapentaenoic acid in sperm from week 4 to 9 by 2.7-fold (P < 0.05) leading to a 1.5-fold increase in total n-3 PUFA in the same period. Ejaculates collected from rams supplemented with FO yielded a higher semen concentration (P < 0.05), however, there was no difference between diets on any of the other semen quality parameters including semen volume, wave motion, progressive linear motion, ability to penetrate artificial mucus, or ability to resist lipid peroxidation. In conclusion, dietary supplementation of rams with n-3 PUFA successfully increased the n-3 PUFA content of plasma and sperm but has limited effects on the quality of liquid stored semen.

Age at puberty and fertility of Rahmani sheep fed on biological inoculated corn silage

The present study aimed to investigate the effect of microbial inoculation adding to corn silage on productive and reproductive performance of sheep. The weaning male and female lambs were fed separately in four groups received a basal diet consisting of concentrate feed mixture (CFM) plus wheat straw (WS). The control group of two sex lambs (n=7 males and n=8 females) was fed R1 included CFM+WS+corn silage (CS), whereas treatment group of two sex lambs (n=7 males and 8 females) nourished R2 contained CFM+WS+ microbial inoculation corn silage (MICS). Both R1 and R2 rations were adjusted every 2weeks according feeding requirements. The measurements as body weight, body condition score, progesterone, and testosterone at puberty, semen collection at puberty. The fertility test was assayed with mature rams and ewes. The obtained results showed that the average body weight and body condition score of male and female lambs were higher (P<0.05) with R2 than R1. Both male and female lambs supplied R2 reached puberty faster and sexual hormones (testosterone and progesterone) developed earlier than lambs given R1. The ages at puberty and testosterone hormone were 32.14weeks and 3.12ng/ml for R2 lambs while 36.72weeks and 2.81ng/ml for R1 lambs, respectively. Age at puberty and progesterone concentration averaged 34.12weeks and 1.89ng/ml with female lambs presented R2, while female lambs fed R1 achieved 38.51weeks and 1.53ng/ml, respectively. Moreover, male lambs in R2 group were produced higher quality semen (P<0.05) than those in R1 group. The ram nourished R2 displayed (P<0.05) enhanced fertility 79.17% compared with R1 70.83%. The pregnancy rate and litter size with ewes received R2 were higher 91.67% and 1.30 than ewes fed R1 83.33% and 1.00, respectively. As a result, it may be concluded that addition of microbial inoculation to corm silage had positive effect on fermentation quality of silage and improved palatability and nutritive value that reflected on productive and reproductive performance of sheep.

PENGARUH MALTOSA SEBAGAI KRIOPROTEKTAN EKSTRASELULER DALAM MENINGKATKAN KUALITAS SEMEN BEKU GUNA MENDUKUNG KEBERHASILAN TEKNOLOGI INSEMINASI BUATAN

The research carried out to observe the effect of maltose addition on the quality of frozen semen of garut rams. Semen was collected once a week using artificial vagina from six mature garut rams. Semen was equilibrated at 5oC for four hours, frozen and stored in liquid nitrogen. The thawing was carried out at the temperature 30oC for 30 seconds. The result showed that percentages of viable sperm for addition of maltose 1,2 g / 100 ml extender (68,50 ± 0,84%) was significantly difference (P&lt;0,05) than control (54,83 ± 1,94%) and addition of maltose 0,6 g / 100 ml extender (65,67 ± 1,03 %). The percentages of progressive motile sperm and percentages of plasma membrane for addition of maltose 1,2 g / 100 ml extender (53% and 64,67%) were significantly difference (P&lt;0,05) than control (43% and 53,83%) but were not significantly different (P&gt;0,05) from addition of maltose 0,6 g / 100 ml extender (50,83% and 64,67%)respectively. In conclusion, the addition of maltose 1,2 g / 100 ml extender is optimal dose to improve the quality of frozen semen of garut rams.

Preliminary assessment of the quantitative relationships between testicular tissue composition and ultrasonographic image attributes in the ram

Abstract This study examined the relationships between gross chemical composition and ultrasonographic characteristics of the ram testes. Ten testes from sexually mature Karakul rams were scanned ex situ with an 8-MHz linear-array transducer, in a transverse and longitudinal plane. All ultrasonograms were saved as digital images and subjected to computerized analyses. Crude protein content was determined by the Kjeldahl method, moisture was determined with an oven-drying method, and fat was measured by the Soxhlet extraction of dried samples. Mean pixel values (r = −0.64, P = 0.04), pixel heterogeneity (standard deviation of pixel values; r = −0.64, P = 0.04) and maximum pixel intensity (r = −0.76, P = 0.01) were all negatively correlated with parenchymal protein content. Pixel heterogeneity correlated directly with extractable lipids (r = 0.66, P = 0.02). The quantitative correlations between echotextural and biochemical parameters found in the present experiment confirm the utility of ultrasonographic imaging combined with computer-assisted image analysis for determining changes in testicular histophysiology.

Effects of vitamin B12 supplementation on the quality of Ovine spermatozoa

The present study was undertaken to investigate the effect of various levels of vitamin B12 in Tris extender on semen quality of Dallagh rams following the cooling and freeze/thawing process. Semen was collected from six healthy and mature rams with an average body weight of 60.0 ± 5.0 Kg using an electro ejaculator. High quality samples were mixed and diluted in Tris extender supplemented with different concentrations of vitamin B12 (0, 1, 2 and 3 mg/ml). The semen aliquots were cooled and preserved at 5°C and their qualities were evaluated during pre-freezing and then the cooled semen samples were packaged into 0.25 ml straws. Straws were frozen in the vapor of liquid nitrogen, and were then stored at -196ºC. Straws were thawed seven days later and the characteristics of spermatozoa were examined. Results of this study showed that the effect of vitamin B12 on characteristics such as viability, motility, progressive motility and normality of spermatozoa were significant in pre and post freezing conditions (P<0.05). In conclusion, for long term storage of semen of Dallagh rams, we recommend using 2 mg/ml of vitamin B12 in semen extender.

Association of soybean-based extenders with field fertility of stored ram (Ovis aries) semen: A randomized double-blind parallel group design

Two consecutive randomized double-blind field fertility experiments were conducted over a 4-month period and aimed at evaluating the association of two commercial soybean lecithin-based extenders (AndroMed [Minitub, Tiefenbach, Germany] and BioXcell [IMV Technologies, L'Aigle, France]) with pregnancy rates of chilled-stored (CS) and frozen-thawed (FT) ram semen. Semen samples with more than 2 × 109 sperm per mL and 70% progressive motile spermatozoa were collected via an artificial vagina from twelve proven fertile Chios rams, split-diluted with the above mentioned extenders, packaged in 0.25 mL straws and either stored at 5 ± 1 °C for 30 to 36 hours or frozen and thawed. Non-lactating multiparous ewes were inseminated in progestagen-synchronized estrus either with CS (AndroMed: N = 212 and BioXcell: N = 206; intracervical AI) or with FT (AndroMed: N = 114 and BioXcell: N = 92; laparoscopic intrauterine AI) semen. Ovulation was confirmed in all ewes based on determination of blood plasma progesterone (>1 ng/mL) 8 days post AI. Ewes were screened for pregnancy diagnosis by transabdominal ultrasonography 65 days post AI. BioXcell was superior to AndroMed in preserving the fertilizing potential of CS (P < 0.05) and FT (P < 0.005) semen. In AndroMed-stored semen, young rams (1.5–2.5 years old, N = 8) had a pregnancy rate (59.1%; 124/210) lower than that (72.4%; 84/116) of mature rams (4.5 to 5.5 years, N = 4; P < 0.025). Compared with AndroMed extender, processing of young ram semen in BioXcell extender improved pregnancy rates of CS (66.7%; 88/132 vs. 83.9%; 94/112; P < 0.005) and FT (46.2%; 36/78 vs. 71.0%; 44/62; P < 0.01) spermatozoa. Both extenders were similarly effective in preserving pregnancy rates of mature ram semen (P > 0.05). Ram-by-extender interactions were significant for pregnancy rates of CS and FT semen. Irrespective of extenders, overall pregnancy rates after intracervical and intrauterine AI were 75.1% and 62.2%, respectively (P < 0.001). In conclusion, BioXcell is a suitable extender for short- and long-term storage of ram semen. Selection of the ewes, farms, and extenders for intracervical AI programs can contribute to satisfactory fertility rates with semen preserved more than 24 hours at 5 °C.

Morphometrically-distinct sperm subpopulations defined by a multistep statistical procedure in Ram ejaculates: intra- and interindividual variation

The existence of sperm subpopulations within the mammalian ejaculate has now been widely recognized. However, to the best of our knowledge, no data exist regarding the existence of sperm morphometric subpopulations within the ovine ejaculate. Computer assisted sperm morphometry analysis (ASMA) data and clustering methods were used in this study to identify sperm-head subpopulations in ram semen. Two experiments were carried out. In Experiment 1, ejaculates from 226 mature rams of the Manchega breed belonging to 36 different herds were used. A minimum of 100 sperm heads were analyzed from each male and eight morphometric characteristics for each individual sperm were recorded. Subpopulation analysis was performed in sequential steps: variable group analysis and correlation analysis to select which morphometric characteristics to use in cluster analyses; nonhierarchical clustering analysis using sperm head length and p2a (also known as roundness) shape factor as initial classificatory variables; and hierarchical clustering analysis to obtain the final number of clusters. The clustering analyses, based on 26 306 individual cells, revealed the existence of four sperm subpopulations (SP1, SP2, SP3 and SP4) with different morphometric characteristics. Significant differences in the proportion of spermatozoa in the SP1 and SP3 were found between rams belonging to different herds. In Experiment 2, the intra- and intermale variability on the distribution of sperm subpopulations was assessed. Three ejaculates from each of 21 rams were collected and the same multistep clustering analysis was performed. For all subpopulations defined, the intermale variability resulted in high values, being the intramale variability much lower. This fact would allow the use of sperm head morphometry to characterize a male and might provide valuable information to asses its fertility. In conclusion, our results show that using computer assisted sperm morphometry analysis and multivariate cluster analyses, four sperm subpopulations with different head phenotype were identified in ram ejaculates.

Effect of an inactivated bluetongue serotype 8 vaccine on semen quality in rams

The aim of this study was to determine whether a single dose of an inactivated bluetongue virus serotype 8 (BTV-8) vaccine altered semen quality in rams. Twenty sexually mature rams were assigned to three experimental groups: two groups of four animals were vaccinated and a third group of four animals was unvaccinated. The first group included rams with a history of natural BTV-8 infection in 2007 and the second and third groups included BTV-8 naïve rams. Semen was collected prior to vaccination and for 4 months post-vaccination. There were no significant differences in semen quality traits, including motility and concentration of spermatozoa, and percentages of living, normal dead and abnormal dead spermatozoa, between vaccinated and unvaccinated groups, or over time (P>0.05). The BTV-8 vaccine tested in this study did not appear to have any adverse effect on semen quality in rams.

Effect of feeding olive-pulp silage on the seminal characteristics and fatty acid profile of the sperm plasma membrane in Iranian fat-tailed sheep

This study was conducted to investigate the effect of feeding high levels of olive-pulp silage on the seminal characteristics of Ghezel and Mehraban sheep. Sixteen fertile rams (3.5–4.0 years of age) of the Ghezel or Mehraban breeds (8 rams per breed) were randomly assigned to diets containing 70% olive-pulp or corn silage for 120 days. Semen was collected every 3 weeks by electro-ejaculation. Seminal volume, sperm density, sperm forward motility, sperm numbers, the percentage live sperm, acrosomal integrity, and sperm abnormalities were evaluated immediately after semen collection. The concentration of the seminal malondialdehyde (MDA) was also recorded. Serum testosterone concentrations were determined by ELISA for samples collected monthly. The profile of fatty acids in the sperm plasma membrane of the Mehraban rams was determined by gas chromatography, using samples of semen collected on days 0 and 120. The diet by time interaction significantly (P<0.01) affected the seminal volume, sperm density, sperm number, and MDA concentration. The diet×breed×time interaction was also significant (P<0.01) for sperm density, the percentage live sperm, sperm forward motility, and percentage sperm with normal acrosomes. However, the breed×diet interaction did not have a significant effect on the parameters investigated, other than semen volume. The diet significantly affected the percentage of palmitic, oleic, pentadecanoic, and docosahexaenoic acid in the sperm plasma membrane. Other saturated and unsaturated fatty acids were not significantly affected by the type of silage fed to Mehraban rams. The results indicated that a diet containing 70% olive-pulp silage and 30% alfalfa hay did not have a detrimental effect on the reproductive parameters of Ghezel and Mehraban rams when fed for up to 120 days. On the other hand, it increased the percentage of unsaturated fatty acids in the sperm membrane. Being a cheap by-product, olive-pulp can be economical to feed to mature rams for extended periods of time, without having any detrimental effect on sperm quality.

A Survey of Congenital Reproductive Abnormalities in Rams in Abattoirs in South West England

Congenital abnormalities of the reproductive tract of male sheep were surveyed at three abattoirs in the south west of England during the period June 2000-January 2004. A total of 7307 rams were examined [6521 lambs (prepubescent) and hoggets (aged from their first autumn after birth until first shorn) and 786 adult rams mature rams that had been exposed to ewes]. A total of 156 congenital lesions were detected, 87 of which occurred in lambs. Testicular hypoplasia was the most common lesion occurring in 69 lambs as well as eight hoggets ('microtestes' were recognized in nine other animals in which the testis was disproportionately smaller than the epididymis). The second most common lesion found was notched scrotum occurring in 34 animals (27 young rams and seven adults). Some cases of notched scrotum were accompanied by hypospadias which was seen in a total of seven lambs and eight hoggets. Other lesions, detected in five or less animals (less than approximately 0.05% of the animals examined), included cryptorchidism and various abnormalities of the epididymis (segmental aplasia of the epididymis, blind efferent ducts and epididymal cyst) and congenital scrotal hernia. The overall prevalence of congenital lesions of 2.21% emphasizes the importance of undertaking breeding soundness examinations of young rams before they are put with the flock.