Morphology and head morphometric characters of sperm in Thai native crossbred stallions

<p>Abstract</p> <p>Background</p> <p>One of the semen quality parameters use to determine fertility is the percentage of sperm that express normal morphology. Sperm head morphometry is also correlated with fertility. The objectives of this study were 1) to investigate the sperm morphology and normal sperm head morphometry of Thai native crossbred stallions, and 2) to compare our results with the characteristics of proven fertile sperm from purebred stallions.</p> <p>Methods</p> <p>Semen samples were collected monthly from nine stallions, of which five were Thai native crossbred (T) and four were purebred of proven fertility (F: F1 was a Standard-bred; F2 was a Warm-blood; F3 and F4 were Thoroughbreds). All the animals were aged between 5 and 12 years. Sperm morphological examination was performed using formaldehyde-fixed samples under phase-contrast microscopy (1000×). Normal sperm head morphometry characteristics were measured by Computer-Assisted Semen Analysis (Hamilton Thorne, USA.) after applying the Harris' haematoxylin staining technique.</p> <p>Results</p> <p>The percentages of morphologically normal and abnormal sperm varied among individual stallions in both the T and F groups. The mean percentage of morphologically normal sperm was not significantly different (P > 0.05) between T and F stallions (mean ± SE, 49.7 ± 1.3 and 48.1 ± 2.8, respectively). A comparison between the T and F sperm heads revealed that all the dimensional parameters were significantly different (P < 0.05). The coefficients of within-animal variation (CVs) ranged from 2.6 (shape factor 1) to 7.5 (elongation) and 2.9 (shape factor 1) to 8.1 (elongation) in T and F, respectively. In the case of the T group, those sperm head parameters that featured a low within-animal CV and a high between-animal CV were perimeter (2.9, 19.1), shape factor 1 (2.6, 25.8) and shape factor 3 (3.8, 32.0). In the case of the F group, only shape factor 1 (2.9, 26.1) featured such characteristics.</p> <p>Conclusion</p> <p>We found variability in the percentage of morphologically normal and abnormal sperm, as well as in sperm head dimensions among Thai native crossbred stallions, and these results were similar to those of purebred stallions. Our findings demonstrate that the heads of the T sperm specimens were larger and rounder than that of the F sperm. Perimeter, shape factor 1 and shape factor 3 could be used as parameters for the identification of individual T stallions based on a sperm sample.</p

Non-targeted proteomic analysis of Asian elephant (Elephas maximus) seminal plasma using an in-solution digestion technique and liquid chromatography tandem-mass spectrometry

Seminal plasma proteins have recently been reported to play a significant role as valuable materials for understanding male reproductive biology, identifying causes of fertility problems, and developing reproductive biomarkers. Proteomic analysis of seminal plasma holds promise in advancing the understanding of male Asian elephant reproductive biology. This study aims to explore seminal plasma proteins of Asian elephants and their probable functions to provide fundamental information about male reproduction in this species. The protein solution from pooled seminal plasma from 10 bulls (a total of 33 ejaculates) was digested into peptides and identified using LC-MS/MS. Out of 986 proteins, 597 were mapped and matched with 58 species in UniProt databases, including Elephas maximus. These mapped proteins were mostly involved in binding function, catalytic activity, cellular process, and metabolic process. Only 29 mapped proteins were recognized to be related in reproductive process, mainly associated in spermatogenesis and sperm capacitation. Additionally, several seminal plasma proteins related to fertility or semen quality in other mammals were also found in Asian elephant semen, such as keratin type I, aldose reductase, thrombospondon-1, fibronectin 1, platelet-activating factor acetyl hydrolase, mannosidase, and semenogelin-2. This discovery clearly reveals the beneficial protein profile in seminal plasma of the Asian elephant and serves as a crucial step in investigating infertility and poor semen quality in this valuable species

Successful artificial insemination in the Asian elephant (Elephas maximus) using chilled and frozen-thawed semen

<p>Abstract</p> <p>Background</p> <p>Artificial insemination (AI) using frozen-thawed semen is well established and routinely used for breeding in various mammalian species. However, there is no report of the birth of elephant calves following AI with frozen-thawed semen. The objective of the present study was to investigate the fertilizing ability of chilled and frozen-thawed semen in the Asian elephant following artificial insemination (AI).</p> <p>Methods</p> <p>Semen samples were collected by from 8 bulls (age range, 12-to 42-years) by manual stimulation. Semen with high quality were either cooled to 4°C or frozen in liquid nitrogen (-196°C) before being used for AI. Blood samples collected from ten elephant females (age range, 12-to 52-years) were assessed for estrus cycle and elephants with normal cycling were used for AI. Artificial insemination series were conducted during 2003 to 2008; 55 and 2 AI trials were conducted using frozen-thawed and chilled semen, respectively. Pregnancy was detected using transrectal ultrasonography and serum progestagen measurement.</p> <p>Results</p> <p>One female (Khod) inseminated with chilled semen became pregnant and gave birth in 2007. The gestation length was 663 days and the sex of the elephant calf was male. One female (Sao) inseminated with frozen-thawed semen showed signs of pregnancy by increasing progestagen levels and a fetus was observed for 5 months by transrectal ultrasonography.</p> <p>Conclusion</p> <p>This is the first report showing pregnancy following AI with frozen-thawed semen in the Asian elephant. Successful AI in the Asian elephant using either chilled or frozen-thawed semen is a stepping stone towards applying this technology for genetic improvement of the elephant population.</p

DEVELOPMENT OF SINGLE BLASTOMERES FROM 4-CELL STAGE EMBRYOS AFTER AGGREGATION WITH PARTHENOGENONES IN MICE

This study was undertaken to determine whether diploid parthenogenones can assist the development of single blastomeres of 4-cell embryos to term. Isolated blastomeres of 4-cell embryos were aggregated with parthenogenones at the 2-, 4- and 8-cell stages. After the removal of the zonae, aggregation was done by pushing one blastomere of 4-cell embryos and one parthenogenone into contact using a micropipette. There were no significant differences in the percentages of blastocysts and offspring among all parthenogenones' developmental stages used. It also seemed that the chimerism of the offspring (judged by coat color) was not affected by the developmental stage of the parthenogenone. A total of 19 offspring survived and 12 offspring were coat-colored chimera. From 12 coat-colored chimeric offspring, 9 offspring had germlines derived from the isolated blastomeres of 4-cell embryos, one offspring had a germline derived from both the parthenogenone and the isolated blastomere of a 4-cell embryo and one offspring had a germline derived from the parthenogenone. One offspring however, was infertile. The present study demonstrates that parthenogenones can be used to assist the development of single blastomeres from 4-cell embryos to term

Reproductive characteristics of Holstein Friesian dairy breed after estrous synchronization with select- synch with or without CIDR

The objectives of this study were to determine estrus (ER), conception (CR) and pregnancy rate (PR) of dairy cows after synchronization of estrus and the relationship between synchronization method and vaginal electrical resistance (VER). A total of 52 Holstein Friesian (HF) females were synchronized with Select-Synch or Select-Synch + CIDR protocols. Results showed that the overall ER, CR and PR were 67.30, 55.90 and 37.00 %, respectively. Mean ER was significantly (P < 0.05) higher for Select-Synch + CIDR treatment compared to Select-Synch alone (80.80% versus 53.90 %). Mean PR was higher for Select-Synch + CIDR compared to Select-Synch (46.30% versus 28.00%;

Asian elephant (Elephas maximus) seminal plasma: establishing the proteome and effect on spermatozoa when added to cryomedium

Context. The removal or supplementation of ejaculates with seminal plasma (SP) can affect cryotolerance and post-thaw survival of spermatozoa in many species. In the Asian elephant (Elephas maximus), elucidation of the SP proteome and investigation of how it affects spermatozoa may enable improvement of cryopreservation protocols. Aims. Herein, we characterise the Asian elephant SP proteome and investigate the impacts of SP on sperm cryotolerance in the presence of conspecific or heterospecific SP. Methods. Proteomic analysis of Asian elephant SP was performed using mass spectrometry on nine samples from three individuals. In a separate study, SP was removed from six ejaculates and spermatozoa were resuspended in Tris extender supplemented with: no seminal plasma (NOSP), conspecific SP from ejaculates exhibiting ‘good’ (GSP, >60%) or mixed sperm total motility (MSP), or horse SP (HSP). Samples underwent cryopreservation, and sperm parameters were compared prior to cryopreservation and after thawing (0 and 2 h). Key results. Mass spectrometry identified 155 proteins from an array of families. Significant differences were observed in post-thaw sperm quality between SP treatments: high concentrations of MSP (25%, v/v) displayed greater average path and straight-line velocity immediately after thawing (P < 0.05) and greater sperm motility index and beat cross frequency than NOSP after 2 h post-thaw incubation (P < 0.05). The addition of HSP improved sperm kinematic parameters compared to NOSP and GSP treatments (P < 0.05). Conclusions and implications. These preliminary findings suggest the potential of SP to enhance the cryosurvival of Asian elephant spermatozoa, with HSP showing particularly promising results compared to conspecific SP (GSP). Further research into the specific effects of Asian elephant SP proteins is warranted

The Use of Vaginal Electrical Resistance to Diagnose Estrus and Early Pregnancy and Its Relation with Size of the Dominant Follicle in Dairy Cattle

ABSTRACT The use of vaginal electrical resistance (VER) for estrous detection and early pregnancy diagnosis were evaluated using three experiments in dairy cattle, in Ethiopia. VER was measured: 1) during the natural estrous (n = 60) cycle, 2) during estrus induced by GnRH+ PGF 2· (n = 11) and 3) during post insemination in dairy cows synchronized with GnRH+CIDR+PGF 2· (n = 25). Results from Experiment 1 indicated that VER (mean ± SD) during pro-estrus, estrus, metestrus, diestrus and anestrous was 89.6 ± 3.1, 82.2 ± 2.2 102.9 ± 3.1, 106.8 ± 1.4 and 119.7 ± 1.7 ohm, respectively. Results from Experiment 2 indicated that VER was highest (102.4 ± 2.0 ohm; P &lt; 0.001) at the time of PGF 2· injection and significantly declined to 82.3 ± 0.7 ohm at the time of estrus and increased (94.9 ± 2.0 ohm; P &lt; 0.001) 24 h after estrus. The mean diameter of the largest follicle (DLF) was highest (14.3 ± 0.1 mm; P &lt; 0.001) at estrus and lowest (10.0 ± 0.1) at the time of PGF 2· injection. The VER value was inversely correlated (r = -0.50; P &lt; 0.001) with DLF. Results from Experiment 3 showed that VER significantly (P &lt; 0.01) declined from day 19 to day 21 post insemination in non pregnant cows compared with pregnant cows. The study proved that VER can effectively be used for estrus detection and can be used to diagnose early pregnancy (day 18-21 post insemination) in dairy cows