Clinical Theriogenology

Embryonic diapause: a unique stage of development

Theresa Beachler — Fri, 28 Jun 2024 06:46:40 -0700

Embryonic diapause is a unique stage of development that occurs in some mammalian species. Diapause serves as an evolutionary reproductive strategy to maximize the survivability of dam and offspring. Although individual mechanisms of control vary among species, the overarching physiology of diapause extends the length of pregnancy to delay parturition until either seasonal, environmental, nutritional, or internal physiologic constraints are optimal for parturition and rearing of young. This review discusses concepts and highlights control mechanisms unique to rodents, mink, and tammar wallabies.

Role of trace minerals in bull reproductive physiology and semen quality

Maria Ferrer, Roberto Palomares, Juan Maldonadox-Estrada — Mon, 20 May 2024 13:52:43 -0700

Testicular dysfunction is often associated with an imbalance in antioxidant/oxidant homeostasis, leading to negative effects of oxidative stress on germ cell proliferation, steroidogenesis, and sperm function. Trace minerals (TM) are involved in basic homeostatic and enzymatic processes like free radical detoxification, cellular respiration, carbohydrates, lipids, nucleic acids, synthesis and metabolism of proteins, and stabilization of membranes and DNA. Dietary source of TM is necessary to support these processes. Supplementing cattle with TM is nowadays a common practice to help support growth, reproduction, and immunity. This review provides information on roles of TM in bulls testicular and sperm functions, and effects of TM mineral supplementation on bull reproductive parameters.

Genomic selection in dairy cattle: impact and contribution to the improvement of bovine fertility

Thu, 14 Mar 2024 06:28:00 -0700

Genomic selection has revolutionized the dairy cattle breeding industry, with ripple effects that have greatly impacted dairy herd management. Rate of genetic progress has increased markedly, especially in Holstein and Jersey breeds, for production, health, and fertility traits. Genomic testing of young bulls and heifers provides greater accuracy of selection decisions involving traditional fertility traits, such as daughter pregnancy rate, while creating the opportunity to improve novel traits, such as fetal loss. Cameras, wearable sensors, and other precision livestock farming technologies will allow selection for traits such as estrus duration and intensity that require high frequency phenotyping. At the same time, synergies between genomic testing and advanced reproductive technologies have led to rapid and widespread adoption of sexed semen, coupled with mating of females whose offspring are not needed as herd replacements to beef sires. This strategy produces added-value crossbred calves for the beef supply chain, while allowing genetically inferior mature cows that are still producing at a high level to remain in the herd for additional lactations.

Ovum pick up, in vitro embryo production, and embryo transfer as value-added theriogenology service in miniature Hereford cattle operation

Randa Boler, Ramanathan Kasimanickam — Fri, 28 Jun 2024 07:00:48 -0700

Goal was to provide evidence for adopting assisted reproductive technologies (ART), ovum pick up (OPU), in vitro embryo production (IVP), and embryo transfer (ET) in small beef cattle operations as value-added service. Day 7 embryos (n = 14) were produced via IVP utilizing oocytes (n = 87) collected by OPU from miniature Hereford donor cows (n = 3; mean age: 7 years) and fertilized with semen from miniature Hereford bulls. Irish Black (n = 8; 14 months) and Hereford (n = 1; 20 months) recipient heifers were synchronized using 5-day Select-Synch + controlled internal drug release (CIDR) protocol. On day 9 after CIDR removal, heifers (n = 7) with a corpus luteum (> 2 cm in size) received an embryo in the ipsilateral uterine horn. Pregnancy/ET was 57.1% (4/7). Economic advantage (increase in number of offspring) was realized comparing OPU-IVP and artificial insemination procedures. These ART technologies (OPU, IVP, and ET) can be utilized in genetically superior cows as value-added theriogenology service to increase their offspring.

Diagnosis of clinical cervicitis and vaginitis in dairy cows in relation to various postpartum uterine disorders

Mon, 06 May 2024 07:26:12 -0700

There is poor agreement between clinical findings and results of diagnostic tests in postpartum uterine diseases that may be explained at least in part by the presence of inflammation and infection at sites other than the endometrium. It was hypothesized that clinical cervicitis and vaginitis are components of reproductive tract inflammatory disorders in postpartum dairy cows. A total of 61 postpartum dairy cows were enrolled in a nested case-control design. Periparturient disease occurrence in weeks 1 (1w), 3 (3w), and 5 (5w) postpartum were recorded. Clinical cervicitis was diagnosed in 36.0, 40.1, and 31.1% of cows in 1w, 3w, and 5w postpartum, respectively. Approximately 64% of cows with clinical endometritis in 5w postpartum also had clinical cervicitis (p ≤ 0.05). Prevalence of clinical and cytological vaginitis was 0% in 5w postpartum. Average days open: 110 for healthy cows and 117 for cows with clinical cervicitis (p ≤ 0.001), 145 for cows with clinical cervicitis and clinical endometritis (p < 0.005), and 199 for cows with clinical cervicitis and cytological endometritis (p < 0.001). Contrary to vaginitis, high prevalence of clinical cervicitis and its association with clinical endometritis and longer average days open suggested a substantial role of the condition in postpartum uterine diseases.

Effects of bovine ova density and culture supplements on cleavage and blastocyst development rates of in vitro embryos

Jessica Looman, Zowie Rodriguez, Lyric Waugh, John Gibbons — Fri, 02 Feb 2024 03:50:51 -0800

An optimized in vitro culture system is important to maximize bovine blastocyst development. Four experiments were conducted to explore manipulation of culture environments and investigate the benefits of culturing embryos in groups. Follicles were aspirated from abattoir-derived ovaries and selected oocytes were matured, fertilized, vortexed, and randomly placed in culture groups. Experiment 1 evaluated the effects of ova culture density on blastocyst development among embryos cultured individually or in groups of 5, 10, 20, or 50 embryos. Experiment 2 evaluated the effects of conditioned media from previous replicates on embryo development of the current culture. In Experiment 3, cleaved embryos were grouped together after being in culture for 24 hours. Lastly, in Experiment 4, grouped embryos were placed in 10 μl culture drops to evaluate the effect of high density/low media volume on development. Cleavage and blastocyst rates analyzed via Chi-square indicated that although cleavage rates were similar among culture groups (and experiments), blastocyst development was lower (p < 0.05) in 1 embryo culture group compared to other groups. When conditioned culture media from previous replicates were added to original culture media, blastocyst development was similar among original and conditioned culture groups of 20 and 50 embryos. When cleaved embryos were amalgamated and cultured, blastocyst development was higher (p < 0.05) in culture groups of 10 than 1 cleaved embryo groups but similar to controls for both culture groups. When embryos were cultured in 10 μl drops, embryos cultured in groups of 5 had lower development to blastocysts compared to groups of 2, 10, 25, and control. In conclusion, these data indicated an apparent ‘helper effect’ expressed in culture environments of groups, and this effect apparently occurred after cleavage but before blastocyst development. Direct or indirect role(s) that additional cells have on in vitro culture and the mechanism of this helper effect requires further investigation.

Effect of incorrect storage of bull semen samples on sperm morphology assessment

Allan Gunn, Mark Baker — Thu, 01 Feb 2024 04:08:34 -0800

Thirteen pairs of bull semen samples were assessed. One of each pair of samples was inadvertently stored in phosphate buffered saline (PBS) that was used for analysis of motility immediately after collection. Other sample of the pair that was correctly stored in buffered formol saline (BFS) was assessed later. Proportion of morphologically normal sperm was different (p = 0.0021) between the 2 storage methods. Most of the abnormalities in the PBS samples were loose and detached heads. Closer examination of these sperm illustrated changes in the composition of the tail, with an apparent loss of the plasma membrane. This serendipitous error allowed documentation of the importance of correct storage of semen samples for morphological assessment of sperm, and the tertiary defects detected with the incorrect storage of semen samples in semen extender. Tertiary defects should always be considered a possibility during morphological assessment of sperm via spermiogram.

Stallion sperm concentration measurements: experience and equipment

Dale Kelley, Reed Holyoak — Mon, 22 Jan 2024 03:10:53 -0800

Accuracy is paramount in evaluating sperm concentration and can be a challenge to those with minimal laboratory experience. Purpose of the study was to determine the effect of operator experience on sperm concentrations using 4 methods: Makler^® counting chamber, equine densimeter, iSperm, and NucleoCounter^®. There was no difference (p = 0.64) between experienced and novice processors for Makler^® counting chamber; was difference (p = 0.005) for equine densimeter; was no difference (p = 0.35) for iSperm; and was tending toward difference (p = 0.068) for NucleoCounter^®. Correlation between bias and magnitude for Makler^® counting chamber was –0.74 (p = 0.003); for equine densimeter was –0.44 (p = 0.11); for iSperm was 0.06 (p = 0.83), and NucleoCounter^® was –0.52 (p = 0.06). Makler^® counting chamber produced a mean sperm concentration similar to an experienced processor but had significant variation within novice processors. Equine densimeter significantly overestimated sperm concentrations with novice processors but had the least variation. The iSperm performed poorly for both experienced and novices and produced significantly different concentrations than other methods. Thus, iSperm cannot be recommended to accurately measure sperm concentration. Lastly, NucleoCounter had no difference in mean sperm concentrations or variation and was the best system for a novice processor to gain accurate and repeatable sperm concentration measurements.

Evaluating the use of ultrasonography with Doppler to assess peripubertal development and predict breeding soundness examination classifications in ram lambs

Fri, 28 Jun 2024 07:17:33 -0700

The objectives were to evaluate changes in testicular characteristics of peripubertal rams and determine their association with breeding soundness examination (BSE) classifications. We hypothesized that testicular echotexture and blood flow assessed via ultrasonography with Doppler would predict subsequent BSE classifications. Ram lambs (n = 40) were examined on intake for performance testing in May. In May and June, scrotal circumference (SC) and scrotal skin temperature measurements were obtained. Additionally, ultrasonography with Doppler was used to calculate total testicular volume (TTV), assess pixel intensity, and measure resistive (RI) and pulsatility (PI) indices of the right testicular artery. Rams underwent BSE ~ 10 weeks after the initial evaluation and either passed or failed based on SC and sperm quality. SC, TTV, and pixel intensity increased between May and June, whereas RI and PI decreased (p < 0.01). SC and scrotal skin temperature were greater (p = 0.03) for rams with an ‘excellent’ BSE classification than those that failed. SC was also positively correlated (r = 0.53; p < 0.01) with percent normal sperm at BSE. Testicular pixel intensity, RI, and PI did not differ (p ≥ 0.28) based on BSE classification. Decreased (p = 0.01) heart rates on intake in May were reported in rams with ‘excellent’ BSE classifications and associated with greater percent normal sperm (r = 0.42; p = 0.01) at BSE. In conclusion, ultrasonography with Doppler can be useful for assessing peripubertal development in ram lambs but provided limited capability in predicting BSE classification.

Vaginal lipoma with cervicovaginal and rectal prolapse in a cow

Eduardo Prado, Tulio Prado, Elizabeth Whitt, Alison Bradley, Pierre-Yves Mulon — Wed, 08 May 2024 08:16:11 -0700

A 5-year, mixed breed cow, was presented with cervicovaginal and rectal prolapses. Cow had a vaginal mass on the left caudal aspect of cervicovaginal prolapse. Rectal prolapse was resolved; however, vaginal mass prevented reduction of vaginal prolapse. Next day, vaginal mass was resected that made vaginal prolapse reduction and vulval closure (Bühner stich) possible. Histopathology identified the mass as infected vaginal lipoma.

Modified partial posthectomy surgery for chronic preputial prolapse in a Bos indicus bull

Rory Nevard, Marco Lopes, Heidi Lehmann, Chris Quinn, Cassandra MacDonald — Mon, 06 May 2024 07:45:24 -0700

Preputial prolapses in bulls are frequently encountered by bovine reproductive practitioners and are common physical conditions impairing a bull’s ability to copulate. Marked chronicity or unsuccessful medical management warrant surgical correction. Preputial resection/circumcision (also known as ‘reefing procedure’) or preputial amputation are 2 well-documented procedures performed to restore penile function. It is widely believed that preputial resection is considered superior to amputation, as with the latter procedure, strictures and wound contracture stenosis are common reported sequelae. Therefore, surgery should aim at preserving tissue and resolving the prolapse without interference to complete penile extension. We adapted novel surgical features in a bull with a chronically prolapsed prepuce: an updated preputial amputation technique (i.e. modified posthectomy) and used a single-layer closure pattern with rapidly absorbable suture (not reported for bulls). There was total resolution and bull returned to service. This case illustrated that severe and chronically prolapsed prepuces can be successfully repaired using this updated modification of a historical technique.

Sexual development disorder in a dog

Tue, 30 Apr 2024 05:18:02 -0700

A 1-year intact, phenotypic female Doberman Pinscher dog, was evaluated for suspected sexual development disorder. Patient had a history of white mucoid vaginal discharge with no estrous signs or behavior. Clitoral hypertrophy with a palpable os clitoris were noted. Transabodminal ultrasonography revealed a right gonad and tubular structures (possibly uterus). Exploratory laparotomy revealed 2 underdeveloped gonads in caudodorsal abdomen and a markedly underdeveloped right uterine horn. Histopathology confirmed bilateral ovotestes. Karyotyping (number and morphology of chromosomes) and fluorescence in situ hybridization (XX and XY cells) results were normal. Samples were PCR positive for sex-determining region Y (SRY) and X-linked androgen receptor gene. We concluded that the patient was either a mosaic or chimera with normal female 78,XX and normal male 78,XY cells and genetically a mix of male and female. Final diagnosis was sex chromosome (78,XX/XY), SRY-positive, ovotesticular, disorder of sexual development with female phenotype.

Congenital hydrocephalus in a stillborn Haflinger foal

Thu, 14 Mar 2024 06:42:55 -0700

A 14-year, multiparous Haflinger mare, apparently fullterm (unknown breeding or ovulation date), was presented for dystocia. Mare was transvaginally palpated at the farm by the referring veterinarian; foal was in craniolongitudinal presentation, dorsosacral position with extended forelimbs in the vaginal vault and head just cranial to cervix, and a cranial abnormality of the foal prevented assisted vaginal delivery. Mare was referred. Foal was not alive at presentation and was undeliverable with assistance because of congenital hydrocephalus. Anesthetized mare was placed in Trendelenburg position, controlled vaginal delivery was elected and foal was removed via fetotomy. Mare was negative for β1, 3- N-acetylgalactosaminyltransferase 2 (B3GALNT2) nonsense mutation (reported to be responsible for hydrocephalus). Dystocia in a Haflinger mare because of hydrocephalus is reported for the first time.

Amorphus globosus

Kaylin McNulty, Michael Jaffe, Joanne Yi — Fri, 16 Feb 2024 08:25:39 -0800

Amorphus globosus is a rare malformation that is defined as an acardiac asymmetrical rough spherical mass of tissue covered in skin. To authors’ knowledge, amorphus globosus has not been previously reported in canids. Herein, we describe amorphus globosus in an American Bulldog pup with accompanying radiograph, gross images, and histopathology. Additionally, a systematic review (preferred reporting items for systematic reviews and meta-analyses protocol) was performed for veterinary species; amorphus globosus has been reported in 22 bovids, 3 caprids, 1 ovid, and 1 equid.

Disorders of sexual development in small ruminants

Joaquin Paredes, Lukasz Czochara, Daniel Villagomez, Allan King — Tue, 23 Jan 2024 08:07:44 -0800

Intersex conditions, also known as disorders of sexual development (DSD), are uncommon in small ruminants. This report describes in detail, 2 cases of DSD in small ruminants, including clinical presentation, histopathological and cytogenetic analysis that led to the final diagnoses. Case 1, a mixed-breed ewe, was assessed due to a reported ram-like behavior at ~ 6 months of age. Physical examination revealed abnormal external genitalia with enlarged clitoris and bilateral inguinal gonads, histologically confirmed as testicular tissue. Karyotyping revealed sex chromosome blood chimerism (54XX, 54XY), implicating freemartinism as the cause of DSD. Case 2 was a 1-year Nigerian Dwarf cryptorchid male goat presented for castration. During surgery, bilateral ovoid gonads attached to a bicornuate uterus were identified. Histology revealed testicular tissue and uterus alongside vas deferens were consistent with persistent Müllerian duct syndrome. This report describes presentations, findings, and features of DSD, a rare occurrence in small ruminants.

Modified diff-quick staining for canine sperm morphology

Mariana Mazzuchini, Guilherme Novello, Lorenzo Segabinazzi — Fri, 16 Feb 2024 08:17:40 -0800

Sperm morphology assessment requires specialized microscopes or stains. Diff-quick (DQ) is considered a universal stain that is cost-effective; however, morphological evaluation of sperm using DQ staining is poor and not encouraging. Therefore, this study investigated modifications to the DQ protocol to improve identification of morphological defects of dog sperm and compared the modified DQ techniques with eosin-nigrosin, Karras, and differential interference contrast microscopy [DIC]). One ejaculate from each of 9 dogs was used. To perform the proposed modified DQ techniques (DQ1 and DQ2), dried semen smears were fixed by immersing for 10 seconds in solution 1 of DQ and 5 minutes each in solutions II and III of the kit. After the third stain solution, slides in DQ1 were rinsed in water whereas slides in DQ2 were not rinsed but were vertically supported to facilitate stain drainage. Results suggested that the standard DQ protocol overestimated normal sperm and detached heads whereas underestimated abnormal heads and total defects compared to DIC, Karras, eosin-nigrosin, and DQ2. Acrosome abnormalities were only detectable with Karras, DIC, and DQ2. In conclusion, prolonging exposure to DQ staining solutions enhanced sensitivity in sperm morphological evaluation, and avoiding rinse as a final step in the DQ protocol improved visualization of certain acrosome defects in dog sperm. Therefore, modified DQ techniques can serve as a viable alternative for dog sperm morphology evaluation in clinical practice.