Breeding Soundness Evaluation Research Articles

Selection based on the Breeding Soundness Evaluation is associated with the improvement of the reproductive quality of young Nellore bulls

Breeding soundness evaluation (BSE) is the best methodology to estimate the fertility potential of future bulls and performing indirect selection for their fertility. However, the outcome of the BSE is influenced by several factors, including genetics, environment, and BSE guidelines. Herein, in this retrospective study, our first aim was to characterize the reasons for failure in 46,566 BSE from 2-year-old beef Bos indicus bulls (Nellore) born from 1997 to 2018. Our second aim was to determine whether or not BSE was associated with reproductive potential improvement of the bulls over the years. Due to changes in the BSE criteria, we used the same dataset, but only bulls born from 2002 to 2018 were included resulting in 35,856 BSE. For the second aim, the effect of the year and farm were included in the model of the multivariate logistic regression. We also determined if the main reasons for BSE failure decreased over time. Bulls were classified as approved (satisfactory potential breeders and qualified for natural breeding service) and not approved (deferred and unsatisfactory potential breeders). The reasons for BSE failure in Nellore bulls were poor semen quality (53.1 %) and physical defects (46.9 %), with the main physical defect being testis abnormalities (19.7 %). The overall percentage of bulls approved each year was 87.1 %, with no improvement over the years of study. However, the percentage of approved bulls at the first BSE increased over the years (P < 0.05). This increase was evident by a reduction in the difference between the overall percentage of the bulls approved vs the percentage of bulls approved at the first BSE. Furthermore, there was an increase in the percentage of bulls classified as satisfactory potential breeders in the BSE and an evident decrease in the percentage of bulls qualified only for natural breeding service (P < 0.05). In addition, an increase of the scrotal circumference (SC) of the herd was found (P < 0.05). These results indicate the overall quality of the bulls improved over the years. To associate and identify the main sperm abnormalities, 3461 not approved bulls were clustered. The most frequent defects were strongly coiled tail spermatozoa, proximal droplets, and acrosomal defects. Overall, there was no change in the frequency of bulls not approved by the sperm morphology nor the frequency of the main sperm abnormalities over the years. Nevertheless, the frequency of the defects remained very low, implying they were controlled. Additionally, abnormalities in the testis decreased over the years and was associated with the increase in the SC of the herd and a decrease of culled bulls due to low SC. In conclusion, this study demonstrates that there is an association between implementation and use of BSE with improvements in the reproductive quality of future generation bulls.

Survey of Southeast U.S. beef veterinarians regarding methods for bull breeding soundness evaluation

The purpose of this survey was to describe veterinarians’ methods for performing bull breeding soundness evaluations (BSEs). Veterinarians in Mississippi, Louisiana and Arkansas were emailed a survey regarding their experience, demo­graphics, opinions and perceptions of client pref­erences regarding BSEs. Logistic regression was used to test respondent characteristics for associations with dichotomous outcomes including evaluating semen morphology as part of every BSE and detecting the diadem defect. Of 3,757 veterinar­ians solicited, 204 (5%) responded and 83 (2%) qualified for analysis. Of these, 10/73 (14%) indicated they do not evaluate morphology during every BSE. When shown an image of the diadem defect, 18/73 (25%) indicated seeing it often or some­times, and 55/73 (75%) indicated rarely or never. The only fac­tor associated with evaluating morphology as part of every BSE, was indicating belief that morphology was most predic­tive of bull fertility vs. believing motility was most predictive, or being unsure (OR = 11.2, 95% C.I. = 1.3-94.1). Respondents who always evaluate morphology with bright field microscopy at 1,000X (OR = 4.1, 95% C.I. = 1.2-13.3) or with phase contrast microscopy at ≥ 400X (OR = 5.4, 95% C.I. = 1.1-27.7) had higher odds of indicat­ing they detect the diadem defect sometimes/often. There was an interaction between always using 1000X magnification, or not, and always using 400X, or not, on the reported detection of the diadem defect. Veterinarians’ perceptions of which as­pects of the BSE are most predictive of fertility influence their methods for performing BSEs, and influence the frequency of detecting diadem defects.

Survey of Mississippi cow-calf producers regarding factors associated with veterinarians performing bull breeding soundness evaluations and/or pregnancy diagnosis

Reproductive efficiency is a major driver of profitability in cow-calf herds, yet many beef producers do not hire veterinar­ians to perform services intended to improve reproductive ef­ficiency such as bull breeding soundness evaluation (BSE) or pregnancy diagnosis. The objective of this study was to deter­mine reasons Mississippi cow-calf producers do or do not hire veterinarians to perform these services. Anonymous surveys were mailed to 1,500 randomly selected members of the Missis­sippi Cattlemen’s Association. Multivariable logistic regression was used to test respondent characteristics for association with outcome variables (e.g., respondents hire a veterinarian for BSEs and/or pregnancy diagnosis). Of 414 returned surveys, 397 (96%) qualified for analysis for an overall response rate of 26%. Of respondents that answered the respective ques­tions, 155/386 (40%) hire a veterinarian for BSEs, and 103/392 (26%) hire a veterinarian for pregnancy diagnosis. Of 396 re­spondents, 229 (58%) indicated they had some form of a defined breeding season. The most common reasons for not hiring a veterinarian were lack of time/help (82/202, 41%) for BSEs and cost (91/248, 37%) for pregnancy diagnosis. On in­ferential analysis, the factors positively associated with hiring a veterinarian for BSEs were having a defined breeding season (OR = 6.8, 95% C.I. = 4.1-11.1) and raising seedstock cattle (OR = 1.7, 95%C.I. = 1.0-13.3). The only factor positively associ­ated with hiring a veterinarian for pregnancy diagnosis was having a defined breeding season (OR = 4.2, 95%C.I. = 2.5-7.3). Management style and operation type influenced producers hiring a veterinarian for BSEs and pregnancy diagnosis.

Genetic parameters for yearling male reproduction traits in tropical composite cattle population.

Fertility is economically important but is hard to quantify and measure in breeding programs which has led extensive breeding programs to ignore fertility in their selection criteria. While female fertility traits have been extensively researched, male fertility traits have been largely ignored. It is estimated that 20% to 40% of bulls have sub-fertility, reducing the number of calves born and profits, highlighting the importance of investigating bull fertility. The most practical measure of male fertility is a bull breeding soundness evaluation (BBSE) which assesses structure as well as semen quality and quantity. Generally, traits recorded in a BBSE are neither genetically evaluated nor used for selection in breeding programs. All traits recorded during a BBSE were analyzed through a series of univariate and bivariate linear mixed models using a genomic relationship matrix to estimate genetic parameters. All genotype and phenotype data were obtained from a tropical composite commercial cattle population and imputed to 27,638 single-nucleotide polymorphisms (SNPs) with a total of 2,613 genotyped animals with BBSE records ranging from 616 to 826 animals depending on the trait. The heritabilities of the 27 traits recorded during a BBSE ranged from 0.02 to 0.49. Seven of the male fertility traits were recommended to be included in a breeding program based on their heritability and their phenotypic and genetic correlations. These traits are scrotal circumference, percent normal sperm, proximal droplets, distal midpiece reflex, knobbed acrosomes, vacuoles/teratoids, and sheath score. Using these seven traits in a breeding program would result in higher calving rates, increasing production and profitability.

Bull Breeding Soundness Assessment Using Artificial Neural Network-Based Predictive Models

For years, efforts have been devoted to establishing an effective bull breeding soundness evaluation procedure; usual research on this subject is based on bull breeding soundness examination (BBSE) methodologies, which have significant limitations in terms of their evaluation procedure, such as their high cost, time consumption, and administrative difficulty, as well as a lack of diagnostic laboratories equipped to handle the more difficult cases. This research focused on the creation of a prediction model to supplement and/or improve the BBSE approach through the study of two algorithms, namely, clustering and artificial neural networks (ANNs), to find the optimum machine learning (ML) approach for our application, with an emphasis on data categorization accuracy. This tool was designed to assist veterinary medicine and farmers in identifying key factors and increasing certainty in their decision-making during the selection of bulls for breeding purposes, providing data from a limited number of factors generated from a deep pairing study of bulls. Zebu, European, and crossbred bulls were the general groupings. The data utilized in the model’s creation (N = 359) considered five variables that influence improvement decisions. This approach enhanced decision-making by 12% compared to traditional breeding bull management. ANN obtained an accuracy of 90%, with precision rates of 97% for satisfactory, 92% for unsatisfactory, and 85% for bad. These results indicate that the proposed method can be considered an effective alternative for innovative decision-making in traditional BBSE.

A proteomic approach to identifying spermatozoa proteins in Indonesian native Madura bulls.

Proteins assist sperm mature, transit the female reproductive tract, and recognise sperm oocytes. Indigenous Indonesian bulls, Madura bulls, have not been studied for reproductive proteomics. As local Indonesian beef livestock, Madura cattle assist in achieving food security; hence, their number must be improved. Thus, the identification of molecular proteomics-based bull fertility biomarkers is needed. This study aimed to characterise the sperm fertility function of the superior Madura bull (Bos indicus × Bos Javanicus) spermatozoa proteome. Frozen semen from eight Madura superior bulls (Bos indicus × Bos javanicus) aged 4-8 years was obtained from the artificial insemination centre (AIC) in Singosari and Lembang. Madura superior bulls are those that have passed the bull breeding soundness evaluation. Frozen sperm were thawed and centrifuged at 3000 × g for 30 min. Proteins in sperm were characterised through proteomic analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The resulting gene symbols for each protein were then subjected to bioinformatics tools, including UniProt, DAVID, and STRING databases. Regarding sperm fertility, the analysis revealed that 15 proteins were identified in the sperm of Madura bulls. Amongst the identified proteins, the superior Madura bull sperm contained several motilities, energy-related proteins, and chaperone proteins. A substantial portion of characterised proteins are linked to metabolic pathways and the tricarboxylic acid (TCA) cycle, contributing to sperm energy production. In conclusion, the first in-depth proteome identification of sperm related to sperm quality and bull fertility of a unique indigenous Madura breed of Indonesia was performed using the LC-MS/MS proteomic method. These findings may serve as a reference point for further studies related to the functions of bovine sperm and biomarkers of fertility and sperm quality.

Relative Abundance of Spermadhesin-1 in the Seminal Plasma of Young Nellore Bulls Is in Agreement with Reproductive Parameters.

This study aimed to evaluate the proteomic profile of seminal plasma from young Nellore bulls. We used 20 bulls aged between 19.8 and 22.7 months, divided into two groups according to the results of the Breeding Soundness Evaluation (BSE): approved (FIT n = 10) and not approved (UNFIT n = 10). The scrotal perimeter was measured and a semen collection was performed through electroejaculation. The percentage of sperm motility, mass motility, and sperm vigor were calculated using conventional microscopy, and the percentage of sperm abnormalities was calculated using phase-contrast microscopy of all ejaculates. Seminal plasma was separated from spermatozoa using centrifugation and processed for proteomic analysis by LC-MS/MS. Seminal plasma proteins were identified using MASCOT Daemon software v.2.4.0 and label-free quantification analysis was carried out by SCAFFOLD Q+ software v.4.0 using the Exponentially Modified Protein Abundance Index (emPAI) method. Functional classification of proteins was performed based on their genetic ontology terms using KOG. Functional cluster analysis was performed on DAVID. There were no differences in scrotal perimeter and physical semen characteristics between FIT and UNFIT groups of bulls. The percentage of sperm abnormalities was higher (p < 0.05) in the UNFIT group of bulls. A total of 297 proteins were identified for the two groups. There were a total of 11 differentially abundant proteins (p < 0.05), two of them more abundant in FIT bulls (Spermadhesin-1 and Ig gamma-1 chain C region) and nine in UNFIT bulls (Vasoactive intestinal peptide, Metalloproteinase inhibitor 2, Ig lambda-1 chain C regions, Protein FAM3C, Hemoglobin beta, Seminal ribonuclease, Spermadhesin 2, Seminal plasma protein BSP-30kDa, and Spermadhesin Z13). Spermadhesin-1 was the protein with the highest relative abundance (36.7%) in the seminal plasma among all bulls, corresponding to 47.7% for the FIT bulls and 25,7% for the UNFIT bulls. Posttranslational modification, protein turnover, and chaperones were the functional categories with the highest number of classified proteins. Protein functional annotation clusters were related to Phospholipid efflux, ATP binding, and chaperonin-containing T-complex. The differentially abundant proteins in the group of FIT bulls were related to sperm capacitation and protection against reactive species of oxygen. In contrast, differentially expressed proteins in the group of UNFIT bulls were related to motility inhibition, intramembrane cholesterol removal and oxidative stress. In conclusion, the proteomic profile of the seminal plasma of FIT bulls presents proteins with participation in several biological processes favorable to fertilization, while the proteins of the seminal plasma of UNFIT bulls indicate a series of alterations that can compromise the fertilizing capacity of the spermatozoa. In addition, the relative abundance of spermadhesin-1 found in the seminal plasma of young Nellore bulls could be studied as a reproductive parameter for selection.

Oxidative stress associated with proteomic and fatty acid profiles of sperm from Nellore bulls at rest†.

Sexual rest is a transient condition, which compromises conception rates, characterized by large volumes of ejaculate with high percentages of dead sperm observed in bulls. The biochemical mechanisms leading to this ejaculate pattern are not fully understood. Six adult resting Nellore bulls were submitted to Breeding Soundness Evaluation by four consecutive semen collections through the electroejaculation method during a 30min period. Each ejaculate had its semen phenotypic parameters; morphology and physical aspects were evaluated. To assess enzymatic activity (superoxide dismutase, catalase, and glutathione S-transferase), lipid peroxidation (concentrations of malondialdehyde and nitric oxide), fatty acid, and proteomic profile aliquots of spermatozoa from the first and fourth ejaculates were used. All sperm parameters differed between the first and fourth ejaculates. Spermatozoa from the first ejaculate showed lower enzymatic activity and a higher concentration of lipid peroxidation markers. Among the 19 identified fatty acids, 52.7% are polyunsaturated. Relative abundance analysis showed that C12:0 and C18:0 fatty acids differed between the first and fourth ejaculates, being the fourth ejaculate richer in spermatozoa. The proteomics analysis identified a total of 974 proteins in both sample groups (first and fourth ejaculates). The majority of identified proteins are related to cellular processes and signaling. Quantitative proteomics showed 36 differentially abundant proteins, 6 up-regulated proteins in the first ejaculate, and 30 up-regulated proteins in the fourth ejaculate. Spermatozoa from bulls at sexual rest have less antioxidant capacity, causing changes in their fatty acid composition and protein profile, which generates the observed sperm pattern and lower fertilization capacity.

Risk factors associated with calf mortality in Western Canadian cow-calf operations.

This study examined the influence of management practices and herd demographics on calf mortality proportions in Western Canadian cow-calf operations, utilizing data from the second Western Canadian Cow-calf Survey. The survey was conducted between October 23, 2017, and February 28, 2018. The survey, which was open to all cow-calf producers across Western Canada, provided producer-reported data regarding calf death loss and corresponding herd-level factors. A fractional logit model was employed to identify significant factors associated with calf mortality proportions. The findings revealed that shorter breeding seasons (<63 days), calves born within the same season, and regular pregnancy checks for breeding females were negatively associated with calf mortality proportions. Conversely, regular breeding soundness evaluations for breeding bulls, traditional weaning methods, and vaccinating heifers for scours showed positive associations with increased calf mortality proportions. Herd operations where dams were vaccinated against clostridial and bovine respiratory diseases had lower calf mortality proportions. Notably, operations with experienced primary decision-makers holding off-farm jobs had lower predicted calf mortality proportions compared to those managed by full-time cattle producers. Higher predicted calf mortality proportions were observed in operations employing a backgrounding system. The study's limitations included potential biases due to its cross-sectional nature and reliance on producer-reported data, which might lead to an underestimation of calf mortality proportions. Also, the limited sample size and missing data might have affected the statistical significance of some variables. This study contributed to the research on cow-calf operation by using a fractional logit model to analyze the correlation between risk factors and calf mortality proportions, and by identifying novel herd-level risk factors. It provided a basis for future research aimed at developing empirically-based management strategies to optimize calf health outcomes.

Comparison of bull sperm morphology evaluation methods under field conditions

Sperm morphological assessment is a critical component in bull breeding soundness evaluations. Although sperm morphology is an important parameter to identify subfertile from fertile bulls, the evaluation can be biased because sperm staining methods used under field conditions may not be exact due to various factors, including artifacts. Objective was to compare 2 sperm morphological evaluation methods. Prebreeding season ejaculates of 1,216 Angus cross bulls collected via electroejaculation were evaluated. For each bull, an unstained (UNS) and an eosin-nigrosin stained (ENS) semen smear were viewed under a phase contrast microscope and a brightfield microscope with an oil immersion lens, both at 1,000 × magnification. Normal and percentage of abnormal sperm were identified by counting 200 sperm. Inter-rater agreements between 2 clinicians for the percentage of abnormal sperm determination and its categories were very good (ENS method, r = 0.84 – 0.96; UNS method, r = 0.76 – 0.96; p &lt; 0.01). No differences (p &gt; 0.1) were observed for abnormal sperm percentage determination and its categories between 2 methods. Correlation was very good between 2 methods for total abnormal sperm percentage determination (r = 0.91; p &lt; 0.01) and its categories (r = 0.84 – 0.96; p &lt; 0.05). Additionally, 60 ejaculates were evaluated by triple stain (TS), ENS, and UNS methods. Agreements between TS (percentage of sperm with damaged membrane) and ENS (percentage of abnormal sperm) and between TS and UNS methods were moderate (r = 0.58; p &lt; 0.05) and fair (r = 0.43; p &lt; 0.05), respectively. Based on our findings, either technique can be used for bull sperm morphological evaluation under field conditions. Considering the ease of semen smear preparation, the UNS method can be a viable alternative to the ENS method.

Calving date as a potential predictor for the probability of approval in the first breeding soundness evaluation of Nellore bulls.

Beef production systems primarily use natural service (NS) for breeding. However, a significant number of bulls used for NS are subfertile, limiting the profitability of the cow-calf operations. Therefore, producers should select bulls based on breeding soundness evolutions (BSE) to ensure higher pregnancy rates. Several factors can affect the bull ability to pass a BSE. We hypothesize that calving date would be a factor that affects the bull probability of approval at the first BSE. For this purpose, a multivariate logistic regression in a dataset of 14,737 BSEs from young Nellore bulls was used. Correlations between calving date, biometrics, and semen traits were evaluated using Pearson's correlation coefficient. Our results demonstrated that the calving date affected the probability of approval at the first BSE (p < .05). Indeed, the variable that added more information to our model was the calving date, far more than the age group of the bulls according to Akaike's information criterion. Hence, bulls born on day 0 of the calving season have 1.26 more chances to be approved at the first BSE than bulls born 21 days later. This result highlights the importance of getting the dams of future bulls pregnant as soon as possible in the breeding season. In addition, the calving season should be no longer than 47 days to achieve 80% BSE approval in 20-22 months old Nellore bulls. The strongest correlation was with SC, which decreased as the calving date increased. Therefore, the calving date may be used as a predictor of the outcome of the first BSE in young bulls. In that way, the calving date can help seedstock producers to maximize efficiency in making crucial management decisions during the breeding and calving season including nutrition, reproductive, and culling.

Retention and recovery of different on-animal sensors for monitoring behavior of beef bulls during breeding

On-animal sensors (OAS) are utilized to monitor behavioral and physiological characteristics remotely, allowing producers and veterinarians to make inference about the health and reproduc­tive status of livestock. Breeding soundness evaluations (BSEs) performed on bulls prior to the breeding season are useful for identifying preexisting conditions, however, these are not reli­able for identifying breeding impediments (e.g., lameness) that develop during the breeding season which can result in subfer­tility or even infertility. Thus, there is potential for the applica­tion of OAS for the monitoring of beef bulls during breeding, however, relatively little research has been done on this topic. The objective of this study was to characterize retention and functional recovery for different OAS on beef bulls during the breeding season. In addition, we explored potential risk factors associated with retention and functional recovery.

Incorporation of Testicular Ultrasonography and Hair Steroid Concentrations in Bull Breeding Soundness Evaluation.

Testicular ultrasonography and steroid concentrations (cortisol, dehydroepiandrosterone sulfate (DHEA-S), cortisol/DHEA-S ratio, testosterone) in hair were examined for their utility in the bull breeding soundness evaluation (BBSE). Beef and dairy bulls (n = 16; 2.7 ± 0.4 years old; body condition score 3.2 ± 0.1) of five breeds were maintained under the same conditions at an accredited semen collection center. Bulls underwent routine semen collection twice weekly for 12 weeks and semen was processed and cryopreserved. Ultrasonography and hair sampling were undertaken at the last semen collection. Bulls with homogeneous testicular parenchyma (n = 8) had a higher (p < 0.05) percentage of motile sperm post-thawing compared with bulls with heterogeneous parenchyma (n = 8). There were no differences (p > 0.05) in the hair concentrations of cortisol, DHEA-S, and testosterone between bulls with homogeneous and heterogeneous parenchyma. In bulls with homogeneous parenchyma, hair DHEA-S concentration was positively correlated with percentage motile sperm (R2 = 0.76), progressively motile sperm (R2 = 0.70), and motility yield (R2 = 0.71). The findings indicate that the integration of testicular ultrasonography and hair DHEA-S status in the BBSE could provide a more comprehensive assessment of indicative fertility in bulls. Additionally, ultrasonography can be used in the BBSE when the evaluation of semen parameters is not available.

Lesions of the prepuce and penis in rams: A retrospective study

In the ovine reproductive management, a thorough breeding soundness evaluation including specific inspection of the male genital tract represents a valuable tool for assessing the reproductive potential of a selected subject and for diagnosing genital disorders. During examination, accurate inspection on penis and prepuce is necessary, since conditions affecting these structures may hamper regular coitus. Records from 1270 males undergoing breeding soundness evaluation (n = 1232) or admitted for genital disorders to the Section of Obstetrics and Gynaecology (n = 38) of the Department of Veterinary Medicine, were collected, and lesions of penis and prepuce were therefore classified. The data collected revealed that 47/1270 rams examined presented lesions of the penis and prepuce. The most frequent condition was urolithiasis accounting for over 2% of the cases, followed by lack of the urethral process (0.39% incidence), lack of the glans penis and hypospadias (0.23% cases). Moreover, most of the conditions (40%) were observed in animals less than 2 years old, suggesting the importance of a careful breeding soundness evaluation in animals at young age.

A matter of agreement: The effect of the technique and evaluator on the analysis of morphologic defects in stallion sperm.

Analysis of sperm morphology is an important part of the stallion breeding soundness evaluation since it provides an objective measure of a stallion's sperm quality and is one of many factors that estimate a stallion's fertility potential. To describe the effect of sperm quality level on the technique (Differential Interference Contrast - DIC; Phase-contrast - PH; Dip-Quick staining - DQ; and eosin-nigrosin staining - EN; semen samples fixed in buffered-formal saline) and evaluator (three evaluators; using only DIC), stallions were categorized based on sperm quality into three categories: High: >57% normal sperm, Moderate: 23-56% normal sperm, or Low: <23% normal sperm (four stallions per category). The data were analyzed using three different statistical methods: Analysis of Variance (ANOVA), correlative analysis, and Bland-Altman method (agreement). A higher level of agreement among techniques was observed between DIC and PH for morphologically normal sperm. The agreement between the alternative methods (EN, DQ, or PH) and the standard method (DIC) varied, depending on the sperm quality level (High, Moderate, or Low). Some morphological defects (e.g., AH, AMP) were constantly underestimated with the staining methods (DQ, EN) compared to DIC and PH, particularly in ejaculates with low sperm morphology. Underestimation of some abnormalities, due to the technique or the evaluator, has the potential to alter the clinical interpretation of stallion fertility.

Aniline blue test for sperm protamination-a valuable add-on to the bull breeding soundness evaluation.

Bull breeding soundness evaluation (BBSE) is the most common procedure used to predict bull potential fertility. However, the use of traditional methods for semen evaluation can affect its reliability. The inclusion of additional advanced test in BBSE may increase its accuracy. This study aimed to investigate the correlation between the degree of sperm protamination and BBSE main parameters of scrotal circumference (SC), progressive motility (PM), morphologically normal sperm (NS), and different categories of morphological defects. In addition, to determine the correlation between the three methods used for protamine assessment, five Brangus bulls were subjected to the BBSE. Semen samples were collected via electro-ejaculation and evaluated using traditional methods. Three different methods were used to determine the degree of sperm protamination: aniline blue (AB) staining, chromomycin A3 staining with fluorescent microscope (CMA3-FLM), and CMA3 with flow cytometry (CMA3-FCM). Sperm protamine deficiency assessed using the three methods exhibited significant differences among bulls according to their classification by BBSE, and showed significant negative correlation with semen quality parameters of NS and PM. A significant positive correlation was found between AB positivity and morphological abnormalities. The three methods used for protamine assessment also revealed significant positive correlations. Among the three tests, AB staining was the cheapest and easiest test that offers an objective assessment method for sperm protamination. Hence, it can be concluded that the assessment of protamination using AB staining test might serve as an additional valuable parameter or a replacement whenever detail sperm motility and morphology analyses in conducting BBSE to predict bull fertility are not possible.

Quality of ram semen in relation to scrotal size

Aim of this study was to select superior rams by assessing their scrotal size and quality of semen. In ten indigenous Bangladeshi rams, the body weight, scrotal circumference, and scrotal volume of rams increased with age (P&lt;0.05). Body weight at 381-410 days (13.6 ± 1.5 kg) was higher than at 169-200 days (10.2 ± 0.1 kg) and 201-230 days (10.4 ± 1.2 kg) (p&lt;0.05). Scrotal circumference at 381 - 410 days (19.1 ± 0.3 cm) was higher (p&lt;0.05) than at 169 - 200 days (17.2 ± 0.1 cm), 201 - 230 days (17.2 ± 0.6 cm), and 231 - 260 days (17.2 ± 0.5 cm). At 381 - 410 days, scrotal volume (87.4 ± 5.5 cm3) was higher than in the five youngest groups (p&lt;0.05). Both scrotal circumference and volume were positively correlated (R2=0.519) with the increased body weight. Semen volume increased with age, which varied from 0.4 ± 0.0 - 1.2 ± 0.3 ml. The semen volume at 381 - 410 days (1.2 ± 0.3 ml) was higher than other age groups (P&lt;0.05) except for 351 - 380 days. The mass activity of sperms of different age groups varied from 2.8 ± 0.4 to 4.3 ± 0.3. Sperm concentration, progressive motility (%), and normal spermatozoa (%) improved progressively with age, but significant changes in these parameters were seen when the animals reached 291 days or more (P&lt;0.05). However, normal spermatozoa (%) improved from the age of 261 days. The mass activity was positively correlated with sperm concentration (R2 = 0.568) and with progressive motility (%) (R2 = 0.616). Measurements of scrotum could provide a reliable guide in estimating sperm production capacity, which are important for breeding soundness evaluation, and genetic improvement of indigenous rams.&#x0D; Bangl. vet. 2021. Vol. 38, No. 1-2, 1–9

Bull breeding soundness and cryopreservation of semen

The Society for Theriogenology (SFT) adopted the current form for the bull breeding soundness evaluation (BSE) in 2018. The BSE consists of four parts: a physical exam, a minimal scrotal circumference by the age of the bull, minimum progressive motility of 30%, and minimum morphology of 70% normal cells. A bull deemed to be a satisfactory potential breeder should unequivocally meet or exceed these four requirements. These standards as set forth by the SFT, give the veterinar­ian an objective approach to evaluating a bull. It has been said that “rarely are bulls infertile, but there are a lot of sub-fertile bulls”. Identification of these sub-fertile bulls by veterinarians, allows cattle producers to negate a potential negative impact on the overall productivity of the herd due to poor reproductive efficiency.&#x0D; Each part of the exam should be of equal importance to the vet­erinarian and no part should be omitted if an accurate assess­ment of the bull is to be determined. Carson et al in review of BSE trends for the past 20 years, deemed that overwhelmingly the most common cause of unsatisfactory or deferred classi­fication of bulls was due to unacceptable semen morphology. The preparation and interpretation of the morphology slide must be proficient and consistent for the results of the exam to be valid.&#x0D; The challenges that food animal practitioners encounter re­garding remaining relevant in the livestock industry continue to surface, and the profession must find means to maintain their position in a changing world. Promoting ourselves as ex­perts and the benefits of a professional exam by a veterinarian are essential to suppressing emerging imitators that provide a mediocre version of this exam sometimes referred to as the “se­men check”.

Application of ultrasound technique to evaluate the testicular function and its correlation to the sperm quality after different collection frequency in rams.

The frequency of semen collection is a crucial factor to consider in the rams performance inside breeding centers workout. To evaluate this factor, ram Breeding Soundness Evaluation could include sperm quality evaluation and new predictive and non-invasive tools such as ultrasound technique. In this work, an advanced ultrasonography technology, analyzing the testicular volume, echotexture, and vascular function, was used in three different frequencies of semen collection (abstinence frequency, AF; standard frequency, SF; and intensive frequency, IF). Semen samples were cooled (15°C, 6 h) and evaluated in terms of production, motility, viability, apoptosis, and content of reactive oxygen species. Correlation coefficients were calculated between ultrasonography measurements of echotexture and blood flow and sperm quality parameters. Our results showed an increase in the testicular echotexture when the frequency of semen collection was intensified. Doppler parameters (PSV, RI, PI, TABF) increased (P ≤ 0.05) when the frequency of semen collection was intensified. The sperm motility and functionality decreased in the samples of IF (P ≤ 0.05), evidencing the frequency of semen collection's influence. Moreover, moderate positive correlations were established among echotexture and different Doppler parameters with motility parameters in SF. Furthermore, the influence of abstinence days on AI success was analyzed in a field assay. The highest fertility rates were obtained when males had two to five abstinence days. To conclude, frequency of semen collection could be influenced in terms of semen quantity and sperm quality, showing changes in parenchyma echotexture and testicular vascularization. The standard semen collection frequency was the most adequate option. In addition, ultrasonography may be a predictive tool for estimating variations in the sperm quality of donor rams subjected to different frequencies of semen collection in reproduction centers.

Diagnostic tests in canine andrology - What do they really tell us about fertility?

Dog breeders often require breeding soundness evaluations which include andrological examinations of the genital organs, hormone measurements, and semen analyses. During the past decades, a considerable number of research results have been published, allowing diagnoses of specific andrological conditions and fertility assessment.For specific examinations, however, no standard procedures have been defined and for some parameters different reference ranges have been published. Therefore, examination results from different facilities are difficult to compare and profound conclusions regarding health and fertility of a male dog are not always possible.Conventional semen examination, however, is still useful in identifying deviations or no deviations from normality, especially if confounding factors are taken into account and if the exam is repeated in case of inconclusive findings. A standardization of examination procedures and reference ranges would help to harmonize the exchange of examination results and interpretation of the findings.