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1. Building on established understandings regarding hormonal and metabolic-driven processes of avian embryo’s growth and development, this paper proposes a novel method, focusing on sex-related dimorphism. Such processes involve crucial activities, e.g. nutrition delivery, gas exchange and waste disposal. These are influenced by interactions among various structures within embryonic compartments, whose sequential patterns between males and females have been proven different.2. The embryonic compartments, having undergone physiological changes during d 8–12, were acquired from candled images. Their temporal appearance model was developed from a non-linear classifier. It was hypothesised that if there is any distinctive pattern associated with the embryonic compartments between embryo sexes, then the classifier can be trained to recognise the dimorphism.3. The results revealed that the proposed method could separate sexes in ovo with accuracy, recall, precision and balance accuracy of 94.71, 93.47, 95.92 and 94.72%, respectively. Error analyses found 4.82% false discovery and 9.78% false omission rates. The method was expected to enhance farming resource management and leads to better animal welfare. [ABSTRACT FROM AUTHOR]

Objectives: The objectives of this study were to evaluate the accuracy of morphometry of skull base and palate in gender discrimination using cone beam computed tomography (CBCT) scanning and to assess the accuracy of the results among a sample of the Arab population Materials & Methods: Using CBCT scans, a cross-sectional analysis was conducted on 142 consented patients who underwent various dental procedures at the University Dental Hospital, Sharjah (UDHS). Of these patients, 70 were females and 72 were males, with respective means of 38.5 and 36.2 years. Eleven parameters related to skull base and palatal region were measured on the CBCT scans by two expert radiologists followed by statistical analysis. Results: There was significant gender-based difference in the mean palatal width (PW) (p = 0.001), mean palatal height (PH) (p = 0.005). Among other skull base region parameters that were significant in term of gender-based difference like; the clivus length (CL) (p < 0.001), occipital condyle height (OCH) (p < 0.001), basal angle (BA) (p = 0.006) and transverse diameter of foramen magnum (p = 0.003). Only palate variables showed a significant age difference. Discriminant analysis related to gender showed that occipital condyle height was the most accurate and best discriminator among the skull base region parameters. Conclusion: The use of discriminant analysis in CBCT based on skull base and palatal region variables provides an efficient method for determining gender, which is particularly valuable in forensic science and anthropological research. Significance of study: Accurate gender identification is crucial in forensic investigations, and the skull base region, being a stable and sexually dimorphic anatomical feature, can serve as a reliable marker for this purpose. [ABSTRACT FROM AUTHOR]

Simple Summary: The great cormorant has become a model taxon in the study of the ecology and ecotoxicology of fish-eating species. In this study, we used 157 adult and 222 juvenile dead individuals sexed by dissection to provide a method of sexing this species using external measurements. Males were larger than females in all linear body measurements, but there were no significant differences between adults and juveniles. Thus, in further analyses data on juveniles and adults within a sex was combined. The discriminant equations provided, with wing length and bill length, provided high accuracy, with 6.2% of individuals misclassified. The method presented here makes it possible to account for sex-specific patterns in ecological studies of the great cormorant and may be applied to data collected in the past. The possibility of sex identification of birds has substantial importance for studies on different aspects of bird ecology and behaviour. Using discriminant functions is becoming increasingly popular in studies of bird species that are monomorphic in plumage characteristics because they are cheap, hardly invasive and may be applied to data collected in the past. In this paper, we provide a discriminant function to sex great cormorants using external measurements. Males were larger than females in all linear body measurements, but there were no significant differences between adults and juveniles. Thus, data on juveniles and adults within a sex was combined. Discriminant equations with the most commonly used linear measurements, wing length and bill length, were provided. If identifying birds with discriminant function values D2 < −1.256 as females and those with D2 > 0.916 as males, 99% of birds will be correctly sexed. The method presented here makes it possible to account for sex-specific patterns in ecological studies of the great cormorant and may be applied to data collected in the past. The cross-application of discriminant functions developed for other populations of the great cormorant produces a 5.4% and 7.5% misclassification rate for birds from northern Poland using discriminant equations developed for populations in Greece and the Netherlands, respectively. [ABSTRACT FROM AUTHOR]

The Great Knot is a species from the Scolopacidae family of waders migrating within the East Asian-Australasian Flyway, and studies on this species have contributed greatly to understanding of migration ecophysiology and migration strategies in long-distance migrants. In this paper, we provide the first description of biometric variability and sexual size dimorphism in Great Knots. During the study on the Kamchatka Peninsula, 683 adults and 229 juveniles were measured and sexed molecularly. In adults, the mean measurements of females were larger than in males, except for tarsus length. In juveniles, at the early stage of migration from breeding to wintering grounds, apparently growth was not complete. Sexual dimorphism was small, with only wing length being significantly longer in females than in males. All dimensions of juveniles were smaller than those of adults, especially in bill length. The most sexually dimorphic trait in both adults and juveniles was wing length, and the most effective discriminant function with wing length as a single predictor correctly identified the sex of 76% of birds in both age classes. However, molecular sexing is the method of choice for reliable sexing, especially in juveniles. [ABSTRACT FROM AUTHOR]

Demand towards healthy, high-quality animal products is growing, and at the same time, more ethical animal husbandry methods which consider animal welfare and sustainability are under a high social spotlight. Culling of day-old male layer chicks is one of the main animal welfare concerns in the poultry sector, along with cage use, also in relation to changes in social demands. Political and societal disapproval towards this practice led to consider alternatives to day-old male layer chicks culling such as the rearing of male chicks, the use of dual-purpose strains and in ovo sex determination of embryos. This review summarised the available literature sources about the alternatives to the culling method and the public perspective on these approaches. Regarding in ovo sex determination several techniques were released in the last decades employing genetic, optical, biological, physicochemical, and biotechnological approaches. Animal welfare, costs, and ethical aspects, along with customers' acceptance, are the main aspects to be considered in the choice of alternative methods. Although rearing dual-propose chicken or layer-type cockerels produced very socially acceptable alternatives, their production costs are excessively expensive to be appropriate for mass markets. Based on the literature, in ovo sex determination seems to be the main potential alternative method to male chicks culling and the most preferred by consumers especially if performed during the first days of incubation. However, all the commercially available technologies are applicable only in the late stage of embryo development and are not yet ready to be used on large scales. Therefore, the development of an early, non-invasive, rapid, economical, and ethically acceptable in ovo sexing technique remains the main challenge as well as a priority. Moreover, the potential benefit or risk balance of the use of genetic methodologies needs to be discussed more globally. [ABSTRACT FROM AUTHOR]

Objectives The objectives of this study were to evaluate the accuracy of morphometry of skull base and palate in gender discrimination using cone beam computed tomography (CBCT) scanning and to assess the accuracy of the results among a sample of the Arab population Materials & Methods Using CBCT scans, a cross-sectional analysis was conducted on 142 consented patients who underwent various dental procedures at the University Dental Hospital, Sharjah (UDHS). Of these patients, 70 were females and 72 were males, with respective means of 38.5 and 36.2 years. Eleven parameters related to skull base and palatal region were measured on the CBCT scans by two expert radiologists followed by statistical analysis. Results There was significant gender-based difference in the mean palatal width (PW) (p = 0.001), mean palatal height (PH) (p = 0.005). Among other skull base region parameters that were significant in term of gender-based difference like; the clivus length (CL) (p

Sandflies serve as carriers for numerous tropical diseases, including leishmaniasis, bartonellosis, and sandfly fever. Furthermore, sandflies are species-specific when it comes to transmitting corresponding pathogen species. Hence, accurate classification and identification of sandfly species and gender are essential for various purposes such as disease monitoring and control, population management, research and development, and epidemiological investigations. Most of the sexing and taxonomy keys are based on internal morphological features, which may lead to errors due to some features being missed by the naked eye. In this paper, we describe the process we used to collect and prepare samples of three sandfly species (Ph. alexandri, Ph. papatasi, and Ph. sergenti). The dataset described in this article contains two images per sample, representing the pharynx in the head and the genitalia in the abdomen. The dataset is organized into male and female categories for each of the three species. The sex and species were determined manually by two specialists. This dataset can be used to develop automated methods for sex identification and taxonomy. Additionally, it can be used to train students in speciation and taxonomy. To the best of our knowledge, this is the first publicly available dataset of images of this kind.

The Great Knot is a species from the Scolopacidae family of waders migrating within the East Asian-Australasian Flyway, and studies on this species have contributed greatly to understanding of migration ecophysiology and migration strategies in long-distance migrants. In this paper, we provide the first description of biometric variability and sexual size dimorphism in Great Knots. During the study on the Kamchatka Peninsula, 683 adults and 229 juveniles were measured and sexed molecularly. In adults, the mean measurements of females were larger than in males, except for tarsus length. In juveniles, at the early stage of migration from breeding to wintering grounds, apparently growth was not complete. Sexual dimorphism was small, with only wing length being significantly longer in females than in males. All dimensions of juveniles were smaller than those of adults, especially in bill length. The most sexually dimorphic trait in both adults and juveniles was wing length, and the most effective discriminant function with wing length as a single predictor correctly identified the sex of 76% of birds in both age classes. However, molecular sexing is the method of choice for reliable sexing, especially in juveniles.

Undeveloped eggs occur frequently in birds and are often considered infertile, and discarded. However, the majority of undeveloped eggs may in fact have been fertilised and embryos might have died at an early stage. Such eggs contain valuable information, for example about offspring sex and paternity, and level of inbreeding. Obtaining such information may also give insight into the patterns and causes of early embryo mortality. Here we describe a simple technique for removing embryo cells from the blastoderm to obtain DNA to genotype the offspring and unequivocally ascertain fertilisation status, while retaining the overlying perivitelline layer (PVL) for sperm counts over the entire membrane. We tested this method on freshly collected eggs (high‐quality material), as well as on eggs from abandoned clutches and unhatched eggs (potentially deteriorated material) of blue tits (Cyanistes caeruleus). We sampled a total of 707 eggs from a wild population of blue tits, extracted DNA from the eggs' blastoderm using a Qiagen kit, and genotyped the samples with 14 polymorphic microsatellite markers, plus one sexing marker. Overall, we successfully genotyped 97% of all eggs. Our study is the most extensive dataset of genotyped undeveloped eggs to date and demonstrates that one can reliably genotype undeveloped fertile eggs as well as retain the PVL for observations of sperm and embryo cells. [ABSTRACT FROM AUTHOR]

The possibility of sex identification of birds has substantial importance for studies on different aspects of bird ecology and behaviour. Using discriminant functions is becoming increasingly popular in studies of bird species that are monomorphic in plumage characteristics because they are cheap, hardly invasive and may be applied to data collected in the past. In this paper, we provide a discriminant function to sex great cormorants using external measurements. Males were larger than females in all linear body measurements, but there were no significant differences between adults and juveniles. Thus, data on juveniles and adults within a sex was combined. Discriminant equations with the most commonly used linear measurements, wing length and bill length, were provided. If identifying birds with discriminant function values D2 < −1.256 as females and those with D2 > 0.916 as males, 99% of birds will be correctly sexed. The method presented here makes it possible to account for sex-specific patterns in ecological studies of the great cormorant and may be applied to data collected in the past. The cross-application of discriminant functions developed for other populations of the great cormorant produces a 5.4% and 7.5% misclassification rate for birds from northern Poland using discriminant equations developed for populations in Greece and the Netherlands, respectively.

Spermatozoa sexing requires a diluent that can protect and provide an optimal environment to maintain the quality of spermatozoa. This study targets to determine the effectiveness of adding sucrose to tris-egg yolk diluent on the sperm quality of the swamp buffaloes produced by sexing with the egg albumin method. Semen was collected once a week for 12 consecutive weeks with an artificial vagina from three male buffaloes at the Indonesian Center for Animal Research and Development (ICARD) in April - June 2021. Semen was separated by sedimentation using 10% and 30% egg albumins. Semen from sexing was divided into four diluent treatments, namely 20% tris-egg yolk (TEY), TEY+0% sucrose, TEY+0.2% sucrose, TEY+0.3% sucrose, and TEY+0.4% sucrose. Parameters measured included: motility, viability, intact plasm membrane, and intact acrosome cap of buffalo sperm. The results showed the motility of X sperm: 43.75-47.5%, Y sperm: 40-45%, the viability of X sperm: 78.25-79.75% and Y sperm: 77.25-79.75%, intact plasm membrane of X sperm: 70.5-71.5% and Y sperm: 70.5-71%, and viable acrosome-intact for X sperm: 79-80% and Y sperm: 78.75-79.5%. The addition of sucrose up to 0.4% into tris-egg yolk diluent was proven can maintain motility, viability, and integrity of cell membrane and acrosome of spermatozoa of water buffalo that was sexed with egg albumin.

Abstract Undeveloped eggs occur frequently in birds and are often considered infertile, and discarded. However, the majority of undeveloped eggs may in fact have been fertilised and embryos might have died at an early stage. Such eggs contain valuable information, for example about offspring sex and paternity, and level of inbreeding. Obtaining such information may also give insight into the patterns and causes of early embryo mortality. Here we describe a simple technique for removing embryo cells from the blastoderm to obtain DNA to genotype the offspring and unequivocally ascertain fertilisation status, while retaining the overlying perivitelline layer (PVL) for sperm counts over the entire membrane. We tested this method on freshly collected eggs (high‐quality material), as well as on eggs from abandoned clutches and unhatched eggs (potentially deteriorated material) of blue tits (Cyanistes caeruleus). We sampled a total of 707 eggs from a wild population of blue tits, extracted DNA from the eggs' blastoderm using a Qiagen kit, and genotyped the samples with 14 polymorphic microsatellite markers, plus one sexing marker. Overall, we successfully genotyped 97% of all eggs. Our study is the most extensive dataset of genotyped undeveloped eggs to date and demonstrates that one can reliably genotype undeveloped fertile eggs as well as retain the PVL for observations of sperm and embryo cells.

Background and Aim: To enhance the reproductive potential and increase productivity and population of cows, spermatozoa sex-sorting technology is required. This study aimed to examine the effect of sexing sperm, separated using a bovine serum albumin (BSA) column with varying incubation durations and centrifugation methods, for successful artificial insemination. Materials and Methods: Six Simmental bulls and 30 cows (n = 30) as the recipients were selected for this study at Balai Pembibitaan Hijauan Pakan Ternak Sembawa Indonesia. The study parameters included sperm motility, viability, plasma membrane integrity, and conception rate (CR). The experiment was divided into three protocols to find out differences in some parameters: (1) BSA incubation time effect (P) with P1 (40 min), P2 (50 min), and P3 (60 min); (2) freezing time effect with before freezing and after-thawing treatments; and (3) CR determined by measuring the proportion of pregnant cows following insemination with non-sexed, X-bearing, and Y-bearing sperms without centrifugation (n = 15) (A0, A1, and A2) and with centrifugation (n = 15) (B0, B1, and B2) in the acquired data, which were counted using the Statistical Package for the Social Sciences version 21 program. Analysis of variance was utilized to evaluate all treatments at various levels. Results: The results demonstrated that centrifugation time influenced all sperm quality metrics for sperm containing X and Y (p < 0.05). The non-return rate (NRR) of non-sexed frozen semen, both centrifuged (A0) and not centrifuged (B0), was more significant than frozen semen produced by sexing X and Y spermatozoa. The NRR indicated a value of 80% based on the number of lactating cows. Conclusion: Bovine serum albumin incubation and centrifugation protocols influenced and decreased all sperm quality indicators throughout the sexing procedure and could still be used as a sexing protocol. Furthermore, regarding NRR and service per conception, non-sexual treatment is superior to sexing treatment.

Taking advantage of the unique system of doubly uniparental inheritance (DUI) of mitochondria, we developed a reliable molecular method to sex individuals of the marine bivalve Macoma balthica rubra. In species with DUI (~100 known bivalves), both sexes transmit their mitochondria: males bear both a male‐ and female‐type mitogenome, while females bear only the female type. Male and female mitotypes are sufficiently divergent to reliably PCR‐amplify them specifically. Loop‐mediated isothermal amplification (LAMP) is a precise, economical and portable alternative to PCR for molecular sexing and we demonstrate its application in this context. We used 154 individuals sampled along the Atlantic coast of France and sexed microscopically by gonad examination to test for the congruence among gamete type, PCR sexing and LAMP sexing. We show an exact match among the sexing results from these three methods using the male and female mt‐cox1 genes. DUI can be disrupted in inter‐specific hybrids, causing unexpected distribution of mitogenomes, such as homoplasmic males or heteroplasmic females. To our knowledge, DUI disruption at the intra‐specific scale has never been tested. We applied our sexing protocol to control for unexpected heteroplasmy caused by hybridization between divergent genetic lineages and found no evidence of disruption in the mode of mitochondrial inheritance in M. balthica rubra. We propose LAMP as a useful tool to accelerate eco‐evolutionary studies of DUI. It offers the opportunity to investigate the potential role of, previously unaccounted‐for, sex‐specific patterns such as sexual selection or sex‐specific dispersal bias in the evolution of free‐spawning benthic species. [ABSTRACT FROM AUTHOR]

Introduction: Tiliqua scincoides coexists with human activity and is frequently presented for rehabilitation due to injury. The correct identification of sex is important as animals identified as female should be subject to a different decision‐making matrix for rehabilitation. However, identification of sex is notoriously difficult in Tiliqua scincoides. We describe a reliable, safe and cost‐effective morphometry‐based method. Materials and methods: Adult and sub‐adult, wild Tiliqua scincoides dead on presentation or euthanased due to their presenting injuries were collected in South‐East Queensland (SE Qld). Head‐width to snout‐vent length ratio (H:SV) and head‐width to trunk length ratio (H:T) were measured and sex was defined at necropsy. Similar data were obtained from a previous study in Sydney, New South Wales (NSW). H:SV and H:T were assessed for accuracy of sex prediction by the area under the receiver operating characteristic curve (AUC‐ROC). Optimal cut‐points were identified. Results: The AUC‐ROC for the H:T test was for NSW adults, 0.99 (n = 29), NSW sub‐adults, 0.95 (n = 10), Qld adults, 0.90 (n = 35) and Qld sub‐adults, 0.79 (n = 25). In all cases, H:T was as good or superior to H:SV. H:T cut‐points optimized for female sexing or both sexes ranged from 0.20 to 0.23 depending on State and adult status. Sensitivities and specificities of the test at suggested optimal cut‐points ranged from 0.54 to 1.0. Conclusion: We describe how H:T can be used as an accurate method to determine sex in Tiliqua scincoides. However, it is more accurate in adults than sub‐adults and more accurate in NSW skinks than in SE Qld skinks. [ABSTRACT FROM AUTHOR]

The Eurasian tree sparrow (Passer montanus) is a monomorphic passerine, for which it is impossible to differentiate between males and females based on external characteristics. Being a species frequently captured for ringing, having a reliable method to determine sex from conventional biometric measurements would facilitate its study and be very useful for the correct management and conservation of this declining species. In the present study, we used biometric measurements recorded in 66 individuals captured with mist nets in communal roosts in northern Spain during the winter and sexed them using molecular techniques. We conducted a discriminant function analysis (DFA) to derive equations that allowed us to determine the sex of the specimens from some of the measurements recorded in the field. Significant differences were found between males and females in wing length, third primary length, badge width and height and body weight. The DFA provided two functions that correctly classified the sex of 94.7% of the individuals using wing length and badge width, and 98.2% if weight was added to the analysis. Our results allow sexing from measurements that can be easily recorded in the field with the tools commonly used in banding sessions and without the need for additional training. Considerations of Bergmann’s and Allen’s rules on body size and the use of DFA in different populations are discussed.

This review presents information on biochemical features of spermatozoa bearing X or Y chromosome, enabling production of a sperm fraction with pre-defined sex chromosome. The almost only technology currently used for such separation (called sexing) is based on the fluorescence-activated cell sorting of sperm depending on DNA content. In addition to the applied aspects, this technology made it possible to analyze properties of the isolated populations of spermatozoa bearing X or Y chromosome. In recent years, existence of the differences between these populations at the transcriptome and proteome level have been reported in a number of studies. It is noteworthy that these differences are primarily related to the energy metabolism and flagellar structural proteins. New methods of sperm enrichment with X or Y chromosome cells are based on the differences in motility between the spermatozoa with different sex chromosomes. Sperm sexing is a part of the widespread protocol of artificial insemination of cows with cryopreserved semen, it allows to increase proportion of the offspring with the required sex. In addition, advances in the separation of X and Y spermatozoa may allow this approach to be applied in clinical practice to avoid sex-linked diseases. [ABSTRACT FROM AUTHOR]

Spermatozoa sexing requires a diluent that can protect and provide an optimal environment to maintain the quality of spermatozoa. This study targets to determine the effectiveness of adding sucrose to tris-egg yolk diluent on the sperm quality of the swamp buffaloes produced by sexing with the egg albumin method. Semen was collected once a week for 12 consecutive weeks with an artificial vagina from three male buffaloes at the Indonesian Center for Animal Research and Development (ICARD) in April - June 2021. Semen was separated by sedimentation using 10% and 30% egg albumins. Semen from sexing was divided into four diluent treatments, namely 20% tris-egg yolk (TEY), TEY+0% sucrose, TEY+0.2% sucrose, TEY+0.3% sucrose, and TEY+0.4% sucrose. Parameters measured included: motility, viability, intact plasm membrane, and intact acrosome cap of buffalo sperm. The results showed the motility of X sperm: 43.75-47.5%, Y sperm: 40-45%, the viability of X sperm: 78.25-79.75% and Y sperm: 77.25-79.75%, intact plasm membrane of X sperm: 70.5-71.5% and Y sperm: 70.5-71%, and viable acrosome-intact for X sperm: 79-80% and Y sperm: 78.75-79.5%. The addition of sucrose up to 0.4% into tris-egg yolk diluent was proven can maintain motility, viability, and integrity of cell membrane and acrosome of spermatozoa of water buffalo that was sexed with egg albumin. [ABSTRACT FROM AUTHOR]

When necessary, RNA-sequencing data or polymerase chain reaction (PCR) assays can be used to determine the presence of the chromosome Y (ChrY) in samples. This information allows for biological variation due to sexual dimorphism to be studied. A prime example is when researchers conduct RNA-sequencing of single embryos, or conceptuses, prior to the development of gonads. A recent publication of a complete sequence of the ChrY has removed limitations for the development of these procedures in cattle, otherwise imposed by the absence of a ChrY in the reference genome. Using the sequence of the cattle ChrY and transcriptome data, we conducted a systematic search for genes in the ChrY that are exclusively expressed in male tissues. The genes ENSBIXG00000029763, ENSBIXG00000029774, ENSBIXG00000029788, and ENSBIXG00000029892 were consistently expressed across male tissues and lowly expressed or absent in female samples. We observed that the cumulative values of counts permillion were 2688-fold greater in males than the equivalent values in female samples. Thus, we deemed these genes suitable for the sexing of samples using RNA-sequencing data. We successfully used this set of genes to infer the sex of 22 cattle blastocysts (8 females and 14males). Additionally, the completed sequence of the cattle ChrY has segments in the male-specific region that are not repeated. We designed a pair of oligonucleotides that targets one of these non-repeated regions in the malespecific sequence of the ChrY. Using this pair of oligonucleotides, in a multiplexed PCR assay with oligonucleotides that anneal to an autosome chromosome, we accurately identified the sex of cattle blastocysts. We developed efficient procedures for the sexing of samples in cattle using either transcriptome data or their DNA. The procedures using RNA-sequencing will greatly benefit researchers who work with samples limited in cell numbers which are only sufficient to produce transcriptome data. The oligonucleotides used for the accurate sexing of samples using PCR are transferable to other cattle tissue samples. [ABSTRACT FROM AUTHOR]

Simple Summary: This study explores the use of biometric analysis to identify the sex of Bonelli's eagles, a bird species with reverse sexual dimorphism where females are usually larger than males. By using linear discriminant analysis of biometric variables, we were able to obtain equations that accurately distinguished between male and female eagles, using just two measurements. The study included 137 Bonelli's eagles, 82 nestlings and 55 adults, sampled in eastern Spain from 2015 to 2022. The validation procedure reduced the number of variables used, increasing the accuracy of sexing and saving time. Results showed that the lateral tarsus length and dorso-ventral tarsus length measurements were the most effective in distinguishing between male and female eagles of all age classes, while other variables showed some overlap between sexes. This non-invasive method has multiple applications, including estimation of sex ratio for further studies on population dynamics and extinction risk assessments, which could contribute to the conservation of this endangered species. Biometric analysis allows the sexing of most vertebrates, particularly birds. Birds of prey, and, especially, the Bonelli's eagle (Aquila fasciata), show reverse sexual dimorphism (i.e., females are usually larger than males). In contrast to blood sampling, the use of morphometrics allows sex determination using a non-invasive method, and, therefore, it facilitates fieldwork. By means of a linear discriminant analysis of biometric variables, we obtained different equations that allow the sexing of nestlings and adult Bonelli's eagles. We sampled 137 Bonelli's eagles, 82 nestlings and 55 adults in eastern Spain during the period 2015–2022. The sexes obtained after linear discriminant analysis were compared with their molecular sexing. The validation procedure of the linear discriminant equations facilitated the reduction of the number of variables used and, consequently, optimised working time and sexing accuracy. After validation, some equations showed a 100% sexing efficiency for Bonelli's eagles, particularly for adults. Our results showed that the variables with smaller overlap between the sexes were the lateral tarsus length and dorso-ventral tarsus length, particularly in nestlings. The rest of the variables showed some overlap between the sexes in both age classes. The results we obtained enable the sexing of juvenile and adult Bonelli's eagles in the field using just these two measurements. Hence, this is an easy, accurate, quick and non-invasive method with multiple applications, including in studies on population dynamics, survival analysis or extinction risk assessments, which, ultimately, could contribute to the improvement of the conservation status of this endangered species. [ABSTRACT FROM AUTHOR]

Background and Aim: To enhance the reproductive potential and increase productivity and population of cows, spermatozoa sex-sorting technology is required. This study aimed to examine the effect of sexing sperm, separated using a bovine serum albumin (BSA) column with varying incubation durations and centrifugation methods, for successful artificial insemination. Materials and Methods: Six Simmental bulls and 30 cows (n = 30) as the recipients were selected for this study at Balai Pembibitaan Hijauan Pakan Ternak Sembawa Indonesia. The study parameters included sperm motility, viability, plasma membrane integrity, and conception rate (CR). The experiment was divided into three protocols to find out differences in some parameters: (1) BSA incubation time effect (P) with P1 (40 min), P2 (50 min), and P3 (60 min); (2) freezing time effect with before freezing and after-thawing treatments; and (3) CR determined by measuring the proportion of pregnant cows following insemination with non-sexed, X-bearing, and Y-bearing sperms without centrifugation (n = 15) (A0, A1, and A2) and with centrifugation (n = 15) (B0, B1, and B2) in the acquired data, which were counted using the Statistical Package for the Social Sciences version 21 program. Analysis of variance was utilized to evaluate all treatments at various levels. Results: The results demonstrated that centrifugation time influenced all sperm quality metrics for sperm containing X and Y (p < 0.05). The non-return rate (NRR) of non-sexed frozen semen, both centrifuged (A0) and not centrifuged (B0), was more significant than frozen semen produced by sexing X and Y spermatozoa. The NRR indicated a value of 80% based on the number of lactating cows. Conclusion: Bovine serum albumin incubation and centrifugation protocols influenced and decreased all sperm quality indicators throughout the sexing procedure and could still be used as a sexing protocol. Furthermore, regarding NRR and service per conception, non-sexual treatment is superior to sexing treatment. [ABSTRACT FROM AUTHOR]

Abstract Taking advantage of the unique system of doubly uniparental inheritance (DUI) of mitochondria, we developed a reliable molecular method to sex individuals of the marine bivalve Macoma balthica rubra. In species with DUI (~100 known bivalves), both sexes transmit their mitochondria: males bear both a male‐ and female‐type mitogenome, while females bear only the female type. Male and female mitotypes are sufficiently divergent to reliably PCR‐amplify them specifically. Loop‐mediated isothermal amplification (LAMP) is a precise, economical and portable alternative to PCR for molecular sexing and we demonstrate its application in this context. We used 154 individuals sampled along the Atlantic coast of France and sexed microscopically by gonad examination to test for the congruence among gamete type, PCR sexing and LAMP sexing. We show an exact match among the sexing results from these three methods using the male and female mt‐cox1 genes. DUI can be disrupted in inter‐specific hybrids, causing unexpected distribution of mitogenomes, such as homoplasmic males or heteroplasmic females. To our knowledge, DUI disruption at the intra‐specific scale has never been tested. We applied our sexing protocol to control for unexpected heteroplasmy caused by hybridization between divergent genetic lineages and found no evidence of disruption in the mode of mitochondrial inheritance in M. balthica rubra. We propose LAMP as a useful tool to accelerate eco‐evolutionary studies of DUI. It offers the opportunity to investigate the potential role of, previously unaccounted‐for, sex‐specific patterns such as sexual selection or sex‐specific dispersal bias in the evolution of free‐spawning benthic species.

Artificial insemination (AI) of dairy cows using sexing semen is the right choice to obtain female calves as replacement stock. The success of AI is influenced by the quality of the spermatozoa used. The purpose of this study was to determine the quality of semen produced by Lembang Artificial Insemination Center. The material used is 30 frozen semen straws of FH cattle produced by Lembang Artificial Insemination Center. This research method uses observational methods. The research variables included individual motility, viability, abnormalities, concentration, total motile spermatozoa, and intact acrosome caps of spermatozoa. The data obtained were analyzed by the Analysis of Variance (ANOVA) test and continued with Duncan's test if significantly different. The results showed that individual motility, concentration, total motile spermatozoa, and intact acrosome caps of spermatozoa had a very significant effect on all treatments (P 0.05) in all treatments. Motility of individual spermatozoa in non-sexing semen (55.80±4.56)%, sperm X (46.30±5.36)%, sperm Y (46.70±6.40)%. Viability of spermatozoa in non-sexing semen (74.57±4.05)%, sperm X (73.24±2.30)%, sperm Y (72.51±2.68)%. Spermatozoa abnormalities in non-sexing semen (2.73±2.24)%, sperm X (4.94±1.57)%, sperm Y (3.25±2.72)%. Concentration of non-sexing semen (33.88±1.98 million/mini straw), sperm X (25.06±4.29 million/mini straw), sperm Y (25.13±5.74 million/mini straw). The number of sperm motile non-sexing (18.60±1.58 million/mini straw), sperm X (11.68±2.82 million/mini straw), sperm Y (25, 11.64±2.68 million/mini straw). Intact acrosome caps, non-sexing semen (78.40±4.84)%, sperm X (74.08±3.80)%, sperm Y (70.70±4.78)%.

When necessary, RNA-sequencing data or polymerase chain reaction (PCR) assays can be used to determine the presence of the chromosome Y (ChrY) in samples. This information allows for biological variation due to sexual dimorphism to be studied. A prime example is when researchers conduct RNA-sequencing of single embryos, or conceptuses, prior to the development of gonads. A recent publication of a complete sequence of the ChrY has removed limitations for the development of these procedures in cattle, otherwise imposed by the absence of a ChrY in the reference genome. Using the sequence of the cattle ChrY and transcriptome data, we conducted a systematic search for genes in the ChrY that are exclusively expressed in male tissues. The genes ENSBIXG00000029763, ENSBIXG00000029774, ENSBIXG00000029788, and ENSBIXG00000029892 were consistently expressed across male tissues and lowly expressed or absent in female samples. We observed that the cumulative values of counts per million were 2688-fold greater in males than the equivalent values in female samples. Thus, we deemed these genes suitable for the sexing of samples using RNA-sequencing data. We successfully used this set of genes to infer the sex of 22 cattle blastocysts (8 females and 14 males). Additionally, the completed sequence of the cattle ChrY has segments in the male-specific region that are not repeated. We designed a pair of oligonucleotides that targets one of these non-repeated regions in the male-specific sequence of the ChrY. Using this pair of oligonucleotides, in a multiplexed PCR assay with oligonucleotides that anneal to an autosome chromosome, we accurately identified the sex of cattle blastocysts. We developed efficient procedures for the sexing of samples in cattle using either transcriptome data or their DNA. The procedures using RNA-sequencing will greatly benefit researchers who work with samples limited in cell numbers which are only sufficient to produce transcriptome data. The oligonucleotides used for the accurate sexing of samples using PCR are transferable to other cattle tissue samples.

Incorporating sex ratios of nestlings into population viability studies increases knowledge of overall health of endangered populations. Currently, a reliable non-invasive method to identify the sex of golden eagle nestlings is not available; however, claims are commonly made based on morphology. Ten biometric measurements from 43 Scottish golden eagles aged 2–7.5 weeks were assessed to see if sex could actually be determined using this non-invasive methodology. Sex was confirmed via molecular analysis of blood samples. Discrete and principal component analyses of the different biometrics could not correctly determine individual nestling sex. Therefore, despite being more invasive, molecular sexing remains the recommended tool of choice for accurate sex identification of Scottish golden eagle nestlings younger than 7.5 weeks of age. This has important implications for golden eagle field studies where empirical morphological measurements are frequently and typically taken, but we have shown are not reliable in determining the sex of such young nestlings. [ABSTRACT FROM AUTHOR]

Simple Summary: We provided basic morphological information on Eurasian Tree Sparrow from the Iberian Peninsula, and sexed a sample of individuals using molecular methods, with the aim of deriving sexing criteria in the field. The use of two measurements, wing length and badge width, allows the correct sexing of more than 90% of the tree sparrows in the Iberian Peninsula using only the usual tools used in ringing programs. The Eurasian tree sparrow (Passer montanus) is a monomorphic passerine, for which it is impossible to differentiate between males and females based on external characteristics. Being a species frequently captured for ringing, having a reliable method to determine sex from conventional biometric measurements would facilitate its study and be very useful for the correct management and conservation of this declining species. In the present study, we used biometric measurements recorded in 66 individuals captured with mist nets in communal roosts in northern Spain during the winter and sexed them using molecular techniques. We conducted a discriminant function analysis (DFA) to derive equations that allowed us to determine the sex of the specimens from some of the measurements recorded in the field. Significant differences were found between males and females in wing length, third primary length, badge width and height and body weight. The DFA provided two functions that correctly classified the sex of 94.7% of the individuals using wing length and badge width, and 98.2% if weight was added to the analysis. Our results allow sexing from measurements that can be easily recorded in the field with the tools commonly used in banding sessions and without the need for additional training. Considerations of Bergmann's and Allen's rules on body size and the use of DFA in different populations are discussed. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the efficacy of separating X- and Y-sperm using nano-albumen (NA). The material used in this study was fresh semen of Ongole Crossbreed bulls with progressive motility of = 70%. Treatments for the top and bottom fractions were T0 (BSA 5%: 10%) as a control, T1 (NA 2%: 4%), T2 (NA 4%: 6%), and T3 (NA 6%: 8%). Sexed semen was evaluated for characteristics and kinematics, and the proportions of sexed semen were validated using morphometric and polymerase chain reaction methods. The data on the characteristics and motility kinematics of X- and Y-sperm were analyzed by ANOVA using Minitab 18. The results revealed that the semen separated by the NA column generally showed the same sperm quality characteristics as the BSA column. However, the total motility of the T3y treatment in the bottom fraction was significantly lower (p<0.05) compared to the control. The kinematics of spermatozoa motility in the top fraction was not significantly different; however, the progressive motility value of T3y was significantly different (p<0.05) compared to that of T1y, and the BCF value of T2y was significantly different from that of the control in the bottom fraction. The acrosome status in the top fraction was better than in the bottom fraction, and the DNA integrity value of the top and bottom fractions showed DNA damage ranging from 2% to 5%. The present study indicated that: (1) the Nano-Albumen gradient column could be used successfully to separate X- and Y-spermatozoa, (2) characteristic values and sperm kinematics, acrosomal status, and DNA integrity were comparable to those of the BSA control, (3) combination column in treatments NA 4% (T2x) and 6% (T2y) appeared the good ability to separated X and Y-sperm. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sandflies serve as carriers for numerous tropical diseases, including leishmaniasis, bartonellosis, and sandfly fever. Furthermore, sandflies are species-specific when it comes to transmitting corresponding pathogen species. Hence, accurate classification and identification of sandfly species and gender are essential for various purposes such as disease monitoring and control, population management, research and development, and epidemiological investigations. Most of the sexing and taxonomy keys are based on internal morphological features, which may lead to errors due to some features being missed by the naked eye. In this paper, we describe the process we used to collect and prepare samples of three sandfly species ( Ph. alexandri, Ph. papatasi , and Ph. sergenti ). The dataset described in this article contains two images per sample, representing the pharynx in the head and the genitalia in the abdomen. The dataset is organized into male and female categories for each of the three species. The sex and species were determined manually by two specialists. This dataset can be used to develop automated methods for sex identification and taxonomy. Additionally, it can be used to train students in speciation and taxonomy. To the best of our knowledge, this is the first publicly available dataset of images of this kind., (© 2024 The Author(s).)

Assisted reproductive techniques (ARTs), such as artificial insemination, in vitro fertilization, and cryopreservation of gametes/zygotes, have been developed to improve breeding and reproduction of livestock, and for the treatment of human infertility. Their widespread use has contributed to improvements in human health and welfare. However, in dogs, only artificial insemination using frozen semen is readily available as an ART to improve breeding and control genetic diversity. A recent priority in sperm cryopreservation is the development of alternatives to egg yolk, which is widely used as a component of the sperm extender. Egg yolk can vary in composition among batches and is prone to contamination by animal pathogens. The latter can be a problem for international exchange of cryopreserved semen. Low-density lipoprotein and skim milk are promising candidates for use as extenders, to ensure fertility after artificial insemination. Although not tested for its effects on fertility following artificial insemination, polyvinyl alcohol may also be a useful alternative to egg yolk as an extender. The development of cryopreservation techniques for canine embryos lags behind that for other mammals, including humans. However, given the success of non-surgical embryo transfer in 2011, studies have sought to refine this approach for practical use. Research on sperm cryopreservation has yielded satisfactory results. However, investigation of other approaches, such as cryopreservation of oocytes and gonadal tissues, remains insufficient. Techniques for the efficient induction of estrus may aid in the development of successful canine ARTs.

The objective of this study was to determine the efficacy of separating X- and Y-sperm using nano-albumen (NA). The material used in this study was fresh semen of Ongole Crossbreed bulls with progressive motility of ≥ 70%. Treatments for the top and bottom fractions were T0 (BSA 5% : 10%) as a control, T1 (NA 2% : 4%), T2 (NA 4% : 6%), and T3 (NA 6% : 8%). Sexed semen was evaluated for characteristics and kinematics, and the proportions of sexed semen were validated using morphometric and polymerase chain reaction methods. The data on the characteristics and motility kinematics of X- and Y-sperm were analyzed by ANOVA using Minitab 18. The results revealed that the semen separated by the NA column generally showed the same sperm quality characteristics as the BSA column. However, the total motility of the T3y treatment in the bottom fraction was significantly lower (p

Sexing cetaceans typically requires extended periods of observation or expensive molecular methods. An alternative approach using photo‐identification may provide a cost‐effective, noninvasive method for assigning a sex to free‐ranging individuals. We investigated two methods for predicting the sex of common bottlenose dolphins (Tursiops truncatus) from Namibia, using the rate of change in dorsal fin (1) trailing edge marks or (2) surface features (scarring and lesions) and binary logistic regression models. Our results suggest animals with frequent and extensive changes to dorsal edge marks, or a high number/proportion of the dorsal fin covered in surface features are likely male, while those with little to no changes in dorsal edge marks or low numbers/proportion of surface features are likely female. Both sex prediction models performed reasonably well (accuracy: edge marks: 100%, surface features: 83%), with a high degree of consensus between models in sex predictions (78.6%). Our models are straightforward to implement and robust for the study population, providing useful insights into individuals' sex and population demographics. This reliable, inexpensive, and minimally invasive framework for assigning sex could be widely applicable, if population‐specific information of known sex individuals is included, due to the variable social systems and behaviors exhibited by Tursiops spp. [ABSTRACT FROM AUTHOR]

Heterotis niloticus is an African species of Osteoglossiformes that presents biological peculiarities and zootechnical performances favorable for fish farming. However, the absence of a sexual dimorphism hinders the optimization of its reproduction in captivity and limits the understanding of its reproductive behavior. This study is aimed at developing a minimally invasive and reliable sexing method to detect vitellogenin (Vtg) in female plasma. A commercial sexing kit (Acobium, Montpellier, France) for Arapaima gigas—a phylogenetically sister species of H. niloticus—successfully identified only 20% of mature H. niloticus females. Enzyme-linked immunosorbent assays (ELISA) were carried out using three Vtg antibodies. The A. gigas Vtg1 antibody cross-reacted significantly with plasma dilutions of female H. niloticus ranging from 1:1000 to 1:10,000, but with relatively low intensity. The Vtg antibody from Osteoglossum bicirrhosum, another species of Osteoglossiformes, showed non-specific binding with the Vtg of H. niloticus female plasma. Finally, an antibody for H. niloticus Vtg developed in this study allowed us to differentiate the two sexes with plasma coating dilutions ranging from 1:1000 to 1:10,000. The results of the assay were validated by a proteomic approach showing that Vtg-targeted mass spectrometry analysis of H. niloticus blood protein extracts could be used to accurately determine the presence of Vtg in the plasma of mature females. The final validation of the ELISA technique using the H. niloticus Vtg antibody was confirmed by visual sexing of a significant number of blood-sampled fish gonads; 100% of the fish were correctly sexed by the ELISA method. [ABSTRACT FROM AUTHOR]

Objective: To develop a computer application with the possibility of being used in the field with high reliability to differentiate the sex of sparrows of the species Centronyx bairdii. Design/Methodology/Approximation: A previously developed neural network was used to predict the sex of C. bairdii individuals. This algorithm was installed in an application developed using the MATLAB GUIDE environment for using graphic user interfaces. Results: The computer application developed allows the introduction of morphometric data of individuals and predicts their sex with a confidence level of 92.3%. Study Limitations/Implications: To install and run the application it is necessary to have a Windows version 7 operating system or later versions and the Matlab Ver. 7.5.0 software. Findings/Conclusions: Through the computational application generated, it is possible to determine the genus of the species Centronyx bairdii with an accuracy of 92.3%. This is a useful tool for sexing birds of this species in the field. [ABSTRACT FROM AUTHOR]

Copyright of Jurnal Veteriner is the property of Fakultas Kedokteran Hewan, Universitas Udayana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • A handheld NIR was evaluated to predict fertility and sex in-ovo. • The NIR method was useful to distinguish between fertile and infertile egg samples. • The classification results are not sufficient for industrial in ovo sexing of chicken eggs. The objective of this study was to evaluate the ability of a handheld near-infrared device (900–1600 nm) to predict fertility and sex (male and female) traits in-ovo. The NIR reflectance spectra of the egg samples were collected on days 0, 7, 14 and 18 of incubation and the data was analysed using principal component analysis (PCA), linear discriminant analysis (LDA) and support vector machines classification (SVM). The overall classification rates for the prediction of fertile and infertile egg samples ranged from 73 % to 84 % and between 93 % to 95 % using LDA and SVM classification, respectively. The highest classification rate was obtained on day 7 of incubation. The classification between male and female embryos achieved lower classification rates, between 62 % and 68 % using LDA and SVM classification, respectively. Although the classification rates for in-ovo sexing obtained in this study are higher than those obtained by chance (50 %), the classification results are currently not sufficient for industrial in-ovo sexing of chicken eggs. These results demonstrated that short wavelengths in the NIR range may be useful to distinguish between fertile and infertile egg samples at days 7 and 14 during incubation. [ABSTRACT FROM AUTHOR]

Although proteomic techniques have been increasingly used to improve our understanding of the human past, few have focussed on the study of tooth enamel for sexing in archaeofaunal remains, despite initial studies over a decade ago investigating human teeth. Here we explore the use of LC-orbitrap-MS/MS for identifying the sex of archaeological domestic cattle remains from the Neolithic enclosure at Kilshane, Ireland (c. 3600 cal. BC), in addition to modern reference materials. Although several individuals could be confidently identified as male, and some less confidently as female, there were also some inconsistencies with predictions based on morphology, albeit such estimations based largely on size. Through comparison with osteometric analyses, the proteomic analyses estimated 14 consistent identifications and six discrepancies, with one of the two speculative males confirmed through the use of proteomics. The male/female proportions for the osteometric analysis based on the metacarpals, the most sexually dimorphic skeletal element, showed that slightly over 50% of the bones were from females and slightly under 50% from males, whereas in the case of proteomics, depending on what level of caution we place on biomarker usage, this is much lower for the identification of males, ranging from 12.5 to 46% (3–11 specimens of 24 successful proteome samples with estimated sex based on their molars). Unexpectedly, our results show evidence of clear differences between modern reference materials and archaeological materials, likely reflecting preservation biases relating to the protein sequences. • Proteomic sexing of domesticated cattle remains from Neolithic enclosure site. • Comparison with morphological sex estimation methods. • Clear differences between ancient and modern enamel proteomes in peptides observed. • Proposed screening criteria relating quality of recovered proteome to ameloblastin relative abundances, in addition to the x-form of amelogenin. [ABSTRACT FROM AUTHOR]

Sexing monomorphic birds by DNA and morphometrics allows researchers to study behavioural differences between the sexes. We aimed to verify the utility of the carpal spur to sex the monomorphic Blacksmith Lapwing or to determine a more suitable method. The Blacksmith Lapwing is a widespread resident of central and southern Africa. We used biometrics and carpal spur features of 116 Blacksmith Lapwings we ringed at five South African sites in 2008–2018 that were DNA-sexed from blood samples. Males were on average larger than females in most morphometrics, but all these measurements largely overlapped. Spur length was the most sexually dimorphic trait, then body mass and tarsus length. Male lapwings use their wing spurs in combat, thus the spurs’ length and sharpness, and body size, are likely subject to intrasexual selection. The male’s longer tarsus may be related to his role in scraping out the ground nest. Our backward stepwise analysis produced the discriminant function D1 = 0.366 tarsus length - 27.541 to determine this species’ sex, which correctly sexed 66% of our sample. If we allowed a 5% misclassification rate then 70% of individuals remained unsexed. Thus we recommend DNA analysis for studies that must accurately sex all Blacksmith Lapwings in a sample. All of the DNA-sexed adult males had sharp ivory tipped spurs but 36% had a spur shorter than 13 mm, proposed previously as the cut-off value between sexes. We suggest that Blacksmith Lapwings with sharp ivory-tipped spurs of 14 mm or longer can be safely sexed as males to reduce the need for expensive DNA tests.

The purpose of this study was to characterize spermatozoa motility of sexed semen (X and Y) using albumin by diluents and antioxidant treatments. The material used in this study was fresh semen of Ongole Crossbreed (OC) bull with progressive motility >70%. The sperm sexing methodology used albumin gradient of 5%, 10%, and 15%. The diluents used were CEP-2 and andromed with or without the addition of 1mM Glutathione as an antioxidant. The sexed semen was made into liquid semen and stored at 3-5°C. The motility was observed at day 0 (H0) and day 5 (H5). Motility was analyzed using SCA v.2.1. The parameters measured were total motility, progressive motility, VCL, VSL, VAP, LIN, STR, WOB, ALH, BCF and sperm hyperactive. The experimental applied was the factorial pattern 2 x 2. The first factor was the type of diluents (CEP-2 and Andromed), and the second factor was additional glutathione (with or without). Data was analyzed by general linear model of SPSS-IBM 24 program. Sexed semen with CEP-2 diluents showed better motility of spermatozoa than andromed in the upper layers (spermatozoa X) and lower layers (spermatozoa Y). The CEP-2 diluent had a big role to maintain motility, progressive motility and velocity spermatozoa during cold storage. The addition of Glutathione 1mM could support the motility of sexed spermatozoa at cold storage, especially for LIN, STR, and WOB values.

Copyright of Gazella is the property of Zoologicka Zahrada v Praze and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sexing monomorphic birds by DNA and morphometrics allows researchers to study behavioural differences between the sexes. We aimed to verify the utility of the carpal spur to sex the monomorphic Blacksmith Lapwing or to determine a more suitable method. The Blacksmith Lapwing is a widespread resident of central and southern Africa. We used biometrics and carpal spur features of 116 Blacksmith Lapwings we ringed at five South African sites in 2008–2018 that were DNA-sexed from blood samples. Males were on average larger than females in most morphometrics, but all these measurements largely overlapped. Spur length was the most sexually dimorphic trait, then body mass and tarsus length. Male lapwings use their wing spurs in combat, thus the spurs' length and sharpness, and body size, are likely subject to intrasexual selection. The male's longer tarsus may be related to his role in scraping out the ground nest. Our backward stepwise analysis produced the discriminant function D1 = 0.366 tarsus length - 27.541 to determine this species' sex, which correctly sexed 66% of our sample. If we allowed a 5% misclassification rate then 70% of individuals remained unsexed. Thus we recommend DNA analysis for studies that must accurately sex all Blacksmith Lapwings in a sample. All of the DNA-sexed adult males had sharp ivory tipped spurs but 36% had a spur shorter than 13 mm, proposed previously as the cut-off value between sexes. We suggest that Blacksmith Lapwings with sharp ivory-tipped spurs of 14 mm or longer can be safely sexed as males to reduce the need for expensive DNA tests. [ABSTRACT FROM AUTHOR]

Sex is an important parameter to consider when studying population dynamics and movement ecology, for example, though sex determination is often difficult in young birds of sexually monomorphic species, with large biometric overlap between sexes. We aimed at determining the sex of first-calendar-year (1cy) Carrion Crows, in order to study temporal trends in sex ratio. We performed molecular sexing of a sample of 48 females and 45 males, creating a statistical framework to confidently discriminate sexes using four morphometric variables. Although biometrics overlapped between sexes, we developed a discriminant function which separated the sexes with high accuracy (88%). Then we applied this discriminant function to biometrics obtained from all 1cy individuals captured, to determine their sex. We found a female-biased overall sex ratio of the captures: female Carrion Crows might therefore be more numerous than males, or more prone to enter traps. There were significant variations in sex ratio between years, but not between months. [ABSTRACT FROM AUTHOR]

Teknik sexing pada burung secara molekuler dengan metode PCR telah banyak dikembangkan, tetapi sampel yang digunakan adalah darah dan bulu yang dianggap invasif. Penelitian ini bertujuan untuk mempelajari efisiensi sampel swab bukal sebagai sumber DNA dalam sexing dengan metode PCR. Penelitian ini menggunakan 10 ekor burung kenari (Serinus canaria) yang terdiri dari 6 ekor burung dewasa (3 jantan dan 3 betina) dan 4 ekor kenari piyikan (umur 14 – 18 hari) yang belum diketahui jenis kelaminnya serta 6 ekor merpati (Columba livia) dewasa (3 jantan dan 3 betina) dan 7 ekor merpati piyikan (umur 14 – 25 hari) yang belum diketahui jenis kelaminnya. Amplifikasi fragmen gen dilakukan menggunakan metode PCR dengan pasangan primer CHD1F/CHD1R.Hasil visualisasi produk PCR menunjukkan semua burung jantan dewasa menghasilkan satu band (± 500 bp), sedangkan burung betina dewasa menghasilkan dua band (± 500 bp dan ± 300 bp). Amplifikasi gen dari swab bukal burung kenari muda didapatkan 2 ekor jantan dan 2 ekor betina, sedangkan dari swab bukal burung merpati muda didapatkan 6 ekor jantan dan 1 ekor betina. Berdasarkan hasil penelitian ini dapat disimpulkan bahwa sampel swab bukal terbukti efisien sebagai sumber DNA dalam sexing burung khususnya burung piyikan.

Artificial Insemination (AI) in this study uses the results of sexing liquid semen, which aims to get the calf following the objective of the breeding institution that is producing Bali cows. The study was conducted at Balai Pembibitan Ternak Unggul and Hijauan Pakan Ternak located in Pangyangan, Pulukan Sub district, Jembrana Regency, Bali. The study was conducted on July 7, 2019 until November 7, 2019. The research material was 45 Bali heifers. Bali heifer was synchronized using Enzaprost@, after showing signs of estrus, double doses artificial insemination at 2 hours after estrus and 8 hours after estrus. The Bali heifer was inseminated with non-sexing and sexing liquid semen using andromed diluent, P0 = non-sexing liquid semen, P1 = liquid semen by the Percoll Density Gradient Centrifugation (PDGC) method in the lower layer and P2 = liquid semen by the Egg White Gradient Sedimentation (EWS) method in the upper layer. Pregnancy evaluation is calculated based on Non-Return Rate (NRR) and Conception Rate (CR). The results showed Non-Return Rate (NRR) P0, P1 and P2 = 86.67%, 60% and 53.33%. While the Conception Rate (CR) at P0, P1 and P2 is 53.33%, 13.33% and 26.67%.

The aim of this study was to obtain an effective tool for sex determination in Eurasian Eagle Owls (Bubo bubo), a species without marked sexual dimorphism, by taking external body and bone measurements. Thirty-one individuals were used for this purpose, 16 males and 15 females, and 42 measurements were obtained: 19 external and 23 bone measurements. Three discriminant analyses were carried out: the first with external measurements only, a second one with bone measurements only, and a third combining both. The validation of the classification was performed by cross-validation. The first analysis led to a discrimination function with five external measures, with a Wilk’s Lambda of 0.064 and 100% of the individuals classified correctly. The second analysis led to a discrimination function with two bone measures, with a Wilk’s Lambda of 0.282 and 90% of individuals correctly classified. The third analysis led to a discrimination function with six external and two bone measures, with a Wilk’s Lambda of 0.022 and 100% of individuals classified correctly. The study has shown that external measurements are more efficient than bone measurements, and likely sufficient for sexing. Nevertheless, bone measurements can provide complementary information, although alone they are insufficient for sexing owls, given that the length of the ulna and the nose bones were the only useful bone measurements. It can be generalized that this work provides an optimal sexing method, useful in ornithological ecology, clinical and forensic medicine, as well as in archaeozoological studies.

The investigation of sex bias and pseudohermaphroditism is a relatively unexplored area of research in the Neostromboidae. Here, we inform on these phenomena in a population of Gibberulus dekkersi Maxwell, Hernandez Duran, Rowell & Rymer, 2021 on Green Island, Great Barrier Reef. We collected 598 individuals, and noted the size of the cluster in which it occurred. Each individual was placed ventral side up and the body of the animal observed at the time of righting. Sex was determined by the presence or absence of a verge. During this sexing process, females were inspected for the presence of external male sexual organs to indicate the presence or absence of pseudohermaphroditism. We found that, overall, the population was not sexually biased towards one sex. However, we did find that individual clusters within the population showed significant sex bias, with different clusters favouring either males or females. Smaller clusters had a structural sex-ratio bias in favour of females. No evidence for pseudohermaphroditism was recorded, which indicates that the marine pollutant tributyltin (TBT) may not be present or at harmful levels in the surrounding environment. This study adds information from an unstudied Queensland taxon to the growing evidence on sex bias, clustering effects and pseudohermaphroditism within the Neostromboidae. [ABSTRACT FROM AUTHOR]