Objetivo. Caracterizar el sistema de producción bovino doble propósito (SPDP) en unidades de producción pecuaria (UPP) de municipios de la Huasteca Alta Veracruzana (HAV) y determinar la tipología de las UPP dentro del SPDP. Materiales y métodos. Con variables sociales (productor), cuantitativas del hato e índices tecnológicos, agrupados en áreas zootécnicas (Reproducción, Salud, Nutrición, Pastos y Administrativa) se analizó la información de 135 UPP del SPDP recabada a través de encuestas y visitas in situ, con registros de sus actividades sociales, económicas y pecuarias; asi mismo, se analizó el panorama climatológico con información de estaciones meteorológicas de la región. Se utilizó el análisis multivariados K-means y Conglomerado (Statistica V10); con ello, se logró identificar cinco grupos de UPP catalogándose como: Empresarial (n= 4), Transición (n= 29), Tradicional Alto (n=34), Medio (n= 37) y Bajo (n= 31). Con ANDEVA de una vía fueron analizadas las variables socioeconómicas, productivas y propias del hato. Resultados. Las UPP Empresarial y Transición se diferenciaron (p < 0.05) de las de tipo Tradicional por poseer una mayor superficie (hectáreas) utilizada para la ganadería, número de vacas y mayores índices tecnológicos de salud, nutrición y económico (p< 0.05), características que describen la obtención de mayores ingresos por venta la de leche y becerros para la engorda. Conclusiones. El índice tecnológico del SPDP es de 0.37 ± 0.01 a 0.61 ± 0.06 (bajo-medio), esta situación y las condiciones climatológicas actuales afectan su productividad.

The domestic turkey is a native breed in danger of extinction due to the introduction of new breeds specializing in meat production and yield. Turkeys have lost some prominence in urban areas, and only certain breeds of turkeys are preserved in rural areas. Wild and domestic turkeys are different; rural or indigenous turkeys, with black plumage, were domesticated from Mexican turkeys and have been reproduced throughout Latin America. Some of them were taken to Europe in the 16th century and later arrived in North America, where they crossed with another wild species, from which the bronze turkey emerged: the ancestor of all commercial turkeys. The objective of the present work was to evaluate the genetic diversity in 10 populations of domestic turkeys worldwide by using breeds from Europe: Spain and Italy; America: Mexico, United States and Brazil; and the Near East: Iran and Egypt. A total of 522 blood samples of both sexes were collected from domestic turkey populations. Thirty-four microsatellites were used to obtain genetic parameters, and genetic diversity was evaluated. All microsatellites used were polymorphic, and a total of 427 alleles were detected across the 34 markers investigated. In this study, a mean number of 13.44 alleles was found. The four most diverse breeds were from the Andalusia, Mexico, United States, and wild populations, which had the highest mean heterozygosity expected (0.619, 0.612, 0.650, and 0.773) and heterozygosity observed (0.422, 0.521, 0.429, and 0.627), respectively. The MNT348 marker deviated from the HWE in all populations. Our study has shown that the populations close to the species origin are more diverse than those resulting from posterior expansions. Mexican birds were the most diverse, followed by the Spanish populations because Spain imported a large number of turkeys coming from America. Such information can be complementary to other genotypic data required to validate the evolutionary relationships among turkey populations.

With the aim of assessing bull fertility before or during its use for reproduction under tropical weather conditions where heat stress is present, and correlating it to herd parameters, BSE was carried out to determine which genetic groups of bulls have better reproductive performance. 223 bulls from different genetic groups, Zebu bulls (N = 72), European bulls (N = 58), and Crossbred Bulls (N = 93), were evaluated in situ over a two-year period, 2018–2019. Bull (age, corporal conditions, libido, and scrotal circumference), semen (concentration, motility and volume), herd (pregnancy rate and calving intervals) and environmental variables (THI, season, sampling month and spermatogenesis month) were analysed with One-Way ANOVA, as well as with factorial, multiple regression, and multivariate analysis. Zebu and European bulls have a higher libido than crossbreed bulls (p < .05), and it decreases with age (p < .05). High-libido bulls (>7) show high correlation (R = 0.70 p < .05) with herd parameters; BCS affects libido (p < .05). Sperm concentration is correlated to herd parameters (R = 0.82 p < .05). European bull sperm concentration and motility showed a decrease in autumn and winter (p < .05) in comparison to other genetic groups. Libido and semen variables are more associated with herd parameters than with other bull characteristics. Environmental variables are not associated with herd parameters (p > .05). Heat stress did not directly affect bull reproductive performance; Zebu bulls and crossbreeds showed better herd parameters (p < .05).

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.

Introduction. In the dairy industry, frozen-thawed semen is crucial for artificial insemination and genetic improvement of cattle. Objective. To evaluate the variation in the kinematic subpopulation structure of frozen-thawed semen in Jersey and Holstein breeds using a CASA-mot system. Materials and Methods. The study was conducted from April to November 2023, at the Animal Reproduction Laboratory (AndroTEC), located at the Campus Tecnológico Local San Carlos, Alajuela, Costa Rica. Eight animals from the Holstein and Jersey breeds were used, and nine doses of frozen-thawed semen per animal were analyzed for each breed. A total of 72 semen doses from eight bulls (four from each breed) were thawed at 37 °C for 30 s. Sperm motility and kinematic variables were analyzed using CASA-mot (Computer-Assisted Semen Analysis) technology. Results. The Jersey breed presented higher percentages of total motile, progressive motile, and rapid spermatozoa compared to the Holstein breed (P < 0.05). Principal component analysis revealed two significant factors explaining 87.5 % of the total variance in kinematic variables. The kinematic variables between sperm subpopulations (SP) showed differences (P < 0.05) in both breeds. Subpopulation SP2 was the fastest, with higher values for curvilinear speed (VCL), straight-line speed (VSL), and average trajectory speed (VAP) in both Holstein and Jersey bulls. Conclusions. Kinematic differences were found between the identified subpopulations in both breeds. The kinematic patterns of the subpopulations present in the ejaculate could influence fertility and reproductive performance.

Sperm morphology assessment is essential for maintaining reproductive efficiency and profitability on farms. In tropical countries and smaller-scale farms, the assessment of sperm morphology of the doses used in artificial insemination is not routinely carried out; therefore, its analysis and standardization are necessary. This study evaluated the influence of age, season, and genetic line on sperm morphology in breeding boars under tropical conditions. The study was conducted on commercial farms in the northern region of Costa Rica from 2019 to 2023, with sampling during both the dry and rainy seasons. Sixty-five boars and 312 ejaculates representing Duroc, Landrace, Pietrain, and Pietrain × Duroc genetic lines were analyzed. Animals were classified by age at collection into three groups according to age at the time of collection: < 24 months (G1, n = 19), 24–48 months (G2, n = 26), and > 48 months (G3, n = 33); some animals were analyzed and classified into different groups. Morphology was assessed by Trumorph® fixation and visual examination using a light microscope at 400× magnification. The percentage of sperm morphological abnormalities varied significantly by year, season, and genetic line (P < 0.05). The Pietrain line showed the highest average abnormality frequency, whereas the rainy season exhibited the greatest proportion of abnormal sperm (P < 0.05). In conclusion, season and genetic line significantly influenced sperm morphology in breeding boars. Standardization and validation of morphological assessment are necessary in semen production centers and commercial pig farms.