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Background: Antioxidants of natural origin can be used to improve cryopreservation of semen. Objective: To evaluate the effect of dietary supplementation with Erythrina americana on the seminal characteristics of rams. Methods: Ten rams were randomly distributed in two treatments: l) Group supplemented with E. americana (20% dry matter basis; AEA, n=5), and 2) Control group not supplemented (SEA, n=5). Both diets were iso-proteic and iso-energetic. The feeding period was eleven weeks. Ejaculates were obtained through an artificial vagina and were evaluated fresh (37 °C) and refrigerated (5 °C). Semen volume (VOL) was assessed by visual examination in a calibrated (mm) tube; sperm concentration (CON x106) with a photometer; and mass motility (MM, 1-5), individual motility (IM), normality (N), and live sperm (L) were assessed by microscopic observation. Results: Feeding E. americana did not affect (p>0.05) VOL, CON, MM, and N in fresh semen, but decreased (p<0.05) IM and L. The L and N variables did not differ (p>0.05) among treatment groups in the refrigerated semen; however, IM improved in the AEA group (p<0.05) compared to the SEA group. Conclusion: Dietary supplementation of rams with E. americana reduces sperm quality in fresh semen but is beneficial for the cooling process of refrigerated semen. [ABSTRACT FROM AUTHOR]

Background: The genetic test for Expected Progeny Differences (EPDs) is one of the newest technologies to reduce uncertainty in calf production. It provides information about the genetic composition of a bull, which relates to its propensity to produce offspring with specific growth and quality characteristics. Objective: To evaluate the influence of EPDs reports on the variation of Nellore bull semen prices for artificial insemination in the Brazilian beef cattle industry. Methods: Ordinary Least Squares (OLS) regressions were estimated. The study utilized genetic data provided by GENEPLUS as well as market prices of semen and physical measurements of the bulls collected from the Alta Genetics Insemination Agency. Results: Genetic results, except for age at first calving, weaning weight, and weight at 120 days EPDs, have little influence on semen prices. For each additional day expected for the first calving of the progeny average price of semen decreases by 0.66%. For each additional kg expected in weaning weight, the semen price was 1.73% higher. Furthermore, for each additional kg expected in the progeny at 120 days, semen price increased by 2.46%. Conclusion: Joint analyses of genetic reports and physical characteristics of bulls may provide a better explanatory power. [ABSTRACT FROM AUTHOR]

Copyright of Revista Estudiantil AGRO - VET is the property of Universidad Mayor de San Andres, Facultad de Agronomia 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.)

Esta publicación está dirigida a los productores de ganado bovino, trabajadores agrícolas y agentes de Extensión, con el propósito de proporcionar información sobre cómo realizar una IA exitosa en bovinos. Este documento, AN380-Span, es uno de una serie del Department of Animal Sciences, UF/IFAS Extension. La publicación original es de marzo 2024.

Foundation: from the positive psychology point of view, working with the infertile couple, who is inseminated, allows to enhance the positive emotions that favor the treatment and strengthen their resilient capacity that leads to greater psychological well-being to face this process.Objective: to apply a psychological intervention strategy in infertile couples during the artificial insemination process.Methods: prospective study, with a mixed approach, which included eleven couples undergoing artificial insemination treatment, treated at the Abel Santamaría Hospital Reproduction Center, in Pinar de Río, from December 2021 to April 2022. The essential route for localization and accessibility of the sample under study was the psychology consultation within the multidisciplinary commission that studies these couples. Clinical interviews, participant observation and psychometric tests were carried out. A psychological intervention strategy based on traditional psychology and positive psychology was applied. The resilience of the couples was measured before and after the intervention.Results: the intervention raised the resilience of infertile couples that are inseminated to medium-high values. It promoted the development of positive thoughts and emotional states, as well as the identification of personal and couple strengths. Conclusions: a psychological intervention strategy based on traditional and positive psychology contributes to increasing the infertile couples’s resilience in the artificial insemination process.

The season of the year (ES), maximum temperature (Tmax) and relative humidity (RH) affect gestation success of Tropical Milking criollo (TM) heifers, but their effects on the gestation of TM cows are not completely known. The study aimed to determine the effects of environmental factors along with artificial insemination (AI) service and calving on the gestation success of TM cows. Data were collected during 14 years, 959 records of AI of 155 cows in three seasons: hotdry (HD), hot-humid (HH) and fresh-dry (FD). The response variables were gestation success of cows at first service after first calving (GF), first calving first to fifth service (GS) and global gestation success (GG). Model effects were ES, Tmax and RH seven days before the AI (PRAI), the day of the service (DAI) and seven days after (POAI); and days open (DO), cumulative milk production (MP), number of service (NS) and calving number (CN). GF was analyzed with logistic regression, and GS and GG with generalized linear models. Over 50 % of estrus occurred in the HH season. Tmax affected GF t β1 = -0.13 ± 0.07 (p ≤ 0.05) and GG t β1 = -0.08 ± 0.04 (p ≤ 0.05) in PRAI. There were no effects of ES, RH, NS or MP on GF, GS and GG for PRAI, DAI and POAI (p > 0.05). DO affected GG in PRAI, DAI and POAI t β2 = -0.005 ± 0.002 (p ≤ 0.01). GG were as close to 52.0 % for the three seasons. Although with no statistical differences in multiparous cows (p > 0.05), for NS maximum gestation were 60 % at first and third, and minimum 40 % at fourth services; for CN they were 60 % at fourth, and 40 % at sixth and seventh calving, respectively. TM cows are adapted to a hot tropical Climate and their seasonal changes, showing similar pregnancy frequencies among seasons. [ABSTRACT FROM AUTHOR]

Background: The use of artificial insemination (AI) in dairy cattle has a direct impact on productivity through genetic improvement and, indirectly, by other technologies that allow for better expression of the genetic potential. Objective: To determine the association between the use of AI and other factors on productive performance of dairy cows. Methods: The study assessed AI impact on 195 dairy farms through the application of structured questionnaires to farmers. Analysis of variance (GLM) was used to evaluate herd milk production and farm size. Multivariate analysis was performed to observe the degree of association between AI and production. Four clusters were formed according to production traits and farm size. Results: Clusters showed high discrimination (90%). Principal factors explained 70% of the variance between clusters. The variables that best explained the variation between clusters were Lactating cows per year, Monthly milk production, Farm area and Total cows. The correspondence analyzes showed that AI use is associated with higher production levels and investment in nutrition, management, genetics, and technology. Conclusion: The use of AI enhances production by increasing productivity and enables greater gains per liter of milk marketed. [ABSTRACT FROM AUTHOR]

Foundation: from the positive psychology point of view, working with the infertile couple, who is inseminated, allows to enhance the positive emotions that favor the treatment and strengthen their resilient capacity that leads to greater psychological well-being to face this process. Objective: to apply a psychological intervention strategy in infertile couples during the artificial insemination process. Methods: prospective study, with a mixed approach, which included eleven couples undergoing artificial insemination treatment, treated at the Abel Santamaría Hospital Reproduction Center, in Pinar de Río, from December 2021 to April 2022. The essential route for localization and accessibility of the sample under study was the psychology consultation within the multidisciplinary commission that studies these couples. Clinical interviews, participant observation and psychometric tests were carried out. A psychological intervention strategy based on traditional psychology and positive psychology was applied. The resilience of the couples was measured before and after the intervention. Results: the intervention raised the resilience of infertile couples that are inseminated to medium-high values. It promoted the development of positive thoughts and emotional states, as well as the identification of personal and couple strengths. Conclusions: a psychological intervention strategy based on traditional and positive psychology contributes to increasing the infertile couples's resilience in the artificial insemination process. [ABSTRACT FROM AUTHOR]

The article presents a study on the impact of a 3D-printed artificial vagina for rabbit meat production in Huaral, Lima. The objective is to improve the reproductive efficiency of rabbits and promote sustainability and competitiveness in the industry. The improvement in efficiency, cost reduction, and environmental sustainability are highlighted as value propositions. The impact analysis anticipates improvements in production, technological development, sustainable practices, and job creation. It is concluded that the 3D-printed artificial vagina not only offers technological development but also drives sustainable development in livestock production. [Extracted from the article]

La hormona liberadora de gonadotropina (GnRH) es un decapéptido, sintetizado por las neuronas GnRH en el hipotálamo, que estimula la síntesis y secreción de gonadotrofinas (hormonas folículo estimulante, FSH y luteinizante, LH) de la hipófisis anterior o adenohipofisis. Agonistas de GnRH con una estructura idéntica o similar a la natural han estado disponible comercialmente desde la década del 70 y han sido utilizadas en un principio para el tratamiento de quistes foliculares y el mejoramiento de la fertilidad en el ganado vacuno (1). La ovulación de folículos ováricos después de la administración de GnRH fue reportada por primera vez por Schams et al. (2) y Britt et al. (3), pero no fue hasta la década del 90 cuando la GnRH se comenzó a utilizar para controlar la dinámica folicular durante el ciclo estral del bovino. Ahora sabemos que una nueva onda folicular emerge dentro de los 2 días después de la ovulación del folículo dominante presente en el momento del tratamiento con GnRH (4,5). Este hallazgo facilitó el desarrollo de protocolos de sincronización a base de GnRH en combinación con prostaglandinas (PGF) que permiten la inseminación artificial a tiempo fijo (IATF), sin necesidad de realizar detección de celo. Estos protocolos a base de GnRH y PGF son parte del manejo reproductivo bovino, sobre todo del ganado lechero, en muchos rodeos comerciales del mundo. Existen numerosos protocolos a base de GnRH y PGF disponibles para la sincronización del estro y la ovulación en el ganado, varios de esos protocolos se han explicado y discutido en detalle en otros artículos (6,7). El objetivo de esta revisión es describir los factores asociados a la liberación de LH y respuesta ovulatoria posterior a la administración de GnRH, dar a conocer información relevante sobre el efecto de las hormonas esteroideas en la respuesta a la GnRH y, por último, brevemente postular estrategias que podrían mejorar la eficacia de los protocolos basados en la aplicación de GnRH y PGF

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The UPSUS SIWAB Artificial Insemination (Special Efforts to Accelerate Pregnant Cattle and Buffalo Populations) Program is a national scale program to ensure cows' pregnancy requires evaluation to determine its success. Farmer satisfaction is one indicator of the success of the program. The research aims were (1) to assess breeder satisfaction at Kadipiro village with service quality and artificial insemination and (2) to determine the level of artificial insemination success at Kadipiro village. This research used descriptive, quantitative methods and collected data by observation and interview using a questionnaire. The data were analyzed by importance-performance analysis (IPA) and customer satisfaction index (CSI). The results indicated satisfaction among all farmers toward the inseminator's performance based on the CSI at 0.87%, the quality of success in artificial insemination based on the conception rate at 65.15% (a fertile category), percentage of non-return rate at 65.90% (a good category), and a calving interval at, on the average, 13 months (the ideal category). In conclusion, the farmers were very satisfied with the services provided by the inseminator. This study suggested that the inseminator needed to improve the service attributes in quadrant I. [ABSTRACT FROM AUTHOR]

Copyright of Revue d'élevage et de Médecine Vétérinaire des pays Tropicaux is the property of CIRAD 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.)

The gonadotropin-releasing hormone (GnRH) is a decapeptide, synthesized by the GnRH neurons in the hypothalamus, which stimulates the synthesis and secretion of gonadotrophins (follicle-stimulating hormone, FSH and luteinizing hormone, LH) from the anterior pituitary or adenohypophysis. GnRH agonists with a structure identical or similar to nature have been commercially available since the 1970's and were initially used for the treatment of follicular cysts and the improvement of fertility in cattle (1). The ovulation of ovarian follicles after GnRH administration was first reported by Schams et al. (2) and Britt et al. (3), but it was not until the 1990's that GnRH began to be used to control follicular dynamics during the bovine estrous cycle. Studies have shown that a new follicular wave emerges within 2 days after ovulation of the dominant follicle present at the time of GnRH treatment (4,5). This finding facilitated the development of synchronization protocols based on GnRH in combination with prostaglandins (PGF) that allow fixed-time artificial insemination (FTAI), without the need for heat detection. These GnRH-based protocols are part of the reproductive management, especially in dairy cattle, in many commercial herds around the world. There are several GnRH and PGF-based protocols available for estrus and ovulation synchronization in cattle, most of these protocols have been explained and discussed in detail in other publications (6,7). The objective of this review is to describe the factors associated with the release of LH and ovulatory response after the administration of GnRH, to present relevant information on the effect of steroid hormones on the response to GnRH and, finally, to briefly postulate strategies that could improve the efficacy of GnRH and PGF-based protocols. [ABSTRACT FROM AUTHOR]

Copyright of Agricultura Sociedad y Desarrollo is the property of Colegio de Postgraduados 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.)

The article titled "Ovarian function and response to estrus synchronization in Criollo cattle in Mexico. Review" analyzes the ovarian function and response to estrus synchronization in Criollo cattle in Mexico. It highlights that Criollo cattle are valuable due to their adaptability to difficult environmental conditions and their resistance to parasites. However, it has been observed that Criollo cows do not respond adequately to hormonal synchronization protocols and achieve lower pregnancy rates compared to other breeds. The objective of the review is to gather existing information on the use of estrus and ovulation synchronization protocols in Criollo cattle in Mexico, in order to identify the necessary research lines for the development of appropriate protocols for this type of cattle. [Extracted from the article]

Con el propósito de analizar cambios en los parámetros reproductivos y productivos en bovinos de las ganaderías lecheras como consecuencia de la pandemia de COVID -19, se realizó una investigación en la provincia de Santo Domingo de los Tsáchilas, región Costa, Ecuador. Para la recolección de la información se emplearon técnicas de investigación (encuestas, entrevistas estructuradas y sesiones grupales) a 86 productores pertenecientes a la Asociación de Ganaderos de la Provincia, bajo los protocolos de bioseguridad; donde se estudiaron las variables: edad del primer servicio (EPS), edad al primer parto (EPP), tipos de servicio (TS), edad al destete (ED) y producción de leche (PL) antes y durante el COVID-19. Los datos recolectados fueron comparados a través de pruebas de Ji-cuadrado y razón de verosimilitud. La PL se comparó con la prueba de t-Student para muestras pareadas. La EPS, EPP y ED resultaron no significativos; pero, se observó un incremento en la proporción de montas naturales (P

The reproductive efficiency of a herd is of enormous importance in the viability of a livestock business. A technical update was made of the most common handling errors that affect artificial insemination (AI) efficiency, with the aim of implementing simple but highimpact corrective measures. The AI technique encompasses multiple management factors that impact on the pregnancy rate, several of them will be considered. The review is framed in the following aspects: a) Errors in the management of heat detection: practical, simple and economical solutions b) Errors in the handling of frozen semen, thawing technique and elements to carry out the AI y c) Rectal-cervical method: difficulties in sowing and errors in the place of semen deposition in the female genital tract. [ABSTRACT FROM AUTHOR]

Introduction: The low fertility is one of the greatest problems in mare reproduction. Preovulatory follicle diameter could be used as estrus predictor. Methods: Forty-three mares, 550 ± 34 kg live weight, 6.00 ± 2.30 years old, and 4.42 ± 0.39 body condition score (CC), without reproductive or sanitary problems were used to study the evolution of follicle diameter (DF) during an estrus cycle. The estrus detection and measurement of DF were done daily, mares with DF > 38 mm were inseminated, pregnancy was tested 16 d postinsemination. Variables evaluated were estrus length (Dcelo) and estrus cycle (Dciclo); DF at 21 d (DF21), at start of estrus (DFcelo), and at artificial insemination (DFIA); corpora luteum diameter lúteo (DCL); and pregnancy rate (TP16). The fixed effects included in the model were age of mare, CC, Dcelo, Dciclo, number of follicles, time to estrus appearance after day 21 (Celoh), DFcelo, and DF21. The statistical analyses were carried out with the MIXED and GLIMMIX procedures of SAS. Results: Age (p ≤ 0.0221) and Dcelo (p ≤ 0.036) were significant for most of the variables analyzed. Mares 9-11 years old had the greatest Dciclo, DCL, and DF. DFcelo was significant (p ≤ 0.0056) for DCL and DF21; while DF21 was (p ≤ 0.0001) for Celoh, DFcelo, and DFIA. The follicle growth showed a cubic trend, with a reduction in growth rate days before ovulation. Conclusion: Age of mare, DF21, and DFcelo, help to predict estrus appearance. Knowledge of ovarian dynamics helps to breed mares at the right time. [ABSTRACT FROM AUTHOR]

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias 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.)

Copyright of ESPOCH Congresses: The Ecuadorian Journal of S.T.E.A.M. is the property of Knowledge E DMCC 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.)

Copyright of Revista de Ciencias Médicas de Pinar del Río is the property of Editorial Ciencias Medicas 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.)

El presente artículo tiene como objetivo analizar la inseminación artificial por donante anónimo a partir de la legislación ecuatoriana, como mecanismo para evitar la vulneración del derecho constitucional de los hijos a conocer su identidad personal. Se pretende la discusión de las implicaciones jurídicas y, por ende, los derechos legales reconocidos que tiene los hijos concebidos por inseminación artificial por donante anónimo, al igual que los derechos que podrían tener los donantes de esperma para conservar su anonimato. La metodología utilizada fue de tipo descriptivo y bibliográfico-documental. El trabajo se argumentó a través del análisis de textos constitucionales, legislación internacional, tratados, convenios y el criterio de juristas en la parte doctrinaria. Los resultados llevan a la conclusión de que el derecho le asiste tanto al hijo cuanto al padre, sin embargo, las legislaciones tienen ciertas restricciones a pretexto de proteger la privacidad.

Background: In artificial insemination, chicken egg yolk is added to bovine semen to protect it during the cryopreservation process, although it contains substances that can affect the microbiological quality and metabolism of sperm. Objective: To evaluate post-thaw quality of bovine cryopreserved semen added with centrifuged and non-centrifuged egg yolk, low-density lipoproteins (LDL), and trehalose (T). Methods: Ten ejaculates from five bulls were cryopreserved under the treatments T1: pure egg yolk (PEY) at 20% v/v, T2: centrifuged egg yolk (CEY) at 20% v/v, T3: LDL at 8% v/v, T4: T at 100 mM, and T5: T at 100 mM plus LDL at 8% v/v (TLDL). Spermatic motility and kinetics, functional membrane integrity (FMI), structural membrane integrity (SMI), sperm vitality (SV) and abnormal morphology (AM) were assessed using the Sperm Class Analyzer (SCA®) system, hypoosmotic test (HOST), SYBR/PI probes, and eosin-nigrosin staining, respectively. A completely randomized design was used. Normal distribution of the variables was validated through the Kolmogórov-Smirnov test. A generalized linear model was used to determine sources of variation. Means were compared using the Tukey test. Results: Inclusion of CEY or LDL had a similar effect on sperm protection, and were superior for motility, kinetics and membrane integrity compared to the other treatments (p<0.05). CEY was superior for progressive motility (p<0.05). The cryoprotective action of LDL was similar to TLDL for motility and kinetics, SMI, SV, and AM (p<0.05). Inclusion of PEY and T resulted in the lowest semen quality (p<0.05). The use of T resulted in a reduction in FMI and SMI (p<0.05). No differences in AM between treatments were found (p>0.05). Conclusions: Egg yolk can be replaced by centrifuged egg yolk or low-density lipoproteins in the freezing extender used for bovine semen used in artificial insemination. [ABSTRACT FROM AUTHOR]

Introduction: the objectives were to evaluate estrus and gestation in Bos taurus cows, treated with a fixed-time artificial insemination protocol (FTAI) that included or not equine chorionic gonadotropin (eCG). Cumulative gestation with resynchronization at 30 days after the first FTAI was also evaluated. Method: the cows were divided into: Treatment 1 (n = 60), synchronized with 2 mg of estradiol benzoate and an intravaginal device (IVD) of progesterone (1.3 g) on day 0; IVD was removed on day 8 and 25 mg of prostaglandin F2-alpha, 1 mg of estradiol cypionate and 300 IU of eCG were injected; 48-52 hours later the FTAI was performed. Treatment 2 (n = 50) consisted in the same protocol, not including eCG. Ovulation was resynchronized in cows that were no pregnant in the pregnancy diagnosis, performed 30 days after the first FTAI. The same protocol applied in Treatment 1 for the first FTAI was used in all animals. The second FTAI was performed 40 days after starting the program. Body condition score (BCS) was classified as low (< 2.5), moderate (2.5 to 3.5) and high (> 3.5). On the day of the FTAI, the preovulatory follicle diameter (DFP) was classified into three categories (DFP1: < 11 mm; DFP2: 11 to 14 mm; DFP3: > 14 mm). Results: the gestation percentage was different between treatments (p = 0.04; 73 % Group 1 and 53 % Group 2). The proportion of cows in estrus before the FTAI was 75 % in the eCG treatment and 57 % in the control (p = 0.04). Cows with DFP2 and DFP3 registered a higher gestation rate (p = 0.03) than DFP1. The percentage of pregnancies was higher (p = 0.04) in cows with moderate and high BCS. Overall gestation in the first FTAI was 63 %. The gestation percentage with the second FTAI was 51.61 %, accumulating 82.1 % in 40 days. Conclusion: eCG increased the proportion of cows in estrus and gestation; and resynchronization allows the accumulation of an additional percentage of pregnant cows. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to evaluate the effect of pre-synchronization with progesterone (P4) for 3 and 6 days in Nelore cows in postpartum anestrus period, submitted to a fixed-time artificial insemination program (FTAI). Materials and methods: Seventy-four multiparous Nelore cows with a body condition of 2.5 were used. The cows were submitted to three experimental groups, control group and groups pre-synchronized with P4 for a period of 3 and 6 days. For the determination of postpartum anestrus status, ultrasound scans and blood samples were taken to verify the absence of endogenous P4. Forty-five days after AI, gestation was diagnosed. Data were obtained by descriptive analysis and in the case of presentation of significant differences the Chi-square test was used, considering a frequency of P < 0.05. Results: A higher gestation rate was observed for the group that was pre-synchronized for three days with P4 (40 %), in relation to the groups of six days of pre-synchronization and control (25 % and 32 %, respectively). Conclusion: It is possible to conclude that the pre-synchronization with P4 for three days improved the gestation rate of Nelore cows in the postpartum anestrus period. [ABSTRACT FROM AUTHOR]

La rentabilidad de los establos lecheros está fuertemente asociada con el desempeño reproductivo. Por lo tanto, la identificación de factores de riesgo que comprometen este desempeño es primordial para implementar estrategias que mejoren la productividad. En este estudio, se probaron los efectos del uso de inseminación artificial (IA), hatos grandes y seroprevalencia alta de enfermedades infecciosas reproductivas sobre el desempeño reproductivo. Se incluyeron al estudio 52 establos (10-100 vacas; 959 lactaciones) registrando eventos reproductivos durante 18 meses (partos 2011-2012). Las seroprevalencias de neosporosis, rinotraqueitis infecciosa bovina (IBR) y diarrea viral bovina (BVD) se registraron en cada establo. Se utilizaron análisis de regresión logística múltiples para determinar el grado de asociación (razón de momios, OR) entre factores potenciales de riesgo y variables reproductivas. Establos ≥33 vacas y seroprevalencia alta de neosporosis fueron factores de riesgo para Asistencia al Parto (OR 1.5 y 2.3, respectivamente). Seroprevalencias altas de IBR y BVD fueron factores de riesgo para Días a Primer Servicio>70 Días en Leche (DPS>70, OR 1.3 y 1.9, respectivamente). La IA fue un factor de riesgo común para DPS>70 y Días Abiertos>110 Días en Leche (OR 2.4 y 1.3, respectivamente). Establos ≥33 vacas fue un factor de riesgo para Vacas No Gestantes al Primer Servicio (OR 1.7). En conclusión, la IA, establos ≥33 vacas y seroprevalencias altas de neosporosis, IBR y BVD son factores asociados al desempeño reproductivo en establos de producción de leche a pequeña escala en varias regiones geográficas de México.

Introducción. El uso de biotecnologías reproductivas ha significado una mejora relevante sobre los parámetros de eficiencia y rentabilidad en la industria porcina. Objetivo. Determinar el estado del arte en el que se encuentra la biotecnología aplicada al estudio del semen y la implementación; en granjas porcinas; de técnicas de reproducción asistida como la inseminación artificial. Desarrollo. En el sector porcino, la fertilidad de los verracos (Sus scrofa domestica) tiene un efecto significativo sobre la eficiencia general de la reproducción de las piaras. Aunque hay métodos objetivos de valoración precisa de las variables seminales de los verracos, muchas granjas aún continúan realizando sus evaluaciones de forma subjetiva. Los conceptos bioquímicos que determinan la funcionalidad del gameto masculino o espermatozoide son molecularmente complejos, sin embargo, pueden conocerse los aspectos generales de la funcionalidad y desarrollar métodos de manejo del semen que permita el mantenimiento de las condiciones óptimas de las muestras seminales o dosis de semen utilizadas en inseminación artificial (IA). Dentro de la funcionalidad espermática intervienen parámetros clásicos de volumen, concentración y movilidad que son fundamentales para la optimización de las dosis seminales producidas por verraco. Los sistemas CASA (Computerassisted semen analysis) son una aplicación biotecnológica que desplaza el análisis subjetivo tradicional del semen para la valoración de la calidad, estos aportan grandes volúmenes de información que han permitido explorar más en detalle los eyaculados porcinos. Conclusiones. En las granjas que utilizan la inseminación artificial, el uso de técnicas biotecnológicas para el análisis seminal, constituye un valor agregado para el estudio de la calidad del semen y la optimización de dosis seminales producidas.

Objective. To compare the reproductive performance of postpartum and open Bos indicus cows and to study the cost effectiveness of retaining non-pregnant animals after a short breeding season in tropical region of Mexico. Material and Methods. A total of 128 Bos indicus were included, 87 postpartum cows (PP) with ≤90 days after calving and 41 open cows (OC) with >90 days open. The study was divided into three phases: 1) Estrus synchronization followed by FTAI (day 0-10), 2) Estrus detection and AI (day 11-45) and 3) Natural mating (day 46-90). For the first phase, all animals were synchronized and AI at fixed time (day 10). Cows displaying overt signs of estrus (day 11-45) were AI. Open cows during the previous two phases were exposed to the bull. Results. Pregnancy in phase 1 was different (p<0.01) for PP and OC groups, 58.6% and 34.1%, respectively. Overall pregnancy percentage over the second service was 42.5% (p>0.05). No differences (p>0.05) were observed at phase 3, average 44.2%. By the end of the breeding season, the cost of OC, was 3 times more expensive than PP cows. Conclusions. Pregnancy rate at first phase was higher in PP cows than OC cows. At the end of breeding season, a pregnancy rate of 80% was found. Incorporation of open cows from previous breeding season was more expensive than PP cows in all phases of the breeding program. Retaining an open cow for rebreeding one year or more could not be economically feasible. [ABSTRACT FROM AUTHOR]

El objetivo fue evaluar el benzoato de estradiol (BE) o GnRH en tiempo al estro (TE; h), porcentajes de estros (PE) y gestación (PG), área del cuerpo lúteo (aCL; cm2) y niveles séricos de progesterona (NSP4; ng/mL) en vaquillas sincronizadas con progesterona y PGF2; en dos tratamientos: T1 (n=23), CIDR por siete días y 2 mg de BE (día 0), al retirarlo 25 mg de PGF2 y 24 h después 1 mg de BE; T2 (n=23) CIDR por siete días y 100 μg de GnRH (día 0), al retirarlo 25 mg de PGF2 y a la IA 100 μg de GnRH. La IA fue de 12-18 h de iniciado el estro y las que no mostraron estro se IATF 56 h de retirado el CIDR. Los NSP4 y aCL se evaluaron diez días después de la IA. El TE, NSP4 y aCL se analizaron con GLM y el PG con GENMOD considerando el efecto de tratamiento, NSP4 y aCL. El PE fue analizado con CATMOD. Para determinar la correlación entre aCL y NSP4 se utilizó CORR. No se encontró efecto de tratamiento (P>0.05) para TE, PG y aCL; El PE fue mayor (P0.05). El uso de BE incrementó el porcentaje de vaquillas en estro sin mejorar la fertilidad, los niveles séricos de progesterona fueron mayores con GnRH y en gestantes. Abstract The objective was to evaluate the use of estradiol benzoate (EB) or GnRH on time to estrus (TE), estrus percentage (EP), pregnancy rate (PR), luteal area (aCL; cm2) and the serum progesterone levels (NSP4) in heifers synchronized with progesterone and PGF2 in two treatments: T1 (n =23), 7-d CIDR (d =0) and 2 mg of EB at withdrawing 25 mg of PGF2 and 24 h later 1 mg of EB; T2 (n =23), 7-d CIDR and 100 ug of GnRH (d =0), at withdrawing 25mg of PGF2 and at AI 100 ug of GnRH. The AI was performed 12–18 h after estrus detection and for those heifers that were not detected in estrus FTAI at 56 h, was performed after CIDR removal. The NSP4 and aCL were evaluated ten days after AI. TE, NSP4 and aCL were analyzed by PROC GLM. The PR with GENMOD, considering the effect of thetreatment, NSP4 and aCL. The EP was analyzed with CATMOD. A correlation analysis was performed between aCL and NSP4 with CORR. Treatment effect was not found for TE, PR and aCL (P>0.05). The EP was 100% T1 vs 60.8 ± 10.1% T2 (P0.05) between treatments. The NSP4, were 4.9 ± 0.3 T2 vs 3.7 ± 0.4 ng/mL T1 and 4.9 ± 0.4 in pregnant heifers vs 3.8 ± 0.3 ng/mL in open heifers (P0.05). The use of EB increases the percentage of heifers in estrus without improving fertility, the serum progesterone levels were higher with GnRH and in pregnant. Keywords: corpus luteum, beef cattle, artificial insemination, progesterone.

La inseminación artificial en la especie porcina es una herramienta de gran utilidad que permite grandes avances en la industria porcícola, tanto en nuestro país como en el mundo. La inseminación artificial es una herramienta biotecnológica de la reproducción que se aplica en la producción animal con el fin de aumentar la eficiencia productiva, lograr un mayor progreso genético e incrementar el desempeño reproductivo. Existen diferentes métodos de inseminación artificial en porcinos, que permiten variar el volumen y el número de espermatozoides de la dosis inseminante al modificar el lugar de deposición del semen. El objetivo de esta revisión fue recopilar y actualizar información relevante sobre la inseminación artificial en la especie porcina, relacionando la dosis seminal y el método de conservación, con la técnica empleada.

The objective of this work was to evaluate the effect of pre-exposure of progesterone (P4) in Nelore breed cows in the postpartum period, undergoing a fixed-time artificial insemination program (FTAI). 74 multiparous cows with 2,5 body condition, acyclic, were used. For the determination of the state of anestrus, ultrasound scans were performed evaluating the absence of the corpus luteum and taking blood samples in order to verify endogenous P4 levels < 1 ng / mL. The cows were submitted to three experimental groups, being an untreated group and two groups with previous P4 exposure for 3 and 6 days before the start of the estrus synchronization protocol. Animals underwent synchronization protocol based on progesterone, estradiol benzoate, prostaglandin and equine chorionic gonadotropin. 45 days after the IA, the pregnancy diagnosis was made. No differences (P > 0.05) were observed between the gestation rates of the experimental groups. In conclusion, pre-synchronization with P4 in Nelore cows in the postpartum anestrus period did not improve pregnancy rates after artificial insemination. [ABSTRACT FROM AUTHOR]

In the period 1981-1989, companies associated with CABIA (Argentine Chamber of Reproduction Biotechnology and Artificial Insemination) traded an average of 542 thousand doses of semen per year. The most commonly used breeds were Angus (39.3%), Polled Hereford (31.4%) and Brangus (10.5%). It is estimated that the AI (Artificial Insemination) rate in cow-calf operations during this period was 3.5%. In the second half of the '90s, the average amount of semen doses sold by CABIA companies was 607 asothousand, being mostly Angus (47.2%), Polled Hereford (24.0%) and zebu composite breeds (23.8%). The insemination rate in the Buenos Aires province, during this period was 5.6%. From the total inseminated animals, 73.5% were heifers. Nationwide, it is estimated that the insemination rate was 4%. In the early 2000's, this rate continued to be around 4%. As of 2004, there was an increase in the use of AI, accentuated since 2010, mainly due to the growth of the FTAI (Fixed Time Artificial Insemination) technique. Angus (42.4%), Braford (19.7%) and Brangus (15.7%) were the most used breeds in the period. The amount of beef semen doses marketed annually by CABIA companies between years 2015-2018, was 2.5 million, mostly Angus (45.1%), Brangus (23.7%) and Braford (17, 9%). An average of 3 million FTAI treatments per year were carried out, which represented more than 90% of total AI in beef cattle. The AI rate during this period was 12.8%. The evolution analysis of the beef AI market in the last 40 years shows a significant growth, going from 3.5% to 13% rate. The growth of the FTAI led to a pronounced increase in the proportion of inseminated breeding cows with calf at foot. [ABSTRACT FROM AUTHOR]

In order to determine the correlation between the cinquemia and the reproductive indicators of the dairy cow and the concentrations of Zn in blood serum that constitute a significant risk for the presentation of the postpartum anestrus and the repetition on service of Artificial Insemination, 143 animals with six to eight elderly years and third and fourth lactation were selected. The correlation between the cinquemia and the reproductive indicators and the association between different concentrations of Zn in blood serum and the anestrus and the repetition on service of Artificial Insemination were determined. The herds present low reproductive efficiency and the cinquemia had a negative correlation (p= 0.0000) with the postpartum anestrus and the interval parturition. For the postpartum anestrus when the lower cinquemia than 15 µmol/L, constituted a relative risk (RR) 1. 74 (p= 0. 0070) and lower than 14 µmol/L, RR 2.69 (p= 0. 0000) and lower to 16 µmol/L was not, RR 1.04 (p= 0.8282). For the repetition of service of Artificial Insemination, the lower cinquemia to 15 µmol/L constituted a relative risk (RR) factor, RR 3.83 (p= 0.0000), lower to 14 µmol/L, RR 5.20 (p= 0.0000) and was not when its concentrations were under 16 µmol/L, RR 1.77 (p= 0.119. It is concluded that that the cinquemia had a negative and highly significant correlation with the reproductive indicators and when it descends from 15 µmol/L it constitutes a significant relative risk to the presentation of anestrous and repetition of service of Artificial Insemination. [ABSTRACT FROM AUTHOR]

The cryopreservation of sheep semen represents a challenge to increase pregnancy rates in cervical artificial insemination programs. Decreased sensitivity at low temperatures could counteract certain detrimental effects on sperm. It has been reported that the addition of seminal plasma improves the functionality and fertility in cryopreserved ram spermatozoa. However, this role played by the seminal plasma could be altered by the presence of the components of the extender, among them the egg yolk, cryoprotectant commonly used in the media of dilution and cryopreservation. [ABSTRACT FROM AUTHOR]

Antecedentes: el extensionismo rural desarrollado por el Servicio Nacional de Aprendizaje va enfocado a apoyar a la formación profesional integral y el mejoramiento de unidades productivas de los porcicultores del departamento por medio de estrategias de investigación y desarrollo tecnológico. Objetivo: desarrollar una metodología de transferencia de biotecnología reproductiva a porcicultores de las ciudades de Duitama, Sogamoso y Paipa en el departamento de Boyacá. Métodos: se identificaron en total 51 participantes entre productores y operarios de granjas de cría en las ciudades de Duitama, Paipa y Sogamoso, se impartió formación profesional integral en inseminación artificial y un programa de Técnico en Producción Porcina, visitas técnicas y apoyo con insumos para el proceso de inseminación artificial postcervical en sus cerdas de cría para la obtención inicial de hembras F1 50 % Landrace x otras genéticas. Resultados: de manera general se certificaron 51 productores, 17 en Sogamoso, 12 en Paipa, y 22 en Duitama, gracias a este proceso de extensionismo, se inició por primera vez el programa Técnico en Producción Porcina, en el departamento de Boyacá en la ciudad de Duitama con 22 inscritos, se inseminaron un total de 100 cerdas en el proceso por cada uno de los propietarios en acompañamiento de los profesionales de investigación de la estrategia Sennova con lo que se obtuvo un reemplazo inicial de un 10 % de las hembras de las granjas con un 50 % Landrace y 50 % otras genéticas para futuros reemplazos y disminución de hembras criollas de baja productividad. Conclusiones: la transferencia de la biotecnología reproductiva por medio de la formación profesional integral y desarrollo de la técnica de inseminación postcervical, permitió que productores dependientes de mano de obra externa en el proceso manejaran la inseminación artificial de manera independiente y el inicio del programa de mejoramiento genético de obtención de hembras de reemplazo mejoradas y la eliminación de machos de monta de mala calidad genética en sus granjas. [ABSTRACT FROM AUTHOR]

Antecedentes: el acceso a un servicio educativo de calidad que responda de manera oportuna y pertinente a las características individuales‚ culturales y contextuales de un entorno social‚ podrá traducirse en mejores posibilidades de trabajo y de bienestar‚ tanto para profesionales del sector agropecuario como también‚ para los pobladores rurales que participan en cursos de extensión. Objetivo: evaluar la percepción en la pertinencia‚ la metodología‚ la aplicabilidad y el interés en participantes de un curso interdisciplinar sobre inseminación artificial‚ liderazgo rural y fundamentos del agronegocio bovino. Métodos: 35 participantes del curso de extensión anteriormente mencionado fueron capacitados en tres temáticas: i) liderazgo y agronegocio bovino; ii) inseminación artificial (IA); iii) anatomía del aparato reproductor de la hembra bovina (ARF). Luego‚ una encuesta de percepción basada en cinco preguntas orientadoras con una escala de medición tipo Likert de 1 a 5‚ donde 1 era la percepción más negativa y 5 la más positiva‚ fue aplicada en cada participante. Se realizó una estadística descriptiva y se hizo un análisis de varianza para comparar las medias de cada pregunta entre las temáticas. Resultados: al indagar sobre la pertinencia de las temáticas‚ un 97 % de los participantes coincidió sobre la importancia del agronegocio bovino‚ 91 % consideró importante la IA y un 91 % afirmó que ARF era una temática vital para entender la técnica de la IA. Por otra parte‚ el 94 % consideró que la metodología de desarrollo didáctica aplicada por cada docente fue acertada y el 97 % estuvo completamente de acuerdo con la aplicabilidad de las temáticas en el campo profesional. Además‚ un 89 % manifestó el deseo de ampliar los conceptos sobre las temáticas ofrecidas. Finalmente‚ no observó diferencia estadística (p > 0‚05) entre las percepciones de pertinencia‚ importancia y metodología de desarrollo de las tres temáticas encuestadas. Conclusiones: los resultados indican una percepción altamente positiva sobre la implementación de cursos de extensión didácticos e interdisciplinarios orientados a mejorar los procesos educativos en el sector agropecuario. [ABSTRACT FROM AUTHOR]

Se evaluó el comportamiento de la eficiencia técnica de la inseminación artificial en empresas lecheras vacunas en la provincia de Camagüey, Cuba. Fueron utilizados los datos de reproducción (entre enero de 2009 y diciembre de 2015) de los archivos de la subdelegación de ganadería de la delegación del Ministerio de la Agricultura en la provincia. Se calculó la eficiencia técnica de la inseminación a partir del total de hembras inseminadas y las que resultaron gestantes al diagnóstico de gestación en cada mes y empresa. Se realizaron análisis gráfico y de frecuencias por rango y se determinaron los componentes de la serie por el método multiplicativo. Se realizó el análisis de autocorrelación y la descomposición estacional, teniendo en cuenta como criterio para la estacionalidad ± 10 %. La eficiencia técnica de la inseminación artificial alcanzó valores que oscilaron entre 40 y 64 %, con valor medio de 51,49 %. Las frecuencias más observadas oscilaron entre 48 y 56 %, con un comportamiento estable e índices estacionales que oscilaron desde 90,21 (en mayo) hasta 108,91 (en septiembre). La disminución en los valores medios de la eficiencia técnica de la inseminación artificial estuvo caracterizada por ausencia de comportamiento estacional e indica la necesidad de evaluar otros factores relacionados con el trabajo técnico y aspectos organizativos de la reproducción, relacionados con las medidas administrativas adoptadas en el año 2008.

En México las unidades de producción lechera son altamente heterogéneas en cuanto a las condiciones tecnológicas y agroecológicas en que se desarrollan, lo que influye directamente sobre el rendimiento de la ordeña. Este trabajo evalúa la influencia de variables de tipo económico y tecnológico como la escolaridad del productor, el nivel de tecnificación, el tamaño del hato productivo, la inseminación artificial, la presencia de asesoría técnica y el uso de alimento concentrado, sobre el rendimiento obtenido en unidades familiares de producción de la cuenca de Tecamachalco; Puebla. Para verificar este planteamiento empírico se construyó un modelo lineal múltiple y se llevó a cabo una regresión mediante mínimos cuadrados ordinarios. Los resultados mostraron que, a excepción del nivel de tecnificación, todas las variables contempladas en el modelo tuvieron un efecto positivo y significativo sobre la cantidad de litros producidos por vaca por día. Estos resultados cuestionan en buena medida la política de fomento agropecuario que se ha enfocado a la dotación de equipos y habilitación de infraestructura. Se perciben como necesarias políticas públicas y acciones de auto-organización, dirigidas a la mejora de la alimentación de los hatos, a la generalización de la inseminación artificial y a la garantía de asesoría técnica oportuna y de calidad.

La inseminación intrauterina (IIU), una técnica que utiliza un número menor de espermatozoides que la inseminación artificial convencional (IAC), podría contribuir a mejorar la eficiencia reproductiva de los verracos. Sin embargo, dado que algunos informes de pruebas de campo muestran un rendimiento subóptimo para la IIU, es necesario continuar evaluando y estandarizando esta técnica. En este trabajo se evaluó el uso de cantidades reducidas fijas de espermatozoides y volúmenes por dosis para IIU en comparación con la IAC, utilizando las mismas muestras de semen. Los resultados muestran un incremento del índice de partos con IIU comparada con la IAC (84.80 ± 0.36 vs 71.44 ± 2.63, P<0.05). También se analizaron parámetros tales como el tamaño de la camada, el número de lechones vivos por camada y el número de lechones mortinatos o de fetos momificados, y las diferencias encontradas entre estas técnicas no fueron significativas. Los análisis estadísticos de correlación positiva demuestran que únicamente en el caso de la IAC existe una correlación positiva entre el número de lechones vivos por camada y el número de lechones mortinatos, así como entre el número de lechones mortinatos y el número total de lechones. En conclusión, la inseminación intrauterina tuvo un impacto positivo en el rendimiento reproductivo y en los parámetros económicos de la producción porcina. [ABSTRACT FROM AUTHOR]

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Selenium is a mineral that contributes to animal reproduction. The objective of this work was to evaluate conception rate and progesterone concentration in landrace ewes, during the reproductive season by organic selenium intake. 27 multiparous ewes were used with a body condition of 2.5; two groups were randomly designed: 11 ewes without selenium and 16 with selenium. Estrus was synchronized with intravaginal sponges containing fluorogestone acetate for 14 days, at the time of sponges removal, application of 400 UI of eCG was made. Artificial insemination (IA) was developed at a fixed time (55 hours after removal of sponges), consecutive application of 0.3 ppm day-1 of oral organic selenium was started seven days before IA. Progesterone concentration was evaluated in blood samples obtained along one estrus cycle (21 days), gestation diagnosis was developed at 35 days after the IA. Progesterone concentrations, between without selenium (5.28 ng mL-1) and treatment with organic selenium (6.58 ng mL-1), were not different between groups or between days (p ≥ 0.05), although in both groups the maximum progesterone concentration was observed on day 14 after the IA, in coincidence with a normal corpus luteum time. Also, conception rate was not different (p ≥ 0.05); in the group without selenium 81.8% and with organic selenium 75%. Based on the results, it is concluded that organic selenium application for seven days before IA did not influence progesterone concentration and conception rate in ewes. [ABSTRACT FROM AUTHOR]

En el estudio se evaluó el efecto de descongelar y aplicar semen de bovinos Bos Taurus en 33 ganaderías del Magdalena Medio colombiano, y se estudió in vitro el efecto de la injuria encontrada sobre la integridad de las membranas espermáticas. La información en fincas se recopiló mediante formulario específico, mientras que el estudio in vitro se ejecutó en el laboratorio de Biotecnología Reproductiva Animal del Instituto Universitario de la Paz (Barrancabermeja, Santander). El estudio consistió en someter pajillas comerciales de 0.5 ml de toros Holstein y Pardo Suizo a la técnica convencional y a tres modificaciones de esta (injurias) mediante un diseño randomizado. Ninguna de las fincas evaluadas aplicó correctamente la práctica de la inseminación artificial; errores notorios fueron: exceso de tiempo durante la extracción de la pajilla, descongelación en la región axilar y no combinación correcta entre tiempo y temperatura. Los resultados evidenciaron diferencia significativa (P