Search

Criollo horse breeding is an important economic activity in South America. Because of their athletic performance, these animals tend to show great incidence of musculoskeletal disorders, many of them diagnosed by means of perineural blocks. However, incorrect interpretation of these blocks may be due to anatomical differences in nerve distribution. The objective of this study was to describe the innervation of the digit region of thoracic limbs in Criollo horses, in order to improve the interpretation of tests for claudication diagnosis based on nerve block. Thirty thoracic limbs from Criollo horses were dissected. It could be observed that in 90% of the limbs, dorsal branches of the palmar nerve originated proximally to the proximal sesamoid bone. In 93% of the cases, the palmar digital nerve and the dorsal branches communicated; in 87% of the cases, communication between branches of the dorsal branch was observed; and in 27% (8/30) of the limbs, the palmar metacarpal nerve and the dorsal branch presented communications. None of the specimens showed complete symmetry in the distribution of nerves in contralateral limbs. The high frequency of communication between the nerves may be a particularity of the Criollo breed that may interfere with the interpretation of perineural blocks. Based on the anatomical position, it may be inferred that divergent results in Criollo horses may occur when abaxial sesamoid nerve block is used. Palmar digital nerve block may be less influenced by these variations, provided it is performed as distal as possible from the ungular cartilage.

ilustraciones La criopreservación de semen equino facilita su uso en programas de inseminación artificial y mejoramiento genético, independientemente de la ubicación, disponibilidad o estado del ejemplar equino. Adicionalmente, su uso se ha extendido al desarrollo de biotecnologías de la reproducción asistida y a procesos de producción de embriones tanto in vivo como in vitro. Sin embargo, con el semen criopreservado se han conseguido tasas más bajas de fertilidad comparadas con las obtenidas con semen refrigerado. A nivel mundial se llevan a cabos múltiples estudios enfocados a mejorar los procesos de congelación del semen equino y a encontrar sustancias que atenúen los daños producidos por el estrés oxidativo y el choque osmótico ocasionados por este proceso. Precisamente, para contribuir al conocimiento sobre moléculas que disminuyan el estrés de la célula espermática durante el proceso de congelación, disminuyendo el daño a su estructura, maquinaria molecular y fisiología, en este trabajo evaluamos el efecto de dos antioxidantes no enzimáticos, Quercetina (Q) y L-Ergotioneína (E) y un inhibidor de la PKA (H89), adicionados al diluyente de congelación seminal, sobre la integridad y funcionalidad espermática. Con este fin, en la posdescongelación, en la primera parte del estudio evaluamos la cinemática espermática, la integridad de membrana, y la capacidad de fertilización in vitro. Posteriormente, en la segunda parte se evaluó el estrés oxidativo y en la última fase se evaluó la viabilidad, actividad mitocondrial y la estabilidad de la membrana celular. Se utilizó el análisis espermático computarizado (CASA), el test hiposmótico, la fertilización heteróloga in vitro, la espectroflurimetría y la citometría de flujo. En los 6 grupos experimentales evaluados (Control, Q, E, H89, H89Q, H89E), en el primer estudio se evidenció que H89 disminuye la hiperactivación y Q incrementa BCF. Sin embargo, la combinación de ambas moléculas altera patrones cinemáticos importantes para llevar a cabo la fertilización. No se observaron diferencias estadísticas significativas entre tratamientos y el control en otros patrones cinemáticos, integridad de membrana o capacidad fertilizante. En la segunda parte se encontró que todos los tratamientos, excepto el H89 disminuyeron la cantidad de especies reactivas de oxígeno en el semen criopreservado, siendo Q el mejor tratamiento. Por otro lado, todos los tratamientos, excepto E disminuyeron la peroxidación lipídica con respecto al control, siendo mejor la combinación de H89 y Q. Aunque Q tuvo un efecto positivo en el decrecimiento de la peroxidación lipídica, su combinación con H89 mostró una reducción mayor, sugiriendo un efecto sinérgico con el H89. Por su parte, en la fase final se encontró que la combinación H89 + E tuvo una tendencia a mejorar la actividad mitocondrial alta. Sin embargo, ninguno de los seis tratamientos evaluados tuvo efecto estadístico significativo sobre la estabilidad de membrana, la viabilidad, contenido o captación de calcio y actividad mitocondrial. Con estos resultados se concluyó que la Q y E actúan como antioxidantes de manera diferencial para la protección del espermatozoide durante la criopreservación. Adicionalmente se encontró que la combinación Q y E con H89 muestra efectos contrastantes entre la cinemática y su capacidad antioxidante, alterando la primera, pero favoreciendo la segunda. Estos resultados abren una ventana de estudio en los mecanismos moleculares que pueden acompañar el sinergismo entre H89 con Q y E, explorar combinaciones de otras concentraciones de las tres moléculas y llevar a cabo estudios más extensos de las vías de señalización asociadas. (Texto tomado de la fuente) Equine semen cryopreservation is used in artificial insemination and genetic improvement programs, it does not depend on the location, availability or condition of the equine specimen. Its use has been extended to the development of biotechnologies of assisted reproduction and to embryo production processes both in vivo and in vitro. However, cryopreserved semen has lower fertility rates compared to those obtained with refrigerated semen. Worldwide, multiple studies have been focused on improving the freezing processes of equine semen and finding substances that mitigate the damage caused by oxidative stress and osmotic shock. In order to contribute to the knowledge about molecules that decrease the stress of the spermatic cell during the freezing process, reducing the damage to its structure, molecular machinery and physiology, in this work was evaluated the effect of two non-enzymatic antioxidants, Quercetin (Q) and L -Ergotioneine (E) and a PKA inhibitor (H89), added to the seminal freezing diluent, on sperm integrity and functionality. Subsequently, in the second part, oxidative stress was evaluated and in the last phase, viability, mitochondrial activity, and cell membrane stability were evaluated. Computerized sperm analysis (CASA), hyposmotic test, heterologous in vitro fertilization, spectrofluorimetry and flow cytometry were used. In the 6 experimental groups evaluated (Control, Q, E, H89, H89Q, H89E), in the first study it was shown that H89 decreases hyperactivation and Q increases BCF. However, the combination of both molecules alters important kinematic patterns to carry out fertilization. No significant statistical differences were observed between treatments and control in other kinematic patterns, membrane integrity or fertilizing capacity. In the second part, it was found that all treatments, except H89, decreased the amount of reactive oxygen species in cryopreserved semen, with Q being the best treatment. On the other hand, all the treatments, except E, decreased lipid peroxidation with respect to the control, the combination of H89 and Q being better. Although Q had a positive effect in the decrease of lipid peroxidation, their combination with H89 showed a greater reduction, suggesting a synergistic effect with H89. On the other hand, in the final phase it was found that the H89 + E combination had a tendency to improve high mitochondrial activity. However, none of the six treatments evaluated had a statistically significant effect on membrane stability, viability, calcium content or uptake, and mitochondrial activity. With these results, it was concluded that Q and E act as antioxidants in a differential way for the protection of sperm during cryopreservation. In addition, it was found that the combination Q and E with H89 shows contrasting effects between the kinematics and its antioxidant capacity, altering the first, but favoring the second. These results open a window of study in the molecular mechanisms that can accompany the synergism between H89 with Q and E, to exploring combinations of other concentrations of the three molecules and and carry out more extensive studies of associated signaling pathways. Doctorado Doctor en Biotecnología Biotecnología reproductiva

En este estudio se determina el grado de relación existente entre diferentes variables corporales en 52 machos Criollo Araucano, mediante un análisis de componentes principales. Los caracteres corporales empleados fueron 20: perímetro torácico, diámetro longitudinal, diámetro dorso-esternal, alzada a la cruz, diámetro bicostal, altura del espacio subesternal, anchura de pecho, perímetro de la caña anterior, longitud de cabeza, anchura de cabeza, longitud de cráneo, anchura de cráneo, longitud de cara, anchura de cara, profundidad de la cabeza, alzada a la grupa, largo de grupa, anchura de grupa, altura al nacimiento de la cola y altura al corvejón. Se analizaron igualmente las posibles diferencias morfológicas entre cuatro fincas de la zona. Del estudio puede concluirse que la población de caballos criollos araucanos, aunque bastante uniforme, presenta diferencias morfológicas entre fincas, siendo estas diferencias de aspecto general más que centradas en regiones corporales determinadas.

This text details two inter-related Envoy works, Criollo and The Athens-Kassel Ride: The Transit of Hermes, commissioned for documenta 14, Athens and Kassel, 2017. Both works respond to Tschiffely’s Ride (1933), an account of a 10,000 mile journey from Buenos Aires to New York (1925–1928) by Swiss-Argentine horseman, Aime Felix Tschiffely, riding two Argentine criollos, Mancha and Gato. The film Criollo features an Argentine criollo horse standing at the Artists’ Gate entrance to Central Park at the end of sixth Avenue / Avenue of Americas, New York. Criollo, a variant of ‘creole’, holds associations of ‘creolisation’, ‘cultural mixing’ (Hall) and ‘entanglement’ (Glissant) in the context of globalisation and migration. Criollo also prompts consideration of the animal in the development of capitalism (Berger, Raulff) and a reading, in turn, of the concepts of ‘bare life’, ‘bios’ and ‘zoe’ (Agamben). These contexts also frame The Athens-Kassel Ride: The Transit of Hermes, a 3000km equestrian journey performed over 100 days by four Long Riders traversing Greece, Macedonia, Serbia, Croatia, Slovenia, Austria and Germany, accompanied by a Greek arravani horse ‘Hermes’ named after the god of border crossings who – as angel messenger – is a key figure in the thought of Michel Serres.

The aim of this study was to estimate the genetic parameters of performance in a 750-km, 15-day ride in Criollo horses. Heritability (h2) and maternal lineage effects (mt2) were obtained for rank, a relative placing measure of performance. Additive genetic and maternal lineage (rmt) correlations among five medium-to-high intensity phase ranks (pRK) and final rank (RK) were also estimated. Individual records from 1,236 Criollo horses from 1979 to 2012 were used. A multivariate threshold animal model was applied to the pRK and RK. Heritability was moderate to low (0.156-0.275). Estimates of mt2 were consistently low (0.04-0.06). Additive genetic correlations between individual pRK and RK were high (0.801-0.924), and the genetic correlations between individual pRKs ranged from 0.763 to 0.847. The pRK heritabilities revealed that some phases were explained by a greater additive component, whereas others showed stronger genetic relationships with RK. Thus, not all pRK may be considered as similar measures of performance in competition.

Criollo horse populations descend from horses brought from the Iberian Peninsula over the period of colonization (15th to 17th century). They are spread throughout the Americas and have potentially undergone genetic hybridization with other breeds in the recent past. In this study, 25 autosomal microsatellites were genotyped in 50 horse breeds representing Criollo populations from 12 American countries (27 breeds), breeds from the Iberian Peninsula (19), one breed each from France and Morocco and two cosmopolitan horse breeds (Thoroughbred and Arabian). The genetic relationships among breeds identified five clusters: Celtic; Iberian; North American with Thoroughbred influence; most Colombian breeds; and nearly all other Criollo breeds. The group of "all other Criollo breeds" had the closest genetic relationship with breeds originating from the Iberian Peninsula, specifically with the Celtic group. For the whole set of Criollo breeds analysed, the estimated genetic contribution from other breeds was approximately 50%, 30% and 20% for the Celtic, Iberian and Arab-Thoroughbred groups, respectively. The spatial distribution of genetic diversity indicates that hotspots of genetic diversity are observed in populations from Colombia, Ecuador, Brazil, Paraguay and western United States, possibly indicating points of arrival and dispersion of Criollo horses in the American continent. These results indicate that Criollo breeds share a common ancestry, but that each breed has its own identity.

The goal of this research was to evaluate the ability of the genotyping information available in the Brazilian Criollo Horse Stud Book to describe the genetic variability of the breed and the exclusion probability determined in comparative tests. Altogether, two softwares were used in the analyses of the available genotypes: Cervus 3.0.3 and Genepop 4.0. Eight microsatellite markers totaled 109 alleles, with an average of 13.6 +/- 0.6 alleles per locus. Large differences between expected and observed heterozygosity were ubiquitous (0.821 +/- 0.07 and 0.470 +/- 0.17, respectively). Although the estimated null allele frequency caused initial concern (0.284 +/- 0.199), it is likely that it was a reflection of the inbreeding coefficients found (0.432 +/- 0.184). All loci showed significant deviation from Hardy-Weinberg equilibrium, with heterozygote deficit (P0.0001) and genotypic linkage disequilibrium with at least one marker. The high polymorphic information content (0.798 +/- 0.088) could not warrant exclusion power for three loci (HMS7, HMS6 and HTG4) above 50% (0.491 +/- 0.158). However, combined exclusion probability reached 99.61%, a level close to ideal. The results demonstrate the excellent performance of the markers assessed in describing the genetic status of the breed and suggest the considerable ability to establish parentage.

SummaryThe Criollo horse bred in Uruguay is a direct descendant of the Andalusian horses that were brought to America by the Spanish conquerors. It is not an isolated population. Ever since its coming into existence it has been related to the other populations of the southern countries of South America (Chile, Argentina and Uruguay). It is adapted to the most divergent regions of the continent, evolving through natural selection into a versatile breed, suited in particular for farm work because of its endurance, courage and capacity for recuperation.At the beginning of this century, its existence was endangered because of the tendency of crossing with European breeds. Around this time, breeder organisations appeared in various countries and with them the standardisation of the Criollo horse as a breed. From this moment on, its growth was well maintained and constant, and today it is also being bred in Germany and Italy.

Various horse populations in the Americas have an origin in Spain; they are remnants of the first livestock introduced to the continent early in the colonial period (16th and 17th centuries). We evaluated genetic variability within the Venezuelan Criollo horse and its relationship with other horse breeds. We observed high levels of genetic diversity within the Criollo breed. Significant population differentiation was observed between all South American breeds. The Venezuelan Criollo horse showed high levels of genetic diversity, and from a conservation standpoint, there is no immediate danger of losing variation unless there is a large drop in population size.

O objetivo do presente estudo foi determinar variações da Espessura da Unidade Útero Placentária (EUUP) através do exame ultra-sonográfico transretal da placenta e caracterizar a conformação vulvar durante a gestação em éguas da raça Crioula. Foram utilizadas 63 éguas Crioulas sadias prenhes, com idades que variaram de 4 a 22 anos e que nunca foram submetidas à vulvoplastias. As éguas foram examinadas mensalmente a partir do quarto mês de gestação, para avaliação do escore corporal, análise da conformação vulvar e para medida da Espessura da Unidade Útero Placentária (EUUP). A conformação vulvar foi avaliada pela caracterização do comprimento vulvar efetivo e total (CE e CT), ângulo de inclinação (A) da vulva e tônus muscular da região perineal. O produto CE x A nos forneceu o Índice Caslick (IC). A condição corporal média das reprodutoras foi 3,5 (±0,4); o ângulo de inclinação (A) médio foi de 10,4º (±7,4); o comprimento vulvar efetivo (CE) médio foi de 3,8 cm (±0,9) e o comprimento vulvar total (CT) médio foi de 8,2 cm (±1,2); o tônus muscular perineal médio foi de 2,3; o Índice Caslick (IC) médio na população estudada foi de 40,6 (±33,5). A EUUP foi influenciada pela idade gestacional (P

The Criollo Horse breed is gaining increasing importance in our state, due to competition to economic and cultural aspects. However, few studies were developed with this horse breed. Under seasonal and natural photoperiod influence, in a stud farm at 29º38 South latitude, the length of gestation, foal s heat occurrence and duration of partum to ovulation interval, fall transition, anestrous, vernal transition and estrous were evaluated in 82 Criollo mares, with age between three and 28 years. Palpation per rectum and ultrasonography were performed daily from the beginning of the breeding season in September/2005 until December/2006. The mean and standard deviation (±SD) of gestation length in 70 mares was 335.6±10.5 days, varying from 312 to 364 days. The mean interval from parturition to first ovulation (±SD) of 42 mares that foaled between September and December of 2005 and 2006 was 20.0±14.0 days. The longer period was 71 days. A foal heat ovulation shorter then 20 days was shown on 83.3% (35/42) of the mares and, on them the mean parturition to ovulation interval (±SD) was 14.2±3.0 days. The results of estrus evaluation, during the six days prior to ovulation, showed a daily enlargement of follicle diameter of about three millimeters. The mean diameter varied from 30.1mm at the 6th day pre-ovulation to 45.6mm on the day before corpus luteum detection. The vernal transition was evaluated in 14 mares in two consecutive years. On them, 64.3% finished their transitional period between the second half of September and the first fortnight of October, close to the spring equinox. The fall transition started on May and 75% (6/8) of the mares entered the anestrous period at the second half of that month Os eqüinos da raça Crioula se destacam pela sua importância cultural, atlética e econômica no Rio Grande do Sul. Entretanto, poucas pesquisas têm sido desenvolvidas com enfoque nos aspectos fisiológicos da reprodução da égua Crioula que ainda requerem melhor compreensão. Em uma propriedade situada à latitude 29º38 Sul e sob a influência do fotoperíodo natural, 82 éguas da raça Crioula, com idade entre três e 28 anos, foram avaliadas a duração da gestação, a ocorrência do primeiro cio pós-parto e duração do intervalo parto-ovulação, período de transição vernal e estros, período de transição outonal e ocorrência da fase de anestro. A partir do início da estação reprodutiva, de setembro de 2005 até dezembro de 2006, examinou-se diariamente o trato reprodutivo das éguas por palpação retal e ultra-sonografia. A duração da gestação (n=70) foi de 335,6±10,5 dias, variando de 312 a 364 dias. O intervalo parto-ovulação de 42 reprodutoras paridas de setembro a dezembro de 2005 e 2006 teve duração média (±DP) de 20,0±14,0 dias, sendo de 71 dias o período mais longo. Oitenta e três porcento das éguas apresentaram cio do potro e primeira ovulação até o 20° dia após o parto (35/42), com mé dia (±DP) de 14,2±3,0 dias. O crescimento médio do folículo dominante durante o cio foi de três milímetros ao dia, variando de 30,1mm no sexto dia pré-ovulação, para 45,6mm no dia que antecedeu a detecção do corpo lúteo. A transição vernal foi avaliada em 14 éguas em dois anos consecutivos. Destas, 64,3% encerraram a fase transicional entre a primeira quinzena do mês de setembro e a primeira quinzena do mês de outubro, próximo, ou até duas semanas após o equinócio de primavera. A transição outonal teve início no mês de maio, sendo a partir da segunda quinzena deste mês, 75% (6/8) das reprodutoras avaliadas iniciaram a entrada na fase de anestro

South America has numerous Criollo horse breeding farms; however, information on foal hoof growth is still limited and identifying the ideal periods to apply corrective trimming is a frequent concern for horse owners. In the present study, a morphometric analysis of hoof growth was performed on 46 Criollo foals from birth to weaning (0-8 months). Results showed that hoof growth rate was higher in the first four months followed by a decrease until the eighth month. Average growth rate of the hoof was 0.21cm per month, whereas that of the heel was 0.14cm per month. However, no significant differences were observed between medial and lateral heel length or between limbs. Coronary band perimeter and solar width showed an average increase of 0.97cm and 0.46cm per month, respectively, and were significantly correlated (r=0.99, P≤0.01). The characteristic most positively correlated to biometric variables was foal age, followed by solar width, toe length, and coronary band perimeter. In conclusion, hoof length increase in Criollo foals was more intensive during the first four months of life. RESUMO: A América do Sul possui um grande número de criatórios da raça Crioula, no entanto, há uma carência de informações sobre o desenvolvimento natural dos cascos dos potros, tornando a identificação de períodos ideais para o casqueamento corretivo uma dúvida frequente entre os criadores. Portanto, o objetivo deste estudo foi realizar a biometria natural (do nascimento aos 8 meses) no casco de 46 potros da raça Crioula. Os resultados indicaram uma taxa de crescimento mais rápido nos primeiros 4 meses, com subsequente desaceleração até o desmame. O crescimento médio do casco foi em média 0,21cm mo-1, enquanto o comprimento do talão foi de 0,14cm mo-1. Não foram observadas diferenças significativas no equilíbrio médio/lateral do casco ou entre os membros durante o período experimental. O perímetro da banda coronária e a largura solar do casco apresentaram um crescimento médio de 0,97 e 0,46cm mo-1, respectivamente, e foram altamente correlacionados (r=0,99, P≤0,01). A idade dos potros foi a característica mais correlacionada positivamente, seguida da largura solar, do comprimento do casco e do perímetro da banda coronária. Nós concluímos que o crescimento do casco em potros da raça Crioula foi mais intenso durante os quatro primeiros meses de vida.