Polymorphisms associated with the number of live-born piglets in sows infected with the PRRS virus in southern Sonora Mexico

The porcine reproductive and respiratory syndrome (PRRS) is a viral disease that decreases the reproductive performance in breeding sows and leads to economic losses to the swine industry. The objective of the present study was to identify single nucleotide polymorphisms (SNP) associated to the number of live-born piglets in the first (LBP1) and second birth (LBP2) in breeding sows exposed to PRRS virus. The study included 100 pregnant females of the Landrace(¾)/ Yorkshire(¼) line, 75 of which were infected with the PRRS virus and 25 were free of PRRS. Individual blood samples (6-8 drops) were obtained and spotted onto FTA cards and subsequently processed for DNA extraction, which was genotyped using a 10,000 SNP chip for genomic profile. Resulting genotypes were analyzed using a multi-locus mixed model that detected three SNP associated to LBP1 and five SNP associated to LBP2 (P<0.001). These eight SNP were validated using an associative mixed effects model which included the terms genotype and age of dam as fixed effects, and sire as random effect. Allele substitution effects were estimated using the same model including the term genotype as covariate. The SNP rs81276080, rs81334603 and rs80947173 were associated to LBP1 (P<0.001), whereas the SNP rs81364943, rs80859829, rs80895640, rs80893794 and rs81245908 were associated to LBP2 (P<0.001). Only two SNP were in functional chromosomal regions and the remainder SNP were within an intergenic position. In conclusion, these results suggest the existence of gene variants associated with the reproductive performance of sows infected with the PRRS virus.The porcine reproductive and respiratory syndrome (PRRS) is a viral disease that decreases the reproductive performance in breeding sows and leads to economic losses to the swine industry. The objective of the present study was to identify single nucleotide polymorphisms (SNP) associated to the number of live-born piglets in the first (LBP1) and second birth (LBP2) in breeding sows exposed to PRRS virus. The study included 100 pregnant females of the Landrace(¾)/ Yorkshire(¼) line, 75 of which were infected with the PRRS virus and 25 were free of PRRS. Individual blood samples (6-8 drops) were obtained and spotted onto FTA cards and subsequently processed for DNA extraction, which was genotyped using a 10,000 SNP chip for genomic profile. Resulting genotypes were analyzed using a multi-locus mixed model that detected three SNP associated to LBP1 and five SNP associated to LBP2 (P<0.001). These eight SNP were validated using an associative mixed effects model which included the terms genotype and age of dam as fixed effects, and sire as random effect. Allele substitution effects were estimated using the same model including the term genotype as covariate. The SNP rs81276080, rs81334603 and rs80947173 were associated to LBP1 (P<0.001), whereas the SNP rs81364943, rs80859829, rs80895640, rs80893794 and rs81245908 were associated to LBP2 (P<0.001). Only two SNP were in functional chromosomal regions and the remainder SNP were within an intergenic position. In conclusion, these results suggest the existence of gene variants associated with the reproductive performance of sows infected with the PRRS virus

Enfriamiento al inicio de verano para mitigar el estrés por calor en vacas Holstein del noroeste de México

The objective of this study was to determine the physiological, endocrine and productive response in lactating dairy cows under several series of artificial cooling at the beginning of the summer (June to July, 2011). Fourteen multiparous Holstein cows were assigned in one of two treatments: Cooling (C) before milking (0700 and 1700 h) and additional cooling (AC) each 2 h (from 0700 to 1700h) in the holding pen of the milking parlor. Milk yield (MY), and serum levels of prolactin (PRL) and IGF1 were measured. Rectal temperature and respiratory rate were registered and included as physiological markers of heat stress. Ambient temperature and relative humidity were also collected and used to calculate temperature-humidity index (THI). Both markers of heat stress showed a significant interaction (P<0.001) between treatment and time/week, which were lower in AC treatment (-3.8 breaths per minute and -0.2 °C) during wk 6 and 7. Serum levels of PRL were higher under additional cooling (AC: 35.1 vs C: 29.4 ng/ml; P=0.004), while  IGF1 serum levels showed variation only through the sampling weeks (P=0.014). The MY increased (P<0.05) in AC only during wk 6 (+3.1 kg/d) and 7 (+3.1 kg/d). It was concluded that additional cooling at the beginning of the summer reduced heat stress in dairy cows allowing a better productive performance at the end of the study because such effect relied on the variable time/week.El objetivo de este estudio fue determinar la respuesta fisiológica, endócrina y productiva en vacas lactantes sometidas a varias series de enfriamiento artificial al inicio de verano (junio a julio de 2011). Se asignaron 14 vacas Holstein multíparas a uno de dos tratamientos: enfriamiento (E) antes de la ordeña (0700 y 1700 h) y enfriamiento adicional (EA) cada 2 h de 0700 a 1700 h en el corral de espera a la ordeña. Se midió la producción de leche (PL), niveles de prolactina (PRL) e IGF1, mientras que la temperatura rectal y frecuencia respiratoria fueron registradas y consideradas como indicadores fisiológicos de estrés por calor. La temperatura ambiental y humedad relativa también fueron registradas y utilizadas para calcular el índice de temperatura-humedad (ITH). Los indicadores de estrés calórico mostraron una interacción significativa (P<0.001) entre tratamiento y tiempo/semana, los cuales fueron menores con EA (-3.8 respiraciones por minuto y -0.2 °C) sólo durante las semanas 6 y 7. Los niveles séricos de PRL fueron mayores bajo enfriamiento adicional (EA: 35.1 vs E: 29.4 ng/ml; P=0.004), mientras que los de IGF1 solo variaron a través de las semanas de muestreo (P=0.014). La PL se incrementó (P<0.05) en EA durante las semanas 6 (+3.1kg/día) y 7 (+3.1 kg/día). Se concluye que la mayor frecuencia de baños mitigó la condición de estrés calórico al inicio de verano, permitiéndole a la vaca expresar un mejor desempeño productivo al final del estudio, ya que dicho efecto dependió de la variable tiempo/semana

Tecnologias moleculares ômicas aplicadas ao estudo do estresse calórico em bovinos.

The ability to tolerate extreme heat has been proposed as an important selection criterion to promote the breeding of thermo-tolerant animals, especially in climates characterized by environmental heat stress during most of the year. Novel genomic technologies are available to study genetic bases supporting the thermo-tolerance in cattle, among which are: Genome-wide association studies, validation of markers and candidate genes, RNA sequencing and transcriptome analysis. These technologies currently allow faster progress in the identification of thermotolerant cattle, which is highly relevant from the perspective of the current problems as global warming and food security. So, the objective of this review is to analyze the current status of the use of omics technologies in animal production studies under heat stress.La habilidad para tolerar el calor extremo ha sido propuesta como un importante criterio de selección para promover la cría de animales termo-tolerantes, sobre todo en climas caracterizados por estrés térmico ambiental gran parte del año. Novedosas tecnologías genómicas están disponibles para estudiar las bases genéticas que sustentan la termo-tolerancia del ganado, entre las que se encuentran: estudios asociativos del genoma completo, validación de marcadores y genes candidatos, la secuenciación de ARN y análisis de transcriptomas. Estas tecnologías actualmente permiten avanzar más rápido en la identificación de ganado termotolerante, lo cual tiene gran relevancia desde la perspectiva del problema del calentamiento global y la seguridad alimentaria. El objetivo de esta revisión es analizar el estado actual del uso de las tecnologías ómicas en estudios de producción animal bajo estrés por calor.&nbsp;&nbsp; &nbsp;&nbsp;A capacidade de tolerar calor extremo tem sido proposta como um importante critério de seleção para promover a reprodução de animais termotolerantes, principalmente em climas caracterizados por estresse térmico ambiental durante grande parte do ano. Novas tecnologias genômicas estão disponíveis para estudar as bases genéticas que suportam a termotolerância do gado, entre as quais: estudos associativos de todo o genoma, validação de marcadores e genes candidatos, sequenciamento de RNA e análise do transcriptoma. Atualmente, essas tecnologias permitem avanços mais rápidos na identificação de bovinos termotolerantes, o que é altamente relevante do ponto de vista do problema do aquecimento global e da segurança alimentar. O objetivo desta revisão é analisar o estado atual do uso de tecnologias ômicas em estudos de produção animal sob estresse térmico

Blood Transcriptomic Analyses Reveal Functional Pathways Associated with Thermotolerance in Pregnant Ewes Exposed to Environmental Heat Stress

Environmental heat stress triggers a series of compensatory mechanisms in sheep that are dependent on their genetic regulation of thermotolerance. Our objective was to identify genes and regulatory pathways associated with thermotolerance in ewes exposed to heat stress. We performed next-generation RNA sequencing on blood collected from 16 pregnant ewes, which were grouped as tolerant and non-tolerant to heat stress according to a physiological indicator. Additional samples were collected to measure complete blood count. A total of 358 differentially expressed genes were identified after applying selection criteria. Gene expression analysis detected 46 GO terms and 52 KEGG functional pathways. The top-three signaling pathways were p53, RIG-I-like receptor and FoxO, which suggested gene participation in biological processes such as apoptosis, cell signaling and immune response to external stressors. Network analysis revealed ATM, ISG15, IRF7, MDM4, DHX58 and TGFβR1 as over-expressed genes with high regulatory potential. A co-expression network involving the immune-related genes ISG15, IRF7 and DXH58 was detected in lymphocytes and monocytes, which was consistent with hematological findings. In conclusion, transcriptomic analysis revealed a non-viral immune mechanism involving apoptosis, which is induced by external stressors and appears to play an important role in the molecular regulation of heat stress tolerance in ewes

Estudios anatómico patológicos, serológicos e histopatológicos de perros positivos a Coccidioidomicosis infectados naturalmente

Coccidioidomycosis, classified as such as a saprozoonosis disease, which is produced by Coccidioides spp. So far this ailment just had been categorized in two strains C. immitis and C. posadassi. The disease had frequently been associated to dried environments and alkaline soils, where, after rain, fungus spread arthroconidea. The aim of this research was to study the pathological aspects found at necropsy, the serological presence and the spherules existence of the Coccidioides spp. microscopically in naturally infected dogs. From 90 tested animals, serology showed 78.88% positives using Particles agglutination Latex (PAL), and just 21.12% animals were serum-negatives. At necropsy, there were just 25% animals with suggested lesions to the disease in one or more organs, while 75% animals did not show affected organs. Cachexia, cough and limp were significant sources of variation (P 0.05). PAL was poorly correlated with affected organs at necropsy and with spherule presence at histopathology (Kappa= 0.1047, p 0.05). PAL está pobremente correlacionada con la aparición de lesiones en órganos durante la necropsia y a la presencia de esférula en la histopatología (Kappa= 0.1079, p>0.05). De los 22 animales afectados, el 100% presentó lesiones pulmonares y el 77.27 % en hueso. La histopatología reveló el 25% (22 casos) presentaron la esférula de Coccidioides spp., y el 75% (66 casos) sin lesión. La correlación entre las lesiones sugestivas a Coccidioidomicosis y la presencia de esférulas de Coccidioides spp. es alta (Kappa= 1, p>0.001). Es recomendable realizar estudios de concordancia de estos animales positivos a serología con el uso de una técnica más sensible como la reacción en cadena de la polimerasa (PCR)

Identificación de un polimorfismo del gen PAPP-A2 asociado a la fertilidad en vaquillas Romosinuano criadas en subtrópico

The objective was to identify single nucleotide polymorphisms (SNP) associated to fertility in cows raised under a subtropical environment. Re-sequencing of nine genes associated to GH-IGF endocrine pathway, which are located in bovine chromosomes 5, 16 and 20, identified 73 SNP useful for associative genetic studies, however, only seven resulted as polymorphic and unique to the Romosinuano breed. Then, DNA samples were extracted from 129 beef heifers and used to determine genotypes corresponding to each SNP. Mixed model analysis identified one SNP from the PAPP-A2 gene (C/T, rs110490898) as predictor (PEl objetivo fue identificar polimorfismos de un solo nucleótido (SNP) asociados a la fertilidad en hembras bovinas criadas en subtropico. La re-secuenciación de nueve genes relacionados al eje endocrino GH-IGF, localizados en los cromosomas 5, 16 y 20 del bovino, identificó 73 SNP útiles para estudios genéticos asociativos, sin embargo, sólo siete resultaron polimórficos y exclusivos de la raza Romosinuano. Muestras de ADN se extrajeron de 129 vaquillas Romosinuano y usadas para determinar los genotipos correspondientes a cada SNP. Un análisis de modelos mixtos identificó únicamente a un polimorfismo del gen PAPP-A2 (C/T, rs110490898) como predictor (

Detección de Escherichia coli productora de toxina-Shiga en bovinos asintomáticos del sur de Sonora, México

Abstract The breeding and fattening of cattle are necessary for the production of meat; in Mexico it is an essential activity. Cattle is an asymptomatic carrier of Shiga toxinproducing Escherichia coli (STEC), and they are considered the main reservoir and super-shedder of serotype O157: H7. The aim of this work was to identify the STEC O157: H7 serotype in asymptomatic cattle raised in southern Sonora, Mexico, using multiplex PCR in order to understand of its propagation capacity. The incidence of serotype O157:H7 was 3.1% and STEC non-O157 was 19.8%. These results suggest cattle as a primary reservoir of STEC in this region of the country; nonetheless, studies are still needed to establish whether excreted strains contaminate the food, environment and/or water streams.Resumen La crianza de ganado bovino es vital para la producción de carne, que en México es una actividad esencial. El bovino es portador asintomático de Escherichia coli productora de toxina Shiga (STEC), y son considerados el principal reservorio y súper propagadores del serotipo O157:H7. Este representa el primer reporte sobre STEC O157:H7 detectada en heces de bovinos asintomáticos, criados para abasto de carne en el noroeste de México. El objetivo fue identificar el serotipo STEC O157:H7 en bovinos asintomáticos criados en el sur de Sonora, México empleando PCR multiplex para con ello avanzar en el entendimiento de su capacidad propagadora. La incidencia de la STEC O157:H7 fue del 3.1% y de STEC no O157 de 19.8%. Estos resultados sugieren que el ganado bovino es un reservorio primario de STEC en esta región del país; sin embargo, es necesario profundizar para establecer si el patógeno contamina otras matrices como agua o alimentos