Resumen El objetivo fue analizar la relación entre el perfil de resistencia a antibióticos y la formación de biofilm de aislados de S. aureus provenientes de mastitis bovina. Se analizaron 30 aislados de S. aureus procedentes de casos de mastitis subclínica en granjas lecheras en sistemas de producción semi-intensivo y de traspatio ubicadas en los estados de Guanajuato y Michoacán, México. Se realizó un antibiograma por el método de difusión en disco Kirbi Bauer. La formación de biofilm se determinó por el método de tinción con cristal violeta. Para la evaluación de genes de resistencia a antibióticos y de formación de biofilm se obtuvo ADN genómico de una colonia para la identificación de los genes: blaZ, mecA, tetK, tetM, gyrA y gyrB, y icaA e icaD. Los resultados mostraron que el 100 % de los aislados fueron resistentes a penicilina y dicloxacilina, seguidos por cefotaxima (86.6 %), ampicilina y cefalotina (83.3 %) y ceftazidima (80.0 %), mientras que se observó un 36.6 % de resistencia a oxacilina. Se identificó que todos los aislados de S. aureus presentaron la capacidad de formar biofilm con un rango del 20 a 98 %. Se observó además que los aislados con una multirresistencia elevada presentaron una mayor formación de biofilm; estableciéndose una correlación positiva significativa. En conclusión, los aislados de S. aureus provenientes de mastitis bovina presentaron elevados niveles de resistencia a antibióticos; así como una importante capacidad formadora de biofilm, demostrando la existencia de una correlación positiva entre estos dos factores.

Abstract The objective was to analyze the relationship between the antibiotic-resistance profile and the biofilm formation of S. aureus isolates from bovine mastitis. Thirty (30) isolates of S. aureus from cases of subclinical mastitis in dairy farms in semi-intensive production and backyard production systems, located in the states of Guanajuato and Michoacán, Mexico, were analyzed. An antibiogram was performed by the Kirbi-Bauer disc-diffusion method. Biofilm formation was determined by the violet crystal staining method. For the evaluation of antibiotic resistance genes and biofilm formation, genomic DNA was obtained from a colony for the identification of the genes: blaZ, mecA, tetK, tetM, gyrA and gyrB, and icaA and icaD. The results showed that 100 % of the isolates were resistant to penicillin and dicloxacillin, followed by cefotaxime (86.6 %), ampicillin and cephalotin (83.3 %) and ceftazidime (80.0 %), while a 36.6 % resistance to oxacillin was observed. It was identified that all isolates of S. aureus had the ability to form biofilm with a range between 20 to 98 %. It was also observed that isolates with a high multi-resistance presented a greater formation of biofilm, establishing a significant positive correlation. In conclusion, S. aureus isolates from bovine mastitis presented high levels of antibiotic resistance; as well as an important biofilm-forming capacity, demonstrating the existence of a positive correlation between these two factors.

Resumen: El objetivo de la investigación fue conocer el comportamiento y la habilidad materna del Cerdo Pelón Mexicano (CPM) mediante el análisis de parámetros reproductivos y productivos desde el parto al destete. Se evaluaron dos ecotipos de CPM provenientes de Huehuetla, Hidalgo (CPH) y de Atlequizayán, Puebla (CPP). Las variables por lechón fueron peso al nacimiento (PN) y peso al destete (PD). En los partos no se registraron distocias, ni muertes y presentaron anidación; el ecotipo CPP presentó el mayor número en los parámetros reproductivo que CPH. Las medias de los PN y PD fueron superiores para los lechones CPH que CPP. El comportamiento materno fue favorable, ya que no se presentaron muertes al nacimiento ni en la lactancia. En los parámetros productivos las hembras del CPP tuvieron camadas ligeramente de mayor tamaño en comparación con las CPH, mientras que los lechones de CPH presentaron un mayor peso.

Abstract: The objective of the research was to know the behavior and maternal ability of the Cerdp Pelon Mexicano (CPM) through the analysis of reproductive and productive parameters from birth to weaning. Two ecotypes of CPM from Huehuetla, Hidalgo (CPH) and from Atlequizayán, Puebla (CPP) were evaluated. The variables per piglet were birth weight (PN) and weaning weight (PD). No dystocia, no deaths were recorded in the deliveries and they presented nesting; the CPP ecotype presented the highest number in reproductive parameters than CPH. The means of the PN and PD were higher for the CPH than CPP piglets. Maternal behavior was favorable, since there were no deaths at birth or in lactation. Regarding the productive parameters, the CPP females had slightly larger litters compared to the CPH, however, the CPH piglets presented a higher weight.

ABSTRACT Records of 3716 Nubian goats from the United States (US) were analyzed to estimate relationships between fourteen conformation traits (CT) with lactation average somatic cell score (ASCS). To analyze ASCS, a mixed model was implemented. Linear and quadratic effects of CT traits, days in milk (DIM), and kidding age in months (KA) were considered as fixed covariates, and herd-year (HY) of kidding as a random effect. Correlation coefficients between CT traits and ASCS adjusted for HY and linear and quadratic KA effects were also obtained. The average ± standard deviations for ASCS, DIM, and milk yield were 5.17±0.54 Log2, equivalent to 451.3 cells × 103/mL, 266.3±52.1 days, and 776.3±280.4 kg per lactation, respectively. Significant non-linear relationships with an intermediate maximum were found between ASCS with teat diameter and medial suspensory ligament, while linear relationships were observed with stature, strength, rump width, fore udder attachment, udder depth, teat diameter, teat placement, and medial suspensory ligament. The model explained 53.7% of the ASCS variability, but the contribution of each type variable to increase the coefficient of determination was low (<0.52%). Herd-year explained a large proportion of the variation of ASCS (38.4%). All estimated correlations between CT and ASCS had low values, from −0.04 to 0.11, but most were significant. The results of this study show that conformation traits have few opportunities to contribute phenotypically to assess somatic cell score in Nubian goats.

Abstract Propolis is a resin gathered by honey bees from trees and shrubs but it used in the beehive as building material or as an antibiotic paste. The aim of this study was to determine the content of flavonoids and phenols, as well as the antioxidant capacity of propolis from various regions of Guanajuato, Mexico. The content of flavonoids and phenols was determined by the aluminum nitrate method and the Folin-Ciocalteu method. The antioxidant capacity was determined using the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH•) method and the ferric reduction of Fe3+ to Fe2+ (FRAP•) assay. The flavonoid content varied from 13 to 379 mg of quercetin equivalents (QE) per g of propolis and the phenolic content ranged from 68 to 500 mg of caffeic acid equivalents (CAE) per g of propolis. The trolox equivalent antioxidant capacity (TEAC) per g of propolis varied from 39.8 to 54.4 for the DPPH• method and from 50 to 2000 for the FRAP• assay. Propolis rich in flavonoids and phenols possesses a low antioxidant capacity. The results show that propolis from different areas of Guanajuato are rich in flavonoids and phenolics compounds while their antioxidant capacity is variable.

Abstract In this work, we use the records from 643 goats in order to evaluate the phenotypic relationships between conformation traits and milk production in goats. Correlations were estimated using data on goats which included fifteen conformation traits and first lactation milk yield adjusted for age, calving month and 305 milking days (MY1). We also compared the average scores for type traits on the goats under study with those on a sample of goats from the United States of America (USA). Correlations between conformation traits and MY1 were estimated and an analysis was performed to evaluate the nonlinear relationships between them. The highest correlations were found between milk production and udder depth (-0.22), stature (0.18) and rear udder side view (0.12) (p < 0.05), non-linear (cubic) effects for stature and strength being significant (p < 0.05). American goats had a better overall conformation than the Mexican ones but results indicated that goats with better body conformation were not the best for milk production.

Resumen Con el objeto de evaluar las relaciones fenotípicas entre características de conformación y la producción de leche en cabras, se utilizó la información de 643 animales. Los datos de las cabras incluyeron quince rasgos de conformación y la producción de leche de la primera lactancia ajustada a edad, mes de parto y 305 días de ordeño (MY1, por sus siglas en inglés). Se compararon también los promedios de las calificaciones de tipo de las cabras de este estudio y de una muestra de cabras de los Estados Unidos de América (USA, por sus siglas en inglés). Se estimaron correlaciones entre las características de conformación con MY1 y se efectuó un análisis para evaluar las relaciones no lineales entre ellas. Las correlaciones más altas fueron entre MY1 y la profundidad de ubre (-0.22), estatura (0.18) y ubre trasera vista de lado (0.12) (p < 0.05) y los efectos no lineales (cúbicos) para estatura y fortaleza resultaron significativos (p < 0.05). Las cabras de USA tuvieron una mejor conformación general que las cabras de México; sin embargo, los resultados indican que las cabras con mejor conformación corporal no fueron las mejores para producir leche.