This study aimed to genetically evaluate part of the breeding population of guinea pigs, Peru genotype, of the Experimental Station of Instituto Nacional de Innovación Agraria, Ayacucho, Peru, for two parameters: body weight at slaughter (WL) and growth rate (SG). Productive data of of the animals and their family members were collected (n=162 animals), plus environmental factors such as sex, type of birth, month of birth and parturition weight of the mother. The statistical significance on the studied variables was conducted by a fixed effects model. The estimation of breeding values of the offspring wad done by the animal model-BLUP unicharacter. The model included fixed effects that had statistical significance plus the derivative random effects of animal genetic factors. The components of (co) variance included in the model and computational algorithms were solved using the software...

The present study was carried out in the E.E.A. Canaan from INIA (Ayacucho, Peru) with the objective of estimating the individual heterosis in F1 guinea pigs from the crosses between the genotypes Peru (P), Andean (A) and Inti (I) for the characteristics of weight at slaughtering, growth, carcass yield, fat deposition and feed conversion. Information was obtained from 115 descendants between pure lines and crosses of the genotypes PxA, AxP and PxI, being reared as contemporary groups throughout the rearing phase. The incidence of the fixed effects of litter size, sex of the offspring and number of parturition of the mother on the variables under study was analysed through a model of fixed effects, estimating correction factors by least squares for those that had significant incidence (p<0.05). The individual heterosis was estimated as the deviation of the mean of the reciprocal cross ...

The aim of this study was to identify, serotype and determine the sensitivity profile of Salmonella enterica strains isolated from red-eared slider turtles (Trachemys sp) from two breeding centres in Lima, Peru, through cloacal swabs. The samples were isolated using tetrathionate enrichment broth, specific media such as Salmonella-Shigella agar and xylose lysine deoxycholate agar. The identification was made through biochemical tests. Serotyping through the recognition of somatic (O) and flagellar (H) antigens of the Kauffmann-White system, and the determination of sensitivity using the Kirby Bauer diffusion disk test. The results showed that 6.1% (4/66) of Salmonella enterica isolates were obtained, identifying the serotypes Salmonella Saintpaul and Salmonella Infantis. Antibacterial sensitivity tests indicated differences between strains, showing 100% sensitivity against nalidixic acid...

The present study aimed to determine the contribution of the genetic effect of bulls used via artificial insemination on the dairy production of Brown Swiss cows from the El Mantaro Agricultural Experiment Station of the National University of Central Peru, in terms of daily milk production (PLD) and by lactation (PLC). In total, 112 lactations were used, from a total of 49 cows, daughters of 7 Brown Swiss bulls, standardized to 305 days (PLE) and two milking by non-linear projection. The statistical analysis was carried out by using a mixed linear model, considering as fixed factors the number of lactations, year, season and age at calving of the cow, and as a random factor the genetic effect of the bull. Corrected phenotypic means were obtained for PLD and PLC with the correction factors obtained from the model, and predictions of the predicted transmission ability (PTA) of the evaluat...

El presente estudio tuvo por objetivo la evaluación genética de parte de los animales del plantel de cuyes reproductores de genotipo Perú pertenecientes a la Estación Experimental Agraria Canaán del Instituto Nacional de Innovación Agraria de Ayacucho, Perú, para características de peso vivo al beneficio (PB) y velocidad de crecimiento (VC). Se empleó la información productiva y de parentesco de 162 cuyes, además del sexo, tipo de parto, mes de nacimiento y peso de la madre al parto, cuyo análisis de incidencia sobre las variables estudiadas se efectuó mediante un modelo de efectos fijos. La estimación de los valores de cría se realizó a través de un modelo animal-BLUP unicarácter, el cual incluyó como efectos fijos a aquellos factores ambientales sistemáticos de incidencia significativa, además de los efectos aleatorios derivados de los factores genéticos de los an...

El estudio se realizó en la E.E.A. Canaán del INIA (Ayacucho, Perú) con el objetivo de estimar la heterosis individual en cuyes F1 de cruces entre los genotipos Perú, Andina e Inti para las características de peso al beneficio, velocidad de crecimiento, rendimiento de carcasa, grasa de deposición y conversión alimenticia. Se obtuvo información de 115 descendientes entre puros y cruces de los genotipos Perú x Andina, Andina x Perú y Perú x Inti, siendo criados como grupos contemporáneo durante la fase de recría. La incidencia de los efectos fijos de tamaño de camada, sexo de la cría y número de parto de la madre sobre las variables en estudio fue analizada a través de un modelo de efectos, estimándose factores de corrección por mínimos cuadrados para aquellos efectos fijos que tuvieron incidencia significativa (p<0.05). La heterosis fue estimada como el desvío del ...

The aim of this study was to identify, serotype and determine the sensitivity profile of Salmonella enterica strains isolated from red-eared slider turtles (Trachemys sp) from two breeding centres in Lima, Peru, through cloacal swabs. The samples were isolated using tetrathionate enrichment broth, specific media such as Salmonella-Shigella agar and xylose lysine deoxycholate agar. The identification was made through biochemical tests. Serotyping through the recognition of somatic (O) and flagellar (H) antigens of the Kauffmann-White system, and the determination of sensitivity using the Kirby Bauer diffusion disk test. The results showed that 6.1% (4/66) of Salmonella enterica isolates were obtained, identifying the serotypes Salmonella Saintpaul and Salmonella Infantis. Antibacterial sensitivity tests indicated differences between strains, showing 100% sensitivity against nalidixic acid...

El estudio se realizó en la E.E.A. Canaán del INIA (Ayacucho, Perú) con el objetivo de estimar la heterosis individual en cuyes F1 de cruces entre los genotipos Perú, Andina e Inti para las características de peso al beneficio, velocidad de crecimiento, rendimiento de carcasa, grasa de deposición y conversión alimenticia. Se obtuvo información de 115 descendientes entre puros y cruces de los genotipos Perú x Andina, Andina x Perú y Perú x Inti, siendo criados como grupos contemporáneo durante la fase de recría. La incidencia de los efectos fijos de tamaño de camada, sexo de la cría y número de parto de la madre sobre las variables en estudio fue analizada a través de un modelo de efectos, estimándose factores de corrección por mínimos cuadrados para aquellos efectos fijos que tuvieron incidencia significativa (p<0.05). La heterosis fue estimada como el desvío del pro...

El presente estudio tuvo por objetivo la evaluación genética de parte de los animales del plantel de cuyes reproductores de genotipo Perú pertenecientes a la Estación Experimental Agraria Canaán - Ayacucho del Instituto Nacional de Innovación Agraria, Perú, para características de peso vivo al beneficio (PB) y velocidad de crecimiento (VC). Se empleó la información productiva y de parentesco de 162 cuyes, además del sexo, tipo de parto, mes de nacimiento y peso de la madre al parto, cuyo análisis de incidencia sobre las variables estudiadas se efectuó mediante un modelo de efectos fijos. La estimación de los valores de cría se realizó a través de un modelo animal-BLUP unicarácter, el cual incluyó como efectos fijos a aquellos factores ambientales sistemáticos de incidencia significativa, además de los efectos aleatorios derivados de los factores genéticos de los ani...

The aim of this study was to evaluate the influence of the age of bulls at grazing on their diurnal behaviour in Setaria sphacelata meadows. The forage variables were the availability and nutritive value of the diet, and the animal variables were body weight, size and frequency of bites, and diurnal behaviour. Four Brown Swiss x zebu crossed bulls with an initial live weight of 285.8 ± 18.1 kg that grazed in an area of 29 ha (11 paddocks) were selected from a group of 36 bulls. The evaluations were done when the animals reached the ages of 12 (T1), 15 (T2) and 18 (T3) months. A randomized complete block design was used. Forage availability showed differences (p<0.05) between treatments; however, the forage allocation and the nutritional quality of the diet did not compromise their performance. Bite weight was higher in T3 (0.87 ± 0.22 g per bite; p<0.05), but without differences ...

Antibiotic resistance is increasing worldwide, being of special concern in low- and middle-income countries. The aim of this study was to determine the antimicrobial susceptibility and mechanisms of resistance in 205 enterotoxigenic Escherichia coli (ETEC) isolates from two cohort studies in children <24 months in Lima, Peru.