Ernestina Gutiérrez-Vázquez

Evaluation of DNA extraction methods of rumen microbial populations.

The dynamism of microbial populations in the rumen has been studied with molecular methods that analyze single nucleotide polymorphisms of ribosomal RNA gene fragments (rDNA). Therefore DNA of good quality is needed for this kind of analysis. In this work we report the evaluation of four DNA extraction protocols (mechanical lysis or chemical lysis with CTAB, ethylxanthogenate or DNAzol®) from ruminal fluid. The suitability of two of these protocols (mechanical lysis and DNAzol®) was tested on single-strand conformation polymorphism (SSCP) of rDNA of rumen microbial populations. DNAzol® was a simple method that rendered good integrity, yield and purity. With this method, subtle changes in protozoan populations were detected in young bulls fed with slightly different formulations of a supplement of multinutritional blocks of molasses and urea. Sequences related to Eudiplodinium maggi and a non-cultured Entodiniomorphid similar to Entodinium caudatum, were related to major fluctuating populations in an SSCP assay.

Effect of diet on live weight and egg weight of backyard hens during the rainy season

espanolRESUMEN: El objetivo del estudio fue determinar el efecto de la dieta sobre el peso vivo (PV) y peso del huevo (Phvo) de las gallinas de traspatio (GT) durante la epoca de lluvias en la region Bajio del estado de Michoacan, Mexico. Se muestrearon 17 municipios, en donde se capturaron y se pesaron 101 GT (seis/municipio) y se recolectaron y pesaron 101 huevos (seis/municipio). Se extrajeron, postsacrificio, los buches de las gallinas capturadas, cuyo contenido organico/buche (COB) fue clasificado y pesado por componentes, para posteriormente realizar el analisis bromatologico. La informacion se analizo mediante modelos lineales generalizados y las diferencias entre municipios se obtuvieron por la metodologia de medias de minimos cuadrados. El peso del COB (36,4 ± 22,4 g) fue afectado por el municipio (P0,05). En COB se encontro: alimento comercial (8,1 ± 6,0 g), granos: maiz y sorgo (13,9 ± 13,5 g), desperdicios de cocina (1,5 ± 2,9 g), herbaceas (0,6 ± 0,9 g) e insectos (0,3 ± 0,7 g). De acuerdo con el componente alimento comercial (AC) se identificaron dos sistemas de alimentacion (SA): SA tradicional, sin AC y SA no tradicional, con AC. Las dietas de ambos SA fueron similares (P>0,05) en composicion nutrimental y no cumplen con los requerimientos nutricionales de estas aves. El PV (1,567 ± 0,316 kg) y el Phvo (51,3 ± 1,0 g) de las GT no pueden ser completamente atribuidos a la dieta consumida durante la epoca de lluvias. EnglishABSTRACT: The objective was to determine the effect of diet on live weight (LW) and egg weight (EW) of backyard hens (BH) during the rainy season in the Bajio region of the state of Michoacan, Mexico. Seventeen municipalities were sampled, where 101 BH (six hens/municipality) were captured and weighed and 101 eggs (six eggs/municipality) were harvested and weighed. The crops of the captured hens were removed Post-sacrifice, the organic content/crop (OCC) was classified and weighed by components, to later perform chemical compositional analysis. Data were analysed using generalised linear models and the differences between municipalities were obtained by the method of least squares means. The weight of the OCC (36.4 ± 22.4 g) was affected by the municipality (P0.05). Commercial feed (8.1 ± 6.0 g), grains: maize and sorghum (13.9 ± 13.5 g) kitchen waste (1.5 ± 2.9 g), herbaceous (0.6 ± 0.9 g) and insects (0.3 ± 0.7 g) were found in the crop. According to the commercial feed (COF) component, two feeding systems (FS) were identified: traditional FS, without COF and nontraditional FS, with COF. The diets of both FS were similar (P>0.05) in nutritional composition and do not meet the nutritional requirements of the hens. The LW (1.567 ± 0.316 kg) and EW (51.3 ± 1.0 g) of the BH cannot be completely attributed to the diet consumed during the rainy season.

Efecto del fenotipo (color de plumaje) sobre el peso del huevo y peso vivo de la gallina de traspatio

The objective of the study was to determine the effect of phenotype on body weight (BW) and egg weight (EW) from the backyard hen (BH) (Gallus gallus domesti...