Ana González

Prediction of carcass composition, ham and foreleg weights, and lean meat yields of Iberian pigs using ultrasound measurements in live animals.

The most valuable lean cuts from Iberian pigs are the hams, forelegs, and loins, which yield high quality cured meat products. This study aimed to assess the correlation between body composition measurements taken in vivo by ultrasonography in Iberian pigs and those taken on the carcass, which were then used to develop predictive models to estimate the weight and yield of these cuts. Before slaughter, 241 Iberian pigs were weighed (slaughter BW) and ultrasonically scanned. Ultrasound images were collected at 3 locations: the 10th intercostal space, caudal to the last rib to image the loin muscle, and the rear gluteal region [ultrasound gluteal backfat (u-GBF)]. After slaughter, the weight of the carcass (CW), ham (HW), foreleg (FW), and loin (LW) were determined, and the sum of these lean cuts weights (CLPW) and the corresponding yields were calculated. A portion of loin with the associated bones, backfat, and skin was obtained by cutting the carcass between the 10th and last ribs and was used to measure, at the 10th (10) and last (14) rib locations, the total backfat thickness, the area of the loin muscle (c-LA), and the thickness of the 4 backfat (BF) layers, namely, the outer (c-OBF), middle (c-MBF), outer plus middle (c-OMBF), and the inner (c-IBF). Finally, intramuscular fat percentages (IMF) were obtained from the meat samples. Corresponding measurements from the ultrasound (u) images were similarly taken at the same 2 ribs (u-BF, u-LA, u-OBF, u-MBF, u-OMBF, and u-IBF). The correlation was greatest between u-MBF10 and c-MBF10 (0.84). Most correlations between ultrasound and carcass measurements were lower at the last rib than at 10th rib. The greatest correlation of IMF10 occurred with u-IBF10 (0.40). Ham weight and HL were more correlated with u-BF10 than with u-BF14 whereas FW was more correlated with u-BF14. The u-LA was more correlated with HW, FW, and LW at the last rib than at the 10th rib. Slaughter live weight accounted for 0.84, 0.42, 0.36, and 0.54% of the variation for the prediction of CW, HW, FW, and CLPW, respectively. The u-LA10 and u-LA14 increased the variation explained by the model up to 0.89, 0.48, 0.39, and 0.62% for CW, HW, FW, and CLPW, respectively. Including u-GBF in the models also increased the R(2) values for predicting HW, LW, HY (ham yield), and LY (loin yield). In conclusion, u-LA10, u-LA14, and u-GBF may improve weight of commercial cuts and yield prediction in live Iberian pigs.

Use of Morphometric Variables for Differentiating Spanish Hound Breeds

El termino Podencos se refiere a un grupo de razas de perros originarios de Espana y clasificados en el grupo 5 de razas caninas por la Federacion Cinologica Internacional (FCI). El objetivo del presente trabajo fue comparar caracteristicas morfometricas de las razas caninas de Podencos; Canario, Ibecenco, Andaluz (pequeno, medio y grande) y Orito. Se midieron diez variables morfometricas en 385 animales (245 hembras y 140 machos); longitud de la cabeza, la longitud hocico, altura a la cruz, alzada a la grupa, la longitud del cuerpo, ancho de la cabeza, ancho de la grupa, la profundidad del pecho, la circunferencia del pecho y la circunferencia de la cana. Las variables morfoestructurales fueron mas homogeneas en el Podenco Ibicenco y el Podenco Canario, porque por muchos anos fueron fijados gradualmente los rasgos distintivos para los estandares de cada raza. El analisis discriminante manifesto diferencias morfoestructurales entre todas las razas, lo que se refleja en la significativa distancia de Mahalanobis, y confirmo que el podenco Orito puede ser aceptado como una poblacion de perros diferentes.

Effects of stress by unfamiliar sounds on carcass and meat traits in bulls from three continental beef cattle breeds at different ageing times

One-hundred-and-twenty-four young bulls of three Continental beef cattle breeds were used to study the effect of pre-slaughter stress by unfamiliar sounds on carcass traits and quality characteristics of beef aged for three different periods. Stress due to unfamiliar noises had a moderately negative effect on carcass and meat quality. Carcasses from group Stressed had higher (P<0.05) values of pH0, pH24, a*, and Warner-Bratzler shear force, and lower (P<0.05) values of L*, b* and pressure losses than from Unstressed animals. There were significant differences (P<0.05) among breeds in L*, a* and pressure losses. The ageing time had a significant effect on chromatic variables, WBSF and pressure losses. The cooking losses were not significantly affected by any of the three factors discussed. These results emphasize the importance of implementing appropriate management practices during pre-slaughter handling of cattle in order to reduce any possible risk factor for stress, as well as the different sensitivity of the breeds to similar stimuli.

Conservation of Endangered Spanish Cattle Breeds Using Markers of Candidate Genes for Meat Quality

The aim was to analyze the allelic and genotypic frequencies for two genes associated with tenderness of meat (CAPN1 and CAST) and one with fat deposits (DGAT1) in three endangered Spanish cattle breeds: Berrenda en Colorado (BC), Berrenda en Negro (BN), and Cardena Andaluza (CA) to utility of their involvement in the selection of them and to help the adoption of conservation measurement. Seventy-five males and 298 females of those breeds were genotyped. Genotypic and allelic frequencies for each polymorphic locus were estimated. There were significant differences in the genotypic frequencies among breeds in CAPN1 and DGTA1 genes and in the case of the genic frequencies in CAPN1, CAST, and DGAT1 genes. The three breeds analyzed (BC, BN, and CA) presented high allelic frequencies for the favorable allele of the three markers (from 0.41 to 0.75). The association between the favorable allele and meat quality must be confirmed. In cases of association with differences in quality meat, the absence of differences in the genotypic and genic frequency distributions between the sexes is advantageous in mating planning because it implies that there is no handicap to be overcome for the conservation program and it would allow the use of sires to promote the increase in improvements within a short period of time.

Identificación de los polimorfismos G1 y G8 del gen GDF9 en ovinos criollos Araucanos

SUMMARY Polymorphisms in major gene effect related to reproductive activity have been described in sheep. Mutations located in the GDF9 gene have been associated with increased ovulation rate and litter size. GDF9 factor is secreted by the oocyte and is a member of the family of transforming growth factors (TGF-β) located on chromosome 5. The aim of this study was to identify the presence of polymorphic regions (G1 and G8) in the GDF9 gene in Araucano creole sheep. DNA was extracted from 100 blood samples and the presence of mutations was determinated using PCR-RFLP. Two regions were amplified, one corresponding to exon 1 of 462 bp digested with restriction enzyme HhaI and a 139bp fragment corresponding to exon 2 digested with enzyme DdeI. The presence of polymorphisms in G1 of GDF9 gene were detected with a genotype frequency of 0.56 (genotype GG), 0.44 (genotype GA) and an allele frequency of 0.78 for the allele (G) and 0.22 for the allele (A). No polymorphisms were detected in G8. This is the first report of this polymorphism in sheep in Chile that could serve as a genetic marker for marker for prolificacy selection in the the Araucano creole sheep.

Proteomics Analysis of Plant Tissues Based on Two-Dimensional Gel Electrophoresis

Proteomics, either considered as being a scientific discipline or a methodological approach, will be presented from a historical perspective, as the heir of the classical protein chemistry or biochemistry. In the last 20 years, classical techniques for protein extraction and resolution such as electrophoresis and liquid chromatography have been continuously improved and implemented with those of mass spectrometry, gene sequencing, and bioinformatics tools, providing a new horizon in molecular biology research, and revealing the never-before imagined complexity of the protein world. The application of proteomics to plant biology research will be briefly discussed, focusing on descriptive and comparative studies and on two-dimensional electrophoresis-based platforms. There will be sections devoted to the different steps in a standard proteomics workflow: protein extraction, fractionation, electrophoresis, mass spectrometry, and data analysis. As each technique and protocol has to be adapted and optimized to the experimental system under investigation, rather than providing specific detailed protocols, general guidelines are presented, with reference to previous original publications and reviews from the author’s group and the current relevant literature. More than to scientists with real expertise in proteomics, this chapter is dedicated to plant physiologists, who aim to enter the field.