ABSTRACT
The productivity of smallholder dairy farms is very low in developing countries. Important genetic gains could be realized using genomic selection, but genetic evaluations need to be tailored for lack of pedigree information and very small farm sizes. To accommodate this situation, we propose a flexible Bayesian model for the genetic evaluation of milk yield, which allows us to simultaneously account for nongenetic random effects for farms and varying SNP variance (BayesR model). First, we used simulations based on real genotype data from Indian crossbred dairy cattle to demonstrate that the proposed model can separate the true genetic and nongenetic parameters even for small farm sizes (2 cows on average) although with high standard errors in scenarios with low heritability. The accuracy of genomic genetic evaluation increased until farm size was approximately 5. We then applied the model to real data from 4,655 crossbred cows with 106,109 monthly test day milk records and 689,750 autosomal SNPs. We estimated a heritability of 0.16 (0.04) for milk yield and using cross-validation, a genomic estimated breeding value (GEBV) accuracy of 0.45 and bias (regression of phenotype on GEBV) of 1.04 (0.26). Estimated genetic parameters were very similar using BayesR, BayesC, and genomic BLUP approaches. Candidate genes near the top variants, IMMP2L and ARHGEF2, have been previously associated with milk protein composition, mastitis resistance, and milk cholesterol content. The estimated heritability and GEBV accuracy for milk yield are much lower than those from intensive or pasture-based systems in many countries. Further increases in the number of phenotyped and genotyped animals in farms with at least 2 cows (preferably 3-5, to allow for dropout of cows) are needed to improve the estimation of genetic effects in these smallholder dairy farms.
Subject(s)
Milk , Models, Genetic , Female , Cattle/genetics , Animals , Farms , Bayes Theorem , Milk/metabolism , Genotype , Phenotype , Lactation/geneticsABSTRACT
Salamanca is the centre of a large industrial complex associated with the production and refining of oil-derived products in the state of Guanajuato, Mexico. The city also hosts a large chemical industry, and in past years a major fertilizer industry. All of them followed NORM (naturally occurring radioactive materials) industrial activities, where either raw materials or residues enriched in natural radionuclides are handled or generated, which can have an environmental radiological impact on their environmental compartments (e.g. soils and aquatic systems). In this study, activity concentrations of radionuclides from the 238U and 232Th natural series present in superficial urban soils surrounding an industrial complex in Salamanca, México, have been determined to analyse the possible environmental radiological impact of some of the industrial activities. The alpha-particle and gamma-ray spectrometry is used for the radiometric characterization. The results revealed the presence of 10-42, 11-51 and 178-811Bq/kg of 238U, 232Th and 40K, respectively, without any clear anthropogenic increment in relation to the values normally found in unaffected soils. Thus, the radioactive impact of the industrial activities on the surrounding soils can be evaluated as very low, representing no radiological risk for the health of the population.
Subject(s)
Background Radiation , Environment , Industrial Waste/analysis , Radiation Monitoring/methods , Radioactive Waste/analysis , Radioisotopes/analysis , Soil Pollutants, Radioactive/analysis , Mexico , Radioisotopes/chemistry , Reproducibility of Results , Sensitivity and Specificity , Soil Pollutants, Radioactive/chemistryABSTRACT
Se determina la prevalencia de Dematofitos y Cándida en región podal sana mediante un estudio micológico en 313 personas sin lesiones dérmicas de la Provincia de Lima-Perú. Las muestras de piel se sembraron en Agar Sabouraud Glucosado más Antibiótico, incubándose a 26 grados centigrados por 20 días. Se demostró que 129 personas (41.2 por ciento) presentaron infección por Dermatofitos o Cándida. De ellos, 5 (1.91 por ciento) presentaron infección mixta. Se observó mayor colonización en el sexo Masculino (62.69 por ciento), en el grupo etáreo de 21-30 años (31.00 por ciento) y en el grupo ocupacional de Estudiantes (52.99 por ciento). Un alto porcentaje (84.50 por ciento) de los colonizados habita en viviendas que tienen ducha. Los hongos aislados por orden de frecuencia fueron: T. mentagrophytes (38.06 por ciento), C. albicans (35.82 por ciento), otras especies de Cándida (14.92 por ciento), T. rubrum (6.71 por ciento), T. tonsurans (1.5 por ciento), E. Hoccosum (1.5 por ciento), M. canis (0.75 por ciento) y M. gypseum (0.75 por ciento). Se discute la implicancia epidemiológica de los resultados.