Search results for "genomica"

Effects of different simplified milk recording methods on genetic evaluation with Test-Day animal model

2007

The aims of the present study were to compare estimated breeding values (EBV) for milk yield using different testing schemes with a test-day animal model and to evaluate the effect of different testing schemes on the ranking of top sheep. Alternative recording schemes that use less information than that currently obtained with a monthly test-day schedule were employed to estimate breeding values. A random regression animal mixed model that used a spline function of days in milk was fitted. EBVs obtained with alternative recording schemes showed different degrees of Spearman correlation with EBVs obtained using the monthly recording scheme. These correlations ranged from 0.77 to 0.92. A redu…

Policy di genomica in Sanità Pubblica: risultati di una survey condotta tra i Chief Medical Officers.

2015

Policy; Genomica in Sanità Pubblica; Survey

Receiver-operating characteristic curves for somatic cell scores and California mastitis test in Valle del Belice dairy sheep.

2013

Using receiver-operating characteristic (ROC) curve methodology this study was designed to assess the diagnostic effectiveness of somatic cell count (SCC) and the California mastitis test (CMT) in Valle del Belice sheep, and to propose and evaluate threshold values for those tests that would optimally discriminate between healthy and infected udders. Milk samples (n = 1357) were collected from 684 sheep in four flocks. The prevalence of infection, as determined by positive bacterial culture was 0.36, 87.7% of which were minor and 12.3% major pathogens. Of the culture negative samples, 83.7% had an SCC < 500,000/mL and 97.4% had <1,000,000 cells/mL. When the associations between SC score (SC…

Connecting the data landscape of long-term ecological studies: the SPI-Birds data hub

2021

The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and eco-logical processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change).

Caratterizzazione genomica delle razze bovine autoctone italiane

2018

Negli ultimi cinquant'anni, a causa della sostituzione con le razze cosmopolite, le razze zootecniche locali hanno subito una forte contrazione numerica. Tuttavia, esse rappresentano un’importante patrimonio, in grado, tra le altre cose, di valorizzare ambienti marginali. Sono spesso legate anche a produzioni tipiche di alta qualità. La loro caratterizzazione rappresenta un passo essenziale verso eventuali piani di recupero, conservazione e valorizzazione. Il presente studio è stato condotto al fine di caratterizzare a livello genomico le razze bovine locali allevate in Italia. Sono stati campionati un totale di 814 animali appartenenti a 30 razze italiane e a 2 razze cosmopolite (Charolais…

La Genetica ... sulle tavole di Ustica

2019

Quale variabile crescente fa in modo che dei gemelli monozigoti, che notoriamente condividono DNA identico, mostrino, dalla nascita alla vecchiaia, sempre maggiori differenze fra loro? Si potrebbe intuitivamente rispondere: il tempo e l’ambiente, o meglio il tempo passato a vivere in un diverso ambiente. Ma fino a qualche decennio fa nessun genetista avrebbe mai ammesso che l’interazione fra il DNA e l’ambiente potesse influenzare l’espressione genica anche non mutando il DNA. Oggi, invece, e ormai da circa 15 anni, è oggetto di studio, l’Epigenetica, secondo la quale possono esistere modificazioni chimiche ed ereditabili del DNA che non scaturiscono da mutazioni della sua sequenza nucleoti…

Genetica

2006

Algoritmica Per Le Scienze Della Vita

2011

Capito dove si esemplifica come l' algoritmica contribuisce a carpire i segreti della Monna Lisa della scienza moderna.

Genetic selection for reduced Somatic Cell Counts in sheep milk: A review

2015

Mastitis is an inflammation of the udder, mainly caused by bacteria, and leads to economic loss, due to discarded milk, reduced milk production, reduced milk quality and increased health costs in both dairy sheep and cattle. Selecting for increased genetic resistance to mastitis can be done directly or indirectly, with the indirect selection corresponding to a prediction of the bacteriological status of the udder based on traits related to the infection. The most frequently used indirect method is currently milk somatic cell count (SCC) or somatic cell score (SCS). This review reports the state of the art relating to the genetic basis of mastitis resistance in sheep and explores the opportu…

Genetic parameters for somatic cell score according to udder infection status in Valle del Belice dairy sheep and impact of imperfect diagnosis of in…

2010

Abstract Background Somatic cell score (SCS) has been promoted as a selection criterion to improve mastitis resistance. However, SCS from healthy and infected animals may be considered as separate traits. Moreover, imperfect sensitivity and specificity could influence animals' classification and impact on estimated variance components. This study was aimed at: (1) estimating the heritability of bacteria negative SCS, bacteria positive SCS, and infection status, (2) estimating phenotypic and genetic correlations between bacteria negative and bacteria positive SCS, and the genetic correlation between bacteria negative SCS and infection status, and (3) evaluating the impact of imperfect diagno…