Search results for "SHEEP BREED"

Analysis of acetyl-CoA carboxylase gene polymorphisms in Valle del Belice dairy breeds

2015

Acetyl-CoA carboxylase is the flux-determining enzyme in the regulation of fatty acid synthesis within animal tissues. The expression of the mammary gland isoform of this enzyme, during lactation, is regulated by the acetyl-CoA carboxylase-α (ACACA) gene. The ovine ACACA gene, with 51 coding exons, is responsible for phenotypic variability observed in milk fat content and milk fatty acids (FAs) composition. However, before attempting association analyses between this enzyme and phenotypic traits of interest, a study on the genetic variability within this locus is required. The aim of this work was to sequence the encoding region of ACACA gene in Valle del Belice dairy ewes in order to ident…

Genetic diversity and phylogenetic relationships among four breeds reared in Sicily using β-lactoglobulin promoter region polymorphisms

2011

The aim of this work was to analyze the genetic diversity and the phylogenetic relationships among the Valle del Belice (VDB) breed and the other sheep breeds considered as ancestors, using -lactoglobulin (BLG) promoter region polymorphisms. The BLG promoter region of 50 randomly chosen animals from the four breeds (VDB n=20; Comisana (COM) n=10; Pinzirita (PIN) n=10; Sarda (SAR) n=10) were sequenced and aligned, and results showed the presence of 36 single nucleotide polymorphisms (SNPs) and one deletion. The number of polymorphic sites identified showed high variability within breeds. Nucleotide (π) and haplotype (Hd) diversity were estimated with DnaSP software, whereas PHASE software w…

Selection signatures of fat tail in sheep

2017

The investigation of the genes with a role in lipid metabolism enjoy considerable scientific and commercial interest because of the strong correlations between fat deposition and the risk of cardiovascular disease. The fat tail characteristic of sheep is the adaptive response to harsh environment, and beyond representing a valuable energy reserve for facing future climate changes provides clues for elucidating the physiology of fat deposition. Studies on various sheep populations detected fat-tail signatures on chromosomes 2, 3, 5, 6, 7 and 13. Fat-tailed sheep represent about 25% of the world’s sheep population, and the genes with a role in this phenotype are likely not the same for every …

Genetic diversity and population structure of Sicilian sheep breeds using microsatellite markers

2012

Abstract Genetic diversity studies in domestic animals aim at evaluating genetic variation within and across breeds mainly for conservation purposes. In Sicily, dairy sheep production represents an important resource for hilly and mountain areas economy. Their milk is used for the production of traditional raw milk cheeses, sometimes protected designation of origin (PDO) cheeses. In some cases, the quality of these products is linked to a specific breed, i.e. mono-breed labelled cheeses and it is therefore important to be able to distinguish the milk of a breed from that of others, in order to guarantee both the consumer and the breed itself. In order to investigate the genetic structure an…

Relationship between beta lactoglobulin and subclinical mastitis in Valle del Belice sheep breed

2010

The objective of the following research was to determine the effect of LGB genotypes on subclinical mastitis in Valle del Belice dairy sheep. Ewes were classified as affected or not by subclinical mastitis within a lactation based on i) a positive culture in one of the test-days and ii) more than 750,000 somatic cells. Generalized linear mixed models were fitted to assess the significance of LGB genotypes on MTB and MTC. The LGB genotypes significantly affected MTB (p=0.0387), and showed a tendency on MTC (p=0.1104). Least square means showed that in the analysis for MTB, individuals with genotypes BB and AB had a higher frequency of subclinical mastitis. Moreover, the least square differen…

OPERATIONAL STRATEGIES FOR IMPROVING THE COMPETITIVENESS OF THE VALLE DEL BELÌCE SHEEP BREED

2021

A Combined Multi-Cohort Approach Reveals Novel and Known Genome-Wide Selection Signatures for Wool Traits in Merino and Merino-Derived Sheep Breeds.

2019

Merino sheep represents a valuable genetic resource worldwide. In this study, we investigated selection signatures in Merino (and Merino-derived) sheep breeds using genome-wide SNP data and two different approaches: a classical F-ST-outlier method and an approach based on the analysis of local ancestry in admixed populations. In order to capture the most reliable signals, we adopted a combined, multi-cohort approach. In particular, scenarios involving four Merino breeds (Spanish Merino, Australian Merino, Chinese Merino, and Sopravissana) were tested via the local ancestry approach, while nine pair-wise breed comparisons contrasting the above breeds, as well as the Gentile di Puglia breed, …

Investigation of coat colour affecting genes in several sheep breeds

2009

Polymorphisms at β-defensin genes and mastitis in Valle del Belice dairy sheep: a case control study

2015

Mastitis is the most common and costly pathology affecting dairy animals. The identification of genetic markers that allow the inclusion of mastitis resistance in selection programs would help to reduce the costs due to the disease and the use of antibiotics. In recent years, β-defensin genes have been studied in several domestic species due to their important role in the innate immune response. The aim of this study was to determine whether β-defensin genes variability, β-defensin 1 (SBD1) and β-defensin 2 (SBD2), could distinguish between infected cases and healthy controls in Valle del Belice dairy sheep. Somatic cell count (SCC) is a powerful tool to identify animals with intramammary i…