Search results for "miglioramento genetico"

Economic values for production and functional traits in Valle del Belice dairy sheep using profit functions

2011

Abstract A deterministic static model was used to estimate the economic values (EV) of production (MY, milk yield; BW, birth weight; and ADG, average daily gain) and functional traits (ASR, adult survival rate; LSR, lamb survival rate; FE, fertility; PR, prolificacy; and LW ewe , mature weight of ewe) in Valle del Belice dairy sheep. In this study, values for the biological parameters and the production traits used in the model were taken from real data, by surveying 15 Valle del Belice farmers and reflected the production circumstances of pasture based dairy production systems. In this system feed cost accounted for 95% of total variable costs, whereas fixed costs were low and reflected tr…

In vivo application and dynamics of lactic acid bacteria for the four-season production of Vastedda-like cheese.

2014

article Twelve lactic acid bacteria (LAB), previously selected in vitro (Gaglio et al., 2014), were evaluated in situ for their potential to act as starter cultures for the continuous four-season production of Vastedda-like cheese, made with raw ewes' milk. The strains belonged to Lactobacillus delbrueckii, Lactococcus lactis subsp. cremoris, Leuconostoc mesenteroides subsp. mesenteroides and Streptococcus thermophilus .L AB werefirst inoculated in multiple-strain combinations on the basis of their optimal growth temperatures in three process conditions which differed for milk treatment and medium for strain development: process 1, growth of strains in the optimal synthetic media and pasteu…

Identification, typing, and investigation of the dairy characteristics of lactic acid bacteria isolated from 'Vastedda della valle del Belìce' cheese

2013

Traditional cheeses made without starter cultures can be characterised by the attribute of instability. The addition of autochthonous starter cultures can ensure stability without compromising the characteristics of the final product. This study aimed to characterise the autochthonous lactic acid bacteria (LAB) population in “Vastedda della valle del Belice” cheeses, which have a protected designation of origin (PDO) status, in order to develop an ad hoc starter culture to be used in its future production. Winter and spring productions were analysed to ensure isolation of specific LAB that had adapted to perform fermentation at low temperatures. Plate counts revealed total microbial numbers…

Genome-wide analyses reveal population structure and identify candidate genes associated with tail fatness in local sheep from a semi-arid area.

2021

Abstract Under a climate change perspective, the genetic make-up of local livestock breeds showing adaptive traits should be explored and preserved as a priority. We used genotype data from the ovine 50 k Illumina BeadChip for assessing breed autozygosity based on runs of homozygosity (ROH) and fine-scale genetic structure and for detecting genomic regions under selection in 63 Tunisian sheep samples. The average genomic inbreeding coefficients based on ROH were estimated at 0.017, 0.021, and 0.024 for Barbarine (BAR, n = 26), Noire de Thibar (NDT, n = 23), and Queue fine de l'Ouest (QFO, n = 14) breeds, respectively. The genomic relationships among individuals based on identity by state (I…

Seven Shades of Grey: A Follow-Up Study on the Molecular Basis of Coat Colour in Indicine Grey Cattle Using Genome-Wide SNP Data

2022

Shades of grey and brown are a dominant component in mammal coat colours, representing a fundamental trait involved in a great number of processes including cryptism, sexual selection and signalling. The genetic mechanisms of the grey colouration in mammals are very complex and controlled by hundreds of genes whose effects and interactions are still largely unclear. In this study, we adopted a robust multi-cohort Fst outlier approach based on pairwise contrasts between seven grey indicine cattle breeds and both taurine and indicine non-grey cattle breeds in order to find genomic regions potentially related to the grey colouration. On the basis of three main drawn settings, built in order to…

Test-Day Model Heritabilities for somatic cvell score and production traits in primiparous Valle del Belice sheep

2006

A repeatability test-day animal model was used to investigate heritabilities of somatic cell score (SCS) and milk production traits in Valle del Belice sheep. The heritability estimate for SCS falls within the range reported in literature (0.14±0.03), while estimates for milk production and composition traits were below those obtained by others, 0.12±0.03, 0.09±0.02, 0.14±0.03, 0.14±0.03, and 0.12±0.03, respectively, for milk yield, fat %, fat yield, protein %, and protein yield. Flock-test-day had a substantial effect on milk production traits but not on SCS. These results provide the basic parameters required for discussion of selection strategies and objectives in Valle del Belice sheep.

Polymorphisms of β-defensin genes in Valle del Belice dairy sheep

2011

The aim of this work was to study β-defensin 1 (SBD1) and β-defensin 2 (SBD2) genes in Valle del Belice dairy sheep in order to identify polymorphisms that can be utilized as markers of the analyzed genes, and search for the functional effects and roles of the identified polymorphisms (variation of the amino acid sequence of the protein and stability of mRNA molecule). The study was conducted on 300 randomly selected animals belonging to four flocks. A total of seven SNPs were identified, two in SBD1 and five in SBD2. The two SNPs identified in SBD2 coding region, at position 1659 and position 1667, were non-synonymous, leading to amino acid changes in the protein product. Nevertheless, the…

STUDY OF FATTY ACIDS PROFILE IN OVINE AND CAPRINE SICILIAN DAIRY BREED AND ASSOCIATION WITH POSSIBLE CANDIDATE GENES

In Sicilia, le razze bovine, ovine e caprine e le produzioni lattiero-casearie rappresentano una risorsa importante per l’economia del settore zootecnico. L’importanza economica del latte ovino e caprino è soprattutto legata per il primo alla sua trasformazione in prodotti lattiero-caseari, per il secondo al possibile utilisso per il consumo fresco. Per entrambe queste specie, il contenuto di grasso e proteine è importante tanto quanto la produzione di latte. L’individuazione dei geni responsabili delle caratteristiche quanti-qualitative del latte dei piccoli ruminanti permetterebbe quindi di aumentare l’efficienza del miglioramento genetico e di considerare nuovi obiettivi di selezione com…

Genetic polymorphism at the CSN1S1 gene in Girgentana dairy goat breed

2013

The aim of this work was to evaluate the variability of the αs1-casein locus in the endangered Girgentana dairy goat breed in order to define genetic improvement and a conservation program for this breed. The study was performed on 200 dairy goats by means of different PCR protocols. The most frequent alleles were A (0.590) and F (0.290) followed by B (0.065) and N (0.047). CSN1S1 E allele was identified with a very low frequency (0.008). The most common genotype was AF (0.365) followed by AA (0.340). The high frequency of the strong genotypes is associated with the production of milk with high fat and protein content and with optimal technological properties. In Girgentana goat breed, the …

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…