44 research outputs found

    Estimation of Genetic Parameters for Peak Yield, Yield and Persistency Traits in Murciano-Granadina Goats Using Multi-Traits Models

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    This paper studies parameters of a lactation curve such as peak yield (PY) and persistency (P), which do not conform to the usual selection criteria in the Murciano-Granadina (MG) breed, but are considered to be an alternative to benefit animal welfare without reducing production. Using 315,663 production records (of 122,883 animals) over a period of 24 years (1990–2014), genetic parameters were estimated with uni-, bi- and multivariate analysis using multiple trait derivative free restricted maximum likelihood (MTDFREML). The heritability (h2)/repeatability (re) of PY, yield (Y) and P was estimated as 0.13/0.19, 0.16/0.25 and 0.08/0.09 with the uni-trait and h2 of bi- and multi-traits analysis ranging from 0.16 to 0.17 of Y, while that of PY and Y remained constant. Genetic correlations were high between PY–Y (0.94 ± 0.011) but low between PY–P (–0.16 ± 0.054 to –0.17 ± 0.054) and between Y–P (–0.06 ± 0.058 to –0.05 ± 0.058). Estimates of h2/re were low to intermediate. The selection for Y–PY or both can be implemented given the genetic correlation between these traits. PY–P and Y–P showed low to negligible correlation values indicating that if these traits are implemented in the early stages of evaluation, they would not be to the detriment of PY–Y. The combination of estimated breeding values (EBVs) for all traits would be a good criterion for selection

    On the use of elo rating on harness racing results in the genetic evaluation of trotter

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    The official results of trotters in Italian harness racings have been used to get AM-BLUP estimates of genetic parameters, EBVs and rTI of three groups of traits: speed (racing time, annual best time, best time in career between 2- and 5-year old), earnings (earnings/start, annual earnings, total earnings between 2- and 5- year old) and Elo system traits (underlying performance and final rating). The Elo system has been used for half a century in chess players rating, and it has been modified and fitted to several games and sports: it has already been used for genetic evaluation of sport horses in France. The highest heritability estimates in each group of traits have been found for best time (.430±.014), total earnings (.271±.013) and Elo final rating (.270±.008). The choice of "k", the Elo ratings updating factor, did not show a key role in affecting the results. The underlying performance heritability and repeatability have been estimated .159±.004 and .420±.007 respectively. The Elo-based systems proved to be very promising in objectively evaluating trotters

    Primera valoración genética Blup en el caballo trotador español

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    Tras la aprobación del Esquema de Selección específico para el Caballo Trotador Español (l de septiembre de 2005), se ha realizado la primera Valoración Genética para carreras de trote con metodología BLUP modelo animal en España, en base a los resullados deportivos obtenidos por los animales de esta raza en 4.180 carreras celebradas durante los años 2003-2005. Trabajando con un total de 42.993 registros de participación pertenecientes a 1.580 animales (832 machos, 593 hembras y 155 castrados), se estimaron los parámetros genéticos y los valores de cría para los tres caracteres seleccionados: ganancias anuales (GA), mejor tiempo anual (MTPA) y porcentaje de puestos clasificado entre el primero y el cuarto (PPC). El modelo genético-estadístico empleado incluye el sexo del animal, el año de nacimiento, el año de carrera y el número de participaciones registradas cada año (covariable de GA) como efectos fijos; y el efecto aditivo directo y el efecto ambiental permanente como factores aleatorios

    Biofilm production and antibiotic resistance of human and veterinary Staphylococcus strains.

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    Staphylococcus spp. is widely distributed in medical and veterinary pathology and represents one of the most important causes of infection. Many strains are antibiotic-resistant even for the presence of an eso-polysaccharide matrix. The aim of this work was to individuate, among 396 different Staphylococci of human and animal origin, the slime producing strains and to correlate the presence of biofilm to the resistance to eight antibiotics. A total of 185 coagulase negative staphylococci (CNS) and 211 S. aureus isolated from different sources and identified with Sceptor System, were tested for antibiotic susceptibility (Kirby Bauer method) and for slime production (Polystyrene plates – stained with Alcian blue – Spectrophotometric reading at 450 nm). The strains were classified as weak, strong and no slime-producing on the basis of OD results. The results were submitted to statistical analysis using Student’s t-test and chi-square tests. Evaluating the differences of slime production among medical and veterinary strains, we found different statistical frequencies (P > 0.001). No statistical differences wereobtained between S. aureus and the other CNS. Instead, the statistical analysis on S. epidermidis vs. the other staphylococci has shown no statistical differences among average values using Student’s ttest (P < 0.052) and significant frequency differences using chi square tests (P < 0.02). Finally in the CNS, between S. epidermidis and the other strains, no statistical differences were found. The relation between slime production and the origin of strains was evaluated and no correlation was found. About the correlation between antibiotic-resistance and slime production a resistance increment of about 30% was obtained in strongly slime producing strains. Staphylococcus spp. is often involved in nosocomial infections as complication of post-surgery wounds, catheters and orthopaedic devices. The presence of antibiotic-resistant strains interferes in the therapy successes and seems to be strictly related to biofilm production beyond that genetically acquired. Human and veterinary strains have shown a similar behaviour towards biofilm production and antibiotic-resistance. The results confirm that S. epidermidis is one of the most slime-producer and introduce S. aureus as a new high slime-producer

    BOVITA: a first overview on genome-wide genetic diversity of Italian autochthonous cattle breeds

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    Analysis of genomic data is increasingly becoming part of the livestock industry and is an invaluable resource for effective management of breeding programs in small populations. The recent availability of genome-wide SNP panels allows providing background information concerning genome structure in domestic animals, opening new perspectives to livestock genetics. BOVITA was established to join local efforts and resources for the genomic characterization of Italian local cattle breeds. Despite the growing diffusion of some cosmopolite specialized breeds, several autochthonous breeds are still bred in Italy. The main aim of the BOVITA is to investigate the genomic structure of Italian local cattle breeds, to provide information on their genetic status that will be useful for the management of the genetic variability, as a contribution to biodiversity conservation and prioritization actions. A total of about 800 animals (20-32 per breed) belonging to thirty Italian cattle breeds (Agerolese, Bar\ue0-Pustertaler, Burlina, Cabannina, Calvana, Chianina, Cinisara, Garfagnina, Italian Brown, Italian Holstein, Italian Simmental, Marchigiana, Maremmana, Modenese, Modicana, Mucca Pisana, Pezzata Rossa d\u2019Oropa, Piedmontese, Pinzgau, Podolica, Pontremolese, Pustertaler, Reggiana, Rendena, Romagnola, Rossa Siciliana, Sarda, Sardo-Bruna, Sardo-Modicana and Ottonese-Varzese) and two cosmopolitan breeds (Charolaise and Limousine) genotyped with the Illumina BovineSNP50 v2 BeadChip array were collected for the analysis. The genotypes of several breeds were detected in the frame of the project, whereas for some breeds these data are derived by previous studies. The dataset will be analyzed to: study several aspects of population genetic diversity, multi-dimensional scaling plot, population structure, linkage disequilibrium, and runs of homozygosity. In addition, comparative analysis of conserved haplotypes will be conducted to identify genomic segments under selection pressure. Such information also provides important insights into the mechanisms of evolution and is useful for the annotation of significant functional genomics regions. Data analysis will also be useful to select SNPs suitable for parentage test and breed genetic traceability. The analysis of the data will pinpoint the genetic distinctiveness of Italian breeds. Moreover, the obtained results contribute to a better characterization of history and genetic structure of Italian cattle breeds

    A genome-wide perspective on the population structure of Italian cattle breeds

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    Despite the growing diffusion of cosmopolite specialized breeds, several autochthonous populations are still farmed in Italy. The aim of this study was to provide a high-resolution picture of the genome-wide diversity and population structure of Italian local cattle breeds using medium-density genome-wide SNP markers. After data editing, the dataset included 800 samples from 32 breeds that were genotyped for 31,013 SNPs. For several breeds we observed a low level of polymorphism and genetic diversity that confirmed threat of extinction. Shared ancestry, admixture events, and reticulations observed on the phylogenetic tree between some breeds, all suggest high levels of gene flow. Clear clusters and relationships between breeds that originated from the same geographical area were detected. However, in spite of the complex admixture history, many of the local Italian cattle breeds have retained unique identities and are clearly differentiated breeds. Differences in their origin, in climate characteristics of farming areas, the genetic isolation, and the inbreeding can be the main reasons for such differentiation. This study represents the first exhaustive genome-wide analysis of Italian cattle diversity. The results largely agreed with the breeding history of the Italian cattle breeds. The population structure and the low genetic diversity presented here for several breeds should be evaluated in adopting conservation strategies. Thus, efforts should be made to improve genetic diversity in these breeds. Control of inbreeding, breeding stations development and improvement of recording system are strategies to conserve these breeds under in situ conservation situation, and in this context, genomic information may play a crucial role for the preservation and management of these populations
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