Genetic parameters of the prolificacy in the segureña sheep. Preliminary results

In the present paper the genetic parameters for the prolificacy of the Segureña sheep are presented. They have been obtained using an animal model enclosing repeated observations over the information collected from the meat control program of the breed. The model enclosed as fixed effects the combination of herd-year, the season and the age of the ewe as a lineal and quadratic covariate; and the animal additive genotype and permanent environmental effects as randomized. We have used a data base enclosing 100534 registered births in 54674 ewes of 151 farms, between the years 1999 and 2002, resulting a mean of 1.8 parturions by ewe, what is sufficient to get a good estimation of the permanent environmental effect. The values obtained for the heritability and the repeatability have been 0.04 and 0.08 respectively. These values are enclosed in the limits of the specie. We are also showing the values of the additive and phenotypic variances, together with the permanent environmental variance. This is the first estimation of genetic parameters developed in this breed with real data obtained in a meat control program, what is an important advance in the scientific knowledge of the breed.En el presente trabajo se presentan los valores de los parámetros genéticos para la prolificidad de la oveja Segureña, obtenidos a partir de la utilización de un modelo animal con observaciones repetidas sobre la información generada en los núcleos de control de rendimiento cárnico de la raza. El modelo ha incluido como efectos fijos la combinación rebaño-año, la época del año y la edad de la oveja como covariable lineal y cuadrática; y como efectos aleatorios, el genotipo aditivo del animal y el efecto ambiental permanente. Se ha utilizado una base de información de 100534 partos registrados en 54674 animales de 151 ganaderías entre los años 1999 y 2002, lo que supuso un promedio de 1,8 partos registrados por animal, suficiente para obtener una buena estimación del efecto ambiental permanente. Los valores observados para la heredabilidad y para la repetibilidad han sido de 0,04 y de 0,08 respectivamente. Valores dentro de los límites de la especie. También se aportan valores de las varianzas aditiva, fenotípica total y ambiental permanente. Es ésta la primera estimación de parámetros genéticos que se realiza en esta raza con datos de campo, lo que supone un importante avance en el conocimiento científico de la misma

Genetic evolution of weights and growing in segureño sheep in a decade of mass selection

The evolution of the mean breeding values and its mean fiability of the weight and growing traits are descrived in the Segureño sheep breed have been studied using the information of the breeding program of the breed. These values have been obtained using BLUP animal model enclosing maternal effects, what permited observe the evolution along a decade of mass selection. In this estimation have been employed 36000 values from 105 herds of the meat control program of the breed collected during the period 1999-2002.Se describen la evolución de los valores genéticos promedio así como de la fiabilidad media de los mismos en los caracteres productivos de peso y crecimiento en el ovino Segureño utilizando la información resultante del esquema de selección de la raza. Los mencionados valores se han obtenido utilizando un BLUP modelo animal con efectos maternos, obteniéndose así tanto los valores genéticos directos como maternos, lo que nos ha permitido observar la evolución de los mismos durante una década de selección masal. En esta estimación se han utilizado más de 36000 observaciones obtenidas en 105 rebaños del núcleo de control de rendimientos cárnicos de la raza, recogidos entre los años 1999 y 2002

Genetic Footprints of Iberian Cattle in America 500 Years after the Arrival of Columbus

Background: American Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, andmay have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources. Methodology/Principal Findings: We sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu. Conclusions/Significance: Nearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental condition

Consanguinidade e depressâo consanguínea num effectivo ovino da raça churra badana

Resumen de la comunicación presentada al III Congreso Ibérico sobre Recursos Genéticos Animale

Caracterizaçao demográfica da raça bovina mertolenga

Resumen de la comunicación presentada al III Congreso Ibérico sobre Recursos Genéticos Animale

Parâmetros reproductivos na raça equina lusitana

Resumen de la comunicación presentada al III Congreso Ibérico sobre Recursos Genéticos Animale

Caracterizaçâo productiva da raça ovina saloia

Resumen de la comunicación presentada al III Congreso Ibérico sobre Recursos Genéticos Animale

Variabilidade genética em raças ovinas de corte através de polimorfismos de proteínas e sua relaçaco com resisencia à verminose

Resumen de la comunicación presentada al III Congreso Ibérico sobre Recursos Genéticos Animales