Examinando por Autor "Faletti, Cintia"

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  • Miniatura
    ÍtemAcceso Abierto
    Peso corporal y peso del huevo en híbridos experimentales de gallinas ponedoras. Análisis multivariado
    (2002-09-20) Dottavio, Ana María; Faletti, Cintia; Peralta, Leticia; Font, María Teresa; Di Masso, Ricardo José; Dottavio, Ana María [0000-0002-2402-6702]; Di Masso, Ricardo José [0000-0001-6221-5523]; Sociedad Argentina de Genética
    En gallinas ponedoras son deseables individuos de bajo peso asintótico, con una alta tasa de maduración que produzcan rápida y regularmente huevos dentro de un rango de pesos comercializable. La utilización de genotipos livianos y ultralivianos como progenitores para reducir el consumo de alimento mediante la reducción del peso adulto, produce modificaciones en los patrones de crecimiento y de aumento de peso del huevo. Se estudiaron estos patrones con las funciones de Gompertz y de Weatherup & Foster, respectivamente, en ponedoras híbridas con genotipo materno Plymouth Rock Barrado y genotipo paterno Fayoumi (ultraliviano), Leghorn (liviano) o Rhode Island Red (semipesado). El análisis conjunto de ambos patrones mediante la técnica de componentes principales permitió identificar tres componentes que en conjunto explicaron el 85% de la variancia: la primera (50%) discriminó por el peso corporal y el peso del huevo, dos variables estrechamente asociadas; la segunda (18%) por tasa de maduración para peso corporal y la tercera (17%) por tasa de maduración para peso del huevo. Dado que las tres componentes explican fracciones independientes de la variancia total, se postula que representarían fracciones independientes de la variancia genética hecho que permitiría utilizarlas como criterio selectivo para modificar en forma simultánea el comportamiento dinámico de las dos variables de interés productivo.
  • Miniatura
    ÍtemAcceso Abierto
    Yolk:albumen ratio in experimental hybrid layers with different paternal genotype.
    (Cordoba University Press (UCOPress Editorial Universidad de Córdoba), 2005) Dottavio, Ana María; Canet, Zulma Edith; Faletti, Cintia; Alvarez, Marianela; Font, María Teresa; Di Masso, Ricardo José; Dottavio, Ana María [0000-0002-2402-6702]; Canet, Zulma Edith [0000-0002-4993-3173]; Di Masso, Ricardo José [0000-0001-6221-5523]
    Egg weight and major egg components, with Egg weight and major egg components, with special emphasis on yolk:albumen ratio, were studied in three experimental hybrids of laying hens with Barred Plymouth Rock maternal genotype and either Fayoumi (F), White Leghorn (L) or Rhode Island Red (R) sires. Data were collected from eggs laid in the first (37 weeks of age) and in the second (85 weeks of age) laying cycle. Asymptotic body weight ranked following the same order as paternal genotypes (F < L < R) and, at both ages, mean egg weight ranked following the same order as hens’ average body weight. F birds, with the lightest eggs, showed the highest shell and yolk proportions, the lowest albumen percentage and the highest yolk to albumen ratio, in both laying cycles. Significant genotype and laying cycle effects and a nonsignificant interaction between them were observed for all traits. The joint variation of the three major egg components - yolk, albumen and shell - expressed as a percentage of egg weight was analysed using a multivariate principal component technique. The two first principal components explained almost all the generalized variance (99.93 percent) grouping hens by the paternal genotype. The first principal component discriminated birds for their yolk and albumen percentages while the second one was correlated with percent shell values. Fayoumi genes diminished body weight, food intake and egg weight and augmented yolk to albumen ratio. These modifications could be considered suitable in terms of the human target population with unsatisfied nutritional requirements to whom these hens are provided. They are also remarkable because the introgression of Fayoumi genes in commercial populations would be useful to enhance yolk production.