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- Avances en el estudio de la curva de crecimiento del ganado bovino Marismeño.Publication . Nogales, Sergio; Lupi, Teresa Marta; León, José Manuel; Arando, Ander; Miró-Arias, M.; Delgado Bermejo, Juan Vicente; Camacho Vallejo, María EsperanzaLa raza bovina Marismeña es muy característica por estar localizada casi exclusivamente en el Entorno Natural de Doñana (Parque Natural y Nacional). Con objeto de caracterizar el crecimiento, se tomaron pesos individualizados de los animales durante los últimos cinco años. En total se recogieron 1771 pesos, 470 de machos y 1301 de hembras. Los datos fueron utilizados para hallar la curva de crecimiento con los modelos de Brody, Von Bertalanffy, Logístico y Gompertz. Para la elección del mejor modelo se usaron dos parámetros: el coeficiente determinativo (R2) y el cuadrado medio del error. El modelo más apropiado fue el de Brody tanto para machos como para hembras, con un R2 de 0,92 y 0,86, respectivamente. El modelo resultante fue: machos, peso = 633,95 * (1 - 9515 * exp (-0,0009 * edad)); hembras, peso = 387.60 * (1 - 0,9429 * exp (-0,0016 * edad)). La raza Marismeña mostró un lento crecimiento y un claro dimorfismo sexual, muy notable a partir de los 2 años de edad.
- Estudo da curva de crescimento comercial em função do sexo e do tipo de parto na raça ovina Mallorquina.Publication . Nogales, Sergio; León, José Manuel; Lupi, Teresa Marta; Palou, T.; Espinosa, M.A.A raça ovina Mallorquina encontra-se localizada na Ilha de Mallorca (Espanha), com um censo, a 31 de dezembro de 2015, de 14635 reprodutores, e está considerada em perigo de extinção. Esta raça, cuja produção principal é o cordeiro pascal e de leite, tem uma função importante na ilha sobre a conservação do meio ambiente pela sua clara adaptação ao meio. O estudo do crescimento é uma ferramenta fundamental para o conhecimento da raça e está integrado no programa oficial de melhora genética.
- Characterisation of biological growth curves of different varieties of an endangered native hen breed kept under free range conditionsPublication . González, Antonio; Nogales, Sergio; Lupi, Teresa Marta; Arando, Ander; Navas González, Francisco Javier; León, José Manuel; Delgado Bermejo, Juan Vicente; Camacho Vallejo, María EsperanzaThe aim of this study is to model the growth samples of four varieties (White, Black, Partridge, Franciscan) of Spanish Utrerana hen breed, which is endangered, by using Brody, Von Bertalanffy, Verhulst, Logistic and Gompertz models. For this purpose, a total of 16,235 weight data observations from 2004 animals reared in free range system were collected. Logistic was the best suited model for predicting the biological growth curve of White variety in both sexes, while Von Bertalanffy was the best fitting model for the rest of individuals of the breed, based on the 5 goodness-of-fit and flexibility criteria: Pseudo-R2 , mean squared error, Akaike information criterion, Bayesian information criterion and the biological coherence of the estimated parameters. Black variety was the heaviest, with values of 2605.96 and 2032.61 g (for males and females, respectively) for a parameter, while White variety presented the lowest maturity weight (a ¼ 2442.99 and 1874.24 g, for males and females, respectively). Conclusively, this growth characterisation is essential for the conservation of the Utrerana hen, to search for new market niches and a greater profitability to this differentiated product.
- A comparison of the growth performance between cattle reared in conventional systems and in feral conditionPublication . Nogales, Sergio; Calderón, Juan; Lupi, Teresa Marta; Bressan, Maria Cristina; Delgado, Juan Vicente; Camacho Vallejo, María EsperanzaFeral and conventional growth performances were compared using Marismeña cattle as a model. Marismeña calves are commonly reared under feral conditions in one of the most important reserves of Europe (Doñana National Park, Spain). Data recording in these natural conditions faces compromises as animals are only handled once per year. This fact has to be saved to obtain efficient estimations for the biological growth curve of cattle reared under feral conditions. On the one hand, we assessed the inference of the theoretical influence of human management on cattle growth. On the other hand, we studied the fitness of the best growth curve, in both feral and conventional systems to use the physiological meaning of the parameters obtained from their study as selection criteria related to the adaptability of potential breeding males and females. Fitting of Brody's, von Bertalanffy, Verhulst, logistic, Gompertz and Richards’ models was tested as these models are the most representative ones for cattle growth. In general, Brody's and Richards’ models presented the best fitting values for the biological curve. According to the biological curve parameters, males and females presented asymptotic weights of 641.71 kg and 403.55 kg, respectively. As expected, the results of the commercial growth curve severely differed from those of the biological curve. The best fitting biological curve was not representative for cattle reared under commercial conditions. The logistic model was the best fitting one for feral females, Gompertz model for feral males, and Verhulst for intensive males and females, respectively. Seasonal oscillations in feeding may be responsible for the earlier achievement of the best performance in feral cattle (7 and 10 months for males and females, respectively), while such best performances were reached at 11 months in intensive calves, what becomes relevant for management and slaughtering decision-making. The study of the biological curve in Marismeña feral breed is very illustrative as this is the first time that feral cattle's growth is approached. Knowledge on the biological growth curve parameters could be used to interpret the strong relation between feral animals and their environment. This research could infer a model to quantify the effects of human management on livestock development, as feral resources offer unique opportunities to study domestic livestock without any human influence.
- Efecto de factores no genéticos en el peso al destete precoz del cordero de raza segureña.Publication . Lupi, Teresa Marta; Nogales, Sergio; León, José Manuel; Delgado, Juan VicenteSe analiza la influencia sobre el peso al destete precoz, comprendido entre los 16 y los 35 días de vida, en corderos de raza ovina Segureña, de los efectos fijos sexo, época de nacimiento, zona geográfica y tipo de parto de la oveja. Se analizaron los datos del peso de 27083 corderos pertenecientes al registro histórico de la Asociación Nacional de Criadores de Ovino Segureño – ANCOS – de los últimos 13 años. Fueron realizados análisis estadísticos en cada factor, basados en el test t para las medias, análisis de varianza y el test de Tuckey para analizar los grupos homogéneos. Se llevó a cabo un análisis de varianza multifactorial mediante la utilización del software IBM SPSS Statistics v.19, utilizando los factores no genéticos como efectos principales y considerando las interacciones dobles significativas. Los machos presentaron un peso promedio superior al de las hembras. El efecto de la época de nacimiento fue significativo (P<0,001), de forma que los corderos nacidos en primavera e invierno, presentaron un peso promedio superior. La localización geográfica no afectó el peso de los corderos (P>0,05). Sin embargo, el tipo de parto influenció el peso promedio de una manera muy significativa (P<0,001), poniéndose de manifiesto que los corderos nacidos de partos simples fueron más pesados que los corderos nacidos de partos múltiples. Las interacciones dobles época de nacimiento × tipo de parto, zona geográfica × época de nacimiento y sexo × tipo de parto fueron significativas (P<0,001) para el modelo, que se presentó con un coeficiente determinativo (R2) de 0,127. Como conclusión general puede indicarse que los factores no genéticos tienen un papel muy importante en peso de los corderos de raza Segureña en el destete precoz. El conocimiento de la influencia de estos factores podrá ser útil en el desarrollo de estrategias de producción para que los promedios totales del peso puedan ser mejorados.