Evaluación del esquema de selección de la raza equina hispano-árabe

El caballo Hispano-Árabe es una raza autóctona española incluida en el Catálogo Oficial de Razas de Ganado de España dentro de la categoría de razas en peligro de extinción (Orden APA/2129/2008, de 26 de diciembre, BOE 23, de 27 de enero de 2009). Raza originada en Andalucía probablemente desde tiempos de la invasión musulmana en la península Ibérica, actualmente tiene a esta región española como principal área de distribución geográfica. Esta raza se formó históricamente por la fijación del cruce entre las dos razas que integran su nombre, con una vocación funcional muy marcada. Se sabe que un plan de selección es un instrumento imprescindible para el progreso genético de una raza, cualquiera que sea el fin productivo buscando el mayor rendimiento de nuestros ejemplares, lo cual consiste en elegir dentro de la propia raza a los individuos que mejores características pueden trasmitir a su descendencia, teniendo en cuenta las condiciones de riesgo de la población, su compleja estructura poblacional, y su versatilidad funcional sin perder la variabilidad genética de esta pequeña población. Sin embargo, previamente a la aplicación de esta herramienta en el campo es necesario estudiar con atención todos aquellos efecto genéticos y no genéticos que están (o muchas veces se cree que están) relacionados con un determinado fenotipo o expresión productiva. Esta labor previa pretende eliminar o reducir los posibles errores de selección sobre la población, como puede ser un incremento excesivo de la consanguinidad o fijar genes letales o indeseados en determinada línea de pedigrí. Tradicionalmente estos animales se han venido seleccionando por características fenotípicas, y en los últimos siete años se ha venido almacenando toda la información generada en diferentes pruebas morfológicas y funcionales. Debido al volumen de información con la que se partía en los inicios del programa fue necesario utilizar toda la información proveniente de dos tipos de controles fenotípicos (valoraciones y concursos). La escasa información funcional estaba motivada por distintos factores, por un lado, al ser una raza en peligro de extinción y por otro, a las condiciones económicas actuales, provocando una falta de motivación por parte de los ganaderos a participar en las diferentes pruebas que se realizan cada año, circunstancias que repercuten directamente en la mejora genética de la raza. En el año 2009, se establece una serie de contactos y reuniones que tenían como objetivos prioritarios el establecimiento de los pasos a seguir para la puesta en marcha del esquema de selección específico de los caracteres conformacionales (armonía) y funcionales (paso, trote y galope) de la raza. Entre los temas analizados estuvieron la optimización de la recolección de la información, establecer las bases para la evaluación genética de los reproductores de la raza Hispano-Árabe, determinar diferentes técnicas estadísticas para el cálculo de parámetros genéticos, y todo aquello que puede afectar directamente al progreso genético de la raza. La mejora genética mediante programas concretos de selección constituye uno de los pilares básicos de la producción animal actual, y con ella se han incrementado de forma espectacular los niveles productivos de la mayor parte de las especies de interés pecuario

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

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

Propuesta didáctica para el desarrollo de las competencias del área de comunicación de cuarto grado de primaria de una Institución Educativa Privada de Punta Negra, Lima

El presente trabajo de suficiencia profesional que a continuación se presenta, tiene como objetivo diseñar una propuesta didáctica para el desarrollo de competencias comunicativas en los estudiantes de cuarto grado de primaria de una institución educativa privada de Lima. Para ello, se basa en el Paradigma Sociocognitivo Humanista de: Jean Piaget, David Ausubel y Jerome Bruner (cognitivo), Lev Vygotsky y Reaven Feuerstein (social y cultural), Robert Sternberg, Martiniano Román y Eloísa Diez (Teoría de la Inteligencia). A través de esta propuesta, el estudiante se vincula con competencias, capacidades y destrezas; donde no solo adquiere conocimientos, sino también aprende valores para que pueda socializar con sus conocimientos en esta sociedad cambiante. Así, esta propuesta contiene en el primer capítulo la planificación del trabajo de suficiencia profesional; el segundo, marco teórico y como último capítulo la programación curricular.The present work of professional sufficiency that is presented below, aims to design a didactic proposal for the development of communication skills in fourth grade students of a private educational institution in Lima. For this, it is based on the Humanistic Sociocognitive Paradigm of: Jean Piaget, David Ausubel and Jerome Bruner (cognitive), Lev Vygotsky and Reaven Feuerstein (social and cultural), Robert Sternberg, Martiniano Román and Eloísa Diez (Intelligence Theory). Through this proposal, the student is linked with skills, abilities and skills; where you not only acquire knowledge, but also learn values so that you can socialize with your knowledge in this changing society. Thus, this proposal contains in the first chapter the planning of the work of professional proficiency; the second, theoretical framework and as the last chapter the curricular programming

Use of Spline function for the characterisation on peak yield, peak day and persistency in lactation curves in Murciano-Granadina goats

The objective of this study was to characterise the peak yield (PY), peak day (PD) and the persistency (P) of the lactation curve of Murciano-Granadina goats by Spline considering the variation factors (region, type of kidding, lactation number and season) and their levels. A total of 1,349,347 test-day records from 180,872 lactations, of 85,404 goats were used. The analysed data with Spline model was considered for adequate fit in lactation curves for others traits in these goats. All factors affected the scale and/or shape of the lactation curve. In the region factor, significant differences (SD, p  .05) between regions. The type of kidding presented SD among its levels (evident between double versus single and triple) with the exception of the PY. The lactation number for the variables of PD, PY and TY from second to fifth lactation showed NSD among themselves; but it did in the case of the first. The P of first lactation was longer, with a decrease in subsequent lactations. In the season factor, PD, TY and P presented SD; where the PD was divided into two groups: late group (winter-spring) and early group (fall-winter). The P, PY and PD can be considered as an additional selection criterion and thus modify the lactation curve.Highlights The biomodeling of individualized lactation curves is an important information resource for farmers and their breeding program. A conglomerate of microeffects such us climate, photoperiod, agroecological aspects, affect parameters of the lactation curve and their productions. It is preferable to achieve lactations with more emphasis on persistency in order to provide animal welfare and obtain adequate economic benefits

Tendencias genéticas y fenotípicas para pico productivo, rendimiento lechero y persistencia de lactación en la raza Murciano-Granadina

El objetivo fue evaluar las tendencias genéticas (TG) y fenotípicas (TF) para los caracteres de pico productivo (PP), rendimiento lechero (RL) y persistencia de la lactación (P) en la curva de lactación de la raza Murciano-Granadina (MG). Para ello se utilizaron 180,872 lactaciones, de 85,404 cabras (registros históricos de 1990-2012). Para la obtención de los caracteres de interés (PP, RL y P) se realizó la biomodelación de curvas de lactación mediante el modelo Spline usando el software "R". Los valores genéticos (VG) se obtuvieron mediante modelo animal univariado con observaciones repetidas, empleándose el paquete MTDFREML. Las TG y TF se estimaron vía mínimos cuadrados en una regresión del promedio de los VG e información productiva conocida según el año de nacimiento. En el cálculo de las TG y TF se obtuvieron coeficientes de regresión lineal (b), donde los valores b para PP, RL y P fueron de +0.00071, +0.00698; +0.00114, +0.01117 y +0.00002, -0.00076; respectivamente. El trayecto de TG, TF de PP y RL se comportó de la misma manera siguiendo una línea de tendencia ascendente con presencia de intervalos de crecimiento y decrecimiento. La TG de P mostró un comportamiento estacional y la TF fue descendente con puntos más consistentes en su recorrido; reforzando la idea de que altas producciones van en detrimento de la P. Estos resultados permiten informar a los criadores del comportamiento de estos caracteres y considerar la incorporación de la persistencia de la lactación como criterio de selección en el programa genético de la raza

Evaluación de la consanguinidad y variabilidad genética del Caballo Peruano de Paso registrado en Ecuador

The Peruvian Paso Horse (CPP) is a breed with a four-stroke gait originating in Peru from the horses that arrived at the time of the conquest of America. The aim of this study was to know the level of inbreeding and the effect on genetic variability in the breed. In total, 8330 animals were analysed that included the population of CPP born in Ecuador and their Peruvian ancestry (PT) and two reference populations of animals born in Ecuador (PE) and born between 2008 and 2018 (PR). The average traced generations were 9.18 ± 3.89 (PT), 11.14 ± 2.23 (PE) and 12.83 ± 1.42 (PR) and the completeness of the pedigree was over 90% in the first, fourth and fifth generations of PT, PE and PR, respectively. Average generation interval of 8.72 ± 4.56 (PT), 8.79 ± 4.30 (PE) and 9.20 ± 4.61 (PR). Average individual consanguinity: 5.97% (PT), 6.83% (PE) and 8.11% (PR) and kinship relationship: 9.02% (PT), 10.56% (PE) and 11.56% (PR). Individual increase in consanguinity per year was 0.13% and per generation 1.13%. The effective size of the population was less than 50. The probabilities of origin of the genes were greater than one. The occurrence of loss of genetic variability due to the bottleneck effect and genetic drift is concluded.El Caballo Peruano de Paso (CPP) es una raza con ambladura de cuatro tiempos originaria de Perú a partir de los caballos que llegaron en la época de la conquista de América. El objetivo del estudio fue conocer el nivel de consanguinidad y el efecto sobre la variabilidad genética en la raza. Se analizaron 8330 animales que incluyó la población de CPP nacidos en Ecuador y su ascendencia peruana (PT) y dos poblaciones de referencia de animales nacidos en Ecuador (PE) y nacidos entre 2008 y 2018 (PR). Las generaciones trazadas promedio fueron de 9.18 ± 3.89 (PT), 11.14 ± 2.23 (PE) y 12.83 ± 1.42 (PR) y la completitud del pedigrí sobre el 90% en la primera, cuarta y quinta generación de PT, PE y PR, respectivamente. Intervalo generacional promedio de 8.72 ± 4.56 (PT), 8.79 ± 4.30 (PE) y 9.20 ± 4.61 (PR). Promedio de consanguinidad individual: 5.97% (PT), 6.83% (PE) y 8.11% (PR) y relación de parentesco: 9.02% (PT), 10.56% (PE) y 11.56% (PR). Incremento individual de consanguinidad por año fue de 0.13% y por generación de 1.13%. El tamaño efectivo de la población fue menor a 50. Las probabilidades de origen de los genes resultaron mayores a uno. Se concluye la ocurrencia de pérdida de variabilidad genética por efecto de cuello de botella y deriva genética

The genetic ancestry of American Creole cattle inferred from uniparental and autosomal genetic markers

Cattle imported from the Iberian Peninsula spread throughout America in the early years of discovery and colonization to originate Creole breeds, which adapted to a wide diversity of environments and later received influences from other origins, including zebu cattle in more recent years. We analyzed uniparental genetic markers and autosomal microsatellites in DNA samples from 114 cattle breeds distributed worldwide, including 40 Creole breeds representing the whole American continent, and samples from the Iberian Peninsula, British islands, Continental Europe, Africa and American zebu. We show that Creole breeds differ considerably from each other, and most have their own identity or group with others from neighboring regions. Results with mtDNA indicate that T1c-lineages are rare in Iberia but common in Africa and are well represented in Creoles from Brazil and Colombia, lending support to a direct African influence on Creoles. This is reinforced by the sharing of a unique Y-haplotype between cattle from Mozambique and Creoles from Argentina. Autosomal microsatellites indicate that Creoles occupy an intermediate position between African and European breeds, and some Creoles show a clear Iberian signature. Our results confirm the mixed ancestry of American Creole cattle and the role that African cattle have played in their development

The genetic ancestry of american creole cattle inferred from uniparental and autosomal genetic markers.

Cattle imported from the Iberian Peninsula spread throughout America in the early years of discovery and colonization to originate Creole breeds, which adapted to a wide diversity of environments and later received influences from other origins, including zebu cattle in more recent years. We analyzed uniparental genetic markers and autosomal microsatellites in DNA samples from 114 cattle breeds distributed worldwide, including 40 Creole breeds representing the whole American continent, and samples from the Iberian Peninsula, British islands, Continental Europe, Africa and American zebu. We show that Creole breeds differ considerably from each other, and most have their own identity or group with others from neighboring regions. Results with mtDNA indicate that T1c-lineages are rare in Iberia but common in Africa and are well represented in Creoles from Brazil and Colombia, lending support to a direct African influence on Creoles. This is reinforced by the sharing of a unique Y-haplotype between cattle from Mozambique and Creoles from Argentina. Autosomal microsatellites indicate that Creoles occupy an intermediate position between African and European breeds, and some Creoles show a clear Iberian signature. Our results confirm the mixed ancestry of American Creole cattle and the role that African cattle have played in their development

Relationship among production traits, somatic cell score and temperature–humidity index in the Italian Mediterranean Buffalo

The temperature–humidity index (THI) has been commonly used to analyse heat stress in dairy cattle, but little is known about its effects on buffaloes. In this study, daily milk yield (MY), fat percentage (FP), protein percentage (PP) and somatic cell count (SCC) data from 808 buffalo cows plus environmental temperature and relative humidity were used to investigate the consequence of heat stress. Two mixed models were used to evaluate the impact of THI on MY, FP, PP and log transformed SCC (SCS). The effect of THI was significant for PP, FP and SCS, whereas its interaction with parity was statistically significant for PP and SCS. The relationship between PP and FP and THI was positive but of different magnitude according to the parity. When THI was below 62, an unfavourable effect was observed, especially in primiparous buffalo cows. A significant interaction between SCS and THI across parities was also observed. The effect of THI on MY across parities was not definite but overall a favourable relationship was observed. Our findings depict a susceptibility of buffaloes to low values of THI, suggesting an optimal THI range for water buffaloes between 59 and 63, although some deleterious effects were observed in primiparous buffaloes at THI values lower than 62. Additional investigations are needed to better elucidate the influence of THI on buffalo species.HIGHLIGHTS The overall effect of THI on buffalo diverges from what commonly observed in dairy cattle Cold stress affects milk and udder health in buffaloes The effect of THI on buffaloes’ performance depends on parity, with a larger susceptibility in primiparous than pluriparous buffalo cows Udder health in buffaloes, evaluated using somatic cell count, is also affected by TH

Genetic diversity of the semi-feral Marismeño horse breed assessed with microsatellites

Marismeño horses originated from primitive horses living around the marshes of the Guadalquivir River in Southern Spain. Throughout their evolution, they have experienced crosses with other breeds, first with horses from North Africa and thereafter with other horses. However, they have not lost their ability to adapt to the demanding marsh environment. Recently, a studbook of the breed was established, and the Breeders Association started a conservation programme. To study the relationship of the Marismeño with other breeds, a microsatellite analysis was developed, which included other ancient Southern Iberian horse populations, such as the Sorraia and Retuertas breeds. Candidates of recent crossbreeding with Marismeño horses, such as the Hispano-Arabian and the Spanish Purebred, were studied, and the Thoroughbred and the Arabian breed were used as international references. The results indicated that the Marismeño horse population maintains a great genetic diversity. Despite recent crossbreeding, the fixation index and the Hardy-Weinberg equilibrium analysis disclosed a certain homogeneity degree. A dendrogram was built using the obtained genetic distances, and clustering was performed with the software STRUCTURE, and the results reflected the genetic differentiation of the Marismeño horse from the other autochthonous Iberian breeds, although the Marismeño population has maintained a tight relationship with the Spanish Purebred. Remarkably, some relatedness between the Marismeño and the Barb horse breeds could be observed and was most likely derived from an ancient gene flow between the horses of the Iberian Peninsula and North Africa