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Scrotal circumference (SC) is the main indicator of sperm production potential, this dimension is used to increase the reproductive capacity of bulls. SC can be used as a criterion for fertility selection in cattle farms. The objective of the research is to review the importance of reproductive evaluation of the bull and the correlation of scrotal circumference with semen quality. A bibliographic review was carried out to demonstrate the main advantages of testicular size and weight in young bulls since it is highly correlated with scrotal circumference, which is the main indicator of sperm production potential. It was concluded that selecting young bulls with a good scrotal circumference has benefits, since they produce more semen of higher quality compared to bulls of the same age, but with smaller testicles. [ABSTRACT FROM AUTHOR]

In Ecuador, introduced coffee cultivars were selected, but there is no history of new cultivars having been developed through conventional genetic improvement. The objective of this research was to obtain improved coffee genotypes for the southern area of Manabí, for this the coffee germplasm bank of the State University of Manabí, located at the Andil Farm, was used in the 2021 campaign, where they were obtained F1 hybrid families using nine parental accessions (Acawa, Arara, Yellow Burbon, Catimor CIFC, Yellow Catuai, Catucai 25L, Catucai 78515, Red Caturra and Geisha), which were recombined in a Griffin diallelic design, obtaining 1477 genotypes. On the same Farm, in the nursery in the 2022 - 2023 campaigns, the materials were planted in a completely randomized experimental design. The general combinatorial aptitude (GCA) and the specific combinatorial aptitude (SCA) were determined for plant height (PH), stem diameter (SD), number of pairs of leaves (NPL), leaf area (LA), heterosis and heterobeltiosis of parents and progenies. The results showed that the Typica parent was salient and significant for PH. SD and LA. The 021-105 family was outstanding for PH, NPL and LA. The GCA for PH, SD, NPL and LA of the parents was good. There was heterosis for PH, SD and LA, in families 021-101 and 021-104; and, heterobeltiosis for PH in families 021-105, 021-106, 021-, 021-108 and 021-109; and, for LA in families 021-105 and 021-109. Genotypes with potential to be future cultivars were identified. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Sport & Health Research is the property of Journal of Sport & Health Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

El objetivo de este trabajo fue estimar los componentes de varianza y correlaciones genéticas para la producción de leche (PLe), el flujo medio (FMd), el flujo máximo (FMx) y la conductividad eléctrica (CE) de la leche, en un sistema de ordeño robotizado. Se analizaron 137 lactaciones de 110 vacas Holstein primíparas y multíparas, con 42,009 observaciones, desde el año 2018 hasta el 2020 en un hato lechero en el estado de Querétaro. Se realizó la evaluación genética utilizando un modelo animal de regresión mixta. Para estimar la heredabilidad (h2) se utilizó el algoritmo de máxima verosimilitud restringida para calcular los componentes de varianza, el estimador BLUE y el predictor BLUP, para cada una de las variables sujetas en la investigación. La h2 estimada para PLe (0.62) fue la más alta de las calculadas, de igual modo se estimó la h2 para FMd (0.44), FMx (0.33) y CE (0.28); se considera que uno de los aspectos que influyó en los valores obtenidos se debió a la variabilidad de cada observación diaria. Las correlaciones genéticas para la PLe fueron negativas para el FMd (-0.6117) y FMx (-0.7666); en contraste, para la característica de CE (-0.1669) la correlación fue baja. Las correlaciones genéticas estimadas para FMx fueron positivas para FMd (0.7422) y CE (0.5351), finalmente se estimó una correlación genética positiva para FMd y CE (0.3546). Los resultados presentados permiten entender las relaciones existentes entre flujo, conductividad y producción e indican la importancia de estas características para un programa de selección genética.

Pinus patula seeds are in high demand for the establishment of plantations in Mexico and around the world because of the fast growth of this species. However, genetically improved germplasm of forest species is scarce in Mexico. For this reason, in 2012, the Mexican government started a program of asexual seed orchards with species of the Pinus genus to meet the germplasm demand. Thus, the objectives of the present research were: to evaluate the height, diameter at breast height, and volume of Pinus patula clones in an asexual seed orchard and to estimate the heritability of these traits. The asexual seed orchard was established in 2012. The diameter at breast height and total height (DBH) were measured and the volume of each ramet was calculated. Subsequently, clonal heritability was estimated for each trait in the four-year-age clones. Differences were found among clones. The average height was 4.38 m, and it varied from 3.39 to 4.80 m for the clones 103 and 28, respectively. The average DBH was 5.46 cm and varied from 3.98 to 6.52 cm for clones 103 and 25, respectively. The average volume was 6.23 dm3 showing a range from 2.62 to 9.53 dm3 for clones 103 and 25, respectively. Clones of Pinus patula had high values of height, DBH, and volume. Heritability values for height, DBH and volume were 0.655, 0.508 and 0.575, respectively. Thus, these traits show high heritability, in other words, they are influenced by genetic component. [ABSTRACT FROM AUTHOR]

A common garden trial with 18-month-old trees from 64 half-sib families of Pinus patula was established to identify genetic variation in growth and survival in response to drought for four months (November 25, 2020 to March 25, 2021, winter). A split-plot design with two moisture levels (Irrigation S0 = 40 - 55 % and Drought S1 = 20 - 39 % volumetric moisture) was used in large plots and families in small plots. At the beginning and end of the trial, the height (HT), diameter of the base (DB), and number of whorls and branches were determined, and the absolute (AGR) and relative (RGR) growth rates in HT and DB were calculated. Differences were found between the moisture levels during growth. Survival was 71 % in S0 and 60 % in S1. In S1, AGR in HT and DB was affected by 52 and 38 %, and RGR by 46 and 32 %, respectively, with respect to S0. In S0, 31.4 % of the plants formed one whorl and 2.1 % two, in S1 only 13.4 % and 0.2 % did. Genetic control was moderate in the joint environments with h²i between 0.03 and 0.17 and h²f between 0.15 and 0.53. The performance of the families between the two humidity conditions was stable (rB from 0.71 to 1.0) in all variables, with greater genetic variation in S0 than in S1. Moderate genetic variability was observed in the growth of Pinus patula families under water restriction. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Ciencias Hortícolas is the property of Revista Colombiana de Ciencias Horticolas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The (co) variance components and genetic parameters were estimated for three pre-weaning growth traits; weight at 4 months (P4M, N = 214), daily weight gain between 4 months and weaning (GDP4M-D, N = 175) and weaning weight (PD, N = 485), in four herds of cattle Blanco Orejinegro (BON) from Colombia, with the objective of comparing two models (with and without genetic covariance between maternal and direct effect) for the genetic evaluation of these traits. The models that present the best description of the variance components and genetic parameters were selected, according to which the covariance is considered equal to zero or different from zero between the additive and maternal genetic effects. Finally, the genetic evaluation and Spearman correlation were performed. The following values were found: for P4M, direct additive heritability (h2a) of 0.46 ± 0.40; 0.0 ± 0.15 (cov = 0) and maternal heritability (h2m) 0.40 ± 0.48; 0.0 ± 0.24 (cov ≠ 0); for PD, h2a 0.56 ± 0.17; 0.06 ± 0.08 (cov = 0) and h2m 0.58 ± 0.22; 0.09 ± 0.14 (cov ≠ 0) and for GDP4M-D, h2a 0.61 ± 0.56; 0.03 ± 0.21 (cov = 0) and h2m 0.19 ± 0.44; 0.35 ± 0.46 (cov ≠ 0). The Spearman correlation obtained between the direct and maternal genetic value of the models with cov = 0 and cov ≠ 0 for the P4M and PD traits was high (0.91 to 0.99), while for GDP4M-D it was low and negative -0.33. [ABSTRACT FROM AUTHOR]

Eucalyptus tereticornis exhibits adaptation to a wide range of soils and environments, making it suitable for various protective and productive purposes throughout the territory of Uruguay. Due to the absence of a locally improved seed source, INIA began a tree breeding program in 2007 using genetic material from two sources: the natural distribution area of the species and local plantations. The performance of the genetic pool was evaluated at different sites over a nine-year growth period. The objectives of this study were to estimate genetic parameters (heritability, genetic correlations, and genotype-by-environment interaction) for growth and stem form traits and to estimate the genetic gains achievable through selection at different ages, in order to guide the breeding strategy for E. tereticornis. The genotype-environment interaction for volume and survival exhibited moderate to low levels, with Type B genetic correlations ranging from 0.68 to 0.82. The combined analysis of the trials revealed that heritability increased with the age of measurement for all traits, with values ranging from low to moderate for growth variables (0.04 - 0.23) and stem form (stem straightness and forking) showing low values (0.05 - 0.12). Genetic correlations between growth traits at different ages and volume at 9 years were positive and high (0.32 - 0.99), while the correlations between stem form (stem straightness and forking) and volume were low to moderate (0.30 - 0.56). The results obtained suggest that it is possible establish a single breeding unit and that through early selection, genetic gains can be maximized, evaluation costs reduced, and improved seed obtained in a shorter timeframe. [ABSTRACT FROM AUTHOR]

Objective: To estimate the heritability (h²) of age at first parturition (AFP), longevity (L), useful life (UL), and productivity (P), as well as the genetic (rg) and phenotypic correlations between those traits in Brown Swiss and Holstein cows in Northwestern Honduras. Materials and methods: Cattle were raised under tropical conditions and intensive management. The model for AFP assessed the effect of contemporary group (herd, year and birth season combination) as fixed. The model used for L, UL and P included the contemporary group, age group at first calving and their interaction. Data were analyzed using restricted maximum likelihood procedure, adjusted to a univariate and to a bivariate animal model. Results: The h² estimated for AFP, L, UL and P were 0.16, 0.18, 0.25 and 0.09, respectively, in Brown Swiss cows, and 0.53, 0.49, 0.7 and 0.22, respectively in Holstein. Negative but favorable rg among Brown Swiss cow traits ranged from 0.31 to 0.46 between AFP and the other traits. However, for Holsteins cows, positive rg among AFP and the other traits here studied varied from 0.49 to 0.96. In both cattle breeds, rg among L, UL and P, traits were positive. Conclusions: For all traits evaluated low to medium heritability’s for BS suggest that a slow genetic improvement could be achieved if independent selection of traits is applied, and better response could be expected for H breed. For both breeds the positive rg among L, UL and P suggest thar similar selection criteria could be used. [ABSTRACT FROM AUTHOR]

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Informacion Tecnica Economica Agraria is the property of Asociacion Interprofesional para el Desarrollo Agrario (AIDA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In Ecuador there is a high genetic variability of Theobroma cacao L. However, its cultivation is mainly based on few materials, so it is necessary to develop and study new hybrids for its use in genetic improvement and commercial plantations. The phenotypic variability in the characteristics of the cobs was evaluated in 10 families of intraspecific cacao hybrids established in the experimental farm "Teodomira" in the province of Manabí, Ecuador, considering qualitative and quantitative descriptors. The specific combining ability (HCE) was calculated in the crosses made and the heritability of the quantitative characters. It was determined that there is a high genetic variability in the characteristics of the fruit at the inter- and intra-family level. However, most of the trees of the families analyzed have elliptical (44%) and ovoid (38%) cobs; more than 50% of the individuals presented cobs with obtuse apex, slight or absent basal constriction, medium or slight roughness, and intense yellow color pigmentation on the back; the average size of the cobs was 17.4 cm long and 8.1 cm diameter; fruit weight was between 624.3 and 422 g; seed weight per pod fluctuated between 130 and 96 g; and an average of 40 seeds per cob. The progeny obtained from the cross CCN51 × EET 103 presented the best HCE in terms of yield and seed weight. The evaluated characteristics of the cobs presented high and medium heritability (41-91%). There is a high genetic variability in the characteristics of the fruit of T. cacao, so it is possible to identify and select plants and progenies with desirable characteristics. Based on the calculated heritability, phenotypic selection is a suitable breeding method for this species. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales is the property of Academia Colombiana de Ciencias Exactas, Fisicas y Naturales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

El objetivo del estudio fue determinar el efecto de la polidactilia en el comportamiento productivo del cuy (Cavia porcellus) cruzados en la etapa de recría. Un total de 27 cuyes machos destetados con 20 días de nacidos y un peso promedio de 450 g, fueron distribuidos al azar en tres unidades experimentales por tratamiento y repetición: T1 = (testigo): cuatro dedos anteriores y tres posteriores, T2 = (cuyes con polidactilia): seis dedos anteriores y seis dedos posteriores y T3 = (cuyes con polidactilia): cuatro dedos anteriores y cuatro dedos posteriores y alimentados a base de forraje (Pennisetum typhoides x P. purpureum), balanceado comercial (engorde) y agua. Se evaluó la ganancia de peso, conversión alimenticia y el rendimiento de carcasa. Los datos fueron analizados a través de ANOVA, aplicándose la prueba de Duncan para la comparación post hoc (P

Quinoa (Chenopodium quinoa Willd.) is a crop with high nutritional and agronomic potential, adapted to environmental stress conditions. It is grown on a small scale in Mexico, and currently improved varieties are not available. In order to establish the basis to guide genetic improvement in Mexico, the objective was to determine the genetic variability, heritability and interrelationships of yield and its components in 16 quinoa genotypes, in a randomized complete block design, in six environments in the central high valleys of Mexico. The proportion of participation of the sources of variation genetic, environmental, and genotype × environment interaction was determined; as well as heritability, response to selection, and phenotypic correlations among morphological characters, yield and its components. Out of 15 variables evaluated, the genetic effects on thousand-grains weight and grain filling period were the most important; whereas for plant height at flowering, harvest index, and stem diameter, environmental effects were the most relevant. The genotype × environment interaction is not greater than 20 % for the 15 variables evaluated. The highest values for additive variance, heritability, and response to selection were for grains per square meter, yield, thousand-grains weight, grain filling period, and panicle emergence. The variables stem diameter, plant height at maturity, grains per square meter, yield per day, grain filling period, and panicle emergence were the most correlated with yield. Therefore, they can be used as indirect yield selection criteria in breeding programs to obtain materials with better agronomic characteristics. Based on the genetic parameters obtained and the association of the variables with yield, grains per square meter, yield per day and plant height at maturity are the most appropriate traits for indirect selection for yield. [ABSTRACT FROM AUTHOR]

Copyright of BIOAGRO is the property of Revista BIOAGRO and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Litter size at birth (LSB) is one of the most important economic traits in sheep and could be used in genetic improvement schemes for meat production. LSB is inherently a categorical trait and should be analysed with threshold models. Objective: Bayesian threshold models were used to analyze sheep LSB to estimate genetic parameters. Methods: Data was based on 7,901 LSB records from 14,968 dams and 682 sires collected from 1986 to 2012 at Makouie Sheep Breeding Station in Iran. Means of posterior distributions (MPDs) of LSB's genetic parameters were estimated, and the best-fitted models were selected using the deviance information criterion. Results: In the repeated measurement analysis, the estimated direct and maternal heritabilities, and permanent environmental effect (±SE), according to the best-fitted model (model 5), were 0.01 (0.010), 0.02 (0.014), and 0.01 (0.011), respectively. In the univariate analysis, the best estimates of direct and maternal heritabilities were 0.12 (0.064) and 0.08 (0.045), respectively. An increasing trend for direct and maternal heritabilities was observed in parity 2 (0.15 (0.082) and 0.25 (0.083), respectively). In the bivariate analysis, the best estimates of direct and maternal heritabilities for LSB were 0.03 (0.027) and 0.22 (0.041), respectively. The direct and maternal genetic correlations among parities were 0.25 (0.054) and 0.12 (0.021), respectively. Conclusions: The results showed a considerable influence of environmental factors on LSB in each parity of sheep; also, statistically different genetic parameters (p<0.05) were obtained from one parity to another, indicating the different and large influences of genetic and environmental factors for each parity. [ABSTRACT FROM AUTHOR]

Copyright of Revista Colombiana de Ciencias Hortícolas is the property of Revista Colombiana de Ciencias Horticolas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

El asma es una patología etiológicamente heterogénea resultante de una compleja interacción entre una susceptibilidad genética, factores del huésped y exposiciones ambientales. En el presente trabajo se revisan los aspectos genéticos implicados en el asma, los cuales fueron analizados desde la perspectiva del modelo tradicional de la herencia multifactorial. Fueron incluidos los estudios sobre su agregación familiar, concordancia en gemelos y heredabilidad, así como el conocimiento actual sobre genes candidatos, estudios de asociación amplia del genoma y las recientes contribuciones de la epigenómica y otros estudios ómicos, que en conjunto han aumentado nuestro conocimiento sobre su fisiopatología e interacciones ambientales.

El objetivo de este trabajo fue estimar la respuesta a la selección a través de diferentes índices de selección entre producción de metano y producción y componentes de la leche en los sistemas de lechería tropical especializada, doble propósito y lechería familiar. El muestreo de las emisiones de metano se realizó durante la ordeña mediante el equipo Guardian-NG. Se tomaron muestras de leche de manera individual durante el muestreo de metano. La extracción de ADN se realizó de folículos pilosos de todos los animales incluidos en el estudio. La estimación de los componentes de varianza y covarianza se realizó mediante la metodología de modelos mixtos. Se utilizaron los marcadores moleculares para construir la matriz de relaciones genómicas (Matriz G), debido a que no se contaba con información genealógica completa. La heredabilidad estimada para las emisiones de metano durante la ordeña fue de 0.18 y 0.32 para los análisis univariados y bivariados, respectivamente. Los resultados de las correlaciones genéticas entre porcentaje de grasa y proteína en leche con las emisiones de metano durante la ordeña fueron negativas, -0.09 y -0.18 respectivamente. La respuesta a la selección estimada mediante los índices de selección demostró que es factible obtener reducciones de hasta 0.021 mg/l de emisiones de metano durante la ordeña en cinco generaciones; lo anterior sin detrimento en los componentes de la leche.

El primer paso en un programa de desarrollo de cultivares es formar una población con variabilidad genética para los caracteres de interés. La selección de progenies provenientes de poblaciones constituye una valiosa herramienta para el mejoramiento genético. El germoplasma estudiado proviene del cruzamiento del compuesto Bulk Vert, formado por la recombinación de líneas endocriadas de buen comportamiento frente a Verticillium dahliae, por el compuesto Bulk AO originado por la recombinación de líneas endocriadas de alto contenido de ácido oleico. Constituyendo la población Bulk Vert x Bulk AO de la EEA INTA Pergamino de citoplasma mantenedor de la fertilidad compuesta por diversas fuentes de germoplasma de origen local y exótico. El objetivo principal de la mejora de esta población es derivar líneas endocriadas para la obtención de híbridos y los objetivos específicos fueron evaluar la heredabilidad y las asociaciones entre caracteres de interés agronómico en familias S0:1 de la población Bulk Vert x Bulk AO de la EEA Pergamino, el avance genético esperado por selección, determinar la influencia de los caracteres estudiados sobre el rendimiento y evaluar el uso de índices de selección para el mejoramiento de la población. Los caracteres evaluados fueron contenido de aceite, altura de planta, días para floración, diámetro del tallo, diámetro del capítulo, número de aquenios/capítulo, peso de 100 aquenios y rendimiento de aquenios por planta. Los resultados obtenidos muestran la variabilidad existente en la población, observándose diferencias entre familias para todos los caracteres. El carácter número de aquenios por capítulo debe ser considerado como criterio de selección para la obtención de genotipos con mayor rendimiento. La utilización de índices de selección en dicha población lograría obtener respuestas mayores a las esperadas por selección de caracteres individuales. La aplicación de estrategias de selección sobre esta población permitiría lograr avances en el mejoramiento de caracteres relacionados con rendimiento de aquenio y contenido de aceite.

Asthma is an etiologically heterogeneous disease resulting from a complex interaction between genetic. The genetic aspects involved in asthma, which were analyzed from the perspective of the traditional model of multifactorial inheritance, were susceptibility, host factors, and environmental exposures. In the present paper, studies on their family aggregation, concordance in twins, and heritability were analized; as well as the current knowledge about candidate genes, genome wide association studies, and epigenomics contributions and other omic studies that have increased our knowledge about their pathophysiology and environmental interactions. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of the Selva Andina Animal Science is the property of Fundacion Selva Andina Research Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Se estudió la variación genética en biomasa aérea (BM) o rendimiento de materia seca (RMS) y sus componentes en 400 familias de medios hermanos (FMH) de alfalfa, derivadas de las cruzas directa (CD, San Miguel x Oaxaca) y recíproca (CR, Oaxaca x San Miguel), y las variedades originales (SM, San Miguel y O, Oaxaca). El experimento se realizó en macetas en condiciones de intemperie en Montecillo, Texcoco, Estado de México, México. Se hicieron cortes de plantas completas a 5 cm de altura, cada cinco semanas en otoño-invierno 2014-2015 y cada cuatro semanas en primavera-verano 2015. El RMS, TAC (tasa absoluta de crecimiento), EUR (eficiencia en el uso de la radiación), NT (número de tallos por planta) y AP (altura de planta) fueron 32, 31, 32, 6 y 36 % más altos en la CD, y el RMS, TAC, EUR y AP fueron 30, 28, 30 y 34 % más altos en la CR que la media de SM y O. La selección permitió identificar 13 y 17 % de FMH sobresalientes en RMS y sus componentes en las CD y CR. El RMS de las FMH sobresalientes de la CD fue 11 % mayor que el RMS de las FMH sobresalientes de la CR, indicando la presencia de efectos genéticos maternos.

El peso vivo (PV) de 2,777 animales (1,377 hembras y 1,400 machos con 53,258 datos individuales entre 30 y 600 días de edad), nacidos entre febrero de 2000 y junio del 2011, se analizaron con un modelo de regresión aleatoria (RA) para estimar los componentes genéticos de (co)varianza a lo largo de la escala edad-sexo. La tasa de gestación (TG) junto con el peso vivo ajustado a 548 días de edad (PA548) se estudiaron mediante un modelo multicaracter (MT) obteniéndose un incremento en los estimados de heredabilidad (h2) para TG respecto al clásico modelo univariado (0.08 ± 0.03 vs 0.11 ± 0.02), aumentando la precisión del valor genético (VG) para TG en 15.7 %. La correlación genética (rg) entre TG y PA548 fue 0.31 ± 0.11. El RA mostró que el PV a través de la edad no puede considerarse como expresión del mismo rasgo en ambos sexos, ya que las rg fueron inferiores a 0.60. El análisis de componentes principales mostró que existen cambios importantes en la forma de crecimiento de los animales en la escala de edad representada en estos datos. Se manifestó un importante dimorfismo de origen genético, estimado como diferencia de los VG de machos y hembras en PV, el cual presenta una relación positiva con los VG de la TG.

La diferenciación entre las nociones de adaptación evolutiva y de adaptación ontogenética puede requerir algunas precisiones que van más allá de aquellas que se introducen en sus presentaciones más habituales. Pero reconocer eso no lleva, ni a invalidar esa distinción, ni tampoco a tornarla menos nítida. Por el contrario, esas precisiones, asociadas todas ellas con la noción de heredabilidad, permiten caracterizaciones de ambas nociones que son más claras que las habituales y que nos evitan la tentación de pensar que las mismas no son más que los polos, ideales e imposibles, de una gradación en la que toda distinción clara se disuelve.

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to evaluate the progress of heritabilities of the traits comprising the linear appraisal system in the Murciano-Granadina breed during the complete decade from December 2011 to December 2021. The estimated values for heritability were obtained from multivariate analyzes using the BLUP methodology and MTDFREML software. For 2021 heritabilities, a simple animal model was applied to records collected from 22,727 primiparous goats and 17,111 multiparous goats belonging to 85 herds. The model included the linear and quadratic and linear components of the covariates age and days in milk, respectively. The fixed effects considered in the model were herd, reproductive status, calving month and herd/year interaction. The animal was considered as a random effect. The variables studied included five characteristics related to Structure and capacity; Height at withers (EST), Body Depth (PC), Chest Width (AP), Rump Width (AG) and Rump Angle (ANG). Two traits related to dairy Structure; Angularity (ANGUL), Bone quality (HUESO). Six related to the mammary system; Anterior Insertion (IA), Rear Insertion Height (AIP), Me)dian Suspensor Ligament (LSM), Udder Depth (PU), Nipple Placement (CP) and Nipple Diameter (DP). Finally, three related to legs and feet; Rear and lateral views of the rear legs (VPPT and VLPT) and Mobility (MOV). The heritabilities for structure and capacity characters progressed from 0.22 to 0.28 including non-convergent variables (PC and ANG) in June 2012 to values between 0.10 and 0.41 with all variables converging in June 2011. 2021. Heritabilities for dairy structure progressed from 0.18 with non-convergent variables (HUESO) in 2011 to 0.17 to 0.25 in 2021. Heritabilities for mammary system traits progressed from 0.12 to 0, 27 with non-convergent variables (AU) in 2012 to between 0.10 and 0.41 in 2021. For legs and feet, heritabilities progressed from 0.16 to 0.17 with non-convergent variables (VLPT) to 0.09 a 0.22. Genetic progress is not only evident in heritability values, but there has been a notable reduction in the standard error of heritabilities from 0.1000 (0.080-0.120) to 0.000 (0.000-0.001) from 2011 to 2021. These results provide evidence of the enhancement in the effectiveness and precision of the linear qualification system applied during the past decade and its successful integration in the breeding program of the Murciano-Granadina breed. [ABSTRACT FROM AUTHOR]

The objective of the study was to evaluate the genetic parameters of the biometric characteristics of the fruit and seeds of C. ebano. The investigation was carried out in Montería, Córdoba (Colombia); ten trees were selected and from each, ten fruits taken at random. Variance analysis and estimation of genetic parameters for nine traits were carried out: fresh fruit weight, fruit length, fruit width, fruit thickness, number of seeds/fruit, weight of seeds by fruit, weight of one seed, volume of one seed and density of one seed. Statistical differences (p < 0.01) were detected between trees, for all traits except for width of the fruit and weight of a seed; denoting the existence of genetic variability between trees for fruit weight, fruit length, fruit thickness, number of seeds and density of a seed. The weight and length of the fruit presented the highest family heritability and narrow sense heritability (h2 Fam > 82 % and h2 E> 30 %). The expected genetic gain was greater than 10 % in five of the nine studied traits, and greater than 20 % for number of seeds and weight of seeds (27.31 and 27.87 %, respectively). The traits fruit weight and length could be transmitted to successive generations, with greater chance of success, by phenotypic selection of trees. [ABSTRACT FROM AUTHOR]

The number of ears per plant or prolificacy is an important yield component in maize varieties adapted to rainfed conditions. The objective of this study was to analyse the genotype × environment interaction in the expression of prolificacy and to estimate genetic effects and their relationship with grain yield in maize. Four lines were included, two selected for prolificacy and two non-prolific. Direct and reciprocal crosses were made between a prolific and a non-prolific line; in each case, backcrosses to both parents and respective F2 were obtained. Prolificacy (PRO), flowering asynchrony (ASI) and grain yield (REND) were considered in this study. The genotype × environment interaction (IGA) was analysed. For each cross and respective filial generations, heterosis and additive genetic effects, dominance and epistatic effects were estimated. PRO and REND were found to depend on environmental conditions, with mean values of 5.53 and 3.53 Mg ha-1 and 1.25 and 1.10 for yield and prolificacy in the two contrasting locations. Prolificacy interacted with environment in similar proportions to grain yield, while heritability for prolificacy was higher than for grain yield with values 0.63 vs. 0.41. The heterosis estimate depends on the specific crosses and it reached respective average values of -13 and 186% in prolificacy and yield. Additive genetic effects determined the expression of prolificacy and flowering asynchrony, while the dominance effect determined grain yield. In the crosses, when the prolific line was used as the male parent, epistatic additive × dominance effects were present in flowering asynchrony, prolificacy and grain yield. [ABSTRACT FROM AUTHOR]

The main objective of this research study was to quantify the genetic parameters of 16 fruit and seed traits of Benincasa hispida (Thunb.) Cogn from Montería (Colombia). Ten families of half siblings (FHM) were evaluated in a completely randomized design with five replications. The results showed differences only between FHM for seed width (SW). The estimates of genetic variability were higher in SW and seed thickness, where the genetic component represented 81.58% and 45.91% of the phenotypic variance. The greatest heritability in broad sense (h2 A = 81.58%) and strict sense (h2 E = 13.05%) occurred in SW. Expected genetic gain expressed as a percentage of the mean occurred in SW and seed volume, being 60% higher than that of the general mean. In conclusion, the genetic parameters obtained here indicate that selecting fruits with broad, thick, and voluminous seeds would allow obtaining vigorous seedlings for propagation. [ABSTRACT FROM AUTHOR]

En Argentina, más específicamente en los pastizales del sur de la provincia fitogeográfica del Monte, Pappophorum vaginatum Buckley es prácticamente la única especie que provee forraje para los animales durante el verano. Debido a esto, se necesitan estudios orientados a lograr la mejora genética en esta especie que combine los efectos de la selección natural en el ambiente local y los de la selección artificial para caracteres de interés agronómico, especialmente los vinculados al control de la implantación y a la producción de forraje y semillas. Los objetivos de este estudio fueron determinar (a) los componentes de la varianza y coeficientes de variación (a nivel fenotípico, genotípico y ambiental), y (b) la heredabilidad en sentido amplio para varios caracteres de interés agronómico vinculados a la implantación, y la producción de forraje y semillas en cuatro poblaciones espontáneas de Pappophorum vaginatum recolectadas en la región semiárida de la provincia de Buenos Aires. También se observaron asociaciones entre dichos caracteres. Según la población, resultaron significativos (p?0,05) del análisis de varianza entre 6 y 12 de los 14 caracteres de interés agronómico estudiados para cada una de las poblaciones, con valores altos de heredabilidad y una relación superior a 1 entre el coeficiente de variación genético y el coeficiente de variación ambiental. Esto muestra que las expectativas de lograr algún avance genético en un programa de selección de Pappophorum vaginatum serían promisorias para varios caracteres de interés agronómico, inclusive en el corto plazo.

Objetivo. Estimar la heredabilidad y las correlaciones de la para tres caracteres relacionados con el crecimiento en bovinos criollos Romosinuano, y construir un índice de selección (IS). Materiales y métodos. Se analizó una base de datos conformada por 4079 registros de peso al nacimiento (PN), al destete (PD) y a los 16 meses de edad (P16m), obtenidos en el periodo 1943 – 2018, proveniente del hato del centro de investigación Turipaná. Se estimaron tanto los valores de heredabilidad para cada carácter como sus correlaciones, mediante el modelo animal multivariado; los valores genéticos (VG) y su relación usando el análisis de componentes principales. Resultados. Las correlaciones genéticas entre PN y PD, PN y P16m, y PD y P16m fueron de magnitud moderada a alta y positivas, lo que indica una asociación genética favorable entre estos caracteres. Los VG estandarizados para PN, PD y P16m exhibieron una alta asociación con el primer componente principal. Las estimaciones de heredabilidad total para PN, PD y P16m fueron igual a 0.18 ± 0.04, 0.16 ± 0.04 y 0.13 ± 0.04, respectivamente. Conclusión. Los caracteres PN, PD y P16m responderán lentamente a la selección, sin embargo, podría mejorarse mediante la construcción de IS basados en los componentes principales.

El objetivo del estudio fue evaluar los parámetros genéticos de las características biométricas del fruto y semillas de Caesalpinia ebano. La investigación se realizó en Montería (Colombia), se seleccionaron diez árboles, y de cada uno diez, frutos tomados al azar. Se realizaron análisis de varianza y estimación de parámetros genéticos para nueve características: peso fresco del fruto, largo del fruto, ancho del fruto, grosor del fruto, número de semillas/fruto, peso de semillas por fruto, peso de una semilla, volumen de una semilla y densidad de una semilla. Se detectaron diferencias estadísticas (p < 0,01) entre árboles, para todas las características, excepto para el ancho del fruto y peso de una semilla; denotando la existencia de variabilidad genética entre los árboles para peso del fruto, largo del fruto, grosor del fruto, número de semillas y densidad de una semilla. El peso y largo del fruto presentaron la heredabilidad media familiar y heredabilidad en el sentido estricto con los valores más altos (h2Fam > 82 % y h2E > 30 %). La ganancia genética esperada fue mayor del 10 % en cinco de las nueve características estudiadas, y mayor del 20 % para número de semillas y peso de las semillas (27,31 y 27,87 %, respectivamente). Los caracteres peso y largo del fruto se podrían transmitir a las generaciones sucesivas, con mayor posibilidad de éxito, mediante la selección fenotípica de árboles.

Copyright of Revista Nacional de Odontología is the property of Universidad Cooperativa de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Colombiana de Ciencia Animal - RECIA is the property of Revista Colombiana de Ciencia Animal - RECIA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tropical Grasslands / Forrajes Tropicales is the property of International Centre for Tropical Agriculture - CIAT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Antecedentes: No existen estudios que permitan desarrollar esos programas para su conservación y mejoramiento genético de cobayos suramericanos. El objetivo de este artículo fue analizar factores genotípicos y ambientales que influyen en los rasgos de crecimiento de una línea nativa de cuyes del sur de la sierra ecuatoriana. Métodos: El trabajo se llevó acabo en la granja experimental de Irquis de la Facultad de Ciencias Agropecuarias de la Universidad de Cuenca, con cobayos pertenecientes a dos sublíneas nativas originarias de criadores rurales de las provincias de Azuay y Cañar. Los rasgos de pesos por edad y las ganancias en peso diario medidos en gramos fueron analizados mediante un modelo de análisis de varianza mixto con los efectos fijos; tamaño de la camada (5), época (semestral), sexo y número de parto de la madre con el software R 3.4.4. Las sublíneas Azuay (1) y Cañar (2) y los padres dentro de sublíneas conformaron los efectos aleatorios. Se determinaron los estadígrafos básicos. Resultados: Los pesos al nacer, al destete y a los 90 días, medidos en gramos, fueron 110,2 ± 1,81, respectivamente, y 117,0 ± 1,44; 212,2 ± 4,30 y 221,13 ± 3,38; 540,7 ± 12,01 y 659,1 ± 9,44. Las heredabilidades para estos caracteres fueron 0,09 ± 0,101; 0,34 ± 0,201 y 0,11 ± 0,111. Además, se analizaron los pesos a los 30; 45; 60; 75 y 90 días de nacidos y las ganancias entre todas las edades. Se determinaron los predictores BLUP para los padres de ambas sublíneas. La variación y las heredabilidades permiten aplicar selección en el peso al destete y a los 90 días. Conclusiones: La línea mostró niveles de crecimiento bajos, pero hay suficiente variación y sus heredabilidades permitirían esperar progresos favorables en caso de realizarse un programa de selección a mediano plazo.

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introducción. La edad de selección temprana permite acelerar los programas de mejoramiento genético y optimizar la producción forestal, en este caso con melina (Gmelina arborea), la cual es la segunda especie forestal más importante para la reforestación comercial en Costa Rica. Objetivo. Determinar la edad óptima de selección de melina en Costa Rica, mediante la evaluación de cuatro caracteres genéticos. Materiales y métodos. El estudio se llevó a cabo en Siquirres y Pérez Zeledón, región Caribe y zona sur de Costa Rica, respectivamente. Se utilizó un diseño de bloques completos al azar con cuatro repeticiones (sitios 1 y 3) y seis repeticiones (sitio 2) por tratamiento. El distanciamiento inicial fue de 4 m x 3 m para el ensayo del El Porvenir y de 4 m x 4 m para los ensayos de Siquirres y La Ceniza. Se calcularon parámetros genéticos a diferentes edades, para las variables diámetro a la altura del pecho (DAP), altura comercial, volumen comercial y calidad del fuste, con el software SELEGEN, el cual se basa en el método REML/BLUP, además, se realizaron correlaciones genéticas entre las variables evaluadas. Resultados. El DAP y el volumen comercial fueron los caracteres con mayor control genético, presentaron los mayores valores promedio de heredabilidad individual y media clonal, entre los 2,8 y 4 años de edad. Las mayores correlaciones genéticas (>80 %), entre las variables DAP y volumen comercial, se presentaron a partir de los 2,8 años de edad, que aumentan en edades posteriores hasta alcanzar valores mayores a 90 %. Conclusión. Pudo determinarse el rango entre los 2,8 y 4 años, como posible edad de selección genética para melina.

El melón, se cultiva en climas templados y cálidos de todo el mundo; no obstante, la información sobre la variabilidad genética del melón criollo ecuatoriano es limitada, para iniciar programas de mejoramiento. El objetivo de esta investigación fue evaluar características de producción y de calidad del fruto, en 20 familias de medios hermanos, seleccionadas de melón criollo ecuatoriano. El estudio, se realizó en el cantón Palenque, Ecuador. La semilla de las 20 familias seleccionadas, se dispusieron en bloques completos al azar, con tres repeticiones. Las diferencias entre familias fueron significativas para siete caracteres. La familia 73 presentó mayor peso, diámetro, longitud, espesor, cavidad del fruto y producción por hectárea; la familia 7 obtuvo el mayor promedio para grosor de corteza, sólidos solubles y firmeza de pulpa, mientras en la familia 196, se destacó la acidez de pulpa. Existen asociaciones fenotípicas altamente significativas entre peso de fruto con diámetro, longitud, espesor de pulpa, cavidad de fruto y producción por hectárea, en donde los coeficientes de variación genotípica fueron mayores que los coeficientes de variación ambiental. Las estimaciones de heredabilidad en sentido amplio fueron de magnitud alta (>60%), para los 10 caracteres evaluados y la magnitud del progreso genético esperado fue alta (>20%), para peso del fruto, producción por hectárea y grosor de corteza; moderada, para cavidad del fruto y sólidos totales. La selección para melones variedad dudaim, se debe centrar en contenido de sólidos solubles y peso del fruto, que presentó una alta correlación con el rendimiento.

Los componentes de varianza y la heredabilidad de características de grano blanco, relacionadas con la calidad industrial de la harina nixtamalizada, fueron estimadas en cinco híbridos de maíz (Zea mayz L.) del tipo "media altura". El objetivo del trabajo fue conocer los componentes de varianza, la heredabilidad y la correlación de características de grano blanco asociadas con la calidad industrial del nixtamal de híbridos de maíz. Durante el ciclo Verano 2003, se estableció el experimento bajo condiciones de riego en tres localidades representativas de la región El Bajío. Se evaluaron nueve características físicas de grano y siete asociadas al proceso de "nixtamalización". Se identificaron cinco rasgos de interés para la industria del nixtamal: Peso o masa hectolítrica (densidad de grano) y peso de 100 granos, asociados al rendimiento de grano a tortilla; endospermo tipos harinoso y córneo, relacionados con la calidad de la tortilla; pericarpio retenido, asociado al rendimiento de grano a tortilla. La variable pericarpio retenido mostró una heredabilidad alta (h2 > 0.50), mientras que los caracteres peso hectolítrico, peso de cien granos, endospermo harinoso y endospermo córneo presentaron baja heredabilidad (h2 < 0.50). De acuerdo a los resultados observados en esta investigación, se recomienda seleccionar grano de maíz con valores de endospermo (porcentaje base seca del grano) de tipo harinoso menor de 36.4 %, tipo duro o córneo mayor de 46.4 %; además, el pericarpio retenido debería ser mayor de 35.8 %. Abstract Components of variance and heritability of white grain characteristics, related to industrial quality of nixtamalized corn flour, were estimated in five maize hybrids (Zea mayz L.) type "media altura". The objective of this study was to know components of variance, heritability and correlation coeficients among grain traits associated to nixtamal quality of white grain maize hybrid. During the Summer-2003 season, an experiment was established under irrigation conditions in three locations representative of the agriculture region "El Bajío". Nine physical characteristics of grain and seven more traits associated to corn "nixtamalización" industrial process were evaluated. Five important characteristics for "nixtamal" industry were identified: Hectoliter weight (grain density) and weight of 100 grains, associated to yield of grain to tortilla; endosperm corn types flour and hard, related to tortilla quality; retained pericarp, associated to yield of grain to tortilla. The variable retained pericarp showed a high heritability (h2 > 0.50), while for the characteristics: Hectoliter weight, weight of 100 grains, endosperm types flour and hard were the estimated heritability values were lower than 0.50. According to the observed results, it is recommendable to select endosperm corn values (percentage based on grain dry weight) type flour below 36.4 %, type hard greater than 46.4 %; moreover, the retained pericarp should be above 35.8 %. Keywords: Components of variance, heritability, genetic variation coefficient, nixtamal quality, retained pericarp

Meat goat breeding programs should prioritize the identification and selection of genetically superior animals for traits related to meat quality and carcass yield in order to increase the value of the final product. Objective: To estimate (co)variance components and genetic parameters for ultrasound-measured carcass traits, body size and body weight in Anglo- Nubian breed goats raised in the Mid-North region of Brazil. Methods: (Co)variance components and genetic parameters were estimated using the single and two-trait animal model analyses via Bayesian inference for loin eye dimensions (area, length, and depth), sternal fat thickness, rump height, chest circumference and depth, leg perimeter, and body weight. Results: Heritability estimates were higher when two-trait analyses were used. This finding implies that it is possible to recover part of the additive genetic variance included in the residual variance due to the correlation between traits. Genetic correlations between carcass and body size traits showed different magnitudes. On the other hand, genetic correlations between the traits related to muscularity showed high magnitudes. Conclusions: Body weight was not a good indicator of muscularity; therefore, it is not recommended as a criterion for indirect selection to improve carcass traits of Anglo-Nubian goats. Leg perimeter and chest circumference may be important to construct selection indexes in meat goat breeding programs. [ABSTRACT FROM AUTHOR]