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The genetic improvement of any breeding population largely depends upon the magnitude of genetic variability present. This study was carried out to estimate parameters of the genetic variation among 13 quantitative traits of bread wheat evaluated at INRAA-Setif institute (Algeria) during the 2020--2021 crop season in a rainfed environment. 34 genotypes including four control checks were planted in a randomized complete block design with three replications. Genotypes showed significant variations for almost all the studied traits. Proline content, spikes weight, and grain yield exhibited a high genotypic coefficient of variation along with moderate to high heritability coupled with a high genetic gain, suggesting the implication of additive gene action. The number of spikes, spikes weight, and thousand kernel weight were significantly and positively correlated with grain yield at both phenotypic and genotypic levels. Path analysis results showed that spikes weight is an important route through which most of the measured traits influenced indirectly grain yield. Lines L1, L20, L28, L16, and L18 exhibited a sizeable grain yield advantage, which suggests they are potential candidates for future release and could be incorporated into the wheat breeding programs as parents to improve yield in the rainfed environments of Algeria. [ABSTRACT FROM AUTHOR]

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 objetivo del presente estudio fue evaluar el impacto de la inclusión de información extranjera de sementales de la raza Holstein, sobre su evaluación genética para las características de producción de leche (PL), grasa (PG) y proteína (PP) en kilogramos. Lo anterior, se logró mediante la comparación de valores genéticos (VG) y confiabilidades (CF), agrupación de sementales por número de hijas, ordenamiento de los sementales y la superioridad genética esperada por año (), con diferentes escenarios determinados por la intensidad de selección () de sementales usados en la evaluación genética nacional (EG-MEX), los incorporados a la evaluación genética internacional con hijas en México (EG-I) y la evaluación genética internacional con o sin hijas en México (EG-MACE). En total, se analizó la información de 5,825 sementales en la para PL y 3,914 para PG y PP. El impacto de la información extranjera en la EG-MEX es positivo, debido a que mejora la CF de los VG de los sementales usados en México. También, permitió observar diferencias importantes de los VG y CF entre las evaluaciones, generando una oportunidad de mejoramiento en la población Holstein mexicana; por lo que, es recomendable continuar con la participación en el programa de Interbull, y considerar el uso de la información validada de manera internacional en los procesos de selección de animales productores de leche y sus componentes. Estas acciones pueden contribuir de manera importante en el incremento del progreso genético productivo a nivel nacional.

Multi-trait best linear unbiased prediction (BLUP) is, generally, the most appropriate method to genetic evaluation because it considers the genetic and residual correlations among traits and conduct to higher selection accuracy. Thus, the present study aimed to identify traits correlated to the fiber length via path analysis under multi-trait BLUP for the cotton breeding. To this end, thirty-six elite lines were evaluated in three environments and phenotyped for many traits related to fiber quality and agronomic traits. Variance components were estimated via residual maximum likelihood (REML). The genetic correlation coefficients among traits were obtained through mixed model output, and to graphically express these results a correlation network was built. Subsequently, we performed path analysis considering fiber length as a principal dependent variable. Genetic parameters obtained by multi-trait BLUP model indicate that the phenotypic variance for most traits is mostly composed of residual effects, which reinforces the need for using more accurate statistical methods such as multi-trait BLUP. The results found for genetic correlations and path analysis under multi-trait BLUP reveal the difficulty of selection based on important fiber quality traits, especially fiber length, since most traits show very low cause-and-effect relationship, and other important traits present undesirable cause-and-effect relationship. Highlights Multiple-trait BLUP is the most appropriate method to predict genetic values. This is the first study in cotton to perform path analysis under multiple-trait BLUP. The findings of this study indicate that there is no genotype presenting all desirable traits.

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]

This study aimed to estimate the response to selection through different selection indices between methane production and milk production and its components in specialized tropical, dual-purpose, and family dairy systems. Methane emissions were sampled during milking using the Guardian-NG gas monitor; milk samples were collected individually during methane sampling. DNA was extracted from the hair follicles of all the animals included in this study. The variance and covariance components were estimated using the mixed model methodology. Due to the incomplete genealogical information, molecular markers were used to build the genomic relationship matrix (Matrix G). The estimated heritability for methane emissions during milking was 0.18 and 0.32 for the univariate and bivariate analysis, respectively. The genetic correlation between the milk fat and protein percentages and methane emissions during milking was negative, -0.09 and -0.18, respectively. The response to selection, estimated through selection indices, demonstrated that it is feasible to reduce methane emissions up to 0.021 mg/L during milking in five generations without detriment to milk components. [ABSTRACT FROM AUTHOR]

To increase yield, breeding programs must search for innovative and efficient methodologies for the development and selection of superior genotypes. Therefore, this study aimed to compare the single- and multiple-trait best linear unbiased prediction (BLUP) in genetic selection of parents and hybrids of grain sorghum. For this, an experiment conducted in alpha-lattice design with two replications was used. Flowering time (FT), plant height (PH), and grain yield (GY) were evaluated in 502 grain sorghum hybrids obtained by the cross of ten restorer lines and 54 male-sterile lines. Variance components were estimated via restricted maximum likelihood (REML). Significant effects of restorer lines, of male-sterile lines, and of specific combining ability were detected by the likelihood ratio test (LRT). The estimates of variance components, genetic parameters, and correlations were similar when obtained via single- and multiple trait- BLUP. Considering hybrids, the multiple-trait BLUP resulted in slightly higher predicted selection gain for the three evaluated traits and, therefore, can be efficiently applied in the genetic selection of grain sorghum.

El objetivo del presente estudio fue evaluar el impacto de la inclusión de información extranjera de sementales de la raza Holstein, sobre su evaluación genética para las características de producción de leche (PL), grasa (PG) y proteína (PP) en kilogramos. Lo anterior, se logró mediante la comparación de valores genéticos (VG) y confiabilidades (CF), agrupación de sementales por número de hijas, ordenamiento de los sementales y la superioridad genética esperada por año (ΔIs/ys), con diferentes escenarios determinados por la intensidad de selección (ips) de sementales usados en la evaluación genética nacional (EGMEX), los incorporados a la evaluación genética internacional con hijas en México (EG-I) y la evaluación genética internacional con o sin hijas en México (EG-MACE). En total, se analizó la información de 5,825 sementales en la para PL y 3,914 para PG y PP. El impacto de la información extranjera en la EG-MEX es positivo, debido a que mejora la CF de los VG de los sementales usados en México. También, permitió observar diferencias importantes de los VG y CF entre las evaluaciones, generando una oportunidad de mejoramiento en la población Holstein mexicana; por lo que, es recomendable continuar con la participación en el programa de Interbull, y considerar el uso de la información validada de manera internacional en los procesos de selección de animales productores de leche y sus componentes. Estas acciones pueden contribuir de manera importante en el incremento del progreso genético productivo a nivel nacional. [ABSTRACT FROM AUTHOR]

The objectives were to analyze the presence of genetic variance in the residual variance of behavior notes in fighting bulls. From a livestock ranch, the conditional residuals were analyzed (RCON; ê = y - [y|a] = y - Xß - Za) and marginal (RMAR; = y - [y] = y - Xß), from the notes of horse tienta (n, 2369), foot tienta (n, 1432), horse bullfight (n, 792) and foot bullfighter (n, 820); in two databases: BD1, logarithmic transformation; BD2, logarithmic transformation eliminating extreme data (x ±2s). With the MTDFREML software, a multivariate analysis (four notes) was performed within the residual type and for each database; heritability (h) and genetic correlations (rg) were calculated through variables. The h2 ranged between 0.14 and 0.96, with an average value of 0.58; h2 of RMAR in BD2 presented above estimates (> 0.78). These results show genetic variability in the residual variance and present the possibility of response to selection (environmental channeling) to reduce environmental variance. The selection for residual variance can improve the response to the concepts of resilience, plasticity, robustness and rusticity. The rg were positive, in the range of 0.01 to 0.99 and an average value of 0.79; with these rg there may be a correlated response in the residuals of the four notes. [ABSTRACT FROM AUTHOR]

Estimates of genetic parameters allow to determine the genetic variability present in a population, constituting one of the initial steps in a breeding program. The objectives of this study were to estimate genetic parameters and identify agronomic traits directly and indirectly correlated with grain yield (GY), as well as to estimate their direct and indirect effects on the yield of special-grain common bean genotypes. The experiment was carried out in the 2016/2017 season, in a complete blocks design, with three repetitions. The evaluated traits were days to flowering, days to maturity, first pod height, plant height, number of pods per plant, number of grains per pod, mass of hundred grains, and grain yield. Data were subjected to analysis of variance, and genetic parameters were estimated followed by phenotypic and genotypic correlations. Phenotypic and genotypic correlations were split into direct and indirect effects by path analysis. The studied population seemed promising for breeding purposes considering most traits. Correlation and path analyses indicated that there was a positive direct effect of days to maturity on grain yield. The traits days to maturity and mass of hundred grains can be used in indirect selection aiming at higher grain yield. Path analysis also revealed that the indirect effects of number of pods per plant and number of grains per pod should be taken into consideration in the genetic breeding of the common bean for the increased grain yield. [ABSTRACT FROM AUTHOR]

An ethogram was designed to disaggregate the behaviour of fighting cattle, quantify bravery and consolidate selection. 933 females and 787 males from the Colombian cattle ranch "Ernesto González Caicedo" (EGC), Santa Coloma lineage, at Popayán, Cauca, Colombia, were analysed. The behavioral units (UC) identified were fixity (FIJ), starting distance (DIS), readiness (PRO), reloading (RGR), absence of pain (DOL), degree of jealousy (GEN), distance (RDO), humiliating (HUM), repeat (REP), lunge type (TEM), bottom (FON), strength (FZA) and absence of defects (AUD). Information was analysed with DeLidia® software, developed for this research. The CU were adjusted according to the effect of age, consanguinity, weight, sex, place, type of celebration, number of rods, bullfighter and picador. Inheritance indices, phenotypic and genetic correlations, and breeding values of stallions were estimated. The resulting h2 values for the UC FZA and REP were 0.06 ± 0.03 and 0.36 ± 0.026, respectively, with an average of 0.21 ± 0.05 for all UC. All rg were positive except for those involved with FZA. The lowest positive value of rg was 0.1 for GEN and HUM, while the highest was 0.79 for FIJ and RDO. Trends of VG were positive and different from zero (P <0.01), except FZA (-0.004 ± 0.0004). The gain per year, as a percentage part of the mean, was -0.191% for FZA and 1.024% for REP. Resultant h2 and VG suggest their usefulness in selection programs, favouring greater genetic progress. [ABSTRACT FROM AUTHOR]

Background: Somatic cell score is an important parameter to predict milk quality and health of cows. However, in countries like Brazil, this trait is still not selected on a large scale, and no genetic parameters are reported in the literature. Objective: To estimate the variance components and genetic parameters for somatic cell score, milk yield, fat yield, protein yield, fat percentage, and protein percentage in Holstein cows. Methods: Records from 56,718 animals were used to estimate variance components, heritability, and genetic correlations using a multi-trait animal model by the REML method. Results: The heritability estimates were 0.19 for somatic cell score, 0.22 for milk yield, 0.26 for fat yield, 0.18 for protein yield, 0.61 for fat percentage, and 0.65 for protein percentage. The estimates of genetic correlations among analyzed traits ranged from -0.50 to 0.82. Conclusion: The low heritability observed for somatic cell score indicates that selection for this trait should result in benefits related to animal health and milk quality, but only in the long term. The low correlation between productive traits and somatic cell score indicates that inclusion of somatic cell score in animal breeding programs does not interfere negatively with the genetic selection for milk yield or solids. [ABSTRACT FROM AUTHOR]

The reproductive performance of the cow and its maternal ability affect the profitability of the cow-calf production systems. The objective of this study was to estimate components of (co) variance, heritability (h2) for the annual productivity index (PI), age at first calving (AFC), calving interval (CI) and weaning weight (WW), and genetic correlations (rg) among these traits, as well as the response to the selection in PI. The PI was calculated as the WW of the calf times 365, divided by the CI. The performance records used are from Brangus Negro (BN), Salers (SA) and Suizo Europeo (SE) cattle, coming from ranches in several Mexican states; the pedigree included 68 474 (BN), 15 594 (SA) and 187 294 (SE) animals. Univariate and bivariate analysis, which consider the animal model, were performed to estimate components of (co) variance and genetic parameters using the restricted maximum likelihood method, with the ASReml program. The direct h2 for PI varied from 0.06 to 0.12, for AFC from 0.01 to 0.15, for CI from 0.07 to 0.12 and for WW from 0.15 to 0.23. The estimators of rg ranged from -0.09 to -0.76 for PI-AFC, from -0.90 to -0.93 for PI-CI and from 0.17 to 0.97 for PI-WW. The selection for WW resulted in higher PI correlated changes (between 0.06 and 1.53 kg cow-1 year-1) than those obtained when using the direct selection for PI. The genetic correlations of PI with the other traits were favorable. The selection for WW, and then for PI, can genetically improve the annual productivity of cows. [ABSTRACT FROM AUTHOR]

El objetivo del presente estudio fue estimar parámetros genéticos para el peso adulto (PEA) y tasa de crecimiento (TAC) de bovinos Tropicarne, derivados del modelo no lineal de Brody; así como analizar las posibles relaciones genéticas de estas variables con el peso al destete (PD). Se analizaron 994 datos de PEA (kg) y de TAC (kg−1 mes−1 ) y 1 506 datos de PD ajustado a 240 d. Los valores promedio y la desviación estándar (±) para PEA, TAC y PD (kg) fueron de 419.1 ± 94.4, 0.0081 ± 0.0039 y 206.8 ± 34.1, respectivamente. El pedigrí se integró por 2 504 individuos. Se realizó un análisis multivariado, a partir de un modelo mixto que consideró como efectos jos los grupos contemporáneos y la covariable edad de la vaca al parto (lineal y cuadrático); y como aleatorios los efectos genéticos directos y maternos, maternos de ambiente permanente y residuales. Se estimó la heredabilidad directa (h2 a ) y materna (h2 m), las correlaciones genéticas entre los efectos directos (raa), los maternos (rmm), y los directos con maternos (ram). Las h2 a oscilaron de 0.18 a 0.30, y las h2 m de 0.07 a 0.39; lo cual indica una probable respuesta a la selección en PEA y TAC. Todas las correlaciones genéticas fueron positivas en un intervalo de 0.09 a 0.87, con excepción de raa entre PEA y TAC (-0.57); este antagonismo genético indica que los individuos con tasas altas de crecimiento no son los de mayor peso adulto.

El objetivo fue estimar los parámetros genéticos para tamaño de camada al parto (LSB), tamaño de camada al destete (LSW), peso de camada al parto (LWB), peso de camada al destete ajustado a 60 días (LW60) y el intervalo de parto (LI) en ovejas de Pelibuey y comparar índices de selección. Heredabilidades y correlaciones genéticas y fenotípicas para las características fueron calculadas usando modelos animales. Dieciséis índices (IS1-IS16) basados en la metodología de ganancia genética deseada fueron comparados. Los índices fueron combinaciones de LW60 con LSB, LSW, LWB y LI. Las heredabilidades para LSB, LSW, LWB, LW60 y LI fueron 0.07, 0.02, 0.08, 0.09 y 0.03, respectivamente. Las correlaciones genéticas variaron de 0 a 0.79, mientras que las correlaciones fenotípicas variaron de -0.07 a 0.62. El mejor índice basado en la eficiencia relativa de un índice fue 2.31*LSB + 0.24*LW60. En conclusión, las heredabilidades estimadas fueron bajas y el mejor índice de selección incluyó LSB y LW60. El número y el tipo de rasgos contenidos en el índice influyeron en el progreso genético.

To increase yield, breeding programs must search for innovative and efficient methodologies for the development and selection of superior genotypes. Therefore, this study aimed to compare the single- and multiple-trait best linear unbiased prediction (BLUP) in genetic selection of parents and hybrids of grain sorghum. For this, an experiment conducted in alpha-lattice design with two replications was used. Flowering time (FT), plant height (PH), and grain yield (GY) were evaluated in 502 grain sorghum hybrids obtained by the cross of ten restorer lines and 54 male-sterile lines. Variance components were estimated via restricted maximum likelihood (REML). Significant effects of restorer lines, of male-sterile lines, and of specific combining ability were detected by the likelihood ratio test (LRT). The estimates of variance components, genetic parameters, and correlations were similar when obtained via single- and multiple trait-BLUP. Considering hybrids, the multiple-trait BLUP resulted in slightly higher predicted selection gain for the three evaluated traits and, therefore, can be efficiently applied in the genetic selection of grain sorghum. [ABSTRACT FROM AUTHOR]

Objective. Evaluate genetically the traits of birth weight and weaning weight in commercial Brahman cattle. Materials and methods. A total of 1.015 records of birth weight (BWT) and weaning weight adjusted to 270 days (WW270), were evaluated. Data correspond to the offspring born between 2002 and 2014 belonging to "La Envidia" farm, located in the municipality of Planeta Rica, Córdoba. A bi-character animal model that included, additive genetic effect, maternal effect and sex, month, year and age at weaning as fixed effects, was used. Genetic parameters were estimated using the MTDF-REML software. Results. The average and coefficient of variation (CV) of BWT was 29.62±3.13 kg and 10.59%, respectively. The mean and CV for WW270 was 216.71±26.97 kg and 12.45%, respectively. The estimates of direct heritability were 0.44±0.143 and 0.39±0.12 for BWT and WW270, respectively. Maternal heritability was 0.09±0.092 and 0.42±0.087 for BWT and WW270, respectively. The estimated genetic and phenotypic correlation between the evaluated characteristics was 0.11 and 0.13, respectively; with genetic progress per year of -2.02 kg for BWT and 7.81 kg for WW270. Conclusion. The estimations of heritability indicate the existence of direct additive genetic variability, evidencing the opportunity of genetic gain through selection. However, environment have a great influence on birth weight and weaning weight traits, which is why special attention should be paid to the handling and nutrition of females during pregnancy and of calves from birth to weaning. [ABSTRACT FROM AUTHOR]

The 30-day weight (P30; 1072) and the weaning (P75; 1750) of 10 flocks were analyzed in Hampshire lambs, to develop two objectives: to evaluate the expression of the genetic effects in the pre-weaning growth, and to analyze the possible implications in the genetic progress. The analyzes were univariate (ANAU) and bivariate (ANAB), through mixed models that included the fixed effects of contemporary groups and the covariable age of the mother; and as random, the direct and maternal genetic effects, the genetic covariance between them and the maternal effects of the permanent environment. Direct herilabilily (h²) and maternal (m²), genetic correlations (rdm), and genetic values (VG) were estimated. With the rank correlations (CR) in the VG, the ranking of the population and of the sire was analyzed; in addition, the genetic trends (TG) of the VGs were analyzed. The h² was in the range of 0.14±0.03 to 0.19±0.04; the m² in ANAU was 0.08±0.04 and 0.02±0.03, with ANAB the estimate was of 0.22±0.05 and 0.13±0.03. The rdm of ANAU was +1±0.15 in P30 and -1±0.18 in PD, changing in the ANAB to -0.46±0.10 and -0.20±0.07, respectively. The behavior of the TG in the ANAU was associated to the magnitude and sign of the rdm; likewise, the rdm of the ANAU implied changes in the ranking of sires, which was reflected in the TG and the CRs. [ABSTRACT FROM AUTHOR]

Introducción: Los bovinos Romosinuano son originarios de Colombia, pero en México hay ganaderos dedicados a su cría desde hace dos décadas. Su población en México es pequeña y no se encontraron estudios que documenten aspectos elementales para establecer un programa de mejoramiento genético en esta población. El objetivo de este estudio fue estimar los parámetros genéticos de pesos al nacimiento (PN) y al destete ajustado a 240 d (PD), así como documentar las tendencias genéticas para estas dos características en la población Romosinuano de México. Método: La base de datos provino de la “Asociación Mexicana de Criadores de Ganado Romosinuano y Criollo Lechero Tropical, A. C.”. La información utilizada incluyó 895 registros de PN y 517 de PD. El pedigrí incluyó 4,537 animales nacidos entre 1950 y 2016. Los análisis fueron realizados mediante el programa ASReml, preliminarmente usando modelos univariados para identificar los mejores, mediante la prueba de razón de verosimilitudes. El modelo animal bivariado para ambas características incluyó los efectos fijos de grupo contemporáneo (año-hato-época-sexo), la covariable edad de la madre al parto, lineal y cuadrática, y la covariable lineal de la proporción de genes Romosinuano. Los efectos aleatorios fueron los genéticos aditivos directos y la interacción semental por grupo contemporáneo para ambas características, más los genéticos aditivos maternos para PD. Las tendencias genéticas fueron estimadas mediante regresión lineal simple del promedio de los valores genéticos sobre el año de nacimiento de los animales. Resultados: Las estimaciones de heredabilidad para efectos directos fueron 0.19 ± 0.09 y 0.21 ± 0.12, para PN y PD. La heredabilidad materna para PD fue 0.04 ± 0.05. La proporción de la varianza fenotípica explicada por la interacción semental por grupo contemporáneo fueron 0.21 ± 0.05 y 0.11 ± 0.08 para PN y PD. La correlación genética entre PN y PD fue alta y positiva (0.69 ± 0.28). Las tendencias genéticas para PN y PD no fueron diferentes de cero (P > 0.05). Conclusión: Las estimaciones de heredabilidad para PN y PD reflejan variabilidad genética suficiente para implementar un programa de selección en estas características.

Introduction: Romosinuano cattle is a breed originated in Colombia, but in Mexico there are organized breeders since two decades ago. This breed has a small population size in Mexico and no published studies documenting basic aspects to establish a breeding program were found. The objective of this study was to estimate genetic parameters for birth weight (BW) and weaning weight adjusted to 240 d (WW), as well as to document genetic trends for both traits, in the Romosinuano cattle population of Mexico. Method: The database was provided by “Asociación Mexicana de Criadores de Ganado Romosinuano y Lechero Tropical A. C". A total of 895 and 517 records of BW and WW were used. The pedigree included 4,537 animals born between 1950 and 2016. Analyses were carried out with the ASReml program. Preliminarily, univariate models were used to identify the best one for each trait, through the likelihood ratio test. The bivariate animal model included the fixed effects of contemporary group (year-herd-season-sex), calving age as linear and quadratic covariate, and the linear covariate proportion of Romosinuano gene. The random effects were direct additive genetic and sire by contemporary group interaction for both traits, plus maternal additive genetic for WW. Genetic trends were estimated using linear regression of average breeding values on birth year of the animals. Results: Estimations of direct heritability for BW and WW were 0.19 ± 0.09 and 0.21 ± 0.12. Maternal heritability for WW was 0.04 ± 0.05. The proportion of phenotypic variance explained by the interaction of sire by contemporary group were 0.21 ± 0.05 and 0.11 ± 0.08, for BW and WW, respectively. The genetic correlation between BW and WW was strong and positive (0.69 ± 0.28). Genetic trends for BW and WW were not different from zero (P > 0.05). Conclusion: The heritability estimates for BW and WW showed enough genetic variability to implement a selection program for these traits. [ABSTRACT FROM AUTHOR]

El presente estudio tuvo como objetivo evaluar los factores que influyen en el desempeño del sistema doble propósito en el Piedemonte Araucano. Se analizaron los registros productivos de 973 vacas pertenecientes al proyecto "Desarrollo de un programa de gestión tecnológica para la innovación social y productiva de la carne y la leche en sistemas de producción bovina de la región de los Llanos de Colombia (PBA)", liderado por la Universidad Nacional de Colombia, entre 2016 y 2017. En esta investigación se evaluó el potencial genético del recurso animal bovino en el sistema productivo doble propósito bovino, para ello se contó con la participación de 62 predios seleccionados aleatoriamente en los municipios del Piedemonte Araucano (Arauquita, Fortul, Saravena y Tame), se realizaron mediciones de la producción de leche y el peso del ternero desteto que genera este sistema productivo. Se encontró que la característica producción de leche por lactancia (PLL) es mayor o menor de acuerdo con el número de partos, así como también varia significativamente según el municipio, el grupo racial y la duración de la lactancia; en cuanto al peso al destete (PD), se encontró que la duración de la lactancia influye significativamente en este resultado, así como el municipio y el grupo racial, sin embargo, factores como el sexo no arrojaron diferencias significativas para esta variable. Además, se generaron los parámetros genéticos de heredabilidad (h2) y correlaciones genéticas para cada raza establecida en el sistema de producción doble propósito, para estas características productivas mencionadas, en el departamento de Arauca. [ABSTRACT FROM AUTHOR]

Highly accurate predicted genetic values must be obtained at an early age to promote rapid genetic progress. The objectives of this study were to compare accuracies (R2) of genomic values (GVs) and to estimate genetic correlation between true genetic values and genomic values obtained using predicted breeding values (EBV) and deregressed EBV (DEBV) as response variables. A first population, effective population size 800 and 100 generations, was simulated using the QMSim program to generate linkage disequilibrium. Thereafter, 20 males and 200 females were used to generate a second 14-generation population, with 6,400 individuals per generation and its corresponding phenotype and genotype in SNP terms. Generations 7 to 14 of the second population were used in several combinations as training (PEn) and evaluation (PEv) subpopulations. GVs, their accuracies, and genetic correlations were obtained using the GenSel and ASREML programs. When PEn was the largest, the mean R2 of GV was the highest, 0.77 ± 0.01. The closer PEn was to PEv, the higher the R2, and correspondingly, the lower the predicted error variance. The trends for R2 and PEV held true for both EBV and DEBV used as response variables. Genetic correlation estimates between true genetic values and GVs varied from 0.41 to 0.53 in the two scenarios studied. They decreased when PEn and PEv were farther apart. There were only slight advantages of using DEBVs as response variables over using EBVs. [ABSTRACT FROM AUTHOR]

Background: dystocia is one of the most economically significant secondary traits in dairy cows and has adverse effects on the subsequent survival, health, and performance of mothers and offspring. Objective: the aim of this study was to estimate direct and maternal genetic parameters for calving ease (CE) and its relationship with productive and reproductive traits in Iranian Holstein cows. Methods: data from 1991 through 2011 were collected from the Animal Breeding Center of Iran, and contained 132,831 records of CE, 183,203 records of productive traits including 305-d adjusted milk yield (MY305), 305-d adjusted fat yield (FY305) and 305-d adjusted protein yield (PY305), and 129,199 records of reproductive traits including days open (DO), days to first service (DFS) and calving interval (CI). Univariate and bivariate linear animal models were used for the analysis of traits in two different models on which direct genetic effect (model 1) and direct + maternal genetic effects (model 2) using AI-REML algorithm were included. Results: estimated heritabilities for CE in model 1 were 0.02 in univariate and 0.02-0.03 in bivariate analyses. Direct and maternal heritabilities in model 2 were 0.02 and 0.002 for univariate, and 0.03 and 0.0004-0.006 in bivariate analyses, respectively. Genetic correlations between direct effects of CE with MY305, FY305, and PY305 were -0.99, 0.02 and -0.07 in model 1, and -0.2, -0.02 and -0.13 in model 2, respectively. Conclusion: this study suggested that a selection index that includes both direct and maternal effects should be included in CE breeding programs. [ABSTRACT FROM AUTHOR]

Background: the milk yield records measured along lactation provide an example of repeated measures; the random regression models are an appealing approach to model repeated measures and to estimate genetic parameters. Objective: to estimate the genetic parameters by modeling the additive genetic and the residual variance for test-day milk yield in first calving buffaloes. Methods: 3,986 test-day data from 1,246 first lactations of crossbred buffalo daughters of 23 sires and 391 dams between 1997 and 2008 from five farms were used. The model included the genetic and permanent environment additive as the random effect and the contemporary group (year, month of test-day) and age at calving as covariable (linear) fixed effects. The fixed (third order) and random (third to ninth order) regressions were obtained by Legendre polynomials. The residual variances were modeled with a homogeneous structure and various heterogeneous classes. The variance components were estimated using the WOMBAT statistical program (Meyer, 2006). Results: according to the likelihood ratio test, the best model included four variance classes, considering Legendre polynomials of the fourth order for permanent environment and additive genetic effects. The heritabilities estimates were low, varying from 0.0 to 0.14. The estimates of genetic correlations were high and positive among PDC1 and PDC8, except for PCD9, which was negative. This indicates that for any of the selection criteria adopted, the indirect genetic gain is expected for all lactation curves, except for PCD9. Conclusion: heterogeneity of residual variances should be considered in models whose goal is to examine the alterations of variances according to day of lactation.

En el estudio se evaluaron diferentes componentes de producción y se estimaron las correlaciones fenotípicas, genéticas y ambientales, considerando nueve variables relacionadas con el tamaño y la calidad del fruto de tomate de árbol (Cyphomandra betacea Cav. Sendt.); igualmente se establecieron los efectos directos e indirectos de las variables componentes de calidad sobre el peso del fruto. Para el efecto se utilizaron los datos existentes de 81 híbridos (72 híbridos interpoblacionales y nueve testigos) dispuestos en tres repeticiones, en condiciones del departamento de Nariño, Colombia. Los resultados obtenidos indicaron que las correlaciones genotípicas fueron superiores a las fenotípicas y ambientales. El peso de fruto (PF) presentó las mayores correlaciones genéticas con el peso de semilla por fruto (rG = 0.97) y con el peso de pulpa más semilla (rG = 0.92). El análisis de sendero con base en correlaciones genotípicas mostró que el peso de pulpa más semilla fue la variable que tuvo el mayor efecto directo sobre el PF (1.353). Esto demuestra que una selección por peso de fruto da como resultado un aumento en peso de pulpa más semilla. Teniendo en cuenta las correlaciones fenotípicas, este análisis permitió establecer que los efectos directos de peso de semilla de fruto (PSF) y peso de pulpa más semilla (P + S) (1.166 y 0.743, respectivamente) son los que más contribuyen al PF.

En el Centro de Investigaciones Turipaná de la Corporación Colombiana de Investigaciones (Corpoica) (Cereté, Córdoba, Colombia -8° 31' N y 75° 58' O, a 13 m.s.n.m) se estudiaron las correlaciones, ambientales y genéticas entre seis caracteres de 24 cultivares de berenjena (Solanum melongena). Para el efecto se utilizó un diseño de bloques completamente al azar con tres repeticiones y unidades experimentales de 10 m². Los resultados mostraron que las correlaciones fueron de mayor o igual magnitud que las fenotípicas, mientras que las ambientales fueron de escaso valor. El número de frutos y el rendimiento estuvieron genéticamente correlacionados (r = 0.56, P < 0.01), la longitud y la resistencia del fruto mostraron correlación genética negativa (r = -0.68, P < 0.01) y entre el rendimiento y peso de fruto la correlación fue muy baja (r = 0.04). El número de frutos y su peso de frutos se correlacionaron de manera negativa (r =-0.63, P < 0.01). El número de frutos por planta puede ser utilizado como criterio de selección para la obtención de cultivares de berenjena de altos rendimientos.The phenotypic, genotypic and environmental correlations between six characters of 24 cultivars of eggplant (Solanum melongena) were studied in the research centre of Turipaná of Corpoica (Cereté- Córdoba-Colombia -8° 31' N and 75° 58' W, 13 m.a.s.l.). A completely randomized block design was used with three repetitions and experimental units of 10 m2. The analyses showed that genetic correlations were of higher or equal magnitude to the phenotypic correlations, while the environmental ones had low effects on the results. The number of fruits and the yield showed a positive and highly significant (r = 0.56, P < 0.01) genetic correlation. A negative and highly significant (r = -0.68, P < 0.01) genetic correlation was observed between fruit length and fruit strength. No correlation was detected between yield and fruit weight (r = 0.04). Fruit number and fruit weight showed a negative and highly significant genetic correlation (r =-0.63, P < 0.01). It is suggested that the number of fruits per plant could be used as a selection criterium to obtain high yield eggplant cultivars.

Two Acacia mangium Willd. progeny tests were evaluated, pursuing an increment in the profitability of commercial plantations. The 25 open-pollinated families were established in Los Chiles and San Carlos, northern region of Costa Rica, in year 2006, and evaluated in 2007 and in 2010. Genetic material came from plus tree selections obtained by GENFORES, a costarican tree-improvement and gene-conservation cooperative. In each trial, families were represented by 48 progenies, planted in 4 pairs randomly distributed within each of the 6 blocks. In 2010, DBH, survival rate, commercial number of logs per tree, forking, forking height and log quality in the first 4 logs, were evaluated. Based on these measurements, wood commercial volume per tree and per hectare were estimated. Data was analyzed with SELEGEN software from EMBRAPA, Brasil, in order to determine all genetic parameters of the breeding population. All traits evaluated showed family mean heritability values over 0.46. Genetic gain in commercial volume per hectare was estimated as 55.8%, when selecting as parents the 2 best individuals from the top 12 families, which would correspond to an expected commercial volume.ha -1 , at 4 years age, of 78.93 m 3 .ha -1 (around 20 m 3 .ha -1 .year -1 ). The 2 Colombian provenances were significantly superior in growth to the rest of the evaluated materials. No significant gene-environment interaction was observed between both sites. Genetic correlations among evaluated traits showed that diameter growth rate is expressed early in this tree species, thus could be used in shortening future selections.

A multi-trait animal model (15,904 data) and a reaction norm model (13,068 data) were studied, in order to estimate genetic parameters and environmental awareness of the weight at 18 months (P18) and (TDG) of Cuban Zebu during the performance test for future sires. The animals were born between 1981 and 2012 and were the offspring of 295 parents. Multi-trait animal model allowed to obtain the solutions of fixed effect of from the group of contemporaries, heritabilities and genetic tendencies of P18 and trial daily gain TDG. Later, a reaction norm model of sire type was considered, with the group of contemporaries (herd-year-three-month period of animal birth) as fix effect the effect of random regression of sire (cubic, square and linear Legendre polynomials) through an environmental gradient, expressed as solution of fix effect, so a total of 6 environmental classes were created. Estimated values of heritability, through the animal model, were 0.20 ± 0.02 and 0.28 ± 0.02 for TDG and P18, respectively, with a genetic correlation of 0.94 among them. Using the reaction norm model, the estimates varied from 0.13±0.04 to 0.43±0.08, and the highest corresponded to favorable environments or positive gradients. Correlation values, very close to 1, indicate the non-existence of genotype x environment interaction in most of the cases. However, there may be correlations lower than 0.8 in the most unfavorable environment, which indicates that sires selected in favorable environments may not have the same performance after passing to unfavorable environments. [ABSTRACT FROM AUTHOR]

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The aims of this study were to estimate variance components; calculate heritability (h²) and genetic correlations (rg) predict breeding values (VG) and evaluate their trends over time. Behavior information was analyzed for four Mexican bullfighting ranches: Los Encinos (ENC), Montecristo (MCR), San José (SJO) y Fernando de la Mora (FMO). The analyzed information included was horse tienta (TC), foot tienta (TP), horse bullfight (LC) and foot bullfight (LP). The number of observations ranged from 154 to 2,369, the number of animals in the pedigrees varied from 3,246 to 8,962. Multivariate analyses were conducted using the MTDFREML software. The estimates of h² were from medium to high magnitude, in a range from 0.09±0.05 to 0.47±0.22, and an average of 0.28±0.09. The average of h² by trait was 0.33±0.06 for TC and TP, 0.23±0.14 for LC and 0.27±0.12 for LP. All rg were positive and higher than 0.50, with the exception of TP and LP (0.44±0.38) in FMO, and TC and LP (0.28±0.14) in MCR. The average of the rg within ranches was 0.71±0.14 in MCR, 0.77±0.35 in FMO, 0.78±0.18 in ENC, and 0.85±0.31 in SJO. The trends of the VG were positive and nonzero (P<0.02), with the exception of LP in FMO (P>0.05). The magnitude of the genetic gain per year, as a percentage of the mean, ranged from 0.19% in LC of FMO to 1.5% in TP of ENC. The variability of VG suggests its use in breeding programs to promote greater genetic progress. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Applied Technology for Agricultural Science / Revista Brasileira de Tecnologia Aplicada nas Ciências Agrárias is the property of Brazilian Journal of Applied Technology for Agricultural Science 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 Lusitano horse breeders association in Mexico proposed the development of genetic evaluation for morphological traits (VM: headneck (CC), withers (CR), chest (PC), back and loin (DR) and croup (GR)) considered in the selection criteria; however, in earlier studies found high levels of inbreeding (F; 6,6 % average), with constant trend. The objectives were to analyze the effects of F through three indicators (IDF: F of animal (IF); average correlation coefficient (CRP); and, change rate of F (ΔF)) on the average performance, the estimate of heritability (h2) and genetic correlation (rg) for the VM. Including alternately the IDF as covariate of first order were performed four univariate analysis (UNV) for each VM, and four multivariate analyses with the five VM. The covariate solutions of IDF were equal to zero (p>0,05). The h2 with the UNV ranged from 0,08 (DR) to 0,30 (CC), the general average was 0,18. The maximum change with IDF was 0,01. In the MUV, the h2 ranged from 0,11 to 0,35, the general average was 0,198; in the rg, the average without IDF was 0,53, in the interval of 0,01 to 0,97; with IDF the average was 0,59, with estimates above 0,20. The h2 of UNV vs. MUV without IDF were similar. For PC and GR the h2 decreased 0,03 of UNV to MUV with IDF; to contrast of CC, CR y DR with increments of 0,06. Inside MUV, for CC, CR and DR the h2 increased with IDF, with more effect CRP; however, in PC and GR decreased, with more effect of F. [ABSTRACT FROM AUTHOR]

Los modelos de regresión aleatoria (MRA) son utilizados para estudiar las curvas de lactancia individuales como desvíos de la media, mediante el uso de polinomios ordinarios de funciones lineales. Fueron analizados 5.386 registros para La PDC de 1.546 primeras lactancias de búfalas mestizas, hijas de 30 toros y 446 búfalas, entre 1998 y 2005. Los componentes de varianza fueron estimados utilizando el paquete estadístico WOMBAT. El modelo incluyó como aleatorios los efectos genéticos aditivo y de ambiente permanente, como efectos fijos los grupos contemporáneos (mes y año del control) y edad de la búfala al parto (efecto lineal y cuadrático). Las varianzas residuales fueron modeladas utilizando clases de varianza con 4 clases residuales. Los resultados de los criterios de información de Akaike y de Bayesiano de Schwarz, sugirieron que el modelo que considero el 7 orden del polinomio de Legendre para el efecto aditivo y el 6 orden polinomial para el efecto de ambiente permanente fue el mejor. Las heredabilidades variaron desde 0,10 hasta 0,33 a lo largo de la lactancia. En conclusión, los MRA son apropiados para estudiar la curva de lactancia en búfalos lecheros en este rebaño.

Registros de becerros Charolais, proporcionados por la Charolais Herd Book de México y generados en un periodo de ocho años (1997-2005), se analizaron para estimar parámetros genéticos y fenotípicos para peso al nacer (n=39,821), peso al destete ajustado a 205 días (n=39,556) y ganancia posdestete (n=21,831). Estimadores de componentes de (co)varianza se obtuvieron usando Máxima Verosimilitud Restringida con el algoritmo Esperanza-Maximización y modelos animal para una sola característica. Los efectos del ambiente materno permanente no fueron importantes para peso al nacimiento y ganancia posdestete, por lo que no se incluyeron en el modelo final. Los estimadores de heredabilidad directa fueron 0.22, 0.33 y 0.45 para peso al nacimiento, peso al destete ajustado a 205 días y ganancia posdestete, respectivamente. Los estimadores de heredabilidad para el efecto genético materno fueron 0.16, 0.17 y 0.14. Los estimadores de heredabilidad total y de correlación genética entre efectos directos y maternos fueron 0.12 y -0.65, 0.16 y -0.72, y 0.20 y -0.84 para peso al nacimiento, peso al destete ajustado a 205 días y ganancia posdestete, respectivamente. Para peso al destete ajustado a 205 días, el estimador de la varianza del ambiente materno permanente (28.93 kg2) explicó un 4 % del estimador de la varianza fenotípica (765.43 kg2). La respuesta esperada a la selección para una sola característica de crecimiento de ganado Charolais mexicano, podría ser menor debido a las altas y negativas correlaciones entre efectos genéticos directos y maternos.

El objetivo del presente trabajo fue estimar índices de selección de caracteres agronómicos que ayuden a seleccionar los materia les genéticos que se utilizan en la producción de forraje y evaluar la eficiencia relativa de los índices estimados.Se evaluaron 28 cruzas directas (método IV de Griffing),producto de un diseño de cruzas dialélicas, con ocholíneas de maíz de alta calidad proteínica (QPM), en el Rancho Ampuero en Torreón, Coahuila, México, en el año 2003 y 2004. El diseño experimental utilizado fue bloques completos al azar con dos repeticiones, las variables evaluadas fueron:altura de planta (AP), altura de mazorca (AM ), rendimie ntode forraje verde (RFV) y rendimiento de forraje seco (RFS).Se encontró que: a) se obtuvo mayor eficiencia al combinar caracteres correlacionados con el carácter de interés, b) la correlación entre caracteres per se, causó decrementos en laeficiencia del índice, c) la respuesta teórica a la selección,al usar índices, fue mayor que la basada solamente en rendimiento de forraje verde, d) los índices de selección más eficientes fueron los que tomaron en cuenta el rendimiento de forraje verde y aquellas varia bles con más alta correlación genética (AP y AM ), e) el índice seleccionado fue el que incluyó las variables altura de planta, altura de mazorca yrendimiento de forraje verde (I=-20,88 X1 +49,26 X2 -0,11X3) con una eficiencia relativa de 1,5 7%.

Copyright of Archivos de Medicina Veterinaria is the property of Universidad Austral de Chile, 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.)