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Combining ability analysis provides useful information for the selection of parents, also information regarding the nature and magnitude of involved gene actions. Crops improvement involves strategies for enhancing yield potentiality and quality components. Targeting the improvement of respective characters in bitter gourd, combining ability and genetic parameters for 19 characters were estimated from a 6×6 full diallel analysis technique. The results revealed that the variances due to general combining ability (GCA) and specific combining ability (SCA) were highly significant for most of the important characters. It indicated the importance of both additive and non-additive gene actions. GCA variances were higher in magnitude than SCA variances for all the characters studied indicating the predominance of the additive gene effects in their inheritance. The parent P2 (BG 009) appeared as the best general combiner for earliness; P1 (BG 006) for number of fruits, average single fruit weight and fruit yield; P4 (BG 027) for node number of first female flower and days to seed fruit maturity; P3 (BG 011) for fruit length and thickness of the fruit flesh; P5 (BG 033) for 100-seed weight; and P6 for number of nodes per main vine. The SCA effect as well as reciprocal effect was also significant for most of the important characters in different crosses. Resumo A análise da capacidade de combinação fornece informações úteis para a seleção dos pais, também informações sobre a natureza e a magnitude das ações dos genes envolvidos. A melhoria das safras envolve estratégias para aumentar a potencialidade da produção e os componentes de qualidade. Visando ao aprimoramento dos respectivos caracteres em cabaça-amarga, capacidade de combinação e parâmetros genéticos para 19 caracteres, foram estimados a partir de uma técnica de análise dialélica completa 6 × 6. Os resultados revelaram que as variâncias, devido à capacidade geral de combinação (GCA) e capacidade específica de combinação (SCA), foram altamente significativas para a maioria dos caracteres importantes. Indicou a importância das ações gênicas aditivas e não aditivas. As variâncias GCA foram maiores em magnitude do que as variâncias SCA para todos os caracteres estudados, indicando a predominância dos efeitos do gene aditivo em sua herança. O pai P2 (BG 009) apareceu como o melhor combinador geral para o início; P1 (BG 006) para número de frutos, peso médio de um único fruto e produção de frutos; P4 (BG 027) para número de nó da primeira flor fêmea e dias para a maturidade do fruto da semente; P3 (BG 011) para comprimento do fruto e espessura da polpa do fruto; P5 (BG 033) para peso de 100 sementes; e P6 para o número de nós por videira principal. O efeito SCA, bem como o efeito recíproco, também foi significativo para a maioria dos personagens importantes em cruzamentos diferentes.

Made available in DSpace on 2022-04-29T08:37:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Context: Lactation persistency (LP) is an economically important characteristic to include in the selection objectives of the Gyr breed. Two persistency measures were tested to establish their contribution to the genetic evaluation of milk production in this genotype. The second measure of persistency studied would be the more appropriate measure to use in the genetic evaluation of lactation persistency. Aim: The aim of this work was to study LP in Gyr cows by using a random regression model (RRM) in two-Trait analysis. Methods: Test-day milk yields (TDMY) of the first two lactations of Gyr cows were analysed. RRM was performed by Bayesian inference using the GIBBS3F90 program. Fourth-order Legendre polynomials were used to describe the random additive genetic and permanent environmental effects of the animal. The fixed effects included in the model were contemporary group and, as covariates, age of cow at calving and the regression function according to the TDMY class of lactation as the average trajectories of lactation curve, distinguished by calving order. Two persistency measures (PSi, i.e. PS1 and PS2) were used in the analyses. Rank correlations were calculated between the predicted breeding values for PSi, 305-day lactation milk yield (MY305), and the regression coefficients a0 and a1, to determine the percentage of matching animals between rankings when different selection intensities are applied on the basis of the ranking for MY305. Key results: The heritability estimates for PS1, PS2 and for MY305 were 0.19, 0.12 and 0.41 respectively, in the first lactation, and 0.43, 0.27 and 0.38 in the second lactation. The genetic correlation between MY305 and PS1 was negative and of low magnitude. The rank correlation between breeding values for PSi, obtained for bulls with at least five daughters with production records, was higher than 0.80 in the two lactation periods. Conclusions: The results indicated that PS2 is the more suitable of the two persistency measures used in this work, for inclusion in genetic evaluations of lactation persistency in Brazilian Gyr cows. Implications: PS2 must be included as a selection criteria in a breeding program for the Gyr breed. Grupo de Investigación en Biodiversidad y Genética Molecular Facultad de Ciencias Agrarias Universidad Nacional de Colombia, Medellín Grupo de Melhoramento Animal de Mato Grosso Instituto de Ciências Agrárias e Tecnológicas Universidade Federal de Rondonópolis, Avenida dos Estudantes, N 5055, Rondonópolis, MT Centro de Pesquisas de Bovinos de Corte Instituto de Zootecnia, Rodovia Carlos Tonani Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellani, SP Departamento de Zootecnia Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista, Via de Acesso Prof. Paulo Donato Castellani, SP

Genetic selection can be a feasible method to help mitigate enteric methane emissions from dairy cattle, as methane emission-related traits are heritable and genetic gains are persistent and cumulative over time. The objective of this study was to estimate heritability of methane emission phenotypes and the genetic and phenotypic correlations between them in Holstein cattle. We used 1765 individual records of methane emission obtained from 330 Holstein cattle from two Canadian herds. Methane emissions were measured using the GreenFeed system, and three methane traits were analyzed: the amount of daily methane produced (g/d), methane yield (g methane/kg dry matter intake), and methane intensity (g methane/kg milk). Genetic parameters were estimated using univariate and bivariate repeatability animal models. Heritability estimates (±SE) of 0.16 (±0.10), 0.27 (±0.12), and 0.21 (±0.14) were obtained for daily methane production, methane yield, and methane intensity, respectively. A high genetic correlation (rg = 0.94 ± 0.23) between daily methane production and methane intensity indicates that selecting for daily methane production would result in lower methane per unit of milk produced. This study provides preliminary estimates of genetic parameters for methane emission traits, suggesting that there is potential to mitigate methane emission in Holstein cattle through genetic selection.

The objective of this study was to explore the genetic parameters of conformation traits and milk production traits in Chinese Holstein cattle and to provide a reference for dairy cattle breeding. We collected the phenotypic data of 23 conformation traits and five milk production traits of Chinese Holsteins and used animal models to estimate the genetic parameters of conformation traits and milk production traits. The estimated heritability of conformation traits ranged from 0.11 (angularity) to 0.37 (heel depth) and the genetic correlation between conformation traits ranged from −0.73 (bone quality and rear leg-rear view) to 0.76 (chest width and loin strength). The heritability of milk production traits ranged from 0.23 (somatic cell score) to 0.50 (305-d milk yield). The estimated values of genetic correlation between conformation traits and milk production traits ranged from −0.56 (heel depth and 305-d milk yield) to 0.57 (udder texture and milk fat percentage). There was a positive genetic correlation between most conformation traits and milk fat percentage, but a weak negative genetic correlation with milk yield. Strengthening the moderately and highly heritable milk production and conformation traits, especially the selection of rear udder traits and body shape total score, will be beneficial in improving the performance of dairy cows.

A novel method was tested for improving tree breeding strategies that integrate quantitative and population genetics based on range-wide reciprocal transplant experiments. Five reciprocal common garden tests of Populus tremuloides were investigated including 6450 trees across western Canada focusing on adaptation traits and growth. Both genetic parameters and home-site transplant models were evaluated. We found a genetic trade-off between growth and early spring leaf flush and late fall senescence. Coefficients of phenotypic variation (CVp) of cell lysis (CL), a measure of freezing injury, shrank from 0.28 to 0.10 during acclimation in the fall, and the CVp slope versus the freezing temperature was significantly different from zero (R2 = 0.33, p = .02). There was more between-population genetic variation in fall phenology than in spring leaf phenology. We suggest that P. tremuloides demonstrated a discrepancy between the ecological optimum and the physiological optimum minimum winter temperature. The sub-optimal growing condition of P. tremuloides is potentially caused by the warmer ecological optimum than the physiological optimum. Assisted migration and breeding of fast growers to reforest cooler plantation sites can improve productivity. Transferring the study populations to less than 4°C of extreme minimum temperature appears safe for reforestation aligning with the historical recolonization direction of the species. This is equivalent to a 5–10° latitudinal northward movement. Fall frost hardiness is an effective criterion for family selection in the range tested in this study.

Newcastle disease is a devastating poultry disease that often causes significant economic losses in poultry in the developing countries of Africa, Asia, as well as South and Central America. Velogenic Newcastle disease virus (NDV) outbreaks are associated with high mortalities, which can threaten household livelihoods, especially in the rural areas, and lead to loss of high-quality proteins in the form of meat and eggs, as well as household purchasing power. In this study, we exposed unvaccinated Ghanaian and Tanzanian chickens of six local ecotypes to velogenic NDV strains, measured NDV response traits, sequenced their DNA on a genotyping-by-sequencing platform, and performed variance component analyses. The collected phenotypes included: growth rates (pre- and post-exposure); lesion scores (gross lesion severity) in the trachea, proventriculus, intestine, and cecal tonsils; natural antibody levels; anti-NDV antibody levels at 7 days post exposure (dpe); tear and cloacal viral load at 2, 4, and 6 dpe; and survival time. Heritability estimates were low to moderate, ranging from 0.11 for average lesion scores to 0.36 for pre-exposure growth rate. Heritability estimates for survival time were 0.23 and 0.27 for the Tanzanian and Ghanaian ecotypes, respectively. Similar heritability estimates were observed when data were analyzed either separately or combined for the two countries. Survival time was genetically negatively correlated with lesion scores and with viral load. Results suggested that response to mesogenic or velogenic NDV of these local chicken ecotypes could be improved by selective breeding. Chickens that are more resilient to velogenic NDV can improve household livelihoods in developing countries.

Resumen (Introducción): Gmelina arborea se ha consolidado como la segunda especie más utilizada en la reforestación comercial en Costa Rica. (Objetivo): Evaluar el comportamiento de clones G. arborea en condiciones de suelo ácidos. (Metodología): Se utilizó un diseño experimental de bloques completos al azar, con 6 repeticiones, 29 clones y 5 testigos, con un distanciamiento de 4 x 4 m. Se realizó un análisis del suelo y se calcularon parámetros genéticos a diferentes edades, para las variables diámetro a la altura del pecho (DAP), altura y volumen comercial, utilizando el software SELEGEN, el cual se basa en el método REML/BLUP; asimismo, se realizaron correlaciones genéticas entre las variables evaluadas. (Resultados): El análisis del suelo reflejó deficiencias nutricionales de elementos esenciales para el desarrollo de la melina, un pH menor a 5.5, altos contenidos de hierro (Fe) y saturación de aluminio (Al) elevado. Los mayores coeficientes de heredabilidad individual y media del clon se presentaron a la edad de 4.5 años, donde el DAP es el carácter que presentó mayores valores. Las mayores correlaciones genéticas se presentaron entre las variables DAP-volumen comercial a partir de los 3.5 años. Se evidenció que existen 10 clones que mejor se adaptaron a las condiciones del sitio, presentando mayores crecimientos en las variables dasométricas, con ganancias genéticas dentro del rango de 12.7 % y 28 %, comparadas con la media general del ensayo y el material utilizado como testigo. (Conclusiones): Se concluye que existe material genético de melina con potencial para adaptarse a condiciones de suelo ácidos. Abstract (Introduction): Gmelina arborea has become the second most used species in commercial reforestation in Costa Rica. (Objective): To evaluate the behavior of G. arborea clones in acidic soil conditions. (Methodology): A randomized complete block experimental design was used, with 6 replications, 29 clones and 5 controls, with a distance of 4 x 4 m. A soil analysis was performed, and genetic parameters were calculated at different ages, for the variables diameter at breast height (DBH), height and commercial volume, using the SELEGEN software, which is based on the REML/BLUP method, and genetic correlations were made between the evaluated variables. (Results): Soil analysis showed nutritional deficiencies of essential elements for the development of melina, a pH lower than 5.5, high iron (Fe) contents and high aluminum (Al) saturation. The highest individual and mean heritability coefficients of the clone were obtained at the age of 4.5 years, where DBH presented the highest values. The highest genetic correlations were found between the DBH and commercial volume variables from 3.5 years onwards. Ten clones showed the best adaptation to the site conditions, presenting the highest values in dasometric variables, with genetic gains in the range of 12.7 % and 28 %, compared to the general mean of the test and the material used as control. (Conclusions): There is genetic material of melina with potential to adapt to acidic soil conditions.

Objective: A comprehensive study was conducted to study the effects of partition of variance on accuracy of genetic parameters and genetic trends of economic traits in Vanaraja male line/project directorate-1 (PD-1) chicken.Methods: Variance component analysis utilizing restricted maximum likelihood animal model was carried out with five generations data to delineate the population status, direct additive, maternal genetic, permanent environmental effects, besides genetic trends and performance of economic traits in PD-1 chickens. Genetic trend was estimated by regression of the estimated average breeding values (BV) on generations.Results: The body weight (BW) and shank length (SL) varied significantly (p≤0.01) among the generations, hatches and sexes. The least squares mean of SL at six weeks, the primary trait was 77.44±0.05 mm. All the production traits, viz., BWs, age at sexual maturity, egg production (EP) and egg weight were significantly influenced by generation. Model four with additive, maternal permanent environmental and residual effects was the best model for juvenile growth traits, except for zero-day BW. The heritability estimates for BW and SL at six weeks (SL6) were 0.20±0.03 and 0.17±0.03, respectively. The BV of SL6 in the population increased linearly from 0.03 to 3.62 mm due to selection. Genetic trend was significant (p≤0.05) for SL6, BW6, and production traits. The average genetic gain of EP40 for each generation was significant (p≤0.05) with an average increase of 0.38 eggs per generation. The average inbreeding coefficient was 0.02 in PD-1 line.Conclusion: The population was in ideal condition with negligible inbreeding and the selection was quite effective with significant genetic gains in each generation for primary trait of selection. The animal model minimized the over-estimation of genetic parameters and improved the accuracy of the BV, thus enabling the breeder to select the suitable breeding strategy for genetic improvement.

Genetic parameters of litter size (LS) and number of kids born alive (NBA) were estimated across parities in Florida and Payoya goat breeds using a threshold random regression model (RRM). We analysed the reproductive records for the Florida and Payoya breeds separately, and a total of 130.849 and 67.478 reproductive records from the first to the seventh parities from Florida and Payoya, respectively, were included in the analysis. Random regressions on Legendre polynomials of standardised parity were included for permanent environmental and additive genetic effects. We based our estimation of all the covariance components on Bayesian inference under categorical distribution and considered heterogeneous residual variances in the model. The estimates of heritabilities ranged from null to 0.37 for LS and from 0.02 to 0.20 for NBA, while the repeatability estimates were between 0.008–0.60 and 0.03–0.44 for LS and NBA, respectively. Phenotypic correlations within-trait along parities ranged widely from −0.31 to 0.97, while the genetic correlations within-trait through parities showed a wider range and magnitude of values, from −0.98 to 0.99 for LS and from −0.72 to 0.99 for NBA. The estimates of genetic correlations between LS and NBA in the different parities were positive in the first two parities and negative in the later ones. Due to the noticeable changes in variance and the incomplete genetic correlations, the use of a random regression model to analyse LS and NBA is recommended in goat breeds.HIGHLIGHTS A bivariate threshold random regression model has been used for the first time to estimate genetic parameters of litter size and number of kids born alive across parities in Spanish goat breeds. The evolution of genetic parameters along parities is different between Florida and Payoya that have different production systems, being more intensive in the case of the Florida breed. Estimates of variance were not constant across parities for both traits and breeds. Genetic correlations within-trait across parities were different from unity. Thus, LS and NBA should be treated as different traits in successive parities. Given that the estimates of variance and covariances are not constant across parities for both traits and breeds, the use of RRM is highly recommended.

Body weight records of 231,416 Nellore females obtained from the Brazilian Association of Zebu Breeders were used to determine a linear combination between visual appraisal scores (body structure, precocity and muscling) using principal components analysis (PC), and to verify their genetic association with body weight at 12 months (BW) and age at first calving (AFC). The mixed linear model included the fixed effect of the contemporary group and the linear and quadratic effects of age at calving, random effects of genetic additive, maternal environment and temporary environment. Heritability estimates for BW, PC and AFC were 0.51, 0.30 and 0.17, respectively. Genetic additive correlations between BW and PC; BW and AFC, and PC and AFC were 0.48; -0.31 and -0.55; respectively. Spearman's correlations for the best-ranked bulls based on PC prediction were positive between BW and PC and negative among the other combinations. Heritability estimates and correlations indicate potential genetic gains for BW and CP with reduced AFC in cows. The use of PC allows positive responses on precocity and body weight development. RESUMO Utilizaram-se registros de pesos corporais de 231.416 fêmeas bovinas da raça Nelore, oriundos dos registros da Associação Brasileira de Criadores de Zebu-ABCZ, com o objetivo de estabelecer, por componentes principais, uma combinação linear (CP) das características de escores visuais de estrutura (E), precocidade (P) e musculosidade (M), bem como verificar sua associação genética com o peso corporal aos 12 meses (PC) e à idade ao primeiro parto (IPP). O modelo linear misto utilizado incluiu os efeitos fixos de grupo de contemporâneos e os efeitos linear e quadrático da idade da vaca ao parto, os efeitos aleatórios genético aditivo, ambiente materno e ambiente temporário. Estimativas de herdabilidade para PC, CP e IPP foram iguais a 0,51; 0,30 e 0,17, respectivamente. Correlações genéticas aditivas entre PC e CP; PC e IPP; e, ainda, CP e IPP foram iguais a 0,48; -0,31 e -0,55, respectivamente. As correlações de Spearman para os melhores reprodutores classificados em relação à predição de CP foram positivas entre PC e CP e negativas entre as demais combinações. Estimativas de herdabilidade e de correlações indicam possibilidade de ganhos genéticos expressivos para PC e CP com redução para IPP nas fêmeas. A utilização de CP possibilita respostas favoráveis para precocidade sexual e desenvolvimento ponderal.

The study aims to simulate the alternative methods of simplifying weight recording of Tunisian local kids and assesses the impact of their use from a genetic point of view to set up the basis for the future improvement of this important component of efficient production. A total of 13,095 weight records of 945 kids, progeny of 285 females and 19 males were collected over a period of 16 years in the caprine herd of the Arid Areas Institute of Médenine (South East of Tunisia).Weights were taken at six standard ages (10, 30, 60, 90,120 and 150 days) at a weekly pace. Alternative simplified schemes were simulated by skipping from 1–7 weeks of recording and performance in terms of predicting weights at the standard ages was evaluated. In addition, random regression model (RRM) including age of females, interaction sex × type of birth, interaction year × month of birth was used as fixed effects. Also, animal- and maternal permanent environmental as random effects, were fitted to the data set. Alternative simplified recording systems were then evaluated in terms of modifications in estimated genetic parameters and correlations among estimated breeding values. Results showed that 1–3 weeks of time between recordings yielded accurate estimates of weights at the standard ages. The effect of the simplified weight recording was especially relevant at the extreme weights, at 10 and at 150 days of age, that the spacing of successive controls affects the accuracy of the estimate. The lack of registration of birth weight showed a significant deterioration in the estimate of weight at 10 days. Only the simplification of the weights recording to one and two-week resulted in direct and maternal heritability’s for the different growth traits of local kids, similar to those obtained by the standard age growth recording. Selecting the critical ages that define changes in growth components seems to be more critical than using more frequent weighing in terms of estimation of the genetic components of weight of kids in this population.Highlights This type of local kids measurement simplification can be seen as an alternative: ^ To enhance the economical aspect of the sheep recording scheme. ^ Reduce animal disturbance. According to the results of this study, the adoption of a common growth control system seems difficult since the breeding objectives and for farming systems are not the same.

The present research aimed to investigate the genetic trends for udder traits (fore udder attachment; rear udder height; udder depth; front teat placement; rear teat placement; front teat length and rear teat length) and angularity of Holstein Friesian cows in Serbia. A multi-trait animal model was used to estimate genetic parameters, through REML procedures. In the study 10403 first-lactation cows Holstein type from 12 different regions in Serbia were included. The cows were daughters of 221 Holstein Friesian sires. The age at first calving was from 19 to 44 months, and there were 10 stages of lactation. Udder type traits and angularity were classified by 24 classifiers on a linear scale of 1 to 9. Udder type traits had heritability estimates ranging from 0.03 for rear teat placement to 0.12 for fore udder attachment, and angularity had heritability 0.10. Genetic trend for angularity of Holstein Friesian cows in Serbia shows that ribs are becoming less angular and extremely rounded, while genetic trends for udder traits show that teat lengths are becoming longer and inside of quarter, and udder is shallow. The genetic trend for fore udder attachment indicates there is indirect selection for weaker udders. © 2022, Pakistan Agricultural Scientists Forum. All rights reserved.

The objective of this study was to estimate genetic parameters for the analyzed fertility traits of Polish Holstein-Friesian primiparous and multiparous cows, as a step toward the incorporation of new traits into routine genetic evaluation. Lactation records of 116,836 Polish Holstein-Friesian cows were studied. The records cover the first three lactations of all cows. The cows, daughters of 2884 sires, were calved from 2006 to 2020. The conception rate for heifers (CRh) and for cows in the second (CR2) and third parity (CR3), the interval from first calving to first insemination (CTFI), the days open (DO), and the interval from first to successful insemination for heifers (FSh) and for cows in second (FS2) and third (FS3) parity were analyzed. The BLUPf90 package and a Bayesian method via Gibbs sampling were used to estimate (co)variance components. In general, all heritabilities were low and ranged from 0.013 (CTFI) to 0.038 (FS2). The heritability of conception rate and interval from first to successful insemination was slightly lower for heifers than for cows. Genetic correlations were moderate to high with two exceptions: correlation of CTFI with CRh (0.033) and with FSh (−0.051). The results indicate that a few analyzed traits could be used in genetic evaluation of Polish Holstein-Friesian cows. It is suggested to complement the selection index with traits for both heifers and cows, such as the interval from first to successful insemination (i.e., FSh, FS2 and FS3), in order to enable effective improvement of female fertility scores in the Polish Holstein-Friesian population.

The genetic parameters for the survival of Holstein cows, analysed in nine consecutive time periods during the first three calving intervals, were estimated. The earlier the animals are culled, the more they are informationally underestimated. This undervaluing can be remedied by using a weighted analysis that balances the amount of information. If the method of estimating breeding values changes, the genetic parameters will also change. The Holstein cattle dataset from 2005 to 2017 used in this study included 1,813,636 survival records from 298,290 cows. The pedigree with three generations of ancestors included 660,476 individuals. Linear repeatability models estimated genetic parameters for overall and functional survivability. Due to weights, heritability increased from 0.013 to 0.057. Repeatability with weights was 0.505. The standard deviations of breeding values were 1.75 and 2.18 without weights and 6.04 and 6.20 with weights. Including weights in the calculation increased the additive variance proportion and the breeding values’ reliabilities. We conclude that the main contribution of the weighted method we have presented is to compensate for the lack of records in culled individuals with a positive impact on the reliability of the breeding value.

The objective of this study was to establish classification ranges for genetic and additive genetic coefficients of variation, as well as for broad and narrow sense heritability, as a function of growth and wood quality traits for Eucalyptus spp. We conducted statistical analyses to determine differences in this classification the types of coefficients used. The selected studies that met the inclusion criteria, 58 presented genetic variation coefficients (448 data points) and 53 presented heritability coefficients (423 data points). To descriptive statistics and the Shapiro-Wilk test, we confirmed that it was necessary to separate coefficients and traits into groups. Inconsistencies for growth traits were observed, confirming the influence of experimental error, indirect estimation methods, and environmental effects on coefficient estimates. We recommend the use of the classification tables included in this literature review to interpret results in studies so as to standardize the classification of coefficients of genetic variation and heritability.

The objective of this work was to compare different methods to estimate heritability in 30 pigeon pea families from the F3, F4, F5, and F6 generations, for nine variables. The experimental design was a randomized complete block with three replicates and 20 plants per plot. Broad-sense heritability was estimated by the analysis of variance ( A N O V A) [ h 2b-E(MS)], restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) (h2b-REML), parent-offspring regression (h2PO), and standard deviation unit (h2UP). The h2b-E(MS) and h2b-REML estimates were similar for seven of the analyzed variables. For a higher genetic control and easier selection, values of h2b-E(MS) and h2b-REML >0.70 were estimated for two variables in four generations, two variables in three generations, three variables in two generations, and one variable in one generation. Values of h2UP and h2PO >0.70 were obtained for four and five variables, respectively. The estimates via regression or parent-offspring correlation showed some values outside the expected range of 0 to 1. The ANOVA [h2b-E(MS)] and REML/BLUP [h2b-REML] methods are the best to estimate pigeon pea heritability. Resumo O objetivo deste trabalho foi comparar diferentes métodos para estimar a herdabilidade em 30 linhagens de guandu das gerações F3, F4, F5 e F6, para nove variáveis. O delineamento experimental foi em blocos ao acaso, com três repetições e 20 plantas por parcela. Estimou-se a herdabilidade no sentido amplo por meio de análise de variância (ANOVA) [h2b-E(MS)], máxima verossimilhança restrita/melhor predição linear não viciada (REML/BLUP) (h2b-REML), regressão pai-filho (h2PO) e unidade do desvio-padrão (h2UP). As estimativas de h2b-E(MS) e h2b-REML foram de magnitude próxima para sete das variáveis analisadas. Para maior controle genético e facilidade na seleção, valores de h2b-E(MS) e h2b-REML >0,70 foram estimados para duas variáveis em quatro gerações, duas variáveis em três gerações, três variáveis em duas gerações e uma variável em uma geração. Valores de h2UP e h2PO >0,70 foram obtidos para quatro e cinco variáveis, respectivamente. As estimativas via regressão ou correlação pai-filho mostraram alguns valores fora da variação esperada de 0 a 1. Os métodos ANOVA [h2b-E(MS)] e REML/BLUP [h2b-REML] são os melhores para estimar a herdabilidade em guandu.

A total of 1,031,143 records of daily dairy control test of Spanish Florida goats were used for this study. The database was edited, and only the records of the first three lactations were kept. The final database contained 340,654 daily-test somatic cell counts from 27,749 daughters of 941 males and 16,243 goats. The evolution of this count in the last 14 years was analyzed following French and American international associations’ criteria for the risk of mastitis in goats, and confirmed the slight increase in SCS in the last years and the importance of this problem (50% of dairy control tests show a risk of suffering mastitis). For the genetic analysis, the SCS records were log-transformed to normalize this variable. Two strategies were used for the genetic analysis: a univariate animal model for the SCS assuming that SCS does not vary throughout the parities, and a multi-character animal model, where SCS is not considered as the same character in the different parities. The heritabilities (h2) were higher in the multiple traits models, showings an upward trend from the first to the third parity (h2 between 0.245 to 0.365). The genetic correlations of the same trait, as well as between breeding values (GVs) between different parities, were different from unity. The breeding values (EBVs) obtained for both models were subjected to a PCA: the first eigenvector (λ1) explained most of the variations (between 74% to 90%), while the second λ2accounted for between 9% to 20% of the variance, which shows that the selection will be proportionally favorable but not equivalent in all parities and that there are some variations in the type of response.

Determining the genetic and non-genetic sources of variation in a breed is vital for the formulation of strategies for its conservation and improvement. The present study was aimed at estimating the (co)variance components and genetic parameters of Mecheri sheep by fitting six different animal models in the restricted maximum likelihood method, with a preliminary investigation on the performance of animals for non-genetic sources of variation. A total of 2616 lambs were studied, and varying levels of significance were found for the effects of period, season, parity of dam, and birth type on different body-weight traits. Direct heritability estimates derived from the best animal model for body weight at birth, three months, six months, nine months, and twelve months were 0.21, 0.24, 0.10, 0.15, and 0.09, respectively, and the maternal heritability of the corresponding traits was 0.12, 0.05, 0.04, 0.04, and 0.04, respectively. The genetic correlations between the body-weight traits were all positive and moderate-to-strong, except for the correlation between birth weight and the other body-weight traits. The significance of non-genetic factors studied in this work demanded a correction to improve the accuracy of the direct selection of lambs for body-weight traits. The estimated genetic parameters identified the weaning weight as a selection criterion for the improvement in body weight of Mecheri lambs at different ages. Inbred individuals accounted for approximately 13% of the total population in the Mecheri sheep population studied. There were 877 founders in the population, and the actual effective population size was 128.48. The population’s mean generation interval was 3.26. The mean inbreeding values ranged from 0.005 to 0.010 across generations. The population’s average relatedness ranged from 0.001 to 0.014 across generations. Individual inbreeding was found to be 0.45 per cent for the entire population and 3.4 per cent for the inbred population.

The quality and safety of milk is challenged by cow mastitis, and the value of somatic cell score (SCS) in milk is closely related to the occurrence of mastitis. This study aimed to analyze the genetic characteristics of SCS across the first three parities in Chinese Holstein cattle, as well as to investigate potential candidate genes and biological processes that may play a potential role in the progress of cow mastitis. In this respect, we evaluated genetic parameters and conducted a genome-wide association study based on the test-day records of SCS for Chinese Holstein cows; we also validated key candidate genes using a quantitative reverse transcription PCR (RT-qPCR) experiment in primary bovine mammary epithelial cells (bMECs). The heritability of the SCS 305-day performance in milk varied between 0.07 and 0.24, and decreased with increasing parity. As the time interval grew larger, the genetic and permanent environmental correlations with the number of days in milk (DIM) weakened. Six significant single-nucleotide polymorphisms (SNPs) were identified in the association analysis, one of which was located within the exonic region of CD44. This exon-associated SNP may modify the activity of the protein encoded by the CD44. A total of 32 genes within the two hundred kilobase (kb) range of significant SNPs were detected, and these genes were markedly enriched in eight Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and 22 biological processes, mainly participating in the progress of transmembrane transport, inflammatory factor regulation, cellular responses, the Toll-like receptor signaling pathway, and the MAPK signaling pathway. Nine genes, including the PKD2, KCNAB1, SLC35A4, SPP1, IBSP, CD14, CD44, MAPK10, and ABCG2 genes, were selected as candidate genes that could have critical functions in cow mastitis. These findings can serve as a foundation for molecular breeding and as valuable data for reducing the incidence of mastitis of Chinese Holstein cattle at the molecular level.

To ensure that any new technology developed within an experimental station is appropriate to the community’s needs and compatible with the existing systems, on-site farm research is an important component in examining the effectiveness of agricultural research. The present study examined the growth performance and genetics of Thai native chickens under conditions typically experienced by farmers on smallholder farms (on-site farms) compared with at an experimental unit (on-station). There were 1694 Thai native chickens (Pradu Hang dum) used in this experiment, and they were divided into 613 chickens for the on-station and 1081 chickens for the on-site farm experiments. The individual chicken data included the birth weight (BW0) and body weight at 4, 8, 12, and 16 weeks of age (BW4, BW8, BW12, and BW16, respectively), ADG from 0–4, 4–8, 8–12, 12–16 weeks of age (ADG0–4, ADG4–8, ADG8–12, ADG12–16, respectively), and breast circumference at 8, 12, and 16 weeks of age (BrC8, BrC12, BrC16, respectively). A multiple traits animal model and a selection index were used to estimate the variance components, genetic parameters, and breeding values of growth traits. The results showed that the body weight, average daily gain, and breast circumference at 8, 12, and 16 weeks of age of Thai native chickens raised on-station were higher than those raised on-site at the farm among mixed-sex and sex-segregated chickens, while the birth weight and body weight at four weeks of age (BW0 and BW4) and ADG from 0–4 weeks of age (ADG0–4) were not significantly different (p > 0.05). The heritability estimates of body weight, average daily gain, and breast circumference in the chickens raised at the on-site farm and on-station were moderate to high, with on-station values slightly higher than on-site farm values. The heritability estimates of body weight were 0.236 to 0.499 for the on-site farm, and 0.291 to 0.499 for on-station. For average daily gain, the heritability estimates were 0.274 to 0.283 for the on-site farm and 0.298 to 0.313 for on-station; meanwhile, and for breast circumference, the heritability estimates were 0.204 to 0.268 for the on-site farm and 0.278 to 0.296 for on-station. Both phenotypic and genetic correlations among and between growth traits were positive and ranged from low to high values. The top 20% of the estimated breeding values and selection indices in the on-site farm and on-station experiments showed that the body weight at eight weeks of age (BW8), ADG from 4–8 weeks of age (ADG4–8), and breast circumference at eight weeks of age (BrC8) should be used as selection criteria for Thai native chicken breeding programs. In conclusion, the genetic parameters and breeding values in on-station experiments showed that the breeding program by selection index for improving growth performance is valid. Therefore, to implement such a breeding program in an on-site farm, an intensive or semi-intensive farm system should be considered to minimize the effect of genotype-environment interaction.

Maintaining low levels of rust incidence (caused by Puccinia novopanici) in switchgrass (Panicum virgatum L.) breeding populations is a priority for the USDA-ARS program engaged in improving cultivars for high biomass yield and quality. Essential to this goal is the unbiased and accurate estimation of genetic parameters to predict the merits of parents and progeny. Spores of the fungus were inoculated in greenhouse-grown seedling progeny of 31 half-sib families in generation 2 (Gen 2) of a composite Summer × Kanlow population for evaluation of rust incidence on the leaves with a 0–9 rating scale. Two parents were later chosen to cross and develop a linkage mapping population as Gen 3. The Gen 2, 3, and Kanlow seedlings were transplanted into the field located near Mead, NE, in early June 2020 and laid out as a replicated row–column design with six blocks of single-row plots of five plants each. The field trial was rated in September 2021 and 2022 with a 0–4 scale. Lab and field data were subjected to univariate linear mixed models via the restricted maximum likelihood to extract the variance components needed to predict the breeding values. The additive genetic variation was substantial (p < 0.01), enough to result in high heritability estimates ranging from 0.42 ± 14 to 0.73 ± 0.09 at the individual and family mean levels. This result implies that rust resistance is under strong genetic control to use mass selection for obtaining satisfactory gains. A possible rust incidence x year interaction was detected with a Spearman correlation of breeding values of −0.38, caused by significant rank changes of the Gen 3 genotypes in 2022 (a high heat and drought year). Genetic gains were predicted to reduce rust incidence scores by at least two points on the rating scale when selecting backwards, and by one point when selecting individual candidates as parents of the next generation. Faster gains (31 and 59%) were realized relative to the second generation by respectively selecting the top 10% of the families in Gen 3 or the top 10% of genotypes within this group. Based on these results, strategies for controlling the incidence of rust will be developed to optimize gains in the other traits of economic importance.

The objective of this study was to estimate genetic parameters for body weight at 60 (P60), 90 (P90), and 120 (P120) days of age in escargots of the subspecies Cornu aspersum maximum, evaluating the influence of fixed and covariable effects on these traits. The data used were collected from escargots kept in a total confinement system. The significant fixed effects and covariates for these traits were tested in a general linear model by the F-test, considering a level of significance of 5%. Both the fixed effects of box and birth year and the quadratic effect of age of weighing as a covariate were significant (p < 0.05) for P60, P90, and P120. The Restricted Maximum Likelihood (REML) methodology was used to estimate (co)variance components and genetic parameters. High heritability for P60, P90, and P120 (0.38, 0.55 and 0.78, respectively) and high genetic correlations (0.58 to 0.77) among the traits were observed. The genetic parameters can be used as a basis for studies and practical applications to increase zootechnical indexes in this population.

The objective of this study was to define robustness scores based on data collected routinely on farm to allow phenotyping of this trait in fattening pigs. A total of 7256 pigs, from 2 Piétrain paternal lines (Pie and Pie NN), were controlled at the Axiom boar testing station (Azay-sur-Indre, France), in 2019-2021. During the fattening period (from 75 to 150 days of age), individual performance indicators were recorded (growth, backfat, loin depth, feed intake, feed conversion ratio) together with indicators such as mortality, clinical signs, antibiotic and anti-inflammatory injections. These indicators were combined to estimate a set of three categorical robustness traits: R1, R2 and R3. Genetic parameters were estimated using an animal linear model. The robustness score R2 (selectable or not selectable animal) that combines information from status at testing and mortality presented the most interesting heritability, from 0.12 (±0.03) to 0.13 (±0.02) depending of the line. The score R3 that combines information from the score R2 with antibiotic and anti-inflammatory injections presented slightly lower heritability estimates (0.08 ±0.02 to 0.11±0.03). Genetic correlations between R2 and R3 were high and favorable (0.93 ±0.04 to 0.95 ±0.03). These two robustness scores were also highly and favorably genetically correlated with initial body weight, average daily gain and daily feed intake (ranging from 0.73 ±0.06 to 0.90 ±0.08). Estimates of genetic correlations of R2 and R3 with backfat depth and feed conversion ratio were moderate and unfavorable (0.20 ±0.13 to 0.46±0.20). A part of these genetic correlations, that are of low precision due to the number of data available, have to be confirmed on larger datasets. The results showed the interest of using routine phenotypes collected on farm to build simple robustness indicators that can be applied in breeding.

For swine breeding programs, testing and selection programs are usually within purebred (PB) populations located in nucleus units that are generally managed differently and tend to have a higher health level than the commercial herds in which the crossbred (CB) descendants of these nucleus animals are expected to perform. This approach assumes that PB animals selected in the nucleus herd will have CB progeny that have superior performance at the commercial level. There is clear evidence that this may not be the case for all traits of economic importance and, thus, including data collected at the commercial herd level may increase the accuracy of selection for commercial CB performance at the nucleus level. The goal for this study was to estimate genetic parameters for five maternal reproductive traits between two PB maternal nucleus populations (Landrace and Yorkshire) and their CB offspring: Total Number Born (TNB), Number Born Alive (NBA), Number Born Alive > 1 kg (NBA > 1 kg), Total Number Weaned (TNW), and Litter Weight at Weaning (LWW). Estimates were based on single-step GBLUP by analyzing any two combinations of a PB and the CB population, and by analyzing all three populations jointly. The genomic relationship matrix between the three populations was generated by using within-population allele frequencies for relationships within a population, and across-population allele frequencies for relationships of the CB with the PB animals. Utilization of metafounders for the two PB populations had no effect on parameter estimates, so the two PB populations were assumed to be genetically unrelated. Joint analysis of two (one PB plus CB) vs. three (both PB and CB) populations did not impact estimates of heritability, additive genetic variance, and genetic correlations. Heritabilities were generally similar between the PB and CB populations, except for LWW and TNW, for which PB populations had about four times larger estimates than CB. Purebred-crossbred genetic correlations (rpc) were larger for Landrace than for Yorkshire, except for NBA > 1 kg. These estimates of rpc indicate that there is potential to improve selection of PB animals for CB performance by including CB information for all traits in the Yorkshire population, but that noticeable additional gains may only occur for NBA > 1 kg and TNW in the Landrace population.

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.Keywords: Holstein; genetic correlation; genetic parameters; heritability; mastitis; milk quality; milk yield; multi-trait model; somatic cell score; variance components. Resumen Antecedentes: El conteo de células somáticas es un parámetro importante para predecir la calidad de la leche y la salud de las vacas. Sin embargo, en países como Brasil, esta característica aún no se selecciona a gran escala y no se reportan parámetros genéticos en la literatura. Objetivo: Estimar los componentes de varianza y parámetros genéticos para el conteo de células somáticas, producción de leche, producción de grasa, producción de proteína, porcentaje de grasa y porcentaje de proteína en vacas de la raza Holstein. Métodos: Se usaron registros de 56.718 animales para estimar los componentes de la varianza, heredabilidad y correlaciones genéticas usando un modelo animal multicaracterístico por medio del método REML. Resultados: Las estimaciones de heredabilidad fueron 0,19 para el conteo de células somáticas, 0,22 para la producción de leche, 0,26 para la producción de grasa, 0,18 para producción de proteína, 0,61 para el porcentaje de grasa y 0,65 para el porcentaje de proteína. Las estimaciones de correlación genética entre las características analizadas variaron entre -0,50 a 0,82. Conclusión: La baja heredabilidad encontrada para conteo de células somáticas demostró que la selección para esta característica podría resultar en beneficios para la salud animal y calidad de la leche, pero sólo a largo plazo. La baja correlación genética existente entre las características productivas y el conteo de células somáticas indica que la inclusión del conteo de células somáticas en programas de selección no interfiere negativamente en la selección genética para la producción de leche o sólidos.Palabras clave: calidad de leche; correlación genética; conteo de células somáticas; componentes de varianza; heredabilidad; Holstein; mastitis; modelo multicaracteristico; parametros geneticos; producción de leche; selección genetica. Resumo Antecedentes: O escore de células somáticas é um parâmetro importante para a predição da qualidade do leite, bem como para a saúde das vacas. No entanto, em alguns países como o Brasil, essa característica não é selecionada em larga escala e não há parâmetros genéticos disponíveis na literatura. Objetivo: Estimar os componentes de variância e parâmetros genéticos para o escore de células somáticas, produção de leite, produção de gordura, produção de proteína, porcentagem de gordura e porcentagem de proteína em vacas da raça Holandesa. Métodos: Foi utilizado um total de 56.718 animais para estimar os componentes de variância, herdabilidade e correlações genéticas, considerando-se o modelo animal multicaracterística por meio do método REML. Resultados: As estimativas de herdabilidade foram de 0,19 para o escore de células somáticas, 0,22 para a produção de leite, 0,26 para a produção de gordura, 0,18 para produção de proteína, 0,61 para a porcentagem de gordura e 0,65 para a porcentagem de proteína. As estimativas de correlação genética entre as características analisadas variaram entre -0,50 a 0,82. Conclusão: A baixa herdabilidade encontrada para o escore de células somáticas demonstrou que a seleção para esta característica poderá resultar em benefícios para a saúde animal e qualidade do leite, porém, somente a longo prazo. A baixa correlação genética existente entre as características produtivas e o escore de células somáticas demonstrou que a inclusão do escore de células somáticas em programas de seleção não causa interferência negativa na seleção genética para a produção de leite ou sólidos.Palavras-chave: componentes de variância; correlação genéticas; escore de células somáticas; herdabilidade; mastite; modelo multicaracterística; parâmetros genéticos; produção de leite; qualidade do leite; raça Holandesa; seleção genética.

Resumen Introducción. La selección de genotipos con hábito de crecimiento determinado en tomate, debe contemplar criterios adecuados de selección para incrementar la eficiencia del programa de fitomejoramiento. Objetivo. El objetivo de este trabajo fue estimar criterios de selección para líneas de tomate tipo “chonto” con hábito de crecimiento determinado. Materiales y métodos. Este trabajo se llevó a cabo en la Universidad Nacional de Colombia (Sede Palmira), en el año 2016, con siete líneas con hábito de crecimiento determinado y un testigo con crecimiento indeterminado. Se determinó la heredabilidad en sentido amplio (h2g), coeficiente de variación ambiental, coeficiente de variación genética, eficiencia de la selección y ganancia genética, en parámetros morfológicos, fenológicos, de calidad de fruto, forma de fruto y producción, con el empleo del procedimiento RELM/BLUP, del software SELEGEN. Resultados. Hubo tres rangos de h2g, el primero con valores de h2g mayores a 0,76, el segundo entre 0,53 y 0,38, y el tercero con un valor menor a 0,38. Los mayores valores de h2g fueron para altura final de planta con 0,92, altura de planta al momento de la cosecha con 0,88, producción por planta con 0,83, días a floración con 0,83, número de frutos por planta con 0,82, y días a cosecha con 0,82. Para ganancia genética se encontró que el testigo presentó los mayores valores para, altura final de planta, altura de planta a cosecha, longitud de entrenudo, días a cosecha, duración de cosecha, contenido de sólidos solubles, número de frutos por planta, peso de fruto y producción por planta; sin embargo, en algunos parámetros como altura y fenología para selección por hábito de crecimiento determinado, resultaron mejores los valores más bajos. Conclusión. Se evidenciaron parámetros genéticos que podrían considerarse como criterios de selección para líneas de tomate tipo “chonto” con hábito de crecimiento determinado. Abstract Introduction. The selection of genotypes with a determined growth habit in tomato should contemplate adequate selection criteria to increase the efficiency of the plant breeding program. Objective. The objective of this research was to estimate selection criteria for “chonto” tomato lines with determined growth habit. Materials and methods. The research was developed in the Universidad Nacional de Colombia campus Palmira in 2016, using seven determinate habit growth lines (D) and a control with undetermined habit growth. The heritability in a broad sense (h2g), coefficient of environmental variation, coefficient of genetic variation, selection efficiency, and genetic gain was determined, in morphologic, phenological, quality fruit, fruit shape, and productions parameters using the RELM/BLUP process, from the SELEGEN software. Results. Three ranges of h2g were found, the first with values of h2g greater than 0.76, the second between 0.53 and 0.38, and the third with a value less than 0.38. The highest values of h2g were for final height plant with 0.92, height plant to harvest with 0.88, production per plant with 0.83, days to flowering with 0.83, fruit number with 0.82, and days to harvest with 0.82. For genetic gain it was found that the control presented the highest values within the main parameters for final height plant, plant height to harvest, internode length, days to harvest, crop duration, soluble solids content, number of fruits per plant, weight fruit, and plant production; however, in some parameters such as height and phenology for effects of selection by habit of determined growth lower values were better. Conclusion. Genetic parameters were evidenced that could be considered as selection criteria for “chonto” tomato lines with determined growth of habit.

Remarkable increases in the production of dairy animals have negatively impacted their tolerance to heat stress (HS). The evaluation of the effect of HS on milk yield is based on the direct impact of HS on performance. However, in practical terms, HS also exerts its influence during gestation (indirect effect). The main purpose of this study was to identify and characterize the genotype by environment interaction (G × E) due to HS during the last 60 days of gestation (THI_g) and also the HS postpartum (THI_m) over first lactation milk production of Brazilian Holstein cattle. A total of 389 127 test day milk yield (TD) records from 1572 first lactation Holstein cows born in Brazil (daughters of 1248 dams and 70 sires) and the corresponding temperature–humidity index (THI) obtained between December 2007 and January 2013 were analyzed using different random regression models. Cows in the cold environment (THI_g = 64 to 73) during the last 60 days of gestation produced more milk than those cows in a hot environment (THI_g = 74 to 84), particularly during the first 150 days of lactation (DIM). The heritabilities (h2) of TD were similar throughout DIM for cows in THI_g hot (0.11 to 0.20) or (0.10 to 0.22), while the genetic correlations (rg) for TD between these two environments ranged from 0.11 to 0.52 along the first 250 DIM. The h2 estimates for TD across THI_m were similar for cows in THI_g hot (0.07 to 0.25) and THI_g cold (0.08 to 0.19). The rg estimates ranged from 0.17 to 0.42 along THI_m between TD of cows in cold and hot THI_g. The results were consistent in demonstrating the existence of an additional source of G × E for TD due to THI_g and THI_m. The present study is probably the first to provide evidence of this source of G × E; further research is needed because of its importance when the breeding objective is to select animals that are more tolerant to HS.

Young stock survival is a trait of crucial importance in cattle breeding as calf mortality leads to economic losses and represents an animal welfare issue. The aim of this study was to estimate genetic parameters and sire breeding values for young stock survival in beef x dairy crossbred calves. Two traits were analysed with a univariate animal model: young stock survival between 1 to 30 days and 31 to 200 days after birth. Breed combinations with Belgian Blue sires outperformed all other sire breeds. The lowest survival rates were found for breed combinations with Jersey dams or Blonde d'Aquitaine sires. The results showed low but significant heritabilities (0.045 to 0.075) for both survival traits. Differences in breeding values between sires ranged from -2.5% to 3.5% and from -5.4% to 4.7% survival from 1 to 30 days and 31 to 200 days, respectively. Based on these findings, we concluded that it is feasible to breed for improved young stock survival in beef x dairy crossbred calves. This will hopefully contribute to increasing the survival rate of the calves and reduce economic losses for the farmers.

The main objective of this study was to assess the genetic background of colostrum yield and quality traits after calving in Holstein dairy cows. The secondary objective was to investigate genetic and phenotypic correlations among laboratory-based and on-farm-measured colostrum traits. The study was conducted in 10 commercial dairy herds located in northern Greece. A total of 1,074 healthy Holstein cows with detailed pedigree information were examined from February 2015 to September 2016. All cows were clinically examined on the day of calving and scored for body condition. All 4 quarters were machine-milked, and a representative and composite colostrum sample was collected and examined. Colostrum total solids (TS) content was determined on-farm using a digital Brix refractometer. Colostrum fat, protein, and lactose contents were determined using an infrared milk analyzer, and energy content was calculated using National Research Council (2001) equations. Dry period length (for cows of parity ≥2), milk yield of previous 305-d lactation (for cows of parity ≥2), age at calving, parity number, season of calving, time interval between calving and first colostrum milking, and milk yield were recorded. Each trait (colostrum yield and quality traits) was analyzed with a univariate mixed model, including fixed effects of previously mentioned factors and the random animal additive genetic effect. All available pedigrees were included in the analysis, bringing the total animal number to 5,662. Estimates of (co)variance components were used to calculate heritability for each trait. Correlations among colostrum traits were estimated with bivariate analysis using the same model. Mean percentage (±SD) colostrum TS, fat, protein, and lactose contents were 25.8 ± 4.7, 6.4 ± 3.3, 17.8 ± 4.0, and 2.2 ± 0.7%, respectively; mean energy content was 1.35 ± 0.3 Mcal/kg and mean colostrum yield was 6.18 ± 3.77 kg. Heritability estimates for the above colostrum traits were 0.27, 0.21, 0.19, 0.15, 0.22, and 0.04, respectively. Several significant genetic and phenotypic correlations were derived. The genetic correlation of TS content measured on-farm with colostrum protein was practically unity, whereas the correlation with energy content was moderate (0.61). Fat content had no genetic correlation with TS content; their phenotypic correlation was positive and low. Colostrum yield was not correlated genetically with any of the other traits. In conclusion, colostrum quality traits are heritable and can be amended with genetic selection.

The objective of this study was to estimate genetic parameters for daily milk yield (DMY), fat (FC), and protein content (PC) using 329.022 test-day records of 23.756 Alpine does. Single trait repeatability animal model was applied. Parity, litter size, season, and lactation stage (Ali-Schaeffer’s curve) were fitted in the fixed, while herd, herd-test-day, permanent environment (within lactations) and additive genetic effect in the random part of the model. Variance components were estimated using Residual Maximum Likelihood Method in the VCE-6 program. Additive genetic effect explained 23 %, 16 % and 25 % of DMY, FC and PC variability which is in general agreement with numerous previous reports for dairy goat breeds. Among the non-genetic effects, herd explained 24 %, 12 %, and 9 %, herd-test-day 17 %, 29 %, and 30 %, and permanent environment 16 %, 3 %, and 5 % of DMY, FC and PC variability, respectively. The estimated parameters and developed single trait repeatability test-day models will serve as a basic tool in BLUP based genetic evaluation of Alpine breed in Croatia.

Aim: This study aimed to determine the genetic and non-genetic factors affecting pre-weaning body weight (BW) and morphometry in Assam Hill goat along with the genetic parameters. Materials and Methods: The detailed information in respect of BW and body measurements of 960 animals at birth and 3 months of age belonging to three different populations of Assam Hill goat maintained at field units, namely, Batabari, Nahira, and Tetelia under "All India Coordinated Research Project on Goat Improvement" were utilized in the present study. The data were analyzed using least squares technique. Results: The least squares means for BW, height at withers (HW), heart girth (HG), and body length (BL) were 1.166±0.008 kg, 26.198±0.070 cm, 26.695±0.096 cm, and 29.482±0.119 cm at birth and 4.590±0.083 kg, 36.850±0.105 cm, 40.741±0.115 cm, and 39.703±0.108 cm at 3 months of age, respectively. Location had a significant effect on BW, HW, and BL at both birth and 3 months and on HG at 3 months of age. Season of birth exerted significant effect only on BL at birth, whereas the significant effect of sex was observed on HG and BL at 3 months of age. The heritability estimates for BW and body measurements were moderate indicating the scope of selection. The phenotypic and genetic correlations among BWs and body measurements at birth and 3 months of age were positive in direction and high in magnitude. Conclusion: On the basis of the present findings, it could be concluded that the weaning weight of kids can be considered for the selection of parent stock to increase productivity and eventually the economic efficiency. Further, animals with higher body measurements at initial phases of growth will perform better with respect to even BW at later stages of growth. Keywords: Assam Hill goat, genetic parameters, morphometric traits, non-genetic factors, pre-weaning growth.

International audience; Improving feed efficiency is of interest to French beef producers so as to increase their profitability. To enable this improvement through selection, genetic correlations with production traits need to be quantified. The objective of this study was to estimate the genetic parameters for growth, feed efficiency (FE), and slaughter performance of young beef bulls of the French Charolais breed. Three feed efficiency criteria were calculated: residual feed intake (RFI), residual gain (RG), and ratio of FE. Data on feed intake, growth, and FE were available for 4,675 Charolais bulls tested in performance test stations and fed with pelleted diet. Between 1985 and 1989, 60 among 510 of these bulls were selected to procreate one generation of 1,477 progeny bulls which received the same pelleted diet at the experimental farm in Bourges. In addition to feed intake, growth, and FE traits, these terminal bulls also had slaughter traits of carcass yield, carcass composition, and weight of visceral organs collected. Genetic parameters were estimated using linear mixed animal models. Between performance test bulls and terminal bulls, the genetic correlation of RFI was 0.80 +/- 0.18; it was 0.70 +/- 0.21 for RG and 0.46 +/- 0.20 for FE. For carcass traits, RFI was negatively correlated with carcass yield (-0.18 +/- 0.14) and muscle content (-0.47 +/- 0.14) and positively with fat content (0.48 +/- 0.13). Conversely, RG and FE were positively correlated with carcass yield and muscle content and negatively with fat content. For the three FE criteria, efficient animals had leaner carcass. For visceral organs (as a proportion of empty body weight), RFI was genetically correlated with the proportions of the 5th quarter (0.51 +/- 0.17), internal fat (0.36 +/- 0.14), abomasum (0.46 +/- 0.20), intestines (0.38 +/- 0.17), liver (0.36 +/- 0.16), and kidneys (0.73 +/- 0.11). Conversely, RG and FE were negatively associated with these traits. The high-energy expenditure associated with the high-protein turnover in visceral organs may explain this opposite relationship between FE and the proportion of visceral organs. Selection for final weight and RFI increased growth and FE in progeny, and also improved carcass yield and muscle content in the carcass. To conclude, determinations of growth and feed intake in performance test stations are effective to select bulls to improve their growth, FE, and muscle content in carcass.

The objective of this study was to assess genotype by environment interaction for 1000-kernel weight in spring barley lines grown in South Poland by the additive main effects and multiplicative interaction model. The study comprised of 32 spring barley (Hordeum vulgare L.) genotypes (two parental genotypes—breeding line 1 N86 and doubled haploid (DH) line RK63/1, and 30 DH lines derived from F1 hybrids), evaluated at six locations in a randomized complete block design, with three replicates. 1000-kernel weight ranged from 24.35 g (for R63N/42 in 2011) to 61.46 g (for R63N/18 in 2008), with an average of 44.80 g. AMMI analyses revealed significant genotype and environmental effects as well as GE interaction with respect to 1000-kernel weight. In the analysis of variance, 16.86% of the total 1000-kernel weight variation was explained by environment, 32.18% by differences between genotypes, and 24.50% by GE interaction. The lines R63N/61, R63N/22, and R63N/1 are recommended for further inclusion in the breeding program because their stability and the highest averages of 1000-kernel weight. The total additive effect of all genes controlling the trait and the total epistasis effect of 1000-kernel weight were estimated. Additive gene action effects based on DH lines were always larger that this parameter estimated on the basis of parental lines. Estimates of additive gene action effects based on the all DH lines were significantly larger than zero in each year of study. Epistasis effects based on all DH lines were statistically significant in 2011 and 2013.

A field experiment was carried out in the fields of one of the farmers in AL Diwaniyah Governorate for the winter season 2015/2016 using nine varieties of wheat bread (Tamoze 1, Tamoze 2, , Maksebak, Sabah, Eba 95, Latifia, Eba 99, Abu Ghraib and Sham 6). RCBD Used design with three replicate in order to estimation of some genetic parameters and correlation of bread wheat varieties under the experiment Diwaniyah to determine the most effect characters on yield that can be used as guide to select and improve the yield . an account Genetic and phenotypic variation , correlation coefficient, inheritance ratio in broad and narrow Expected genetic improvement ratio for character hight plant , namber of Branches , spike length , number of grains spike ,weight of 1000 and yield .. The results showed that there were significant differences between the cultivars, with the superiority of the Eba 99 by giving the highest rate of 1043.3 kg / dunum between the varieties. There were significant differences between the studied characters Abu99 the superiority in number of branches , length of spick , number of the seed spick and ,weight of 1000 grin their average ( 11.33, 12.0, 66.3 and 47.3 gram, respectively), which were positively reflected in grain yield. The genetic, environmental and morphological differences of the studied character were significant and the values of the genetic and phenotypic factors were correlated to most traits and inheritance in the broad sense higher (0.592 - 0.728) As an average percentage medal of most traits, but genetic and phenotypic correlation were significant in the desired direction of most yield and therefore yield can be considered as an electoral tool in breeding and plant improvement programs. .

The aim of this study was to estimate the genetic parameters of a one-day performance test together with the linear type traits of 3-year-old warmblood horses. The study of genetic parameters was based on 5958 tested horses in the period 1998–2021. A total of 22 traits of linear description, three quantitatively measured traits, and one summary mark from the performance test were tested. The model equation included the fixed effect of gender and combination effects of classifier–year of evaluation–place. A single-trait animal model was used for the estimation of heritability and genetic variance, while the two-trait animal model was applied for the estimation of variance and covariance between all traits. The heritability of the overall score of the performance test was 0.25. The range for heritability was between 0.04 and 0.33 for the linear type traits and between 0.46 and 0.57 for the quantitatively measured traits. Genetic correlations were between −0.47 and 0.92. The estimated genetic parameters suggest that the results from the performance test can be incorporated into genetic evaluation in the Czech Republic.

Alfalfa (Medicago sativa L.) is one of the most important perennial forage crops to build effective diets for livestock producers. Forage crop improvement depends largely on the availability of diverse germplasms and their efficient utilization. The present investigation was conducted at Ismailia Agricultural Research Station to assess twenty-one alfalfa genotypes for yield components, forage yield and quality traits during 2019/2020 and 2020/2021. The genotypes were evaluated in field experiments with three replicates and a randomized complete block design, using analysis of variance, estimate of genetic variability, estimate of broad sense heritability (hb2) and cluster analysis to identify the inter relationships among the studied genotypes as well as principal component analysis (PCA) to explain the majority of the total variation. Significant differences were found among genotypes for all studied traits. The general mean of the studied traits was higher in the second year than the first year. Moreover, the combined analysis showed highly significant differences between the two years, genotypes and the year × gen. interaction for the traits studied. The genotype F18 recorded the highest values for plant height, number of tiller/m2, total fresh yield and total dry yield, while, the genotype F49 ranked first for leaf/stem ratio. The results showed highly significant variation among the studied genotypes for crude protein %, crude fiber % and ash %. Data revealed that the genotypes P13 and P5 showed the highest values for crude protein %, whereas, the genotype F18 recorded the highest values for crude fiber % and ash content. The results revealed high estimates of genotypic coefficient and phenotypic coefficient of variation (GCV% and PCV%) with high hb2, indicating the presence of genetic variability and effective potential selection for these traits. The cluster analysis exhibited considerable genetic diversity among the genotypes, which classified the twenty one genotypes of alfalfa into five sub-clusters. The genotypes F18, F49, K75, S35, P20, P5 and P13 recorded the highest values for all studied traits compared with other clusters. Furthermore, the PC analysis grouped the studied genotypes into groups and remained scattered in all four quadrants based on all studied traits. Ultimately, superior genotypes were identified can be utilized for crop improvement in future breeding schemes.

The commercial beef cattle industry relies heavily on the use of natural service sires. When artificial insemination is deemed difficult to implement, multisire breeding pastures are used to increase reproductive rates in large breeding herds or to safe-guard against bull injury during the breeding season. Although each bull might be given an equal opportunity to produce offspring, evidence suggest that there is substantial variation in the number of calves sired by each bull in a breeding pasture. With the use of DNA-based paternity testing, correctly assigning calves to their respective sires in multisire pastures is possible and presents an opportunity to investigate the degree to which this trait complex is under genetic control. Field data from a large commercial ranch was used to estimate genetic parameters for calf count (CC; 574 records from 443 sires) and yearling scrotal circumference (SC; n = 1961) using univariate and bivariate animal models. Calf counts averaged 12.2 ± 10.7 and SC averaged 35.4 ± 2.30 cm. Bulls had an average of 1.30 records and there were 23.9 ± 11.1 bulls per contemporary group. The model for CC included fixed effects of age during the breeding season (in years) and contemporary group (concatenation of breeding pasture and year). Random effects included additive genetic and permanent environmental effects, and a residual. The model for SC included fixed effects of age (in days) and contemporary group (concatenation of month and year of measurement). Random effects included an additive genetic effect and a residual. Univariate model heritability estimates for CC and SC were 0.178 ± 0.142 and 0.455 ± 0.072, respectively. Similarly, the bivariate model resulted in heritability estimates for CC and SC of 0.184 ± 0.142 and 0.457 ± 0.072, respectively. Repeatability estimates for CC from univariate and bivariate models were 0.315 ± 0.080 and 0.317 ± 0.080, respectively. The estimate of genetic correlation between CC and SC was 0.268 ± 0.274. Heritability estimates suggest that both CC and SC would respond favorably to selection. Moreover, CC is lowly repeatable and although favorably correlated, SC appears to be weakly associated with CC.

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico O avanço da produção mundial de soja se deve principalmente aos programas de melhoramento genético, que buscam desenvolver cultivares com alto potencial produtivo, resistentes aos estresses bióticos e abióticos. As avaliações dos parâmetros genéticos em gerações precoces no melhoramento de plantas consistem em selecionar indivíduos e progênies promissoras em gerações iniciais de endogamia, como F2 e F3, e assim, avançar apenas genótipos com potencial para gerar linhas puras produtivas e com características agronômicas superiores. Os objetivos deste trabalho foram estimar parâmetros genéticos e fenotípicos em populações F2 e F3; avaliar diferentes estratégias de seleção de genótipos e selecionar progênies, visando a melhoria de caracteres agronômicos e a produção de grãos. O experimento foi conduzido na fazenda experimental Capim Branco da Universidade Federal de Uberlândia, em Uberlândia – MG. Foram avaliadas populações precoces nas gerações F2 e F3 derivadas de um cruzamento biparental entre os genitores UFUS 7415 e TMG 7161 RR. Na primeira etapa do experimento avaliou-se os parâmetros genéticos de 360 indivíduos na geração F2 e 150 genótipos de cada parental. A herdabilidade variou de 4,66 % para número de sementes por vagens a 86,06 % para altura da planta no florescimento na geração F2. Obteve-se segregantes transgressivos para todos os caracteres em estudo, exceto para altura da primeira vagem e número de vagens totais. É possível inferir que os maiores ganhos de seleção foram obtidos para os caracteres números de nós no florescimento (19,97 %), altura da planta na maturidade (26,08 %) e altura da planta no florescimento (29,68 %), relacionados com a produção de grãos. Na segunda etapa do experimento foram avaliados 145 genótipos na geração F3 e seus parentais, em delineamento de blocos ao acaso com duas repetições, cada unidade experimental foi constituída por uma fileira de 1,0 m com 10 sementes por metro. Foram avaliados os parâmetros genéticos, as correlações entre caracteres e os ganhos genéticos obtidos pela seleção direta, indireta e baseada nos índices da distância Genótipo-Ideótipo e índice da soma de “ranks” de Mulamba, Mock (1978). Formaram-se distintos grupos de médias para os caracteres em estudo. Com a seleção direta obteve-se ganhos de seleção oscilando de -5,34 % para número de dias para o florescimento a 16,19 % para produção de grãos por linha. O índice da distância genótipo-ideótipo apresentou ganho de seleção total de 40,49 %, enquanto que o índice da soma de “ranks” de Mulamba, Mock (1978) obteve um ganho total de 39,35 % e os ganhos de seleção para os caracteres de ciclo e caracteres relacionados à produção de grãos foram superiores pela soma de “ranks”. The advance of the worldwide production of soy is possible due to genetic improvement programs that seek to develop cultivars with high productive potential, resistant to biotic and abiotic stresses. The evaluation of genetic parameters in early generations in plant breeding consists of selecting individuals and progenies in early generations of inbreeding, such as F2 and F3, and thus advancing only progenies with the potential to generate pure productive lines and with superior agronomic characteristics. The objectives of this work were to estimate genetic and phenotypic parameters in populations F2 and F3; evaluate different genotype selection strategies and select progenies to improve agronomic traits and grain production. The experiment was carried out at the Capim Branco experimental farm at the Federal University of Uberlândia, located in Uberlândia - MG. Early populations in the F2 and F3 generations derived from a biparental cross between the parents UFUS 7415 and TMG 7161 RR were evaluated. In the first stage of the experiment, the genetic parameters of 360 individuals in the F2 generation and 150 genotypes of each parent were evaluated. Heritability varied from 4,66 % for number of seeds per pod to 86.06 % for plant height at flowering in the F2 generation.Transgressive segregants were obtained for almost all characters under study, except for APV and NVT. It is possible to infer that the greatest selection gains were obtained for the characters number of nodes at flowering (19.97 %), plant height at maturity (26.08 %) and plant height at flowering (29.68 %), related to grain production. In the second stage of the experiment, 145 genotypes in the F3 generation and their parents were evaluated in a randomized block design with two replications, each experimental unit was constituted by a 1.0 m row with 10 seeds per meter. The genetic parameters, the correlations between characters and the genetic gains obtained by direct and indirect selection and based on the indexes of the Genotype-Ideotype distance and the index of the sum of “ranks” by Mulamba, Mock (1978) were evaluated. Different groups of averages were formed for the characters under study. With direct selection, selection gains ranged from -5.34 % for number of days for flowering to 16.19 % for grain production per row. The genotype- ideotype distance index showed a total selection gain of 40.49 %, while the Mulamba, Mock (1978) sum of ranks index obtained a total gain of 39.35 %, and the gains of selection for cycle characters and characters related to grain production were superior by the sum of “ranks”. Dissertação (Mestrado)

Background The possibility of assessing meat quality traits over the meat chain is strongly limited, especially in the context of selective breeding which requires a large number of phenotypes. The main objective of this study was to investigate the suitability of portable infrared spectrometers for phenotyping beef cattle aiming to genetically improving the quality of their meat. Meat quality traits (pH, color, water holding capacity, tenderness) were appraised on rib eye muscle samples of 1,327 Piemontese young bulls using traditional (i.e., reference/gold standard) laboratory analyses; the same traits were also predicted from spectra acquired at the abattoir on the intact muscle surface of the same animals 1 d after slaughtering. Genetic parameters were estimated for both laboratory measures of meat quality traits and their spectra-based predictions. Results The prediction performances of the calibration equations, assessed through external validation, were satisfactory for color traits (R2 from 0.52 to 0.80), low for pH and purge losses (R2 around 0.30), and very poor for cooking losses and tenderness (R2 below 0.20). Except for lightness and purge losses, the heritability estimates of most of the predicted traits were lower than those of the measured traits while the genetic correlations between measured and predicted traits were high (average value 0.81). Conclusions Results showed that NIRS predictions of color traits, pH, and purge losses could be used as indicator traits for the indirect genetic selection of the reference quality phenotypes. Results for cooking losses were less effective, while the NIR predictions of tenderness were affected by a relatively high uncertainty of estimate. Overall, genetic selection of some meat quality traits, whose direct phenotyping is difficult, can benefit of the application of infrared spectrometers technology.

Piglet mortality from farrowing to weaning is a major concern, especially in outdoor organic production systems. This issue might impair animal welfare and generate economic losses for the farmer. In particular, it is difficult to apply management tools that are commonly used for indoor pig production systems to organic or outdoor production systems. Genetics and breeding approaches might be used to improve piglet survival. However, knowledge remains limited on the genetic background underlying survival traits in organic pigs that are born and reared outdoors. Here, we investigated the mortality of piglets from farrowing to weaning in an outdoor organic pig population and suggested genetic strategies to reduce piglet mortality in this production system. The experiment included mortality records of piglets from farrowing to weaning (around 69 days of age). Pedigree-based threshold models were used to analyse the mortality traits of piglets at 0-3 days of age, 4-11 days, and 12 days to weaning. Stillborn piglets were included in the group of piglets that died at 0-3 days of age. We found that the mortality rate from farrowing to weaning was, on average, 19.2%. However, most piglet deaths (79.1%) occurred at 0-11 days of age. As the age of piglets increased, the direct heritability of piglet mortality rose from 0 to 0.04, whereas maternal heritability decreased from 0.03 to a non-significant value. Piglets with higher BW had a lower mortality rate. However, the genetic correlations between maternal effects on piglet mortality and piglet BW were not significant; thus, selection for piglets with higher BW at around 10 days of age, through improving maternal genetics, would not reduce piglet mortality. Piglet mortality increased from sows with increasing number of parities. Crossbreeding also reduced piglet mortality. In conclusion, selection focusing on sow genotype, the use of younger sows, and crossbreeding could contribute to maintain piglet mortality at lower levels in outdoor organic pig production systems.

Khon Kaen Agriculture Journal, 49, 1, 213-222

In many agricultural crops, the number of parents used in cross breeding make it difficult to obtain all possible hybrids in diallels. Therefore, using maize as a model plant and based on traits with high and low heritabilities, the aim of the present study was to quantify the correlation estimates of the general combining ability (GCA) and specific combining ability (SCA) between a complete diallel and a circulant diallel, with and without the inclusion of parents. For the high heritability trait, the GCA estimates can be obtained with low s values, whereas for the SCA estimates, s values close to half the number of parents should be used. For the low heritability trait, information from parents must be used to obtain the SCA estimates. For the GCA estimates, considering the stabilization of r above 0.70 for s=7, s values greater than half the number of parents must be used in the circulant models.

Milkability is an important functional trait, which is directly related to milking costs and udder health. There are no milkability traits incorporated in the South African dairy cattle breeding objectives and genetic parameter estimates for these traits are not available in this population. The main objective of the study was, therefore, to estimate the genetic parameters for milkability traits and its correlation with somatic cell scores in South African Holstein cattle. Data consisted of production and milkability records of 2719 Holstein cows, from ten herds, collected from 2016 to 2018. Genetic parameters were estimated by a multi-trait animal model using the restricted maximum likelihood (REML) procedure. Means for milking time (MT), average milk flow (AMF), maximum milk flow (MMF), and somatic cell score (SCS) were 5.20 min, 1.91 kg/min, 2.99 kg/min, and 2.06, respectively. The heritability estimates were low to moderate from 0.19 ± 0.07, 0.24 ± 0.06, 0.36 ± 0.11, and 0.41 ± 0.12, respectively, for SCS, AMF, MT, and MMF. The genetic correlations were significant (P

The random regression test-day model has become the most commonly adopted model for routine genetic evaluations in dairy populations, which allows accurately accounting for genetic and environmental effects over lactation. The objective of this study was to explore appropriate random regression test-day models for genetic evaluation of milk yield in a Holstein population with a relatively small size, which is the common situation in regional or independent breeding companies to preform genetic evaluation. Data included 419,567 test-day records from 54,417 cows from the first lactation. Variance components and breeding values were estimated using a random regression test-day model with different orders (from first to fifth) of Legendre polynomials (LP) and accounted for homogeneous or heterogeneous residual variance across the lactation. Models were compared based on Akaike information criterion (AIC), Bayesian information criterion (BIC), and predictive ability. In general, models with a higher order of LP showed better goodness of fit based on AIC and BIC values. However, models with third, fourth, and fifth order of LP led to similar estimates of genetic parameters and predictive ability. Models with assumption of heterogeneous residual variances achieved better goodness of fit but yielded similar predictive ability compared with those with assumption of homogeneous residual variances. Therefore, a random regression model with third order of LP is suggested to be an appropriate model for genetic evaluation of milk yield in local Chinese Holstein populations.

The present investigation was conducted to determine the genetic variability, Heat Susceptibility Index (HSI) and Heat Tolerance Efficiency (HTE) in 17 wheat genotypes including the checks over timely and late sown condition of rabi 2016-17 and 2017-18. On the basis of HSI for yield per plant, K1006, CG1507, PBW343 and HUW234 while UP2847, RWP 2015-22 and CG 1507 were observed to be tolerant in in 2016-17 and 2017-18, respectively. HSI for 1000 grain weight was observed to be tolerant in genotypes K 1006, RWP 2015-22, CG 1505, Lok-1 and NW 1014 in 2016-17and in genotypes K 1006, HD 2967 and DBW 14 in 2017-18, respectively. For HTE, CG 1507 (92.8%) and NW 1014 (113%) were best in 2016-17 and 2017-18, respectively. The genetic parameters showed significant variability among the genotypes and high broad sense heritability was observed for plant height in 2016-17 and for yield per plant and plant height in 2017-18.

Background One of the biggest challenges in the swine industry is to increase female reproductive efficiency. Recently, vulva score categories (VSC), assessed prior to puberty, has been proposed as an indicator trait of efficient reproductive performance in sows. The objective of this study was to validate the use of VSC as an indicator trait for reproductive performance, and to perform genetic and genomic analyses for VSC. Methods The phenotypic relationship of VSC, using a three-point scale: small (VSC-S), medium (VSC-M), and large (VSC-L), on reproductive performance was evaluated on three farms. VSC was measured at 15 weeks of age, for farms 1 and 2, and at 14 weeks of age for farm 3 on 3981 Yorkshire gilts, in which 1083 had genotypes (~ 50 K SNPs). Genetic parameters for VSC with reproductive traits were estimated using ssGBLUP. A Genome-wide association study (GWAS) for VSC was performed using BayesB. Results For the phenotypic analysis of VSC across datasets, differences in performance were identified there was a significant effect (P ≤ 0.05) for the interaction between Farm and VSC for total number dead (TND), and a trend (P c were identified. Of these, a QTL located on chromosome 3 at 33–34 Mb accounted for about 7.1% of the genetic variance for VSCc and VSCq. This region harbors the gene PRM1 that has been associated with early embryonic development in pigs. Conclusions The results support potential of VSC for improved reproductive efficiency on first-parity performance, but the results might depend on the interaction between environmental factors and VSC, as well as potentially additive genetics.

Growth rate is a major component of feed efficiency when estimating residual feed intake (RFI). Quantile regression (QR) methodology can be used to identify animals with different growth trajectories. The objective of this study was to evaluate the use of QR to identify phenotypic and genetic differences in pigs selected for low RFI. Using performance data on 750 Yorkshire pigs selected for low RFI, individual average daily gain (ADG), average daily feed intake (ADFI), RFI and Gompertz growth curve parameters (asymptotic weight (a), inflection point (b) and decay parameter (c)) were estimated for each pig. Using QR methodology, three Gompertz growth curves were estimated for the whole population for three quantiles (0.1, 0.5 and 0.9) of the BW data. Each animal was classified into one of the quantile regression groups (QRG) based on their overall Euclidian distance between each observed and estimated BW from the quantile growth curves. These three curves were also estimated using only part of the data (generations -1 to 3, and -1 to 4) in order to evaluate the agreement classification rate of animals from later generations into QRGs. We evaluated the effect of QRG on growth parameters and performance traits. Genetic parameters were estimated for these traits, as well as for QRG. In addition, genetic trends for each QRG were estimated. Three distinct growth curves were observed for animals classified into either quantiles 0.1 (QRG0.1), 0.5 (QRG0.5) or 0.9 (QRG0.9). When only part of the data was used to estimate quantile growth curves, all animals from QRG0.1 were correctly classified in their group. Animals in QRG0.1 had significantly lower ADFI, ADG and RFI, and greater a, b and c than animals in the other groups. Quantile regression groups analysed as a trait was highly heritable (0.41) and had high (0.8) and moderate (0.46) genetic correlations with ADG and RFI, respectively. Selection for reduced RFI increased the number of animals classified as QRG0.1 in the population. Overall, downward genetic trends were observed for all traits as a function of selection for reduced RFI. However, QRG0.1 was the only group that had a positive genetic trend for ADG. Altogether, these results indicate that selection for reduced RFI changes the shape of growth curves in Yorkshire in pigs, and that QR methodology was able to identify animals having different genetic potential for feed efficiency, bringing a new opportunity to improve selection for reduced RFI.

In the mink industry, feed costs are the largest variable expense and breeding for feed efficient animals is warranted. Implementation of selection for feed efficiency must consider the relationships between feed efficiency and the current selection traits BW and litter size. Often, feed intake (FI) is recorded on a cage with a male and a female and there is sexual dimorphism that needs to be accounted for. Study aims were to (1) model group recorded FI accounting for sexual dimorphism, (2) derive genetic residual feed intake (RFI) as a measure of feed efficiency, (3) examine the relationship between feed efficiency and BW in males (BWM) and females (BWF) and litter size at day 21 after whelping (LS21) in Danish brown mink and (4) investigate direct and correlated response to selection on each trait of interest. Feed intake records from 9574 cages, BW records on 16 782 males and 16 875 females and LS21 records on 6446 yearling females were used for analysis. Genetic parameters for FI, BWM, BWF and LS21 were obtained using a multivariate animal model, yielding sex-specific additive genetic variances for FI and BW to account for sexual dimorphism. The analysis was performed in a Bayesian setting using Gibbs sampling, and genetic RFI was obtained from the conditional distribution of FI given BW using genetic regression coefficients. Responses to single trait selection were defined as the posterior distribution of genetic superiority of the top 10% of animals after conditioning on the genetic trends. The heritabilities ranged from 0.13 for RFI in females and LS21 to 0.59 for BWF. Genetic correlations between BW in both sexes and LS21 and FI in both sexes were unfavorable, and single trait selection on BW in either sex showed increased FI in both sexes and reduced litter size. Due to the definition of RFI and high genetic correlation between BWM and BWF, selection on RFI did not significantly alter BW. In addition, selection on RFI in either sex did not affect LS21. Genetic correlation between sexes for FI and BW was high but significantly lower than unity. The high correlations across sex allowed for selection on standardized averages of animals' breeding values (BVs) for RFI, FI and BW, which yielded selection responses approximately equal to the responses obtained using the sex-specific BVs. The results illustrate the possibility of selecting against RFI in mink with no negative effects on BW and litter size.

The present study was carried out using 40 mutants along with two check varieties CO(Kv)2 and MDU1 during Kharif 2019. Sixteen characters were studied and out of which only 11 traits showed significant variation. Correlation and path analysis were done for 11 traits viz., number of basal tillers, days to fifty percent flowering, flag leaf length, panicle length, plant height, number of raceme, number of productive tillers, number of leaves in main tiller, average leaves in side tiller, single ear head weight and single plant yield. Among the eleven biometrical traits, high heritability was recorded by traits such as number of basal tillers, days to fifty percent flowering, flag leaf length, plant height, number of racemes, number of productive tillers, number of leaves in main tiller, single ear head weight and single plant yield. Correlation studies showed that number of productive tillers, single ear head weight and plant height possess significant positive correlation with yield at both genotypic and phenotypic level. Path analysis showed that traits like number of basal tillers, single ear head weight and panicle length had high direct effect on yield. Thus, selection of these traits would be rewarding for yield improvement in barnyard millet.

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior A cultura da abobrinha italiana (C. pepo) possui destaque a nível mundial, com demanda por genótipos mais produtivos, precoces, resistentes a doenças e boas características de frutos. Para tal, novas ferramentas são buscadas pelos melhoristas para maximizar a seleção em grandes áreas experimentais no menor tempo possível, sendo que a utilização de drones se mostrou adequada para esta finalidade. Assim o objetivo do presente estudo foi avaliar o potencial agronômico, dissimilaridade genética e validar o uso de imagens aéreas obtidas por drone para auxiliar na seleção, além de se identificar fontes de resistência aos vírus ZYMV e SqMV. O experimento foi conduzido na Estação Experimental de Hortaliças da Universidade Federal de Uberlândia, campus Monte Carmelo. Foram avaliados 65 genótipos de abobrinha-italiana (C. pepo), pertencentes ao programa de melhoramento genético de abóboras da UFU. As variáveis avaliadas foram: produção. planta-1, número de frutos. planta-1, temperatura foliar, precocidade, e os índices de área foliar, SPAD, NDVI e NDRE. Além disto, avaliou-se outros 66 genótipos provenientes do mesmo programa de melhoramento, visando identificar fontes de resistência aos vírus ZYMV e SqMV. Nas inoculações foram observados sintomas mais severos, assim como um maior número de genótipos suscetíveis para o vírus ZYMV. Os genótipos UFU-C X UFU-A#18#3;1, UFU-C X UFU-F#19#11;3, UFU-F#4#9;1, UFU-D X UFU-F#7#21;1 e a cv.“Emanuella” são uma alternativa para a produção de novas cultivares de abóbora ou híbridos resistentes a ZYMV e SqMV. Em relação a fenotipagem por imagem observou-se que o banco de germoplasma analisado possui variabilidade genética e que o uso da fenotipagem por imagem a partir do uso dos sensores NDVI e NDRE foi eficiente para identificar genótipos com diversidade para vigor de plantas em C. pepo. O índice da soma de “ranks” de Mulamba e Mock (1978) foi considerado neste trabalho como o critério mais adequado para a situação analisada. Neste índice foram selecionados os genótipos: Abobrinha 11#1 (8), Abobrinha 62#1 (31), Abobrinha 69#1 (34), Abobrinha 77#1(38), Abobrinha 85#1 (42), UFU-E (64), UFU-B (65), UFU-C (66), PX13067051(67) e UFU-G (68) como os genótipos superiores. The culture of the summer squash (C. pepo) has prominent worldwide, with demand plants for more productive, precocity, disease resistant and good fruit characteristics. For this, new tools are sought by breeders to maximize the selection in large experimental areas in the shortest possible time, and the use of drones proved adequate for this purpose. Thus, the objective of the present study was to evaluate the agronomic potential, genetic dissimilarity and validate the use of aerial images obtained by drone to assist in the selection as well as to identifying sources of resistance to the ZYMV and SqMV viruses. The experiment was conducted at the Experimental Station of Vegetables of the Federal University of Uberlândia, Monte Carmelo campus. Were evaluated 65 summer squash (C. pepo) belonging to the genetic breeding program of pumpkins of the UFU. The variables evaluated were: plant-1 yield, number of plant-1 fruits, leaf temperature, precocity, and leaf area indexes, SPAD, NDVI and NDRE. In addition, 66 other genotypes from the same breeding program were evaluated to identify sources of resistance to ZYMV and SqMV viruses. The inoculations, more severe symptoms were observed, as well as a greater number of susceptible genotypes for the ZYMV virus. The genotypes UFU-C X UFU-A # 18 # 3; 1, UFU-C X UFU-F # 19 # 11; 3, UFU-F # 4 # 9; 1, UFU-D X UFU-F # 7 # 21; 1 and cv. “Emanuella” are an alternative for the production of new cultivars of pumpkin soup or resistant hybrids to ZYMV and SqMV. Regarding imaging phenotyping, it was observed that the germplasm bank analyzed has genetic variability and that the use of image phenotyping from NDVI and NDRE sensors was efficient to identify genotypes with diversity for plant vigor in C. pepo. The index of the sum of ranks of Mulamba and Mock (1978) was considered in this study as the most appropriate criterion for the situation analyzed. This index werw selected the genotypes: Abobrinha 11#1 (8), Abobrinha 62#1 (31), Abobrinha 69#1 (34), Abobrinha 77#1(38), Abobrinha 85#1 (42), UFU-E (64), UFU-B (65), UFU-C (66), PX13067051(67) e UFU-G (68) as the superior genotypes. Tese (Doutorado)