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Age at first calving (AFC) is a measure of sexual maturity associated with the start of productive life of dairy animals. Additionally, a lower AFC reduces the generation interval and early culling of females. However, AFC has low heritability, making it a trait highly influenced by environmental factors. In this scenario, one way to improve the reproductive performance of buffalo cows is to select robust animals according to estimated breeding value (EBV) using models that include genotype–environment interaction (GEI) with the application of reaction norm models (RNMs). This can be achieved by understanding the genomic basis related to GEI of AFC. Thus, in this study, we aimed to predict EBV considering GEI via the RNM and identify candidate genes related to this component in dairy buffaloes through genome‐wide association studies (GWAS). We used 1795 AFC records from three Murrah buffalo herds and formed environmental gradients (EGs) from contemporary group solutions obtained from genetic analysis of 270‐day cumulative milk yield. Heritability estimates ranged from 0.15 to 0.39 along the EG. GWAS of the RNM slope parameter identified important genomic regions. The genomic window that explained the highest percentage of genetic variance of the slope (0.67%) was located on BBU1. After functional analysis, five candidate genes were detected, involved in two biological processes. The results suggested the existence of a GEI for AFC in Murrah buffaloes, with reclassification of animals when different environmental conditions were considered. The inclusion of genomic information increased the accuracy of breeding values for the intercept and slope of the reaction norm. GWAS analysis suggested that important genes associated with the AFC reaction norm slope were possibly also involved in biological processes related to lipid metabolism and immunity. [ABSTRACT FROM AUTHOR]

In tropical beef cattle production systems, animals are commonly raised on pastures, exposing them to potential stressors. The end of gestation typically overlaps with a dry period characterized by limited food availability. Late gestation is pivotal for fetal development, making it an ideal scenario for inter‐ and transgenerational effects of the maternal gestational environment. Intergenerational effects occur due to exposure during gestation, impacting the development of the embryo and its future germline. Transgenerational effects, however, extend beyond direct exposure to the subsequent generations. The objective of the present study was to verify these effects on the post‐natal performance of zebu beef cattle. We extended the use of a reaction norm model to identify genetic variation in the animals' responses to transgenerational effects. The inter‐ and transgenerational effects were predominantly positive (−0.09% to 19.74%) for growth and reproductive traits, indicating improved animal performance on the phenotypic scale in more favourable maternal gestational environments. Additionally, these effects were more pronounced in the reproductive performance of females. On average, the ratio of direct additive genetic variances of the slope and intercept of the reaction norm ranged from 1.23% to 3.60% for direct and from 10.17% to 11.42% for maternal effects. Despite its relatively modest magnitude, this variation proved sufficient to prompt modifications in parameter estimates. The average percentage variation of direct heritability estimates ranged from 19.3% for scrotal circumference to 33.2% for yearling weight across the environmental descriptors evaluated. Genetic correlations between distant environments for the studied traits were generally high for direct effects and far from unity for maternal effects. Changes in EBV rankings of sires across different gestational environments were also observed. Due to the multifaceted nature of inter‐ and transgenerational effects of the maternal gestational environment on various traits of beef cattle raised under tropical pasture conditions, they should not be overlooked by producers and breeders. There were differences in the specific response of beef cattle to variations in the quality of the maternal gestational environment, which can be partially explained by transgenerational epigenetic inheritance. Adopting a reaction norm model to capture a portion of the additive variance induced by inter‐ or transgenerational effects could be an alternative for future research and animal genetic evaluations. [ABSTRACT FROM AUTHOR]

Temperament (docility) is a key breeding goal in the cattle industry due to its direct relationship with animal welfare, cattle handler's safety and animal productivity. Over the past six decades, numerous studies have reported heritability estimates for temperament‐related traits in cattle populations ranging from low to high values. Therefore, the primary objective of this study was to perform a comprehensive systematic review with meta‐analysis to obtain weighted estimates of heritability for temperament‐related traits in worldwide cattle populations. After data editing and quality control, 106 studies were included in the systematic review, of which 29.2% and 70.8% reported estimates of heritability for temperament‐related traits in dairy and beef cattle populations, respectively. Meta‐analyses were performed for 95 heritability estimates using a random model approach. The weighted heritability estimates were as follow: (a) flight score at weaning = 0.23 (95% CI: 0.15–0.32); (b) flight speed at weaning = 0.30 (95% CI: 0.26–0.33); (c) joint analysis of flight speed and flight score at weaning = 0.27 (95% CI: 0.22–0.31); (d) flight speed at yearling = 0.26 (95% CI: 0.21–0.30); (e) joint analysis of flight speed at weaning and yearling = 0.27 (95% CI: 0.24–0.30); (f) movement score = 0.12 (95% CI: 0.08–0.15); (g) crush score at weaning = 0.21 (95% CI: 0.17–0.25); (h) pen score at weaning = 0.27 (95% CI: 0.19–0.34); (i) pen score at yearling = 0.20 (95% CI: 0.17–0.23); (j) joint analysis of pen score at weaning and yearling = 0.22 (95% CI: 0.18–0.26); (k) cow's aggressiveness at calving = 0.10 (95% CI: 0.01–0.19); (l) general temperament = 0.13 (95% CI: 0.06–0.19); (m) milking temperament = 0.16 (95% CI: 0.11–0.21); and (n) joint analysis of general and milking temperament = 0.14 (95% CI: 0.11–0.18). The heterogeneity index ranged from 0% to 77%, and the Q‐test was significant (p < 0.05) for four single‐trait meta‐analyses. In conclusion, temperament is moderately heritable in beef cattle populations, and flight speed at weaning had the highest weighted heritability estimate. Moreover, between‐study heterogeneity was low or moderate in beef cattle traits, suggesting reasonable standardization across studies. On the other hand, low‐weighted heritability and high between‐study heterogeneity were estimated for temperament‐related traits in dairy cattle, suggesting that more studies are needed to better understand the genetic inheritance of temperament in dairy cattle populations. [ABSTRACT FROM AUTHOR]

Karan Fries (KF) cattle is India's newly developed dairy breed with high production potential. The present study was undertaken to evaluate 17 linear-type traits, behavioural and functional traits for estimating the genetic parameters and to find their association with production performance in KF cattle using a multi-trait Bayesian animal model. Among linear-type traits, stature, chest girth, body length and body depth had a high positive genetic and phenotypic correlation (ranging from 0.30 ± 0.01 to 0.74 ± 0.03) with production traits (total milk yield and 305 days milk yield). The majority of the linear-type traits, milking temperament and milking speed were moderately heritable (ranging from 0.25 ± 0.04 to 0.40 ± 0.03), while days open had low heritability (0.20 ± 0.25). This study showed the importance of reliable assessment of genetic parameters and incorporation of a few linear-type traits having high heritability and genetic correlation with production traits, can be utilized for future selection and breeding programmes in KF cattle. [ABSTRACT FROM AUTHOR]

Simple Summary: Reproductive performance is a critical factor for the economic success and long-term viability of dairy herds. Intense selection for milk production has resulted in a decline in fertility traits in Holstein cows, leading to negative consequences for the industry. To combat this, incorporating fertility traits into the genetic evaluation is a potential solution. However, fertility data are often incomplete due to a variety of reasons; in this study, which has a limited dataset, it is essential to address this issue. The study utilized three methods to handle censorship: a linear model, a penalty method, and a threshold linear model with a penalty. The findings revealed that the penalized threshold model showed a slightly higher heritability compared to linear models. Moreover, both the penalty method and the threshold method exhibited comparable predictive abilities and substantial overlap in common animals, suggesting that both methods can be employed to impute days open censored data in this population. Reproductive efficiency is a key element of profitability in dairy herds. However, the genetic evaluation of fertility traits is often challenged by the presence of high censorship rates due to various reasons. An easy approach to address this challenge is to remove the censored data from the dataset. However, removing data might bias the genetic evaluation. Therefore, addressing this issue is crucial, particularly for small populations and populations with limited size. This study uses a Moroccan Holstein dataset to compare two Gaussian linear models and a threshold linear model to handle censored records of days open (DO). Data contained 8646 records of days open across the first three parities of 6337 Holstein cows. The pedigree file comprised 11,555 animals and 14.51% of the dataset was censored. The genetic parameters and breeding values of DO were computed using three different methods: a linear model where all censored records were omitted (LM), a penalty method in which a constant equal to one estrus cycle in cattle was added to the maximum value of DO in each contemporary group to impute the censored records (PLM), and a bivariate threshold model with a penalty (PTM). The heritability estimates were equal to 0.021 ± 0.01 (PLM), 0.029 ± 0.01 (LM), and 0.033 ± 0.01 (PTM). The penalty method and the threshold linear model with a penalty showed better prediction accuracy calculated using the LR method (0.21, and 0.20, respectively). PLM and PTM had a high Spearman correlation (0.99) between the estimated breeding values of the validation dataset, which explains the high percentage of common animals in the top 20% of selected animals. The lack of changes in the ranking of animals between PLM and PTM suggests that both methods can be used to address censored data in this population. [ABSTRACT FROM AUTHOR]

ABSTRACT The aim was to estimate the heritabilities for accumulated weight gain between 60 and 90 days (WG1), 90 and 120 days (WG2) and 120 and 150 days of age (WG3), pre‐slaughter body weight (PRE), meat‐to‐shell ratio (MS), carcass yield (CY) and age at first oviposition (AFO) in a population of snails Cornu aspersum maximum. Single (for heritabilities) and bi‐trait (for genetic correlations) analyses were performed using Bayesian inference. The animal model included the random effect of animal and systematic effects of contemporary groups and covariates. The heritability estimates for WG1, WG2 and WG3 were 0.59, 0.60 and 0.32, respectively. Heritabilities for PRE, MS, CY and AFO ranged from 0.22 to 0.51. Environmental factors mostly influenced PRE among the studied traits. However, for carcass traits and age at first oviposition, the 95% HPD intervals of estimates were large. Only the genetic correlations between weight gains reached chain convergence. The correlation between WG1 and WG2 was 0.74, between WG2 and WG3 was 0.57, and between WG1 and WG3 was 0.22 (not statistically significant). In this sense, WG1 appears to be the optimal period for evaluating the body performance of snails. Genetic improvement in WG2 may be obtained by direct selection for WG1 in this population of Cornu aspersum maximum. [ABSTRACT FROM AUTHOR]

Background: Originating from the cold and arid regions of northwestern China, Kazakh sheep are dual-purpose breeds optimized for both meat and fat production. In contrast, Texel sheep are internationally recognized for their high-quality meat and exceptional flavor. Previous studies have indicated that the hybrids of Texel and Kazakh sheep exhibit significant quality advantages. Additionally, body weight is a crucial indicator of sheep production performance, directly correlating with meat yield and economic returns. Objective: This study aims to identify genetic variations and related genes associated with the body weight traits of hybrid lambs, thereby revealing their genetic mechanisms. Methods: This study genotyped hybrid lambs using a 50K chip and performed rigorous quality control on both genotypic and phenotypic data. The traits examined include body weight traits of lambs at various stages such as birth, pre-weaning, and post-weaning. Various genome-wide association study (GWAS) models were utilized to analyze the association between lamb body weight traits and genetic markers. The study then employed an Ensemble-like GWAS (E-GWAS) strategy to integrate these models, achieving a stable list of SNPs, rather than a mere aggregation. Multiple annotation databases were consulted to further investigate the mechanisms by which genetic markers affect body weight traits. All study results were validated through an extensive literature review. Results: Analyses with multiple statistical models revealed that 48 SNPs were significantly associated with body weight traits. The annotation process identified 24 related genes (including 4 unknown genes) and 9 quantitative trait loci (QTLs). Additionally, 6 Gene Ontology (GO) terms and 22 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were determined. Conclusions: This study identified key genes and pathways in the body weight traits of hybrids between Texel and Kazakh sheep, enhancing our understanding of their genetic mechanisms. [ABSTRACT FROM AUTHOR]

Plant breeding of Coffea canephora is based on the characterization and use of the natural genetic variability of the species. Thus, the objective of this study was to quantify the genetic diversity and gains from selection of the fruit and bean physical traits of the C. canephora plant, seeking to understand the relations among the yield components and identify genotypes with superior traits. For this purpose, 42 genotypes were evaluated over two crop years while considering a randomized block design in a factorial arrangement to quantify the effects of genotypes, crop years, and the interaction between these two factors. Coffee fruit samples in the cherry stage were used to evaluate the weights, volumes, and dimensions of the fresh fruit and beans after drying. Genotypic variance prevailed over environmental variance for all of the fruit and bean physical traits of the coffee plants, except for the greatest fruit width (FWG). These associations indicate that the constituent parts of the fruit increased in a manner proportional to an increase in weight. Such associations can facilitate or hinder plant selection. The total gains obtained through the selection indices were similar to those obtained through direct selection for greater bean weights. However, the use of selection indices made it possible to identify clones with more balanced traits. [ABSTRACT FROM AUTHOR]

Inner Mongolia Cashmere goats are excellent genetic resources in China. Cashmere yield/body weight (g/kg), staple diameter (It is the cross-sectional diameter of coarse wool)/staple length (μm/cm), and fiber diameter (It is the cross-sectional diameter of fluff)/fiber length(μm/cm) were studied as secondary traits. Using the CORR and REG programs of SAS9.2, it was found that there is a significant phenotypic correlation and regression between the three secondary traits. The variance components analysis and genetic parameters estimation using the AIREML of the WOMBAT software. The results showed that all secondary traits have moderate heritability (0.17–0.30), and the heritability of each secondary trait of the long staple type is higher than other types. The genetic correlation of each secondary trait is between −0.39 and 0.27, and the genetic correlation of each secondary trait increases with the increase of staple length. Therefore, selection staple length can be to indirect selection of secondary traits. [ABSTRACT FROM AUTHOR]

White markings are characteristic of many equine breeds, being quite common in the Pura Raza Español horses (PRE). These white markings are the result of a lack of melanocytes in the skin and hair. In certain horse breeds, such as the PRE, the presence and extension of white facial markings is penalised in the breed's patron and morphological competitions, so it would be interesting to include it in their selection genetics programs to select against the presence of this special feature. The aim of this study was to calculate the prevalence of white facial markings in a representative population sample of PRE and determine its prevalence depending on the coat colour, its genetic parameters and the influence of systematic effects. The white facial markings have been classified into 5 score. A total of 42,080 PRE horses were analysed. Genetic parameters were estimated using a Bayesian procedure with the BLUPF90 software. Systematic effects included in the model were: birth period, sex, birth stud geographical area and inbreeding coefficient. The pedigree information included 93,322 horses. The prevalence was 34.2%. Systematics factors were significant in the presentation of facial white markings. Heritability in real scale ranged from 0.53 for black to 0.32 for the chestnut coat colour population, both in the linear heterogeneity model. White facial markings were more prevalent in inbred chestnut males of Spain. The additive genetic base shows that the prevalence could be managed by genetic selection. HIGHLIGHTS: PRE with white marks produce financial losses and those that invade a large portion of the eye orbit cannot registered as animals of the breed The prevalence was 34.2%, being the large white markings more affected by systematic risk effects. Genetic base of white facial markings in PRE is very related with the coat colour, and presents high-moderate heritability. White markings could be reduced by genetic selection using breeding values in all the PRE horses as a selection criterion into its breeding program. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the most important risk factors that influence productive life (PL) and to estimate genetic parameters for PL using a Weibull proportional hazards model in two Spanish dairy goat breeds belonging to different production systems. The dataset consisted of 70,695 and 49,176 lactation records of Florida and Payoya females, respectively, collected over the last two decades. A total of 6,227 (24.21%) Florida and 3,452 (20.42%) Payoya females had censored information. The pedigree included a total of 56,901 animals for Florida and 59,957 for Payoya. The effects included in the model for both breeds were the age at first kidding and the herd-year-season of birth of the doe as time-independent effects; and the age at kidding, the herd-year-season of kidding, the within-herd class of milk production deviation and the combination between the lactation number and the duration of lactation as time-dependent effects. Estimation of genetic parameters was made using a Weibull proportional hazards model using Survival Kit V6.0 software. The results from the Weibull animal models gave estimates of additive genetic variances of 0.99 ± 0.0003 and 0.156 ± 0.021, which corresponds to a heritability of 0.43 ± 0.025 and 0.11 ± 0.021 for Florida and Payoya, respectively. The magnitude of heritability obtained for PL suggests that a substantial response to selection may be expected for longevity, especially in the Florida breed. These results may contribute to the development of a routine genetic evaluation to improve PL in Spanish dairy goat breeds. HIGHLIGHTS: A Weibull proportional hazards model has been used to analyse productive life in Spanish goat breeds raised under different production systems. Productive life is influenced by many factors, with milk production the most important. According to the heritability estimated, a significant genetic response could be obtained by direct selection for productive life, especially in the Florida breed. [ABSTRACT FROM AUTHOR]

Simple Summary: This study aimed to estimate genetic parameters for serum insulin-like growth factor I concentrations and their correlations with performance traits in beef cattle. A divergent selection experiment for this important hormone began in 1989. From the 2009 through to the 2017 breeding season, the selection criterion in the two lines was changed to high vs. low maintenance energy expected progeny differences. Estimates of direct heritability were moderate, ranging from 0.34 ± 0.07 to 0.46 ± 0.07 for insulin-like growth factor I concentrations and from 0.32 ± 0.05 to 0.39 ± 0.07 for the growth traits. The heritability of maternal genetic effects for insulin-like growth factor I concentration ranged from 0.02 ± 0.11 to 0.17 ± 0.05 and was similarly low for the weight traits. Maternal permanent environmental effects were negligible for insulin-like growth factor I but were somewhat larger for the weight traits. Direct maternal correlations for postweaning insulin-like growth factor I concentrations were approximately −0.90. The genetic correlations of insulin-like growth factor I with weight traits were generally positive but small. Environmental and phenotypic correlations between insulin-like growth factor I concentrations and growth traits were generally low, indicating that shared environmental influences are minimal, and that this hormone has a modest impact on growth traits. These findings suggest that while IGF-I concentration has some influence, it is not the primary determinant of weight gain or hip height. This study investigated the genetic parameters for serum IGF-I concentrations and growth traits in beef cattle. A divergent selection experiment for serum IGF-I concentration was initiated in 1989. One hundred spring-calving (50 high line and 50 low line) and 100 fall-calving (50 high line and 50 low line) black Angus cows with unknown IGF-I concentrations were randomly assigned to the two divergent selection lines. For the 2009 through 2017 breeding seasons, the selection criterion in the two lines was changed from serum IGF-I concentration to high vs. low maintenance energy expected progeny differences (ME EPDs). The number of records available for analysis varied from 2056 for IGF-I concentration on day 42 of the postweaning performance test to 2988 for birth weight, with the exception that only 617 records were available for IGF-I concentration at weaning. (Co)variance components were estimated for direct and maternal additive genetic effects using an animal model and multiple-trait, derivative-free, restricted maximum likelihood (MTDFREML) computer programs. Direct heritability estimates for serum IGF-I concentrations ranged from 0.34 ± 0.07 to 0.46 ± 0.07, whereas direct heritability estimates for weight traits ranged from 0.32 ± 0.05 to 0.39 ± 0.07. Maternal genetic effects on IGF-I were low, with estimates ranging from 0.02 ± 0.11 to 0.17 ± 0.05, and were similarly low for weight traits. Maternal permanent environmental effects were negligible for IGF-I but were larger for weight traits, especially for weaning weight (0.22 ± 0.04). Direct maternal correlations for postweaning IGF-I concentrations were approximately −0.90. The genetic correlations of IGF-I with weight traits were generally low, with negative correlations observed for birth weight and small positive correlations for the other weight traits. Environmental and phenotypic correlations between IGF-I concentrations and growth traits were generally small, indicating circulating IGF-I has a modest impact on growth traits in beef cattle. [ABSTRACT FROM AUTHOR]

The aim of this study was to estimate the best covariance function structure, by means of Legendre polynomials using random regression models (RRM) to describe the genetic variability of the weight growth trajectory of quails and to estimate the genetic parameters. Body weight records of animals at 7, 14, 21, 28, 35, and 42 days of age were used. The orders of fit of the polynomials were gradually increased in orders from 3 to 6 for comparison between the models the Akaike information criteria were used. The models included fixed effects of the contemporary group, the fixed regression coefficient of weight on the Legendre polynomial, random regression coefficients of the direct additive genetic, and the permanent environment effects of the animal, in addition to the residual random effect. The RRM with orders five for the additive genetic effect and six for the permanent environment effect, under the assumption of homogeneity, was the most suitable to describe the genetic variability of the birds’ ponderal growth. There was greater expression of additive genetic variability after 21 days, resulting in distinct and increasing heritability estimates between two periods in ponderal development. Estimates of additive genetic correlations for weights between the ages evaluated indicated that genetic associations are more correlated between body weights at closer ages when compared to ages more distant along the growth trajectory. Thus, it is concluded that selection in birds is more efficient from 28 days of age due to the higher heritability values. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The aims of this study were to estimate the genetic parameters of clinical mastitis (CM) and SCS traits, and to compare the performance of genetic evaluations of CM traits using univariate and bivariate analyses (CM-SCS). Data were edited according to the Udder Health Golden Standard harmonization, and then 6 CM traits and 6 SCS traits were considered, as the result of combining 3 lactation classifications (1, 2, ≥3) and 2 milking periods (early, late). The linear mixed animal models included the ratio of period at risk as a covariate, herd-year of calving, month of calving, and lactation-age as fixed effects, and the permanent environmental effect for traits of ≥3 lactations. Prevalence of CM in early lactation was similar regardless the lactation number (5%–6%), and the estimated heritabilities were 0.01. Prevalences in late lactation ranged from 10% to 24% and heritabilities ranged from 0.03 to 0.05. Estimated heritabilities of SCS ranged from 0.06 to 0.16 with univariate analyses. Somatic cell count (therefore its log-transformation SCS) showed a higher probability of correctly identifying healthy cows than infected cows but there was still up to 36% of healthy cows for which CM was not detected by SCS. Genetic correlations between CM-SCS traits ranged from 0.36 to 0.95, and SCS in lactation 3 and later did not add extra information to SCS in the second lactation for predicting CM. Regarding reliabilities of EBVs for CM traits, bivariate CM-SCS analyses led to substantial increases with respect to the single-trait model for sires (7%–12% more in first lactation and 16%–28% more for second lactation). Sire's rank correlations for CM between univariate and bivariate analyses (0.47–0.92) suggest that discarding sires could be more accurate than selecting candidates for sires of dams. We can conclude that SCS in first lactation could be useful to supplement CM data in first and second lactations to improve udder health genetic evaluation. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Traits related to calving have a significant impact on animal welfare and farm profitability in dairy production systems. Identifying genomic regions associated with calving traits could contribute to refining dairy cattle breeding programs and management practices in the dairy industry. Therefore, the primary objectives of this study were to estimate genetic parameters and perform GWAS and functional enrichment analyses for stillbirth, gestation length, calf size, and calving ease traits in North American Jersey cattle. A total of 40,503 animals with phenotypic records and 5,398 animals genotyped for 45,101 SNPs were included in the analyses. Genetic parameters were estimated based on animal models and Bayesian methods. The effects of SNPs were estimated using the single-step GBLUP method. The heritability (SE) estimates ranged from 0.01 (0.01) for stillbirths in heifers to 0.11 (0.01) for gestation length in cows. The genetic correlations ranged from −0.58 (0.11) between calving ease and stillbirths in heifers to 0.44 (0.14) between calving ease and calf size in cows. Calving ease showed the highest genetic correlation between heifers and cows, 0.8 (0.22) respectively. The candidate genes identified, including MTHFR , SERPINA5 , IGFBP3 , and ZRANB1 , are involved in key biological processes and metabolic pathways related to the studied traits. Reducing environmental variation and identifying novel indicators of reproduction traits in the Jersey breed are needed given the low heritability estimates for most traits evaluated in this study. In conclusion, this study provides a characterization of the genetic background of calving-related traits in Jersey cattle. The estimates obtained can be used to improve or build selection indexes in Jersey cattle breeding programs in North America. [ABSTRACT FROM AUTHOR]

Key message:Eucalyptusbreeding can benefit from strategies that capture dominance effects, as shown by the improvement in mean annual increment of wood volume across cycles of RRS. Abstract: There is no empirical validation of reciprocal recurrent selection (RRS) in Eucalyptus breeding. Our study helps to fill this gap by quantifying the realized response to selection achieved after two cycles of RRS involving Eucalyptus urophylla and E. grandis. We also investigated the selection effects on the genetic parameters of the breeding populations. We evaluated 25 trials of the first cycle (C1) of RRS and 12 trials of the second cycle (C2) of RRS. These trials were established in two different regions, separated according to altitude. Fitting linear mixed models enabled the estimation of variance components and the prediction of mean components (general and specific hybridizing abilities). The realized response to selection was calculated as the difference between the mean of the predicted genotypic values of the C1 and C2. The RRS effectively improved the mean annual increment of wood volume by 28.5% in the high-altitude region and 12.3% in the low-altitude region from the C1 to C2. The genetic variability also increased as a result of the new genotypes that arose through recombination. These findings provide insights for decision-making and reinforce that Eucalyptus breeding can benefit from strategies that capture dominance effects. [ABSTRACT FROM AUTHOR]

In this study, we performed spatial analyses to estimate genetic parameters for the incidence of frosty pod rot and yield in two progeny trials of the breeding program of the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP) in Mexico. We identified spatial autocorrelation through graphical analyses of distribution, isotropic variograms, and Moran's index. We used three spatial models for each trait: B-Splines, First-order Autoregressive (AR), and Bayesian Intrinsic Conditional Autoregressive (ICAR). We found that the data correlated over a maximum distance ranging from 6 to 10 m. The intensity of spatial autocorrelation, according to Moran's index, was 0.11 to 0.18 (p < 0.001, Z > 2.5). The Bayesian hierarchical and first-order autoregressive methods improved the model fit compared to the Spline approach. Heritability estimates were h2 = 0.11 ± 0.08 to 19 ± 0.10 for bean dry weight per tree, 0.11 ± 0.08 for the total number of pods per tree, and 0.36 ± 0.15 to 0.42 ± 0.16 for frosty pod rot disease. Correlations between models averaged r = 0.99, p < 0.001, with an average match ranging from 0.77 to 0.96 in the ranking of individuals under a selection pressure of 5%. These models contributed to understanding spatial patterns of disease dynamics and cacao production. Important traits for the INIFAP's breeding program and other programs facing the same challenges were considered in this study, aiming to improve the efficiency of those programs. Incorporation of these methods into breeding programs may allow for accurate estimation of the genetic parameters underlying the quantitative genetics of cacao trees, at the same time saving time and resources. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate (co)variance components and heritability of pre-weaning body weight traits and the Kleiber ratio in Akkaraman sheep. Data collected between 2018 and 2023 from Çankırı province, Türkiye, formed the basis of this research. The considered traits were birth weight (BW), weaning weight (WW), average pre-weaning daily weight gain (ADWG), and Kleiber ratio (KR). Utilizing animal mixed models and the average information restricted maximum likelihood (AI-REML) procedure, genetic parameters were estimated. Direct heritability estimates were 0.30 ± 0.02, 0.23 ± 0.02, 0.23 ± 0.02, and 0.28 ± 0.03 for BW, WW, ADWG, and KR, respectively. Maternal genetic heritabilities were 0.03 for WW and 0.02 for WW, ADWG, and KR. Direct genetic correlations among pre-weaning growth traits were negative for BW-WW and BW-ADWG and positive for WW-ADWG at -0.05, -0.23, and 0.98, respectively. The moderate direct heritability estimate suggests the presence of genetic variability in the Akkaraman sheep breed, indicating potential genetic progress through selective breeding. Despite the low maternal permanent environmental effects, the significant impact of maternal care on lamb growth in this breed underscores the importance of considering both direct and maternal effects in the genetic evaluation of early growth traits. The observed negative genetic correlations among birth weight, weaning weight, and daily live weight gain until weaning emphasize the need for careful consideration in selection programs for the Akkaraman breed. [ABSTRACT FROM AUTHOR]

Insect production for food and feed presents a promising supplement to ensure food safety and address the adverse impacts of agriculture on climate and environment in the future. However, optimisation is required for insect production to realise its full potential. This can be by targeted improvement of traits of interest through selective breeding, an approach which has so far been underexplored and underutilised in insect farming. Here, we present a comprehensive review of the selective breeding framework in the context of insect production. We systematically evaluate adjustments of selective breeding techniques to the realm of insects and highlight the essential components integral to the breeding process. The discussion covers every step of a conventional breeding scheme, such as formulation of breeding objectives, phenotyping, estimation of genetic parameters and breeding values, selection of appropriate breeding strategies, and mitigation of issues associated with genetic diversity depletion and inbreeding. This review combines knowledge from diverse disciplines, bridging the gap between animal breeding, quantitative genetics, evolutionary biology and entomology, offering an integrated view of the insect breeding research area and uniting knowledge which has previously remained scattered across diverse fields of expertise. [ABSTRACT FROM AUTHOR]

Increasing global temperatures and the incidence of extreme weather conditions will result in heat stress becoming a greater issue in production animals. Genetic selection and breeding for heat-tolerant animals have been promoted as a possible mitigation strategy in dairy cattle. The objectives of this study were to obtain in-field skin temperature measurements of the eye, muzzle and udder using infra-red thermography to examine the genetic variation in skin temperature within cows of a dairy herd and to estimate the genetic correlations between skin temperature and production traits. Thermal images and herd test records were obtained for the dairy herd at Massey University’s dairy farm 1. Estimates of (co)variances were obtained using the JWAS program with univariate and bivariate animal models. The heritability estimates for the eye, muzzle and udder temperature were low to moderate at 0.20, 0.24 and 0.39, respectively. All genetic correlations between production and temperature traits were positive except for eye temperature with milk yield and protein yield which was negative and weak. These results indicate that it may be possible to select for a greater skin temperature, however, these results need to be validated using a larger sample size. [ABSTRACT FROM AUTHOR]

Simple Summary: The pH is an important indicator in evaluating the quality of goose meat. SNP genotyping combined with genome-wide association studies (GWAS) is a common method for gene mining related to meat quality traits and has been widely applied in animal breeding research. However, gene mining studies focusing on goose meat quality traits have not yet been conducted. To explore the genetic characteristics of pH traits in goose meat, it is essential to study the SNPs and key candidate genes associated with the pH traits of Sichuan White Goose. In this study, we analyzed 203 male Sichuan White Geese. The results showed that 30 SNPs were associated with the pH traits of Sichuan White Goose meat, and 14 key candidate genes were identified. Our research provides a new perspective for improving goose meat quality and advancing molecular breeding practices. The genetic regulation of goose meat quality traits remains relatively unexplored, and the underlying mechanisms are yet to be elucidated. This study aims to employ single nucleotide polymorphism (SNP) genotyping in conjunction with genome-wide association studies (GWAS) to investigate critical candidate regions and genes associated with the pH trait of meat in Sichuan white geese. A cohort of 203 healthy male Sichuan white geese was randomly selected and slaughtered at 70 days of age. Measurements were taken of meat pH, growth parameters, body dimensions, and post-slaughter traits. High-throughput sequencing on the Illumina HiSeq X Ten platform facilitated gene resequencing and SNP evaluation, and GWAS was employed to detect key genes within quantitative trait loci (QTL) intervals. The sequencing of 203 individuals yielded a total of 2601.19 Gb of genomic data, with an average sequencing depth of 10.89×. Through GWAS analysis, a total of 30 SNPs associated with pH were identified. These SNPs were identified on multiple chromosomes, including on chromosome 17 (chr: 23.57–23.68 Mb) and chromosome 13 (chr13: 31.52–31.61 Mb). By annotating these associated SNPs, nine candidate genes (including C19L2, AMFR, POL, RERGL, ZN484, GMDS, WAC) associated with the pH of goose meat were identified. The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) genotyping of 10 SNPs centered on these nine candidate genes was confirmed. GO enrichment analysis revealed that genes within 1 Mb of the associated SNPs are significantly enriched in pathways involved in lymphocyte activation, in response to hydrogen peroxide, Salmonella infection, and other metabolic processes. This study explores the gene regulatory pathways influencing pH traits in goose meat and provides molecular markers for enhancing meat quality. These findings are expected to facilitate the advancement of molecular breeding programs in geese. [ABSTRACT FROM AUTHOR]

This study utilized a dataset comprising 3023 lactation records for Friesian cows, 596 records for Native cows (Baladi), and 1189 records for Crossbred cows spanning from 1994 to 2015. The objective was to estimate and assess genetic and phenotypic parameters and breeding values for 305-day milk yield (305-DMY), lactation period (LP), calving interval (CI), and days open (DO) within the Egyptian dairy context. The motivation for this research stemmed from the need to understand the genetic potential of different cattle genotypes in Egypt and identify opportunities for enhancing dairy production. Data were analyzed using the linear mixed model least squares and maximum likelihood (LSMLMW) and multiple-trait derivative-free restricted maximum likelihood (MTDFREML) programs. The analytical model included fixed effects such as season and year of calving, parity, and genotype groups, while random effects included animal and error. Unadjusted means for 305-DMY, LP, CI, and DO were calculated for each genotype group. Genotype groups significantly impacted all studied traits. Heritability estimates varied across genotype groups, with higher estimates observed in Crossbred (0.32, 0.26, 0.25, 0.23) and Native cows (0.26, 0.28, 0.28) compared to Friesian cows (0.24, 0.22, 0.16, 0.17) for productive and reproductive traits, respectively. Genetic correlations among traits ranged from 0.10 to 0.86 for the three genotype groups, while corresponding phenotypic correlations were generally small to moderate and positive. Regarding breeding values, the accuracy estimates suggested that both sires and cows could contribute to genetic improvement. This indicates the potential for enhancing dairy production through selective breeding strategies. [ABSTRACT FROM AUTHOR]

This study aimed to estimate genetic parameters, including heritability and repeatability, for milk yield and prolificacy in sheep. It included 3682 records from 1837 ewes across various breeds: Awassi, Assaf, and Awassi x Assaf crosses, two Awassi lines: Improved Awassi, AFEC Awassi. The study measured total milk yield (TMY), yield up to 120 days (TMY120), and yield up to 150 days (TMY150), alongside reproductive traits: litter size (LS), number of lambs born alive (NLBA), and lambing interval (LI). The analysis utilized a mixed model and the REML procedure to estimate genetic parameters. Results indicated that litter size (LS) had no significant impact on milk traits, whereas breed, location, ewe parity, and lambing season showed significant effects. Lactation length also significantly influenced TMY. For reproductive traits, treatment was significant for NLBA, with location associated with breed, parity, and season affecting all traits. Heritability estimates for TMY ranged from 0.00 in Awassi x Assaf crosses to 0.11 in Awassi, and for TMY120 and TMY150, from 0.00 in Awassi x Assaf crosses to 0.16 in Awassi. Estimates for LS and NLBA varied similarly. The heritability for LI was 0.03 in Awassi and zero in other breeds and crosses. The findings suggest that in the northern West Bank regions of Nablus and Jenin, Assaf or Awassi x Assaf breeds are preferable. The study underscores the importance of comprehensive performance and pedigree recording for effective sheep farm management. [ABSTRACT FROM AUTHOR]

ABSTRACT: Traits related to calving have a significant impact on animal welfare and farm profitability in dairy production systems. Identifying genomic regions associated with calving traits could contribute to refining dairy cattle breeding programs and management practices in the dairy industry. Therefore, the primary objectives of this study were to estimate genetic parameters and perform GWAS and functional enrichment analyses for stillbirth, gestation length, calf size, and calving ease traits in North American Jersey cattle. A total of 40,503 animals with phenotypic records and 5,398 animals genotyped for 45,101 SNPs were included in the analyses. Genetic parameters were estimated based on animal models and Bayesian methods. The effects of SNPs were estimated using the single-step GBLUP method. The heritability (SE) estimates ranged from 0.01 (0.01) for stillbirths in heifers to 0.11 (0.01) for gestation length in cows. The genetic correlations ranged from −0.58 (0.11) between calving ease and stillbirths in heifers to 0.44 (0.14) between calving ease and calf size in cows. Calving ease showed the highest genetic correlation between heifers and cows, 0.8 (0.22) respectively. The candidate genes identified, including MTHFR, SERPINA5, IGFBP3, and ZRANB1, are involved in key biological processes and metabolic pathways related to the studied traits. Reducing environmental variation and identifying novel indicators of reproduction traits in the Jersey breed are needed given the low heritability estimates for most traits evaluated in this study. In conclusion, this study provides a characterization of the genetic background of calving-related traits in Jersey cattle. The estimates obtained can be used to improve or build selection indexes in Jersey cattle breeding programs in North America.

ABSTRACT: The aims of this study were to estimate the genetic parameters of clinical mastitis (CM) and SCS traits, and to compare the performance of genetic evaluations of CM traits using univariate and bivariate analyses (CM-SCS). Data were edited according to the Udder Health Golden Standard harmonization, and then 6 CM traits and 6 SCS traits were considered, as the result of combining 3 lactation classifications (1, 2, ≥3) and 2 milking periods (early, late). The linear mixed animal models included the ratio of period at risk as a covariate, herd-year of calving, month of calving, and lactation-age as fixed effects, and the permanent environmental effect for traits of ≥3 lactations. Prevalence of CM in early lactation was similar regardless the lactation number (5%–6%), and the estimated heritabilities were 0.01. Prevalences in late lactation ranged from 10% to 24% and heritabilities ranged from 0.03 to 0.05. Estimated heritabilities of SCS ranged from 0.06 to 0.16 with univariate analyses. Somatic cell count (therefore its log-transformation SCS) showed a higher probability of correctly identifying healthy cows than infected cows but there was still up to 36% of healthy cows for which CM was not detected by SCS. Genetic correlations between CM-SCS traits ranged from 0.36 to 0.95, and SCS in lactation 3 and later did not add extra information to SCS in the second lactation for predicting CM. Regarding reliabilities of EBVs for CM traits, bivariate CM-SCS analyses led to substantial increases with respect to the single-trait model for sires (7%–12% more in first lactation and 16%–28% more for second lactation). Sire's rank correlations for CM between univariate and bivariate analyses (0.47–0.92) suggest that discarding sires could be more accurate than selecting candidates for sires of dams. We can conclude that SCS in first lactation could be useful to supplement CM data in first and second lactations to improve udder health genetic evaluation.

White markings are characteristic of many equine breeds, being quite common in the Pura Raza Español horses (PRE). These white markings are the result of a lack of melanocytes in the skin and hair. In certain horse breeds, such as the PRE, the presence and extension of white facial markings is penalised in the breed’s patron and morphological competitions, so it would be interesting to include it in their selection genetics programs to select against the presence of this special feature. The aim of this study was to calculate the prevalence of white facial markings in a representative population sample of PRE and determine its prevalence depending on the coat colour, its genetic parameters and the influence of systematic effects. The white facial markings have been classified into 5 score. A total of 42,080 PRE horses were analysed. Genetic parameters were estimated using a Bayesian procedure with the BLUPF90 software. Systematic effects included in the model were: birth period, sex, birth stud geographical area and inbreeding coefficient. The pedigree information included 93,322 horses. The prevalence was 34.2%. Systematics factors were significant in the presentation of facial white markings. Heritability in real scale ranged from 0.53 for black to 0.32 for the chestnut coat colour population, both in the linear heterogeneity model. White facial markings were more prevalent in inbred chestnut males of Spain. The additive genetic base shows that the prevalence could be managed by genetic selection.

The aim of this study was to assess the most important risk factors that influence productive life (PL) and to estimate genetic parameters for PL using a Weibull proportional hazards model in two Spanish dairy goat breeds belonging to different production systems. The dataset consisted of 70,695 and 49,176 lactation records of Florida and Payoya females, respectively, collected over the last two decades. A total of 6,227 (24.21%) Florida and 3,452 (20.42%) Payoya females had censored information. The pedigree included a total of 56,901 animals for Florida and 59,957 for Payoya. The effects included in the model for both breeds were the age at first kidding and the herd-year-season of birth of the doe as time-independent effects; and the age at kidding, the herd-year-season of kidding, the within-herd class of milk production deviation and the combination between the lactation number and the duration of lactation as time-dependent effects. Estimation of genetic parameters was made using a Weibull proportional hazards model using Survival Kit V6.0 software. The results from the Weibull animal models gave estimates of additive genetic variances of 0.99 ± 0.0003 and 0.156 ± 0.021, which corresponds to a heritability of 0.43 ± 0.025 and 0.11 ± 0.021 for Florida and Payoya, respectively. The magnitude of heritability obtained for PL suggests that a substantial response to selection may be expected for longevity, especially in the Florida breed. These results may contribute to the development of a routine genetic evaluation to improve PL in Spanish dairy goat breeds.

The study of adaptability, stability, and productivity is essential for selecting and recommending superior genotypes. This fact is particularly the case for the introduction of common bean cultivars in Rio de Janeiro, Brazil, whose production is negligible and does not meet the internal demand. Thus, this study estimated genetic parameters and selection gains and undertake a simultaneous selection for adaptability, stability, and productivity in black bean genotypes via mixed models. The investigation was carried out in three municipalities in the state of Rio de Janeiro during three crop years. The trials were set up in a randomized block design with 11 genotypes and three replications. High mean heritability (81%) and selection accuracy (90%), as well as good selection prospects, were observed. Gains between 1.03 and 9.49% were achieved for grain yield. Simultaneous selection was efficient, indicating two black bean lines (CNFP 15290 and CNFP 15361) as the most productive, adaptable, and stable. As such, these lines have the potential to be released as new black bean cultivars for the state of Rio de Janeiro. [ABSTRACT FROM AUTHOR]

ABSTRACT: In this paper, we present a comprehensive study of gestation length (GL) in 16 cattle breeds by using large genotype and animal record databases. Data included over 20 million gestations since 2000 and genotypes from one million calves. The study addressed the GL variability within and between breeds, estimation of its direct and maternal heritability coefficients, association with fitness and several economic traits, and QTL detection. The breed average GL varied from 279.7 to 294.4 d in Holstein and Blonde d'Aquitaine breeds, respectively. Standard deviations per breed were similar and ranged from 5.2 to 5.8 d. Direct heritability (i.e., for GL defined as a trait of the calf) was moderate to high (h2 = 0.40–0.67), whereas the maternal heritability was low (0.04–0.06). Extreme breeding values for GL were strongly associated with a higher mortality during the first 2 d of life and were associated with milk production of dams for dairy breeds and precocity of females. Finally, several QTL were detected affecting GL with cumulated effects up to a few days, and at least 2 QTL were found to be shared between different breeds. Our study highlights the risks that would be associated with selection toward a reduced GL. Further genomic studies are needed to identify the causal variants and their association with juvenile mortality and other economic traits.

Penaeus vannamei, also known as white foot shrimp, is globally one of the three high-yield shrimp farming varieties. The wild species is found along the Pacific coast of South America. Since 1988, China has introduced P. vannamei. Due to its strong environmental adaptability, high feed conversion rate, fast growth rate, and high tolerance to ammonia nitrogen and nitrite, it has been widely promoted in aquaculture. By 2021, the aquaculture output of P. vannamei in China reached 1.977 million tons, accounting for approximately 37% of the world's total production, and has extremely high economic value.Growth traits are among the most important economic factors in the production of P. vannamei. With the intensive development of shrimp farming and degradation of germplasm, the white spot syndrome virus (WSSV) is a serious disease faced by the global shrimp industry. The infection can cause symptoms such as reduced food intake, enlarged liver and pancreas, pale red body color, and white spots on the head and chest armor in shrimp, resulting in widespread death.At present, China has cultivated 12 new varieties of P. vannamei, which to some extent alleviates its dependence on imports for high-quality P. vannamei. However, the excellent traits of domestic shrimp species are singular, and cultivating new varieties of P. vannamei with fast growth and strong disease resistance is an urgent demand in the market. Genetic parameter evaluation is the fundamental work of selection breeding. Heritability reflects the genetic variation in traits in the breeding population, which is of great significance in the development of a selection index, prediction of selection response, comparison of selection methods, selection breeding planning, and other breeding processes. There are different degrees of genetic correlation among various quantitative traits of shrimp, and genetic correlation coefficients are important for selecting target traits. The estimation of genetic correlation can be used to develop a comprehensive selection index and breeding program of multiple traits, which can improve the selection efficiency and breed better varieties with multiple traits. The higher the genetic correlation between traits, the better the effect of indirect selection. The estimation of genetic parameters is greatly affected by the test population, breeding management, analysis methods, and other factors. To ensure the accuracy of multi-trait composite breeding for growth and WSSV resistance, accurate evaluation of growth and WSSV resistance needs to be carried out for specific breeding populations. There are two commonly used target traits for measuring WSSV resistance in P. vannamei: individual survival time after infection and half-lethal survival rate (SS50) of families. In practice, measuring the half-lethal survival rate of families is more convenient. However, the correlation between these two traits has not yet been reported.To promote the growth and WSSV resistance of P. vannamei, 59 families (1, 770 individuals) were tested for WSSV infection. We recorded the survival time and individual body length of shrimp after infection and analyzed the mean, standard deviation, maximum and minimum values, and coefficient of variation of half-lethal survival rate and test traits for each line. The heritability and genetic correlation coefficients of growth, survival time, and half-lethal survival rate were calculated. Variance components and genetic parameters for growth and survival traits were estimated using a two-trait animal model and a sire-dam threshold model. The genetic parameters of body length were corrected by including age as a covariate. The genetic parameters of WSSV survival time were corrected by including body length as a covariate. The estimated heritability of body length was medium (0.17±0.05), and the estimated heritabilities of survival time and half-lethal survival rate were medium (0.18±0.05 and 0.14±0.05). Further, the estimated heritabilities of the three traits were significantly different from zero (P < 0.01). The genetic correlation between body length and survival time and that of body length and half-lethal survival rate were low (0.15±0.20 and 0.25±0.22). There were no significant differences between the genetic correlations and zero (P > 0.05). The genetic correlation between survival time and half-lethal survival rate was high (0.96±0.03). There was no significant difference between the genetic correlation and one (P > 0.05). The results showed that a comprehensive selection index of growth and WSSV resistance of P. vannamei can be established to carry out multi-trait composite breeding. In this breeding population, the growth and WSSV resistance of P. vannamei can be combined with multiple traits according to the breeding requirements, and the comprehensive selection index can be formulated by assigning values. In addition, to optimize the breeding of each generation, the half-lethal survival rate of WSSV can be used as an indicator of WSSV resistance. This study provides basic data and theoretical support for breeding varieties of P. vannamei with excellent growth and WSSV resistance.

ABSTRACT Electronic feeders record feeding behaviour as feed events by tracking the animal's in‐out visits to the feeder. Another way to measure feeding behaviour is based on meals. However, the two approaches provide different outcomes. The objectives of this study were to estimate genetic parameters (heritabilities and genetic and phenotypic correlations) for feed event and meal traits, and their genetic and phenotypic correlations with feed efficiency traits in Nellore cattle. The present study analysed six feed event traits (DMIFE: dry matter intake per feed event, FED: feed event duration, TBFE: time between feed events, FTd: feeding time per day, FEd: feed events per day, and FR: feeding rate), six meal traits (DMIME: DMI per meal, MED: meal duration, TBME: time between meals, MC: meal criterion, MTd: meal time per day, and MEd: meals per day), and three feed efficiency traits (ADG: average daily gain, DMI, and RFI: residual feed intake). The traits were measured in feed efficiency tests of Nellore cattle (age = 280 ± 41 days and body weight = 258 ± 47 kg at enrolment). The MC was calculated for each animal and ranged from 1.70 to 64.0 min, i.e., any pair of feed events separated by less than the MC value was considered part of the same meal. The heritabilities and correlations were estimated by fitting univariate and bivariate animal models, respectively, using single‐step genomic BLUP. The highest heritabilities for feed event traits were 0.35 ± 0.06 (FED), 0.39 ± 0.06 (FTd), and 0.50 ± 0.05 (FTd), and for meal traits were 0.31 ± 0.06 (MED) and 0.45 ± 0.06 (MTd). The genetic correlation between feed event traits and meal traits were weak. FR, FED, and FTd had moderate genetic correlations with RFI (−0.56 ± 0.11, 0.44 ± 0.11, 0.60 ± 0.08, respectively). These results indicate that more efficient animals spent less time at the feeder per feed event and per day, and eat faster compared to less efficient animals. In conclusion, feed event and meal traits must be treated as distinct groups of traits since the genetic and phenotypic correlations were, in general, weak to moderate. Among feed event versus meal traits, feed event traits are more favourable to explain the genetic relationships of feeding behaviour with feed efficiency‐related traits. [ABSTRACT FROM AUTHOR]

To evaluate the expression of drought tolerance for bread wheat, six parents diverse in their response to drought i.e., Giza 171 (P1), Sakha 95 (P2), Bohouth 6 (P3), Cham 8 (P4), Gemmiza 12 (P5) and Masr 3 (P6) and their 15 F1 crosses at 100% water requirements, and 70% water requirements sown in randomized complete blocks design season 2023/24 to estimate some genetic parameters for day to heading, days to maturity, chlorophyll pigments, superoxide dismutase activity, the activity of ascorbate peroxidase, proline content, number of spikes/plant, number of grains/spike, 100-kernel weight, and grain yield/plant. slightly significant differences were shown for most studied traits across all water regimes. The ratios of general combining ability to specific combining ability exceeded one for the examined traits, with some exceptions, signifying the influence of additive gene effects on the inheritance. The parental genotypes as good combiners, for earliness were P1 under both treatments, as well as P1, P2, and P3 at 70% water requirements, for physiologic and agronomic traits. The crosses P3 × P4 and P4 × P6 were the best combinations across the two treatments depending on physiological response and yield attributes. Most hybrids had significant heterotic values for agronomic and biophysiological traits. The genotypic and phenotypic coefficients of variation varied from 1.71% for days to maturity to 14.83% for proline content, and from 1.90% for days to maturity to 16.64% for the activity of ascorbate peroxidase under well-watered, respectively; likewise, from 2.03% and 1.80% for days to maturity to 14.69% and 14.05% for chlorophyll a, respectively under water deficit. [ABSTRACT FROM AUTHOR]

The six-population model supports the development of strategies for selecting genotypes with enhanced heat tolerance and yield stability, which are crucial for wheat improvement programs targeting adverse climate conditions. This study was dedicated to exploring the genetic control and heterosis of earliness, physiological, and yield traits under optimum and late sowing dates. The used plant material was six populations (P1, P2, F1, F2, BC1, and BC2) derived from two crosses of bread wheat; Cross І (Line 606 × Sakha 95) and Cross П (Cham 8 × Masr 3). The results displayed highly significant mean squares due to generations. Heterosis estimates were negative and significant for earliness traits and positively significant for the remaining traits, with a few exceptions. Moreover, at least one of the non-allelic interactions is significant or highly significant, proving the appropriateness of the six parameters model to estimate the different gene effect types governing most studied characters. However, the simple additive-dominance genetic model clarified the inheritance of the number of spikes/plant and days to maturity in cross І (Line 606 × Sakha 95), and number of spikes/plant and number of grains/spike in cross П (Cham 8 × Masr 3) at late sowing. Heritability estimates are labeled as very high to moderately high in the broad sense and, in the meantime, varied as low, medium, and high in the narrow sense. The expected genetic advance had varied values, which ranged from 4.55% days to maturity at the recommended sowing in the cross П (Cham 8 × Masr 3) to 76.07% for the weight of 100-kernel at the late date in the cross І (Line 606 × Sakha 95). Our findings provide valuable insights for wheat breeding programs targeting enhanced yield and heat tolerance. [ABSTRACT FROM AUTHOR]

The aim of pumpkin breeding programs is to develop cultivars that meet the production, commercial quality, and nutritional value, considering several attributes. Therefore, the objective of this study was to select pumpkin genotypes with high fruit quality for future use in genetic breeding programs. Two production cycles were carried out. The evaluations included the determination of genetic parameters (the additive genetic variance, environmental variance between residual variances and individual phenotypic variance, accuracy of progeny selection, restricted heritability, coefficient of individual additive genetic variation, coefficient of genotypic variation between progenies, coefficient of residual variation, coefficient of relative variation, variance of the prediction error of the genotypic values of the progeny), the prediction of genetic gains, and the selection of genotypes with fruits of better physical and chemical quality attributes. The carotenoid and β-carotene contents of the pulp were distinguished by high values of additive genetic variance, residual variance and individual variance. Additionally, genetic gains were achieved for the main carotenoid compounds, as xanthophyll (68%), lycopene (58%) and β-carotene (49%). In the second production cycle, using the technique of Mulamba and Mock, a new ranking method was used to select the best genotypes. These genetic parameters, especially restricted heritability, indicate the potential for advancing new selection stages to develop pumpkin cultivars with superior qualities, including fruit length (0.976), skin thickness (0.951) and orange pigments, particularly β-carotene (0.894). Additionally, firmer fruits with high ascorbic acid content and a pulp hue angle representing an orange color were ranked among the best genotypes. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. In this paper, we present a comprehensive study of gestation length (GL) in 16 cattle breeds by using large genotype and animal record databases. Data included over 20 million gestations since 2000 and genotypes from one million calves. The study addressed the GL variability within and between breeds, estimation of its direct and maternal heritability coefficients, association with fitness and several economic traits, and QTL detection. The breed average GL varied from 279.7 to 294.4 d in Holstein and Blonde d'Aquitaine breeds, respectively. Standard deviations per breed were similar and ranged from 5.2 to 5.8 d. Direct heritability (i.e., for GL defined as a trait of the calf) was moderate to high (h2 = 0.40–0.67), whereas the maternal heritability was low (0.04–0.06). Extreme breeding values for GL were strongly associated with a higher mortality during the first 2 d of life and were associated with milk production of dams for dairy breeds and precocity of females. Finally, several QTL were detected affecting GL with cumulated effects up to a few days, and at least 2 QTL were found to be shared between different breeds. Our study highlights the risks that would be associated with selection toward a reduced GL. Further genomic studies are needed to identify the causal variants and their association with juvenile mortality and other economic traits. [ABSTRACT FROM AUTHOR]

The genotype-by-environment interaction (G × E) might have crucial impacts on the performance and fitness of agricultural species, such as Pacific whiteleg shrimp (Litopenaeus vannamei). This study explores how enhancements in management practices can counteract G × E effects on growth traits. We analyzed a selectively bred population of whiteleg shrimp spanning the latest two generations, encompassing 259 full-sib and half-sib families with 40,862 individual shrimp, measured for body weight and total length. Our analysis revealed moderate genetic correlations (0.60–0.65) between trait expressions in pond and tank environments, a significant improvement compared to earlier generations. Employing the average information-restricted maximum likelihood (REML) approach in mixed model analysis showed significant differences in heritability (h2) estimates between the two environments; however, the extent of these differences varied by trait (h2 = 0.68 in pond vs. 0.37 in tank for weight, and 0.41 vs. 0.67 for length). Our results indicate that G × E effects on growth traits in this population of L. vannamei were moderate but biologically significant. Consistent with our previous estimates in this population, genetic correlations between body weight and total length remained high (close to one) in pond and tank environments. The present findings collectively demonstrate that management improvements targeting stocking density, aeration, water quality, feeds, and feeding regimes mitigated the G × E effects on two economically significant traits in this population of whiteleg shrimp. [ABSTRACT FROM AUTHOR]

Among the diseases that affect passion fruit (Passiflora edulis Sims), fruit woodiness is considered the most economically important viral disease of the crop, causing great production losses worldwide. This study was developed to estimate the genetic parameters for resistance and agronomic performance, using the REML/BLUP (Restricted Maximum Likelihood/Best Unbiased Linear Prediction) procedure; and compare predicted genetic gains for resistance and agronomic traits, using five selection-index approaches, to determine the most appropriate method for reliably selecting superior genotypes for a new cycle of recurrent selection aimed at effectively increasing the concentration of favorable alleles in the population. The experiment was carried out in the municipality of Campos dos Goytacazes, Rio de Janeiro, Brazil, in a randomized block design consisting of 90 full-sib families (constituting the C0 population of recurrent selection), involving three replicates with three plants per plot. The following variables were evaluated: mean area under the disease progress curve, number of fruits per plant, total production per plant, fruit length, fruit diameter, average fruit weight, pulp weight, mesocarp thickness, soluble solids content, and pulp yield. Simultaneous selection of superior genotypes was carried out by the selection index approach using the Mulamba and Mock rank-sum index; the additive index; the multiplicative index; the mean rank index adapted from Mulamba and Mock; and the combined selection index. The additive index was the most consistent for the combined selection of the 36 genotypes for the evaluated traits, especially resistance, showing that these genotypes have high genetic potential to form the next population. [ABSTRACT FROM AUTHOR]

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

This study characterizes rosé veal from 412 Danish Blue × Holstein heifer and bull calves and beef from 183 highly marbled culled Holstein dairy cows. Furthermore, it investigates the potential for breeding higher meat quality in dairy crossbreeds via genetic parameter estimation. Carcasses were split between the 5th and 6th thoracic vertebra and the meat quality of M. longissimus thoracis was evaluated for pH, color, cooking loss, Warner-Bratzler shear force (WBSF), and chemical intramuscular fat concentration (IMF%). Genetic parameters were estimated using an animal model. The crossbred bull calves outperformed heifers in carcass characteristics, while heifers were superior in redness, cooking loss, WBSF and IMF%. Heritability was significant for WBSF, cooking loss, and IMF%, indicating that meat quality can be improved through selective breeding. The meat quality of highly marbled Holstein cows did not vary across parities, highlighting them as an under-utilized potential source of high-quality beef from a beef-on-dairy system. [ABSTRACT FROM AUTHOR]

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This study aimed to investigate genetic parameters for sow pelvic organ prolapse in purebred and crossbred herds. Pelvic organ prolapse was recorded as normal or prolapsed on the individual sow level across 32 purebred and 8 crossbred farms. In total, 75,162 purebred Landrace sows from a single maternal line were recorded between 2018 and 2023, while 18,988 commercial two-way crossbred (Landrace x Large White) sows were available between 2020 and 2023. There were 5,122,005 animals included in the pedigree. The prolapse in purebreds and crossbreds was considered two different traits in the model. Pedigrees of the crossbred sows were determined based on genotypes through parentage assignment. The average incidence rates were 1.81% and 3.93% for purebreds and crossbreds, respectively. The bivariate model incorporated fixed effects of parity group and region with random effects of contemporary group (farm and mating year and month at the first parity), additive genetic, and residual. Genetic parameter estimates were obtained using BLUPF90+ with the AIREML option. The estimated additive variance was larger in crossbreds than in purebreds. Estimates of heritability in the observed scale were 0.09 (0.006) for purebreds and 0.11 (0.014) for crossbreds, with a genetic correlation of 0.83 using a linear model. Results suggested that including data from crossbreds with higher incidence rate is beneficial and selection to reduce the prolapse incidence in purebred sow herds would also benefit commercial crossbred sow herds. [ABSTRACT FROM AUTHOR]

This study aimed to identify stable and productive genotypes of rubber tree [Hevea brasiliensis (Willd. ex. Adr. de Juss. Müell-Arg.)] in water stress using the linear mixed model approach and to compare genetic parameters estimates of different genotypes groups in different years. The experiment was composed of 58 test clones and control clones (RRIM 600, GT 1 and PB 235) distributed across four trials evaluated in the Centro Avançado de Pesquisa e Desenvolvimento de Seringueira e Sistemas Agroflorestais, Votuporanga, São Paulo, Brazil. Rubber yield was evaluated over four years. The crop water stress index (CWSI) was used to evaluate water conditions over the period. The rubber yield data were analysed by the Restricted Maximum Likelihood model and Best Linear Unbiased Prediction (REML/BLUP) procedure. The plant development conditions were inadequate throughout the period. The effect of genotypes was significant in all analyses, indicating conditions favourable to the selection. The superior clones were V 051, V 006, and V 123 (Trial 1); V 227, V 263, and V 288 (Trial 2); V 744, V 619, and V 582 (Trial 3) and C 311, C 344, and C 33 (Trial 4). These genotypes can be used as parental clones in future breeding cycles. There are clones capable of maintaining yield stability in water deficit periods. The annual genetic variability estimated for rubber yield varies from year to year but is maintained during the breeding cycle. This contributes to the maintenance of the genetic variability among productive genotypes. [ABSTRACT FROM AUTHOR]

Simple Summary: Horse body conformation is an important aspect to evaluate in sport horse selection since the overall body shape determines the limits of the range of movement and function of the horse and, ultimately, its future performance. The genetic improvement of this breed is under the control of the National Association of Maremmano Breeders (ANAM), the first Italian association to use a continuous evaluation scale to evaluate the horses enrolled in the Studbook in the early 1990s. Morphological scoring is a common evaluation method for domestic animals. People employed in this type of role must be able to translate their judgements regarding certain features of the animal's body into numbers or letters, thus avoiding the need to measure the animal. Only a few aspects of the horse's body conformation are actually measured since this activity is difficult and expensive. This study proposes an easier approach to horse scoring in order to obtain genetic proof of morphological traits and, consequently, to support breeders in making targeted selection decisions. Three new factors were computed and summed through an unique New Estimated Breeding Value (NEBV1), with the purpose of supporting breeders in adopting an easier and more accurate selection approach. Morphological scoring is a common evaluation method for domestic animals. The National Association of Maremmano Breeders (ANAM) has provided a dataset containing the records of 600 horses, four metric measurements (cm) and 24 traits with a continuous evaluation scale, each one with 15 classes. Moreover, a body condition score (BCS) with five classes is included. In this study, factor analysis was conducted to create a small number of informative factors (3) obtained from these traits, and a new BLUP-AM-MT index was established. The New Estimated Breeding Value (NEBV1) of each horse was computed by adding the genetic indexes of the three factors, with each one multiplied using a coefficient indicated by ANAM. The practical feasibility of the NEBV1 was evaluated through Spearman correlations between the rankings of the NEBV1 and the rankings of the BLUP-AM-MT, estimated through the four biometric measures and the morphological score (MS) assigned to each horse by the ANAM judges. The factorial analysis was used to estimate three factors: the "Trunk Dimension", "Legs" and "Length". As the explained variance was only 32%, the model was rotated, and the heritability of the three factors were 0.51, 0.05 and 0.41, respectively. After rotation, the estimated correlations between the new NEBV1 and the biometric measures were improved. These results should encourage breeders to adopt a breeding value index that takes into consideration the factors derived from all the variables observed in the morphological evaluation of the Maremmano. In this way, breeders can use it to select the best animals for breeding. [ABSTRACT FROM AUTHOR]

There is growing interest in selective breeding of the honeybee, resulting in the emergence of new breeding projects, often with an emphasis on improving resilience traits, in particular toward brood diseases. Lately, feed autonomy is also gaining importance. Here, we use data from a small breeding nucleus in France to estimate genetic parameters for common bee breeding traits and a novel trait reflecting honey reserves in the brood chamber. Open-mated queens were produced each year from inseminated dams between 2019 and 2021, and ~330 colonies were phenotyped each following year at three periods during the entire beekeeping season. Genetic parameters were estimated using ReML with an animal model. Narrow-sense heritability estimates ranged from low (around 0.15) for calmness and total capped brood surface both measured in early summer, to moderate (0.30 to 0.40) for hygienic behavior in spring, honey yield, and phoretic V. destructor load in early summer. Honey reserves in the brood chamber showed an intermediate heritability throughout the season (around 0.25). Gentleness had a null heritability. Most correlations between phenotypes adjusted for environmental fixed effects were close to zero. Among exceptions, there were honey reserves in the brood chamber in early summer with honey yield (around −0.2) and with the total capped brood surface in early summer (around −0.3). These estimates, although uncertain due to the dataset size, suggest that selection for production and resilience will be effective, even though simultaneous selection for honey yield and feed reserves might be difficult due to a possible genetic antagonism between both traits. [ABSTRACT FROM AUTHOR]

This study carried out early selection of soybean progenies that are productive and resilient to environmental conditions. The experiment took place at the Genetic Breeding Program of UNIJUI (University of the Northwest of the State of Rio Grande do Sul), located in Ijuí - RS, Brazil. The experiment used augmented blocks design with interim checks. The regular treatments correspond to 24 soybean F2 populations and the common treatments were 18 commercial checks, arranged in four replications. At full physiological maturity, in each experimental unit, five plants were randomly collected to obtain seed weight per plant (SWP, g). The Jinks and Pooni methodology was used to calculate the probability of extracting superior lineages from the evaluated populations. The best control and promising cultivars to compose the parent bank are BMX FORÇA RR, FUNDACEP 66 RR and TMG 7062 IPRO. Jinks and Pooni's methodology identified populations IRC001, IRC002, IRC017, IRC019, IRC028, IRC030, IRC032, IRC033, IRC035, IRC036, IRC039 and IRC040 as having high potential for extraction of superior lineages. [ABSTRACT FROM AUTHOR]

Genomic selection (GS) is increasingly used in tree breeding because of the possibility to hasten breeding cycles, increase selection intensity or facilitate multi-trait selection, and to obtain less biased estimates of quantitative genetic parameters such as heritability. However, tree breeders are aiming to obtain accurate estimates of such parameters and breeding values while optimizing sampling and genotyping costs. We conducted a metadata analysis of results from 28 GS studies totalling 115 study-traits. We found that heritability estimates obtained using DNA marker-based information for a variety of traits and species were not significantly related to variation in the total number of markers ranging from about 1500 to 116 000, nor by the marker density, ranging from about 1 to 60 markers/centimorgan, nor by the status number of the breeding populations ranging from about 10 to 620, nor by the size of the training set ranging from 236 to 2458. However, the predictive accuracy of breeding values was generally higher when the status number of the breeding population was smaller, which was expected given the higher level of relatedness in small breeding populations, and the increased ability of a given number of markers to trace the long-range linkage disequilibrium in such conditions. According to expectations, the predictive accuracy also increased with the size of the training set used to build marker-based models. Genotyping arrays with a few to many thousand markers exist for several tree species and with the actual costs, GS could thus be efficiently implemented in many more tree breeding programs, delivering less biased genetic parameters and more accurate estimates of breeding values. [ABSTRACT FROM AUTHOR]

The development of cayenne pepper varieties can be optimized by multiple crossings, transgressive segregant selection based on the selection index, and identification of potential anthocyanins. The study objectives were (1) to develop a transgressive segregation index, and (2) to select transgressive segregation cayenne peppers with high productivity and anthocyanins from F3 multiple cross-generation. The study conducted two experiments at the experimental field, Hasanuddin University, from November 2022 to November 2023. The first experiment implemented an augmented design with a randomized complete block design (RCBD) as an environmental design. The genotypes as treatment consisted of two types: 110 lines of cayenne pepper were not repeated, and the 4 older chili varieties as controls were repeated in each block. All genotypes were categorized and divided into five blocks. The second experiment was the validation of the first trial. There were 13 genotypes tested with RCBD design one factor and repeated three times. Based on the study, developing a semiobjective-based selection index with canopy width, fruit weight, and yield was an innovative and effective approach to selecting F3 transgressive segregants of cayenne pepper. High-yielding transgressive lines were identified as G3-2-7-3, G2.6.9-10, G5-12-1-8, and G4.5.2-12. The G3-2-7-3 line was suggested due to its high yield potential and anthocyanin content. However, the anthocyanin content must be examined more deeply, such as using an omics approach. Nevertheless, these lines are still recommended to be continued in yield testing or crossing to produce hybrid lines that have high yield potential and anthocyanin content. [ABSTRACT FROM AUTHOR]