Principal component analysis of phenotypic and breeding value data for semen traits in Egyptian buffalo bulls.

Buffalo bull semen traits are economically important traits that influence farm fertility and profitability. Genetic improvement of semen characteristics is an important detail of the genetic improvement. This study was conducted to assess the relationship between the breeding values as well as the phenotypic values for semen traits (VOL, MM, LS, AS and CONC) of the Egyptian buffalo bulls. A total of 7761 normal semen ejaculates were collected and characterized at ILMTC laboratory from 26 bulls from 2009 to 2019. For VOL, MM, LS, AS, and CONC, the actual means were 3.89 mL, 62.37%, 60.64%, 3.94%, and 0.67 × 109 sperm/mL, respectively. The prediction of breeding values for semen traits was estimated using a Bayesian procedure. The estimated standardized EBVs and phenotypic values were used in the principal component analysis (PCA). Of five PCs, one PC (PC1) had > 1 eigenvalues that was responsible for 87.19% of the total variation of SEBV, and two PCs had > 1 eigenvalues that were responsible for 59.61% and 21.35% of the total variation of the phenotypic values. Together, PC1 and PC2 accounted for 97.97% of the total variance of SEBV and 80.96% of the total variance of phenotypic values. A graphs of the first two components showed the traits separated into two different directions by group. This indicates each group was under similar genetic influence. Therefore, selection can be done separately for each group without influencing the other. Principal component analysis reduced variables to describe the key information in buffalo semen data.

A Single-Step Genome-Wide Association Study for Semen Traits of Egyptian Buffalo Bulls.

The present study aimed to contribute to the limited research on buffalo (Bubalus bubalis) semen traits by incorporating genomic data. A total of 8465 ejaculates were collected. The genotyping procedure was conducted using the Axiom® Buffalo Genotyping 90 K array designed by the Affymetrix Expert Design Program. After conducting a quality assessment, we utilized 67,282 SNPs genotyped in 192 animals. We identified several genomic loci explaining high genetic variance by employing single-step genomic evaluation. The aforementioned regions were located on buffalo chromosomes no. 3, 4, 6, 7, 14, 16, 20, 22, and the X-chromosome. The X-chromosome exhibited substantial influence, accounting for 4.18, 4.59, 5.16, 5.19, and 4.31% of the genomic variance for ejaculate volume, mass motility, livability, abnormality, and concentration, respectively. In the examined genomic regions, we identified five novel candidate genes linked to male fertility and spermatogenesis, four in the X-chromosome and one in chromosome no. 16. Additional extensive research with larger sample sizes and datasets is imperative to validate these findings and evaluate their applicability for genomic selection.

Estimation of genetic parameters for semen traits in Egyptian buffalo bulls.

This study was conducted to characterize semen traits (ejaculate volume (VOL), mass motility (MM), sperm livability (LS), percentage of abnormal sperms (AS), and sperm concentration (CONC)) of Egyptian buffalo bulls and evaluate the importance of some nongenetic factors (year (YC) and season (SC) of semen collection and age of bull genetically and environmentally at collection (ABC)) affecting the investigated traits. A total of 7761 normal semen ejaculates were collected from 26 bulls from 2009 to 2019. Single-trait and bivariate repeatability animal models using Bayesian methods were used to estimate variance components, heritability, repeatability, and genetic correlations among the investigated semen traits. YC and ABC exerted significant effects on most semen traits, whereas SC exerted no significant effect on all the investigated semen traits. Heritability estimates were 0.08, 0.52, 0.51, 0.04, and 0.49 for VOL, MM, LS, AS, and CONC, respectively. Repeatability estimates were 0.14, 0.82, 0.79, 0.06, and 0.78 for VOL, MM, LS, AS, and CONC, respectively. The genetic correlations between MM and each of LS and CONC were highly significant (0.99 ± 0.01 and 0.95 ± 0.14, respectively), and that between LS and CONC was also highly significant (0.92 ± 0.20). The high heritability estimates for MM, LS, and CONC combined with the favorable high significant genetic correlations between these traits indicated that direct selection for MM may be an effective method to enhance semen quality in Egyptian buffalo bulls and consequently improve fertility.

Genetic parameters and genetic trends for reproductive traits in Egyptian buffalo.

Reproductive traits are important for farm profitability because failure to reproduce is the primary reason for culling animals. Study objectives were to estimate genetic parameters and evaluate the trends for reproductive traits. Age at first calving (AFC), gestation length (GL), postpartum interval to pregnancy (PPIP), calving interval (CI) and calving ease score (CE) were recorded. A total of 38,906 records were available from 2426 buffalo cows. There was evaluation of genetic parameters using three models. The first model was applied to the first three parities fitting animal as a random effect. There was also a repeatability model utilized where data from all parities were evaluated to estimate heritability and repeatability. There was also a bivariate model to estimate genetic correlations between reproductive traits. Heritability estimates ranged from 0.0001 to 0.12 for PPIP and CE, respectively. Repeatability estimates were low to moderate ranging from 0.13 to 0.38 for PPIP and GL, respectively. There were close genetic correlations of 0.99 and - 0.93 between PPIP-CI and GL-CE, respectively. Genetic correlations between the other reproductive traits were low to moderate. Genetic trends for all reproductive traits were negative with and of a small magnitude, and regression coefficients were significant only for AFC and PPIP. The results from the current study supported the urgent need, not only for genetic or genomic selection improvement programs, but also for improving the farm management practices for reproductive traits in Egyptian buffalo.

Principal component analysis of breeding values for birth weight milk and reproductive traits of the Egyptian buffalo.

This study was conducted to estimate the genetic parameters and breeding values for birth weight (BW) and reproductive and milk traits of the Egyptian buffalo. Moreover, the relationship among the estimated breeding values was analyzed using the principal component analysis, and selection index was constructed to improve performance. A total of 65,734 records of 2426 buffalo cows calved from 1980 to 2018 were collected from five buffalo experimental herds to estimate the genetic parameters and breeding values and then standardized for use in the principal component analysis with covariance matrix. The estimated heritability values were low for BW, total milk yield (TMY), gestation length (GL), days open (DO), calving interval (CI), calving ease (CE), and age at first calving (AFC), but they were moderate for lactation period (LP). The repeatability estimates were very low for DO and CI but were low for BW, GL, and CE, whereas they were moderate for TMY and LP. Of eight principal components (PCs), four PCs had > 1 eigenvalues, and the total variance explained was 70.37%. The variances explained for PC1, PC2, PC3, and PC4 were 25.71%, 18.20%, 13.28%, and 13.18%, respectively. The standardized estimated breeding values of CI and DO, TMY and LP, GL and CE, and BW and AFC correlated with PC1 (0.915 and 0.925), PC2 (0.760 and 0.758), PC3 (- 0.622 and 0.567), and PC4 (0.710 and 0.438), respectively. These results suggest that BW and reproduction traits would respond slowly to selection, whereas production traits would respond faster, and the uses of PCs depend primarily on the selection purpose that could be used in the genetic improvement programs of the Egyptian buffalo instead of the traditional selection index.

Factors affecting calving ease in Egyptian buffalo.

Calving ease (CE) is a trait of economic importance that affects animal welfare and farm profitability. The objective of present study was to investigate genetic and environmental factors affecting CE among Primiparous (PP) and multiparous (MP) buffaloes. A total of 9,627 records from 1999 MP and 2,110 PP recorded during the period from 1988 to 2018 were considered. Herd, season of calving, year of calving, birth weight, parity order and gestation length significantly affected CE rate, while age at first calving and sex of calf had no significant effects. Direct and maternal heritabilities of CE in PP and MP were 0.06 and 0.01, respectively. The low heritability of CE indicated that direct selection may not be an effective method to improve CE trait in Egyptian buffalo.

Specific Macronutrients Exert Unique Influences on the Adipose-Liver Axis to Promote Hepatic Steatosis in Mice.

BACKGROUND & AIMS: The factors that distinguish metabolically healthy obesity from metabolically unhealthy obesity are not well understood. Diet has been implicated as a determinant of the unhealthy obesity phenotype, but which aspects of the diet induce dysmetabolism are unknown. The goal of this study was to investigate whether specific macronutrients or macronutrient combinations provoke dysmetabolism in the context of isocaloric, high-energy diets. METHODS: Mice were fed 4 high-energy diets identical in calorie and nutrient content but different in nutrient composition for 3 weeks to 6 months. The test diets contained 42% carbohydrate (sucrose or starch) and 42% fat (oleate or palmitate). Weight and glucose tolerance were monitored; blood and tissues were collected for histology, gene expression, and immunophenotyping. RESULTS: Mice gained weight on all 4 test diets but differed significantly in other metabolic outcomes. Animals fed the starch-oleate diet developed more severe hepatic steatosis than those on other formulas. Stable isotope incorporation showed that the excess hepatic steatosis in starch-oleate-fed mice derived from exaggerated adipose tissue lipolysis. In these mice, adipose tissue lipolysis coincided with adipocyte necrosis and inflammation. Notably, the liver and adipose tissue abnormalities provoked by starch-oleate feeding were reproduced when mice were fed a mixed-nutrient Western diet with 42% carbohydrate and 42% fat. CONCLUSIONS: The macronutrient composition of the diet exerts a significant influence on metabolic outcome, independent of calories and nutrient proportions. Starch-oleate appears to cause hepatic steatosis by inducing progressive adipose tissue injury. Starch-oleate phenocopies the effect of a Western diet; consequently, it may provide clues to the mechanism whereby specific nutrients cause metabolically unhealthy obesity.

Correction: El Azab, I.H., et al. Microwave-Assisted Synthesis of Novel 2H-Chromene Derivatives Bearing Phenylthiazolidinones and Their Biological Activity Assessment. Molecules 2014, 19, 19648-19664.

The authors wish to revise the Author Affiliation section of the title paper, published in Molecules [1], (doi:10.3390/molecules191219648, website: http://www.mdpi.com/1420-3049/19/12/19648). To recognize the fact that the research described was performed in part at the facilities of Taif University and to acknowledge that institution's generous financial support[...].