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This study looked at how spermatogenesis, lipid peroxidation, antioxidant defense mechanisms, and histological changes in testicular, hepatic, and renal tissues were affected by boric acid (H3BO3) added to mixed feed and drinking water at different concentrations for 14 weeks. For this purpose, 60 male Japanese quails (Coturnix japonica f. domestica) were used. From the age of 35 days, the birds were given boric acid added to regular soybean meal maize mixed feed as well as drinking water. Experimental groups: Control (no additive), F100: 100 mg/kg boric acid into feed, F300: 300 mg/kg boric acid into feed, W100: 100 mg/l boric acid into drinking water, and W300: 300 mg/l boric acid into drinking water. Both primordial (P < 0.001) and mature (P < 0.05) sperm counts increased in F300 and W300 groups. Supplemented boric acid in drinking water (300 mg/l) increased the tubule diameters of the testicle (P < 0.05). Because of the rising levels of boric acid in the feed and water groups, lipid peroxidation levels increased in testicular (P < 0.001), hepatic, and renal tissues (P < 0.01). Glutathione (GSH) levels rose in high boric acid groups in testicular and hepatic tissues (P < 0.001). Different tissues responded differentially to high amounts of boric acid in terms of antioxidant enzyme activity (P < 0.001). As a result, boric acid at high doses showed beneficial effects on spermatological activity; however, continued use caused lipid peroxidation in tissues and some pathological problems in liver tissue. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effect of long-term vitamin A and E dietary supplements on the semen traits and morphology of the reproductive system in older roosters to prolong their reproductive contributions to the flock. The research revealed that long-term dietary supplementation of both vitamins A and E maintained the traits of the semen at levels significantly higher than in the control roosters. Vitamin A especially maintained ejaculate volume and semen density, while vitamin E protected semen motility and viability. Vitamin A treatment maintained the uniformity of the epididymal epithelium. No eroded areas were identified in this epithelium. Most epithelial cells were principal cells with uniform stereocilia. The connective tissue which lines the epididymal tubule of the vitamin A treated rooster was thinner than those of the roosters from the control. Vitamin E predominantly protected the structure of the spermatogenesis line. Liver tissue concentrations of vitamins A and E were two times and four times higher respectively than the control. The two vitamins were eliminated in increased quantities through the seminal plasma in supplemented roosters. No mutual inhibition or potentiating effects were found between the two vitamins, suggesting that their combined administration should be further analyzed.

Simple Summary: A study was conducted to investigate five semen traits in Egyptian buffalo bulls using a single-step genome-wide association study for genomic evaluation. The study aimed to identify associated genomic regions and potential candidate genes. The X-chromosome was the most crucial, accounting for 23.43% of the overall genomic variance observed in these semen traits. Numerous potential candidate genes associated with the examined semen traits were identified within the genomic regions under investigation. In addition, a total of five new candidate genes were discovered within the genomic area examined for semen traits in 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. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the effect of long-term vitamin A and E dietary supplements on the semen traits and morphology of the reproductive system in older roosters to prolong their reproductive contributions to the flock. The research revealed that long-term dietary supplementation of both vitamins A and E maintained the traits of the semen at levels significantly higher than in the control roosters. Vitamin A especially maintained ejaculate volume and semen density, while vitamin E protected semen motility and viability. Vitamin A treatment maintained the uniformity of the epididymal epithelium. No eroded areas were identified in this epithelium. Most epithelial cells were principal cells with uniform stereocilia. The connective tissue which lines the epididymal tubule of the vitamin A treated rooster was thinner than those of the roosters from the control. Vitamin E predominantly protected the structure of the spermatogenesis line. Liver tissue concentrations of vitamins A and E were two times and four times higher respectively than the control. The two vitamins were eliminated in increased quantities through the seminal plasma in supplemented roosters. No mutual inhibition or potentiating effects were found between the two vitamins, suggesting that their combined administration should be further analyzed. [ABSTRACT FROM AUTHOR]

AbstractPursuing the community-based breeding program (CBBP) selection of the breeding sire for Bonga sheep estimated breeding value by six months body weight, testicle size, and physical characteristics were used as selection criteria. A study was conducted to investigate the association of sire selection traits with semen characteristics and to estimate their heritability. Data were collected from a total of 101 adult breeding sires of Bonga sheep. Semen was collected using artificial vagina and processed for semen qualities. The variance components and genetic parameters were estimated using multivariate analysis of animal model using restricted maximum likelihood method of WOMBAT software. Six different animal models were compared for the dataset and best-fit model was selected using Akaike information Criteria (AIC). Direct additive effect (model 1) was the best-fit model for the current dataset. The direct heritability for studied traits were 0.23 ± 0.122, 0.13 ± 0.129, 0.13 ± 0.110, 0.09 ± 0.036, 0.37 ± 0.155, and 0.11 ± 0.162 for semen volume, mass motility, concentration, total spermatozoa, six months body weight, and scrotum circumference, respectively. Moderate heritability of six months body weight and semen volume indicated that further breed improvement through selection is possible. Low heritability of semen characteristics traits indicated that good semen quality could be obtained by improving environmental management of the sire. Both six months body weight and scrotum circumference have high and positive correlation with sperm mass motility, and concentration but negatively correlated with semen volume and total spermatozoa production. Given the strong correlation between semen characteristic qualities, the associated response was anticipated.

Simple Summary: Due to the complexity of sperm cell reproduction and maturation, the genetic structure of semen traits remains largely unknown. In our study, we used weighted single-step GWAS to detect genetic regions and further candidate genes related to semen traits in Duroc boars. This study provides in-depth understanding of the genetic structure of semen traits and the biological information provided by gene networks, and can be applied to speed up the genetic process of semen traits in boars. The candidate genes CATSPER1, STRA8, ZSWIM7, TEKT3, UBB, PTBP2, EIF2B2, MLH3, and CCDC70 were associated with semen traits in Duroc pigs. Semen traits play a key role in the pig industry because boar semen is widely used in purebred and crossbred pigs. The production of high-quality semen is crucial to ensuring a good result in artificial insemination. With the wide application of artificial insemination in the pig industry, more and more attention has been paid to the improvement of semen traits by genetic selection. The purpose of this study was to identify the genetic regions and candidate genes associated with semen traits of Duroc boars. We used weighted single-step GWAS to identify candidate genes associated with sperm motility, sperm progressive motility, sperm abnormality rate and total sperm count in Duroc pigs. In Duroc pigs, the three most important windows for sperm motility—sperm progressive motility, sperm abnormality rate, and total sperm count—explained 12.45%, 9.77%, 15.80%, and 12.15% of the genetic variance, respectively. Some genes that are reported to be associated with spermatogenesis, testicular function and male fertility in mammals have been detected previously. The candidate genes CATSPER1, STRA8, ZSWIM7, TEKT3, UBB, PTBP2, EIF2B2, MLH3, and CCDC70 were associated with semen traits in Duroc pigs. We found a common candidate gene, STRA8, in sperm motility and sperm progressive motility, and common candidate genes ZSWIM7, TEKT3 and UBB in sperm motility and sperm abnormality rate, which confirms the hypothesis of gene pleiotropy. Gene network enrichment analysis showed that STRA8, UBB and CATSPER1 were enriched in the common biological process and participated in male meiosis and spermatogenesis. The SNPs of candidate genes can be given more weight in genome selection to improve the ability of genome prediction. This study provides further insight into the understanding the genetic structure of semen traits in Duroc boars. [ABSTRACT FROM AUTHOR]

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.

The QTLome represents the collection of QTLs (quantitative trait loci) documented for each trait within a specific species, detailing the position, effect, and mode of inheritance of each locus. Despite the abundance of known QTLs for productive traits in cattle, only a few genes have been identified as selection markers. This study aimed to prioritize genes within validated QTLs associated with crucial traits in cattle by integrating this information with RNAseq data. Initially, bovine QTLs (n = 161,730) were sourced from the AnimalQTLdb database (version 44), and both graphical and quantitative analyses were conducted using R software. Only annotations within the UMD 3.1 genome were considered, with overlapping QTLs from the same scientific report grouped together. Following quality control measures, the number of QTLs was reduced to 37,146. Validated QTLs were determined by identifying overlapping annotations from various studies or those within a distance of < 1 Mb for the same phenotypic trait, resulting in a total of 3,856 validated QTLs. For gene prioritization, validated QTLs were selected based on semen traits and residual feed intake (RFI). Transcriptomes corresponding to these traits were sourced from NCBI (PRJNA516089 and PRJEB7696). Sequence filtering was performed using the fastp program, and transcript counts were obtained with SALMON software. Sequences were aligned to the Ensembl UMD 3.1 reference genome (version 94), and differential expression analysis was conducted using the R package DESeq2, considering only the group factor (high/low) for each trait (fertility/ RFI). Integration of QTLs and transcriptomes utilized the methodology of the cageminer R package, which prioritizes candidate genes within validated QTLs, identifies those grouped in co-expression modules enriched by reference genes, and correlates with the study phenotype (biserial r > 0.2). Reference genes were obtained from Ignatieva et al. (2021 PMID 34290736) and Chen et al. (2021; PMID 33664767). Among the 18 validated QTLs for semen traits, four candidate genes (TSPAN6, QSER1, ADRB2, AKAP4) were identified. Except for ADRB2, these genes exhibited significant differential expression (P < 0.05) in contrasting groups of Holstein cattle. They are associated with semen traits and perform functions such as regulation of spermatogenesis, development, activation, and cell growth. Regarding RFI, 127 validated QTLs yielded 205 prioritized genes, of which 123 showed significant differential expression (P < 0.05) in divergent groups of the Nelore breed. These genes are involved in the immune response and the polymerization and organization of actin filaments, processes that have been reported as biologically relevant to RFI. The implemented strategy was efficient for gene prioritization through the integration of QTLs and RNAseq. [ABSTRACT FROM AUTHOR]

Semen traits play a key role in the pig industry because boar semen is widely used in purebred and crossbred pigs. The production of high-quality semen is crucial to ensuring a good result in artificial insemination. With the wide application of artificial insemination in the pig industry, more and more attention has been paid to the improvement of semen traits by genetic selection. The purpose of this study was to identify the genetic regions and candidate genes associated with semen traits of Duroc boars. We used weighted single-step GWAS to identify candidate genes associated with sperm motility, sperm progressive motility, sperm abnormality rate and total sperm count in Duroc pigs. In Duroc pigs, the three most important windows for sperm motility—sperm progressive motility, sperm abnormality rate, and total sperm count—explained 12.45%, 9.77%, 15.80%, and 12.15% of the genetic variance, respectively. Some genes that are reported to be associated with spermatogenesis, testicular function and male fertility in mammals have been detected previously. The candidate genes CATSPER1, STRA8, ZSWIM7, TEKT3, UBB, PTBP2, EIF2B2, MLH3, and CCDC70 were associated with semen traits in Duroc pigs. We found a common candidate gene, STRA8, in sperm motility and sperm progressive motility, and common candidate genes ZSWIM7, TEKT3 and UBB in sperm motility and sperm abnormality rate, which confirms the hypothesis of gene pleiotropy. Gene network enrichment analysis showed that STRA8, UBB and CATSPER1 were enriched in the common biological process and participated in male meiosis and spermatogenesis. The SNPs of candidate genes can be given more weight in genome selection to improve the ability of genome prediction. This study provides further insight into the understanding the genetic structure of semen traits in Duroc boars.

Conservation decisions based on neutral genetic diversity have been observed to promote retention of useful quantitative variation in biological populations. An experiment was undertaken to determine the association between microsatellite marker polymorphisms and phenotypic variation in semen production and cryosurvival traits in bulls. Thirty‐five ejaculates were collected from ten bulls of two breeds and evaluated before and after cryopreservation for several semen traits. The bulls were also genotyped using a set of sixteen bovine‐specific microsatellite marker loci. Fixation indices (FST), heterozygosity and Nei's genetic distance measures were computed from allele frequency data for each of the bulls. Molecular and phenotypic data were used to compute tri‐distance matrices for the ten bulls and correlated using Mantel's test in GenAIEx 6.5. The study revealed extensive heterogeneity in semen traits, heterozygosity and FST values among the bulls. Large pairwise phenotypic and genetic distances were also observed. Correlation between pairwise genetic distances and phenotypic distances was significant and highly positive for sperm viability (r =.61, p <.001) and moderately positive for sperm motility (r =.40–42, p <.05) variables. For sperm morphology, ejaculate volume and sperm concentration, correlation with genetic distances was positive, low and not significantly different from zero (p >.05). A tendency for a triangular‐shaped relationship between genetic and phenotypic distances for post‐thaw motility and viability traits was also observed. Accordingly, association with neutral genetic diversity was absent for semen production traits and moderate to highly positive for sperm cryosurvival traits. Given these findings, conservation decisions based on neutral genetic diversity may capture variation in some adaptive traits, but not others. [ABSTRACT FROM AUTHOR]

This study was conducted using 18 Awassi male lambs with an average initial weight 33.57 ± 0.69 kg for the period from 9-12 months of age. Lambs were distributed randomly into three treatments each, included 6 lambs. Lambs in the first treatment (T¹) were fed a diet that includes 11% of sunflower meal, the second treatment (T²) fed diet includes 11% of low degradable sunflower meal, and the third treatment (T³) were fed on a diet containing 11% low degradable sunflower seed. The results were indicated a significant increase (P≤ 0.05) in semen volume in (T²) 2.77 ml compared with the (T¹) 1.98 ml and (T²)1.69 ml. Significant improve (p≤ 0.05)  was noted in T² and T³  in individual motility 87.33 and 87.70%  and sperm concentration 2.45 and 2.62 × 109 / ml compared to the T1 the individual motility was 84.95% and sperm concentration 2.10 × 109 / ml, respectively. Seminal plasma concentration of total protein, globulin, and urea were higher (P≤ 0.05) in T² as compared other treatments. Whereas, feeding low degradable sunflower seed (T³) resulted in a significant increase (P≤ 0.01) of cholesterol concentration 140.05 mg/dl in seminal plasma compared with the T1 122.78 mg/dl and T² 125.81 mg/dl, while triglycerides was decreased (P≤ 0.05) in T1 37.49 mg/dl than T² and T³ 52.72 and 58.92 mg/dl respectivly. [ABSTRACT FROM AUTHOR]

Abstract Background In the pig production industry, artificial insemination (AI) plays an important role in enlarging the beneficial impact of elite boars. Understanding the genetic architecture and detecting genetic markers associated with semen traits can help in improving genetic selection for such traits and accelerate genetic progress. In this study, we utilized a weighted single-step genome-wide association study (wssGWAS) procedure to detect genetic regions and further candidate genes associated with semen traits in a Duroc boar population. Overall, the full pedigree consists of 5284 pigs (12 generations), of which 2693 boars have semen data (143,113 ejaculations) and 1733 pigs were genotyped with 50 K single nucleotide polymorphism (SNP) array. Results Results show that the most significant genetic regions (0.4 Mb windows) explained approximately 2%~ 6% of the total genetic variances for the studied traits. Totally, the identified significant windows (windows explaining more than 1% of total genetic variances) explained 28.29, 35.31, 41.98, and 20.60% of genetic variances (not phenotypic variance) for number of sperm cells, sperm motility, sperm progressive motility, and total morphological abnormalities, respectively. Several genes that have been previously reported to be associated with mammal spermiogenesis, testes functioning, and male fertility were detected and treated as candidate genes for the traits of interest: Number of sperm cells, TDRD5, QSOX1, BLK, TIMP3, THRA, CSF3, and ZPBP1; Sperm motility, PPP2R2B, NEK2, NDRG, ADAM7, SKP2, and RNASET2; Sperm progressive motility, SH2B1, BLK, LAMB1, VPS4A, SPAG9, LCN2, and DNM1; Total morphological abnormalities, GHR, SELENOP, SLC16A5, SLC9A3R1, and DNAI2. Conclusions In conclusion, candidate genes associated with Duroc boars’ semen traits, including the number of sperm cells, sperm motility, sperm progressive motility, and total morphological abnormalities, were identified using wssGWAS. KEGG and GO enrichment analysis indicate that the identified candidate genes were enriched in biological processes and functional terms may be involved into spermiogenesis, testes functioning, and male fertility.

Abstract Background Semen traits are important for the widespread use of superior bulls. Thus, the objective of this study was to estimate the heritability of five semen traits, ejaculate volume (VE), progressive sperm motility (SM), sperm concentration (SC), number of sperm (NSP), and number of progressive motile sperm (NMSP), and their genetic correlations (r g ). The dataset being studied consisted of 1450 Chinese Holstein bulls with full pedigree information, born between 1996 and 2012, representing 11 AI centers. Genetic parameters were estimated in a multivariate analysis using the average information restricted maximum likelihood estimation of variance (AI-REML). Results The estimates of heritability for VE, SM, SC, NSP, and NMSP were 0.15, 0.12, 0.22, 0.16 and 0.12, respectively. The genetic correlations among the five semen traits ranged from 0.02 (VE and SC) to 0.99 (NSP and NMSP). Conclusions Our findings provide useful information on the heritability of semen traits in Holstein bulls and the relationships among them, and should assist in selection for improvement of semen traits in Chinese Holstein bulls.

Artificial insemination (AI) has been used as a routine technology globally in the pig production industry since 1930. One of the preferable advantages of AI technology is that the semen of elite boars can be disseminated to the commercial sow population rapidly. Understanding the genetic background of semen traits may help in developing genetic improvement programs of boars by including these traits into the selection index. In this study, we utilized weighted single-step genome-wide association study (wssGWAS) to identify genetic regions and further candidate genes associated with sperm morphology abnormalities (proximal droplet, distal droplet, bent tail, coiled tail, and distal midpiece reflex) in a Duroc boar population. Several genomic regions explained 2.76%–9.22% of the genetic variances for sperm morphology abnormalities were identified. The first three detected QTL regions together explained about 7.65%–25.10% of the total genetic variances of the studied traits. Several genes were detected and considered as candidate genes for each of the traits under study: coiled tail, HOOK1, ARSA, SYCE3, SOD3, GMNN, RBPJ, STIL, and FGF1 ; bent tail, FGF1, ADIPOR1, ARPC5, FGFR3, PANX1, IZUMO1R, ANKRD49, and GAL ; proximal droplet, NSF, WNT3, WNT9B, LYZL6, FGFR1OP, RNASET2, FYN, LRRC6, EPC1, DICER1, FNDC3A, and PFN1 ; distal droplet, ARSA, SYCE3, MOV10L1, CBR1, KDM6B, TP53, PTBP2, UBR7, KIF18A, ADAM15, FAAH, TEKT3, and SRD5A1 ; and distal midpiece reflex, OMA1, PFN1, PELP1, BMP2, GPR18, TM9SF2, and SPIN1. GO and KEGG enrichment analysis revealed the potential function of the identified candidate genes in spermatogenesis, testis functioning, and boar spermatozoa plasma membrane activating and maintenance. In conclusion, we detected candidate genes associated with the coiled tail, bent tail, proximal droplet, distal droplet, and distal midpiece reflex in a Duroc boar population using wssGWAS. Overall, these novel results reflect the polygenic genetic architecture of the studied sperm morphology abnormality traits, which may provide knowledge for conducting genomic selection on these traits. The detected genetic regions can be used in developing trait-specific marker assisted selection models by assigning higher genetic variances to these regions. • Detected genomic regions explained 2.76%–9.22% of genetic variance of sperm traits. • First three QTL regions explained 7.65%–25.10% of genetic variances of sperm traits. • Results reflect the polygenic genetic architecture of the studied sperm traits. • Functional validation of homologous genes confirmed the mapping results. [ABSTRACT FROM AUTHOR]

The objective of current study was to determine the effect of fat supplement on physiological and reproductive performance of Holstein Friesian bulls during subtropical summer in Pakistan. Eighteen bulls were randomly divided into 3 treatment groups: (1) CTL, basal diet without fat supplementation; (2) FS100, basal diet with 100 g fat supplementation (Energizer-RP-10®, IFFCO, Johor, Malaysia); (3) FS200, basal diet with 200 g fat supplementation. Basal diet consisted of 50% green fodder (corn silage), 25% wheat straw, and 25% concentrate on dry matter basis. Diets were offered for 14 weeks from May to August 2016. The average daily temperature-humidity index ranged from 85 to 88 for the experimental period. The results indicated that there was no difference in dry matter intake, water intake, rectal temperature, pulse rate, and respiration rate among the treatment groups. Fat supplementation did not influence semen traits including sperm motility, progressive motility, amplitude of lateral head displacement, live-to-dead ratio, normal acrosomal ridge, plasma membrane integrity, and DNA integrity. The interaction of season with fat revealed that FA200 significantly increased post thaw semen motility and progressive motility during hot humid summer (P < 0.05). Analysis of blood metabolites showed that blood urea nitrogen was higher in FS200 compared with CTL and FS100 groups (P < 0.05). There was no effect of fat supplementation on blood testosterone level. Glucose showed quadratic trend in response to fat supplementation. It could be concluded that addition of fat only improved motility and progressive motility of sperms during hot humid summer. [ABSTRACT FROM AUTHOR]

The aim of the study was to establish correlation and regression dependencies between some traits of sperm production of terminal boars (Large White x Pietrain). The analyzed material consisted of 347 ejaculates, received in the period from 2011 to 2014. The boars were divided in three groups according to the age the ejaculate was obtained at (up to 12 months, from 12 to 24 months, and above 36 months). A moderate and negative correlation was established (rp=-0.34, p

Efficient production of high-quality semen is a crucial trait in the dairy cattle breeding due to the widespread use of artificial insemination. However, the genetic architecture (e.g., distributions of causal variants and their corresponding effects) underlying such semen quality traits remains unclear. In this study, we performed genome-wide association studies to identify genes associated with five semen quality traits in Chinese Holstein population, including ejaculate volume, progressive sperm motility, sperm concentration, number of sperm, and number of progressive motile sperm. Our dataset consisted of 2,218 Holstein bulls in China with full pedigree information, representing 12 artificial insemination centers, with 1,508 genotyped using the Illumina BovineSNP50 BeadChip. We used a weighted single-step genome-wide association method with 10 adjacent Single nucleotide polymorphisms (SNPs) as sliding windows, which can make use of individuals without genotypes. We considered the top 10 genomic regions in terms of their explained genomic variants as candidate window regions for each trait. In total, we detected 36 window regions related to one or multiple semen traits across 19 chromosomes. Promising candidate genes of PSMB5, PRMT5, ACTB, PDE3A, NPC1, FSCN1, NR5A2, IQCG, LHX8, and DMRT1 were identified in these window regions for these five semen traits. Our findings provided a solid basis for further research into genetic mechanisms underlying semen quality traits, which may contribute to their accurate genomic prediction in Chinese Holstein population.

The objective of this study was to assess the effect of dietary vitamin E (Vit. E) and Selenium (Se) supplementation on physiological and reproductive performance of bulls during humid hot summer in Pakistan. Eighteen Holstein Friesian bulls balanced by age and weight were divided into three treatment groups: 1) CTL, basal diet without Se and Vit. E supplementation; 2) SeS, basal diet supplemented with 3 g Selemax® (Biorigin, USA); 3) ESeS, basal diet with 3 g Selemax® and Vit. E @ 6000 IU/day). Basal diet consisted of 50% green fodder, 25% wheat straw and 25% concentrate on dry matter basis. Diets were offered for 13 weeks from July 2016 to October 2016 having temperature-humidity index ranging from 83 to 87. Data obtained were subjected to repeated measures ANOVA. Supplementation of Vit. E and Se did not affect dry matter intake, water intake, respiration rate, rectal temperature, and pulse rate. The ESeS treatment had higher sperm motility% compared to CTL and SeS (P<0.05). The amplitude of lateral head displacement (ALH) was higher in SeS and ESeS compared to CTL (P<0.05). Straightness was higher in SeS group compared to CTL and ESeS. However, Vit. E and Se had no effect on other semen traits including semen volume, concentration, progressive motility, DNA integrity, plasma membrane integrity, and live to dead ratio. Blood testosterone concentration was significantly higher in SeS and ESeS groups compared to CTL. Blood glucose and blood urea nitrogen were similar among the treatments. Current results indicated that supplementation of Vit. E and Se improved only sperm motility, ALH, straightness and testosterone level during humid hot summer in Holstein Friesian bulls. [ABSTRACT FROM AUTHOR]

Several factors can affect the fertility and seminal fluid characteristics in rams, among them the weather and temperature. Melatonin is a hormone that has recently shown beneficial effects in a variety physiological and pathological conditions. This study was conducted during the period of July the 2nd 2017 to August the 17th 2017 using twelve adult Iraqi Arabi rams (2-3 year). Animals were randomly divided into three groups: control (T1), melatonin 10 mg/head (T2) and melatonin 15mg/head (T3)given orally. Treatment with melatonin significantly improved the physical characteristics of semen. Melatonin (T3) also improved ALT and AST enzymes in seminal plasma. [ABSTRACT FROM AUTHOR]

Summary: The aim of this study was to estimate the non‐additive genetic effects of the dominance component of heterosis as well as epistatic loss on semen traits in admixed Swiss Fleckvieh, a composite of Simmental (SI) and Red Holstein Friesian (RHF) cattle. Heterosis is the additional gain in productivity or fitness of cross‐bred progeny over the mid‐purebred parental populations. Intralocus gene interaction usually has a positive effect, while epistatic loss generally reduces productivity or fitness due to lack of evolutionarily established interactions of genes from different breeds. Genotypic data on 38,205 SNP of 818 admixed, as well as 148 RHF and 213 SI bulls as the parental breeds were used to predict breed origin of alleles. The genomewide locus‐specific breed ancestries of individuals were used to calculate effects of breed difference as well as the dominance component of heterosis, while proxies for two definitions of epistatic loss were derived from 100,000 random pairs of loci. The average Holstein Friesian ancestry in admixed bulls was estimated 0.82. Results of fitting different linear mixed models showed including the dominance component of heterosis considerably improved the model adequacy for three of the four traits. Inclusion of epistatic loss increased the accuracy of the models only for our new definition of the epistatic effect for two traits, while the other definition was so highly correlated with the dominance component that statistical separation was impossible. [ABSTRACT FROM AUTHOR]

Data on 75 567 ejaculates from 1 417 boars of the breeds Czech Large White and Czech Landrace collected in 23 AI centres between 2000 and 2007 were analyzed. Fixed effects were estimated from a four-trait animal model for semen volume, sperm concentration, motility and percentage of abnormal spermatozoa and from single-trait animal models for the total number of spermatozoa and the number of functional spermatozoa. Both the total number of spermatozoa and the number of functional spermatozoa were highest in winter and lowest in summer. Boar's age had a strong influence on semen volume, the total number and the functional number of spermatozoa; these traits increased especially in the first phase. The percentage of abnormal spermatozoa also increased with age. An interval between successive collections of 7 to 10 days yielded the best values for all semen traits. As semen traits are of direct economic importance for AI centres, it can be expected that the estimation of breeding value for semen traits will become important and that AI centres will choose among top boars for production and female reproduction traits the boars with better semen production.

Genetic correlations between production traits (average daily gain from birth till the end of the field test and ultrasonically predicted lean meat content at the end of the field test) and semen traits (semen volume, sperm concentration, motility, percentage of abnormal spermatozoa, total number of spermatozoa and number of functional spermatozoa) were estimated from a large dataset (44 500 observations for production traits and more than 150 000 ejaculates from 2077 boars). The boars belonged to the breeds Duroc, Piétrain and Large White or were crossbreds between them. All estimated genetic correlations were low (maximal absolute value 0.13). Therefore, selection on production traits is expected to have only low effects on semen traits.

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Twenty adult Awassi rams (2-4 year aged) were used in study to evaluate the effect of grazing (GR) and shearing (SH) in body weight (BW) and semen characters, the rams were randomly assigned to 4 groups (5 rams/ group) treated for 3 months as following : 1st group : rams were reared on standard ration with 6 hrs grazing daily and shearing, 2nd group : rams were treated as 1st group without shearing, 3rd group : rams were reared on standard ration with shearing and without grazing, 4th group : rams were reared on standard ration without grazing and shearing. Semen samples were collected monthly for determination of semen characters. Results show a significant increase (P ≤ 0.05) in BW of grazing rams group at 3rd month of treatment, a significant interaction increased in BW in GR+SH treatment at 2nd and 3rd month of treatment. Semen traits significantly (P ≤ 0.05) improved as Ejaculate volume (EV),Texture (TE), Mass motility (MM), Individual motility % (IM), Live sperm % (LS), Abnormal sperm % (AS) and Sperm concentration (SC) at 3rd month of treatment, also a significant interaction recorded in (GR+SH) treatment of BW, EV, MM, IM%, LS%, at 2nd and 3rd month of treatment. In general results showed that GR and interaction between GR and SH improved significantly BW and semen traits in Awassi rams. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of water deprivation ( WD) on reproductive traits of rams. Ten mature rams were used and allocated to two groups balanced for body weight. Control (C) rams had free access to drinking water, while water-restricted rams ( WD) were deprived from water for 3 consecutive days and early on the morning of day 4, they had ad libitum access to water for 24 h, similar to C animals. The experiment lasted 32 days, that is eight 4-day cycles of water deprivation and subsequent watering. Feed and water intake were significantly affected by water deprivation; in comparison with C rams, WD rams reduced their feed intake by 18%. During the watering day of the deprivation cycle, WD rams consumed more water than C rams on the same day (11.8 ( SD = 3.37) and 8.4 ( SD = 1.92) l respectively; p < 0.05). Glucose, total protein and creatinine were increased as a result of water deprivation. However, testosterone levels were lowered as a result of water deprivation and average values were 10.9 and 6.2 ( SEM 1.23) ng/ml for C and WD rams respectively (p < 0.05). Semen traits were less affected by treatment; WD rams consistently had superior sperm concentrations than C animals; and statistical significances were reached in cycles 5 and 8 of water deprivation. Several mating behaviour traits were modified as a result of water deprivation. When compared to controls, WD rams had a more prolonged time to first mount attempt (p < 0.001), their frequency of mount attempts decreased [6.8 vs. 5.2 ( SEM 0.1); p < 0.001] and their flehmen reaction intensity was negatively affected (p < 0.05). Water deprivation may have practical implications reducing the libido and therefore the serving capacity of rams under field conditions. [ABSTRACT FROM AUTHOR]

Oxidative stress has detrimental effects on semen quality during spermatogenesis and semen processing for artificial insemination. This work was conducted to study the effect of different levels of vitamin E on the semen traits, oxidative status and trace minerals in Beetal bucks. Thirty-six bucks of similar body weight and age (1 year) were randomly divided into four groups. One group was kept as control with no supplementation (group 1), and the others were supplemented with 200 (group 2), 400 (group 3) and 800 IU (group 4) vitamin E/animal/day for 2 months. At the end of the experiment, semen samples were collected and evaluated. Seminal plasma was separated to study the concentration of superoxide dismutase ( SOD), glutathione peroxidase ( GPx), aspartate aminotransferase ( AST), alanine aminotransferase ( ALT) and trace minerals (Zn, Cu, Mn and Fe). Group 3 showed significantly higher (p < 0.05) semen volume and per cent motility and lower dead sperm percentage compared to control group. Superoxide dismutase, GPx, Zn, Cu and Mn were higher in the same group. The level of AST decreased in group 3 without any change on the concentration of ALT. It is suggested that vitamin E at the rate of 400 IU/buck/day supported higher semen volume, per cent motility, per cent live spermatozoa, antioxidants ( SOD, GPx) and trace mineral levels (Zn, Cu, Mn) in the seminal plasma. The increased supplementation from 0 to 400 showed a general increasing trend in improving semen quality. However, the dose of 800 IU/kg had no useful effect in further improving the semen quality. [ABSTRACT FROM AUTHOR]

The aim of this study, based on a five-year-long experiment, was to analyse some of the factors that influence rabbit sperm production. A total of 174 bucks between 23 and 44 weeks of age from five successive groups were used for semen collection one day per week, two times, at a 15 min interval (ejaculates of rank 1 and 2), over a period of 21 weeks. Immediately after collection, pH, mass motility, volume and concentration were measured using classical methods, and a set of motility parameters were recorded by a computer-assisted semen analysis system. Between groups, the number of motile sperm per ejaculate, considered as a synthetic criterion combining both qualitative and quantitative aspects of semen characteristics, varied from simple to double (from 150 to 326 × 10 6 ), reflecting the strong influence of uncontrolled environmental factors. Adult (37–43 weeks old) expressed a higher number of motile sperm/ejaculate than younger bucks (300 vs. 205 × 10 6 ). In autumn the number of motile sperm/ejaculate was higher than in summer (287 vs . 188 × 10 6 ). Sperm production was higher on average for the first ejaculate compared to the second one (270 vs . 167 × 10 6 ). For several semen characteristics, the effect of the collector was significant but without any repercussion on sperm production. Bucks born to nulliparous or primiparous does had higher performances. This study highlights the high variability of rabbit semen characteristics and the multitude of factors involved, either controlled or uncontrolled. [ABSTRACT FROM AUTHOR]

Four semen traits: volume (VOL), concentration (CON), progressive motility of spermatozoa (MOT), and abnormal spermatozoa (ABN) provide complementary information on boar fertility. Assessment of the impact of selection for semen traits is hindered by limited information on economic parameters. Objectives of this study were to estimate economic values for semen traits and to evaluate the genetic gain when these traits are incorporated into traditional selection strategies in a 3-tier system of swine production. Three-way (maternal nucleus lines A and B and paternal nucleus line C) and 4-way (additional paternal nucleus line D) crossbreeding schemes were compared. A novel population structure that accommodated selection for semen traits was developed. Three selection strategies were simulated. Selection Strategy I (baseline) encompassed selection for maternal traits: number of pigs born alive (NBA), litter birth weight (LBW), adjusted 21-d litter weight (A21), and number of pigs at 21 d (N21); and paternal traits: number of days to 113.5 kg (D113), backfat (BF), ADG, feed efficiency (FE), and carcass lean % (LEAN). Selection Strategy II included Strategy I and the number of usable semen doses per collection (DOSES), a function of the 4 semen traits. Selection Strategy III included Strategy I and the 4 semen traits individually. The estimated economic values of VOL, CON, MOT, ABN, and DOSES for 7 to 1 collections/wk ranged from $0.21 to $1.44/mL, $0.12 to $0.83/103 spermatozoa/mm3, $0.61 to $12.66/%, -$0.53 to -$10.88/%, and $2.01 to $41.43/%, respectively. The decrease in the relative economic values of semen traits and DOSES with higher number of collections per wk was sharper between 1 and 2.33 collections/ wk than between 2.33 and 7 collections/wk. The higher economic value of MOT and ABN relative to VOL and CON could be linked to the genetic variances and covariances of these traits. Average genetic gains for the maternal traits were comparable across strategies. Genetic gains for paternal traits, excluding semen traits, were greater in selection Strategy I than Strategies III and II. Genetic gains for paternal and maternal traits were greater in the 4-and 3-way schemes, respectively. The selection strategy including the 4 semen traits is recommended because this approach enables genetic gains for these traits without compromising the genetic gains for maternal traits and with minimal losses in genetic gains for paternal traits. [ABSTRACT FROM AUTHOR]

Katanin p60 subunit A-like 1 (KATNAL1) is an ATPase that regulates Sertoli cell microtubule dynamics and sperm retention. We evaluated one novel splice variant and characterized the promoter and a functional single nucleotide polymorphism (SNP) of the bovine KATNAL1 gene to explore its expression pattern, possible regulatory mechanism and relationship with semen traits in Chinese Holstein bulls. A novel splice variant, KATNAL1 transcript variant 2 ( KATNAL1-TV2) of the retained 68 bp in intron 2, was identified by RT-PCR and compared with KATNAL1 transcript variant 1 ( KATNAL1-TV1, NM 001192918.1) in various tissues. Bioinformatics analyses predicted that KATNAL1 transcription was regulated by two promoters: P1 in KATNAL1-TV1 and P2 in KATNAL1-TV2. Results of qRT-PCR revealed that KATNAL1-TV1 had higher expression than did KATNAL1-TV2 in testes of adult bulls ( P < 0.05). Promoter luciferase activity analysis suggested that the core sequences of P1 and P2 were mapped to the region of c.-575˜c.-180 and c.163-40˜c.333+59 respectively. One novel SNP (c.163-210T>C , ss836312085) located in intron 1 was found using sequence alignment. The SNP in P2 resulted in the presence of the DeltaE binding site, improving its basal promoter activity ( P < 0.05); and we observed a greater sperm deformity rate in bulls with the genotype CC than in those with the genotype TT ( P < 0.05), which indicated that different genotypes were associated with the bovine semen traits. Bioinformatics analysis of the KATNAL1 protein sequence predicted that the loss of the MIT domain in the KATNAL1-TV2 transcript resulted in protein dysfunction. These findings help us to understand that a functional SNP in P2 and subsequent triggering of expression diversity of KATNAL1 transcripts are likely to play an important role with regard to semen traits in bull breeding programs. [ABSTRACT FROM AUTHOR]

The study was carried out to determine the semen characteristics: volumes of ejaculate (VEJ), gel fraction (VGF) and strained ejaculate (VSEJ), sperm concentration (SPC), progressive motility (PGM), live spermatozoa (LVS), abnormal spermatozoa (ABS) and pH (SpH)] as well as the reaction time (RT) and ejaculation time (EJT) of Large White (LW) and Large White x native (LW x N) F1 crossbred (CR) boars exposed to direct solar radiation. A total of 24 grower-finisher boars (12/genotype) aged 6 months and of mean body weight 50.14 kg for LW and 46.65 kg for CR were used for the study. The study involved three treatments (8 boars/treatment; 4 boars/replicate) made up of control (T1); 45 min. (T2) and 60 min. (T3) exposures. Boars in T1 were reared intensively while those of T2 and T3 were exposed in outdoor paddocks. A 14 day pre-experimental period was observed for adaptation and to train the boars for semen collection using a dummy and artificial vagina. Mean indoor and outdoor ambient temperatures differed significantly (P ≤ 0.01) (range: 27.2 to 28.5 oC and 39.9 to 41.06 oC, respectively). Result showed significant (P ≤ 0.05) effects of genotype, duration of exposure and genotype x duration of exposure on most of the semen quality traits while volume of gel fraction (VGF), SpH, RT and EJT were less affected. Generally, the crossbred (CR) genotype maintain better semen quality than the LW genotype over the experimental period. It was suggested that crossbreeding involving heat tolerant indigenous breeds and highly performing exotic breeds of pigs should be undertaken to develop swine breeds that combine thermal tolerance with high performance for improved pig production in Nigeria. [ABSTRACT FROM AUTHOR]

Abstract: A crossbreeding program between Aradi Saudi breed (A) of goats with Syrian Damascus breed (D) was practiced for six years in two experiments (dairy experiment in Jouf and meat experiment in Qassim) applying bio-techniques of estrous synchronization and artificial insemination. The breeding plan permitted to produce four genetic groups of AA, DD, ½D½A and ¾D¼A in each experiment separately. A total number of 1800 ejaculates collected from 298 bucks were evaluated for volume of ejaculate (EV), pH, sperm concentration (SC), total motile sperm (TMS), total sperm output (TSO), percentages of motile (MS), live (LS), abnormal (AS) and dead sperms (DS). Animal models were used to estimate the heritabilities and permanent environmental effects, while a generalized least square procedure was used to estimate individual additive genetic effects, individual heterosis, maternal heterosis and individual recombination effects. Heritabilities for most semen characteristics were low or somewhat moderate and ranging from 0.08 to 0.23, while the permanent environmental effects were slightly higher than the respective heritabilities since the estimates ranged from 0.10 to 0.29. Estimates of individual additive effects for SC, TMS and TSO were in favour of Damascus bucks relative to Aradi bucks by 0.2, 0.43 and 0.44×109 per ml in the dairy experiment and by 0.08, 0.13 and 0.11×109 per ml in the meat experiment, respectively. Significant individual heterotic improvements (with a range of 4.9–26.5%) were recorded in the dairy and meat experiments for EV (0.075ml vs. 0.085ml), SC (0.25×109 per ml vs. 0.11×109 per ml), TMS (0.275×109 per ml vs. 0.125×109 per ml), and TSO (0.33×109 per ml vs. 0.155×109 per ml), associated with significant reduction in percentage of DS (5.5% vs. 1.55%). Crossbred dams showed significant maternal heterotic improvements in semen of their crossbred bucks in both dairy and meat experiments for EV (0.058ml vs. 0.055ml; P <0.05), SC (0.15×109 per ml vs. 0.09×109 per ml; P <0.05), TMS (0.225×109 per ml vs. 0.085×109 per ml; P <0.05), and TSO (0.58×109 per ml vs. 0.115×109 per ml; P <0.01), associated with favourable significant increases in MS (3.3% vs. 4.05%; P <0.05) and LS (3.7% vs. 2.25%; P <0.05) along with a reduction in percentage of DS (4.3% vs. 2.25%; P <0.05); the estimates ranging from 3.3 to 34.1%. The estimates of individual recombination losses for most semen parameters were favourable and non-significant. [Copyright &y& Elsevier]

This study was conducted on 10 crossbred rams consisted of 5 ArkharMerino×Moghani (AM×MG) and 5 Baluchi×Moghani (BL×MG), to analyze correlation between semen characteristics and libido activity. The semen samples were evaluated for semen volume, total sperm per ejaculate (TSE), spermatozoa concentration (SC), color, wave motion, spermatozoa progressive motility, percentage of live and abnormal spermatozoa, pH, rate of metabolic activity of spermatozoa and semen index. The libido of rams was measured by two indices including reaction time (RT) and refractory period (RP). While RT only had a negative and significant correlation with semen volume (r=-0.15, P=0.04), but RP had a significant correlation with seminal traits except for TSE. Moreover, libido test scores between two genetic groups did not have a significant difference (P<0.05). Considering the observed significant correlation between RP and semen characteristics, we suggest that a reliable monitoring with the aim of detecting rams of poor semen quality and libido seems worth making an effort for the future of the herd. In summary, the reported correlation between libido and seminal traits will confirm the importance of simultaneous selection for both libido and semen quality in the herd. Finally, the importance of performing an individual evaluation of semen and libido for each male and for using a ram in breeding programs is highlighted, due to the existence of differences among rams as well as a low correlation between semen characteristics and libido indices. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effects of vitamin E, vitamin C, probiotics, dietary protein level, and their combination on semen traits and seminal plasma macro- and microminerals in 65-week-old male broiler breeders after zinc-induced molting. One hundred eighty birds were induced to molt by mixing zinc oxide (3,000 mg/kg) in the diet. The birds were divided into six groups (five replicates) by completely randomized design. One group was kept as control (16% CP), while the other five were supplemented with vitamin E (100 IU/kg feed), vitamin C (500 IU/kg feed) probiotics (50 mg/L), protein level (14% CP), and their combination. Semen samples were weekly collected for determination of semen volume, sperm concentration, motility, and dead sperm percentage. Analyses of Na, K, Ca and Mg, Zn, Fe, Mn, and Cu in seminal plasma were also performed. Overall, mean semen volume was significantly high in vitamin E and C supplemented groups compared to control. Overall mean sperm motility was significantly higher in vitamin E supplemented group, whereas dead sperm percentage was significantly lower in the vitamin C group compared to control. Mineral analyses revealed that overall mean seminal plasma Mg increased significantly in vitamin E and C supplemented groups compared to control. Similarly, significantly high overall mean seminal plasma Cu concentration was observed in vitamins E and C and combination groups. It can be concluded that vitamins have a vital role in improving semen quality and bioavailability of Mg and Cu in seminal plasma of the post-molt cockerels. [ABSTRACT FROM AUTHOR]

Abstract: Reported was an investigation of the effect of vitamin E (Vit.E) and corn oil on semen traits of male Japanese quail (Coturnix coturnix japonica). From 8 to 20wk of age, birds were raised on corn-based diets supplemented with corn oil (0 and 3%) and Vit.E (National Research Council (NRC) recommended 25mg/kg/day/dry matter and 150mg/kg/day/dry matter) in a 2×2 factorial manner. The diet was supplemented with corn oil and Vit.E (E2C2) which provided additional n-6 polyunsaturated fatty acids in the form of 20:4n-6 and 22:4n-6 in spermatozoa phospholipid. The left testes weights were increased (P <0.01) in groups that received Vit.E in the diet (3.95 and 4.12g, respectively) (P =0.03) and combined testes weight was the greatest in E2C2 group (7.57g) (P =0.02). Semen volume increased throughout the experiment in the E2C2 group. E2C1 and E2C2 birds had the greatest (90.05% and 92.1%, respectively) live sperm percent by comparison with other groups. The susceptibility of semen to lipid peroxidation in vitro was increased in quail fed E1C1 and E1C2, but was reduced when 150mg Vit.E kg/day/dry matter feed was provided in the diet. The amount of Vit.E in the seminal plasma of E1C1 and E1C2 groups was (P <0.01) less than that in the other two groups (E2C1 and E2C2). From this study, it may be concluded that increasing diet n-6/n-3 ratio can be beneficial for semen traits, however, this application increased sperm peroxidation sensitivity but it can be controlled by inclusion of antioxidant such as Vit.E (150mg/kg/day/dry matter) to diet. [ABSTRACT FROM AUTHOR]

Abstract: Thirty-one bucks from two lines divergently selected for 63-d body weight (low, L and high, H) were solicited every week (twice at a 15min interval) during 18 weeks resulting in 482 ejaculates. While differing markedly on adult body weight (L: 4650g versus H: 5925g), both lines had the same testis weight. Libido did not differ between the lines. The proportion of ejaculates suitable for insemination was markedly higher in the L line (66.5% versus 44.2%). Mass motility and the volume of the ejaculates were higher in the L line while the sperm concentration was higher in the H line. Overall, the total number of spermatozoa per ejaculate was similar in both lines but the efficient number of spermatozoa per ejaculate, a synthetic criterion taking into account the ability of the ejaculate for insemination was higher in the L line (229 versus 170×106). The L line had higher values of average path velocity, linearity and curvilinear velocity but a lower value of beat cross frequency. In the L line, both ejaculates had the same concentration, while in the H line, the first ejaculate was more concentrated than the second one. Some male reproductive traits are therefore genetically related to body weight. [Copyright &y& Elsevier]

Presents abstracts of several studies on the physiology of poultry animals. "Differential Expression of Mitochondrial and Extra-Mitochondrial Proteins in Heart of Low and High Feed Efficient Broilers Within a Single Male Line," by N. Tinsely et al; "Aorta Pulse Wave Velocity Is Reduced by Intravenous Injections of L-Arginine in Female, But Not Male, White Leghorn Chickens," by C. A. Ruiz-Feria and H. Nishimura; "Pulmonary and Systemic Hemodynamic Responses to Prostacyclin in Broilers," by R. F. Wideman and M. E. Chapman.

Presents abstracts of several studies on the physiology of poultry animals. "Differential Expression of Mitochondrial and Extra-Mitochondrial Proteins in Heart of Low and High Feed Efficient Broilers Within a Single Male Line," by N. Tinsely et al; "Aorta Pulse Wave Velocity Is Reduced by Intravenous Injections of L-Arginine in Female, But Not Male, White Leghorn Chickens," by C. A. Ruiz-Feria and H. Nishimura; "Pulmonary and Systemic Hemodynamic Responses to Prostacyclin in Broilers," by R. F. Wideman and M. E. Chapman.

Presents abstracts of several studies on the physiology of poultry animals. "Differential Expression of Mitochondrial and Extra-Mitochondrial Proteins in Heart of Low and High Feed Efficient Broilers Within a Single Male Line," by N. Tinsely et al; "Aorta Pulse Wave Velocity Is Reduced by Intravenous Injections of L-Arginine in Female, But Not Male, White Leghorn Chickens," by C. A. Ruiz-Feria and H. Nishimura; "Pulmonary and Systemic Hemodynamic Responses to Prostacyclin in Broilers," by R. F. Wideman and M. E. Chapman.

Semen traits are crucial in commercial pig production since semen from boars is widely used in artificial insemination for both purebred and crossbred pig production. Revealing the genetic architecture of semen traits potentially promotes the efficiencies of improving semen traits through artificial selection. This study is aimed to identify candidate genes related to the semen traits in Duroc boars. First, we identified the genes that were significantly associated with three semen traits, including sperm motility (MO), sperm concentration (CON), and semen volume (VOL) in a Duroc boar population through a genome-wide association study (GWAS). Second, we performed a weighted gene co-expression network analysis (WGCNA). A total of 2, 3, and 20 single-nucleotide polymorphisms were found to be significantly associated with MO, CON, and VOL, respectively. Based on the haplotype block analysis, we identified one genetic region associated with MO, which explained 6.15% of the genetic trait variance. ENSSSCG00000018823 located within this region was considered as the candidate gene for regulating MO. Another genetic region explaining 1.95% of CON genetic variance was identified, and, in this region, B9D2, PAFAH1B3, TMEM145, and CIC were detected as the CON-related candidate genes. Two genetic regions that accounted for 2.23% and 2.48% of VOL genetic variance were identified, and, in these two regions, WWC2, CDKN2AIP, ING2, TRAPPC11, STOX2, and PELO were identified as VOL-related candidate genes. WGCNA analysis showed that, among these candidate genes, B9D2, TMEM145, WWC2, CDKN2AIP, TRAPPC11, and PELO were located within the most significant module eigengenes, confirming these candidate genes' role in regulating semen traits in Duroc boars. The identification of these candidate genes can help to better understand the genetic architecture of semen traits in boars. Our findings can be applied for semen traits improvement in Duroc boars., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Simple Summary: The limited studies addressing the estimation of genetic parameters for ram semen traits in different breeds show a wide variation, highlighting the importance of studying these traits for individual breeds. Therefore, this work aimed to estimate genetic parameters for traits related to semen production and quality in five dairy sheep breeds. For that, ejaculates of rams from Assaf, Churra, Latxa Cara Negra, Latxa Cara Rubia, and Manchega breeds were analyzed. Estimates of the genetic covariance structure were obtained with multiple-trait animal models using the average information REML (restricted maximum likelihood) method in the BLUPF90 family of programs. Repeatability estimates for all the traits were also calculated. Heritability estimates were of low to moderate magnitude, although the estimates differed among the breeds. The estimated genetic correlations among the three semen traits showed adequate precision only in the Manchega (MAN) breed. The heritability estimates reported here suggest that improvement of these traits may be achieved by genetic selection. This work aimed to estimate genetic parameters for traits related to semen production and quality in Spanish dairy sheep breeds. For that, ejaculates of rams from Assaf, Churra, Latxa Cara Negra, Latxa Cara Rubia, and Manchega breeds were analyzed to measure volume, semen concentration, and motility. Estimates of variance components were obtained with multiple-trait animal models using the average information REML method in the BLUPF90 family of programs. Repeatability estimates for all the traits were also calculated, with values ranging from 0.077 to 0.304 for the motility and the semen concentration traits, respectively. Heritability estimates were of low to moderate magnitude, ranging from 0.014 (motility in Latxa Cara Rubia) to 0.198 (volume in Churra), although the estimates differed among the breeds. The estimated genetic correlations among the three semen traits showed adequate precision only in the MAN breed. The heritability estimates for the semen traits reported in the present paper suggest an adequate response to selection. The practical extension of these results to the other breeds studied here will be secondary to the estimation of more reliable genetic correlations in these breeds. [ABSTRACT FROM AUTHOR]