Semen Production Research Articles

Genetic evaluation of semen production potential in Indigenous bulls using random regression models in a Bayesian framework

Genetic potential of indigenous bulls with respect to semen production traits over the age of the bulls at semen collection was analyzed using random regression models (RRMs). Data pertaining to 59,641 ejaculates from 189 bulls of 18 indigenous breeds collected from BAIF (Bharatiya Agro Industries Foundation) was utilized for this study. Six semen production traits, viz., ejaculate volume (EV, ml), sperm concentration (SC, 109/ml), initial sperm motility (ISM, %), post-thaw motility (PTM, %), the total number of spermatozoa per ejaculate (TNS, 109/ejaculate), and the theoretical number of semen doses (TNSD) were studied. Univariate and RRM were used to obtain variance components and genetic parameter estimates. Two hundred thousand Gibbs samples were generated for each trait with a burn-in of 20,000 and thinning interval of 50 in a Bayesian framework. Legendre polynomials with orders of fit up to 5 for additive and permanent environmental effects were used. RRM modeled the heritability and repeatability for all ages between 3 and 10years (productive lifespan). Heritability estimates ranged from 0.18 to 0.36, 0.18 to 0.45, 0.02 to 0.06, 0 to 0.001, 0.09 to 0.32, and 0.14 to 0.42 while the repeatability estimates ranged from 0.41 to 0.72, 0.36 to 0.79, 0.04 to 0.10, 0 to 0.001, 0.37 to 0.56, and 0.32 to 0.57 for EV, SC, ISM, PTM, TNS, and TNSD, respectively. Variability of estimates over the age of the bulls obtained through RRM could be useful to further refine the breeding program for age at selection, deciding the production period and age at culling.

Hepatoprotective and Anti-Oxidant Study of Mukta Bhasma (Calx of Cultured Pearls) Against CCl4-Induced Hepatic Damage in Rats (In-Vivo).

Mukta Bhasma (MB) is a traditional Ayurvedic preparation for upper respiratory and lower respiratory conditions, eye disorders, powerful cardiac tonic, immune-regulator, mood elevator and known to promote strength, intellect and semen production. Mukta bhasma is prepared using direct heat as a media of transformation. Mukta Bhasma was evaluated for its hepatoprotective and antioxidant activities against Carbon tetrachloride (CCl4) induced liver damage in wistar albino rats. Mukta Bhasma (100mg/kg, 200mg/kg and 300mg/kg) was administered to experimental rats for 10 days. Silymarin (25mg/kg) was given as the standard drug. The hepatoprotective activity was assessed using various serum biochemical parameters like (SGOT), (SGPT), Total and Direct bilirubin (TB and DB), Alkaline phosphatase (ALP), Total Triglycerides (TG) and Total Cholesterol (TC). Lipid peroxidation (LPO), Reduced Glutathione (GSH) and Catalase (CAT) were determined to explain the antioxidant activity of Mukta Bhasma. The substantially elevated levels of SGOT, SGPT, TB and DB, ALP, TG and TC due to CCl4 treatment were restored towards near normal by Mukta bhasma (MB) of 200mg/kg dose. Administration of MB 200mg has shown significant reduction in the biochemical parameters like SGOT, SGPT, ALP, Bilirubin, Total cholesterol and Total triglycerides with significance of p<0.001 in all the parameters when compared to CCl4 group. Also, they were near to the standard Silymarin group. Mukta bhasma 200mg has shown significant (p<0.001) reduction in the LPO level, increase in CAT and GSH representing significant antioxidant activity of Mukta bhasma. The histopathological study showed reduction in fatty degeneration of liver in MB 200mg/kg body weight. Thus, results revealed that Mukta bhasma afford significant hepatoprotective and antioxidant effects in CCl4 induced hepatic damage.

Genomic dissection of repeatability considering additive and nonadditive genetic effects for semen production traits in beef and dairy bulls.

The low heritability and moderate repeatability of semen production traits in beef and dairy bulls suggest that nonadditive genetic effects, such as dominance and epistatic effects, play an important role in semen production and should therefore be considered in genetic improvement programs. In this study, the repeatability of semen production traits in Japanese Black bulls (JB) as beef bulls and Holstein bulls (HOL) as dairy bulls was evaluated by considering additive and nonadditive genetic effects using the Illumina BovineSNP50 BeadChip. We also evaluated the advantage of using more complete models that include nonadditive genetic effects by comparing the rank of genotyped animals and the phenotype prediction ability of each model. In total, 65,463 records for 615 genotyped JB and 48,653 records for 845 genotyped HOL were used to estimate additive and nonadditive (dominance and epistatic) variance components for semen volume (VOL), sperm concentration (CON), sperm motility (MOT), MOT after freeze-thawing (aMOT), and sperm number (NUM). In the model including both additive and nonadditive genetic effects, the broad-sense heritability (0.17 to 0.43) was more than twice as high as the narrow-sense heritability (0.04 to 0.11) for all traits and breeds, and the differences between the broad-sense heritability and repeatability were very small for VOL, NUM, and CON in both breeds. A large proportion of permanent environmental variance was explained by epistatic variance. The epistatic variance as a proportion of total phenotypic variance was 0.07 to 0.33 for all traits and breeds. In addition, heterozygosity showed significant positive relationships with NUM, MOT, and aMOT in JB and NUM in HOL, when the heterozygosity rate was included as a covariate. In a comparison of models, the inclusion of nonadditive genetic effects resulted in a re-ranking of the top genotyped bulls for the additive effects. Adjusting for nonadditive genetic effects could be expected to produce a more accurate breeding value, even if the models have similar fitting. However, including nonadditive genetic effects did not improve the ability of any model to predict phenotypic values for any trait or breed compared with the predictive ability of a model that includes only additive effects. Consequently, although nonadditive genetic effects, especially epistatic effects, play an important role in semen production traits, they do not improve prediction accuracy in beef and dairy bulls.

Seasonal effects on the semen production of Bali bulls (Bos javanicus) in West Nusa Tenggara's Lelede regional artificial insemination center

<p class="MDPI17abstract"><strong>Objective: </strong>The purpose of this research is to determine the effect of the rainy and dry seasons on the sperm qualities and frozen sperm production of Bali bulls at the Lelede Regional Artificial Insemination Center (RAIC) in West Nusa Tenggara.</p><p class="MDPI17abstract"><strong>Methods: </strong>A total of 1226 ejaculates were examined from five Bali bulls during a 24-month period (November 2018–October 2019), which was classified into rainy (November–April, 658 ejaculates) and dry (May–October, 568 ejaculates) seasons. Semen volume (mL), sperm velocity (1-4), motility (%), concentration (x106 cell/ml), pre-freezing motility (%), post-freezing motility (%), recovery rate (%), and total frozen semen production were examined as sperm quality measures.<strong></strong></p><p class="MDPI17abstract"><strong>Results: </strong>The results indicated that during the rainy season, ejaculates and processed sperm were more abundant than during the dry season. Additionally, the features of discarded fresh semen in the volume parameter were significantly (P<0.05) larger during the dry season than during the rainy season. The pattern in semen output rises during the dry season and decreasing during the rainy season.<strong></strong></p><p><strong>Conclusions: </strong>It was concluded that the rainy season results in a higher number of ejaculates and total sperm production than the dry season. Meanwhile, no differences in sperm characteristics exist between the two seasons.</p>

Genom-wide analysis identifies single nucleotide polymorphism variations and altered pathways associated with poor semen quality in breeding bulls.

The reason for poor semen quality among the breeding bulls is not well understood. In the present study, we performed high-throughput RNAseq analysis of spermatozoa to identify the SNPs present in good and poor-quality semen-producing Holstein Friesian breeding bulls. A total of 21,360 and 44,650 SNPs were identified in good and poor-quality semen with a minimum read depth of 20, among which 4780 and 8710 novel variants were observed in good and poor-quality semen, respectively. Greater SNPs and indels variations were observed in poor compared to good-quality semen. In poor-quality semen, SNP variations were observed in ZNF280B, SLC26A2, DMXL1, OR52A1, MACROD2 and REV1 genes, which are associated with regulation of spermatogenesis, post-testicular maturation, Cl- channel activity, V-ATPase-mediated intracellular vesicle acidification, a mono-ADP-ribosyl hydrolase and ATR-Chk1 checkpoint activation. GO analysis of filtered genes with significant variations between good and poor-quality semen showed enrichment in important pathways related to semen quality such as MAPK signalling pathway, Akt signalling pathway, focal adhesion, cAMP signalling pathway, and Rap1 signalling pathway. Network analysis of filtered genes in poor-quality semen showed variations in pathways of purine metabolism, pyrimidine metabolism, prolactin signalling pathway and RNA cap-binding complex. It is inferred that SNP in genes involved in maintaining sperm functions could be the reason for poor-quality semen production in bulls, and the identified SNPs hold potential to be used as biomarkers for semen quality in bulls.

Linseed oil in boar’s diet during high temperature humidity index (THI) period improves sperm quality characteristics, antioxidant status and fatty acid composition of sperm under hot humid sub-tropical climate

Environmental heat stress in sub-tropical climates negatively impacts boar semen production and its quality. The present study aimed to examine the heat stress alleviating effects of dietary linseed oil on semen quality and antioxidant status of boar, in the summer and winter seasons in sub-tropical climate. Six Hampshire crossbreed boars were fed with 90 mL linseed oil (treatment) whereas six boars of the same breed were fed 90 mL vegetable oil (control) for sixteen weeks during both season. Sperm quality was assessed for motility, viability, abnormality, acrosomal integrity, and Hypo-osmotic swelling test (HOST). Sperm velocity attributes were assessed by computer-assisted semen analysis (CASA). Antioxidants (glutathione peroxidase; GPx, catalase; CAT, total antioxidant capacity; TAC and nitric oxide; NO) and lipid peroxidation (malondialdehyde; MDA) were measured in seminal plasma and serum. Gas chromatography-mass spectrometry (GC-MS) was used for the estimation of fatty acid composition of seminal plasma and spermatozoa. Feeding linseed oil to the boars significantly (p < 0.05) improved sperm quality at the fresh stage and after 72 h of liquid storage in both season. There was a significant (p < 0.01) effect of treatment and season on semen quality parameters. Significant boar (p < 0.05) effect was recorded on reaction time, semen volume, sperm abnormality, acrosomal integrity and HOST reactive sperm. There was a significant (p < 0.01) effect of treatment and season on the velocity attributes viz. VAP, VSL, VCL, ALH, BCF and STR%. Linseed oil supplementation significantly (p < 0.01) enhanced antioxidant and lowered MDA levels in serum as well as seminal plasma. The concentration of alpha-linolenic (ALA), arachidonic and docosahexaenoic (DHA) fatty acids were significantly (p < 0.01) increased in seminal plasma and sperm after linseed oil supplementation. In conclusion, linseed oil supplementation to boar during high THI months improved the semen quality parameters viz. semen volume, sperm concentration, and progressive motile sperm, along with enhanced antioxidant capacity.

Seasonal variations on semen quality attributes in turkey and egg type chicken male breeders.

A biological experiment was carried out in twenty-four adult healthy breeder males each in turkey (Beltsville small white) and egg type chicken (White Leghorn Babcock) in order to assess the seasonal influence on semen production and quality. The birds were maintained in individual cages under uniform husbandry conditions throughout the year. The birds were fed with breeder ration and water ad libitum was offered with a constant photoperiod of 14h/day. Physical and biochemical characteristics of semen, serum hormones (testosterone and thyroxine), and antioxidant activity (catalase and lipid peroxidation) were evaluated throughout the year (January-December). Based on the THI calculations, the observations were classified under three different seasons, namely, winter (November-February), spring (March, April, and October), and summer (May-September). Semen physical parameters, sperm concentration, motility, live sperm percentage, and sperm plasma membrane integrity were superior during the winter season. In seminal plasma, biochemical parameters (phosphorus, ALT, ALP, AST, and uric acid) had a significant (P < 0.05) difference between seasons. There was a significant difference (P < 0.05) among serum hormones (testosterone and thyroxine) that were higher during the winter season. Significant variation was observed in catalase and lipid peroxidation antioxidant enzyme activities (seminal and blood plasma) in winter than in the other two seasons. Both the turkey and egg type chicken breeders exhibited superior seminal characteristics, sex hormone profile, and antioxidant enzyme activity during winter seasons.

Synergistic Effect of Moringa Leaf Extract (Moringa Oleifera Lam) and Purwoceng (Pimpinella alpine Molk) Supplementation on the Quality of Rural Chicken Semen

This study was conducted to examine the synergistic effects of moringa oleifera and purwoceng (Pimpinella alpine molk) supplementation on the quality of chicken semen. In this study used roosters aged about 1 year weighing an average of 2.0 kg as much as 18 tails divided into 6 treatments, each 3 repeats, each repeat consists of 1 tail. The first group of chickens were used as controls, not given treatment, only given basal feed (T0). The second group of chickens were given moringa leaf extract as much as 1 gram / liter of drinking water (T1), chicken group 3 was given purwoceng extract as much as 1 gram / liter of drinking water (T2). Furthermore, chickens in group 4 (T3) were given moringa leaf extract supplements of 250 mg / liter of drinking water and 750 mg / liter per head per day and the 5th group (T4) were given moringa extract supplements as much as 500 mg / liter of drinking water and purwoceng 500 mg / L of drinking water ml every day (T5). The last group (T6) supplemented moringa leaf extract of 750 mg/L of drinking water and purwoceng of 250 mg/l of drinking water. Basal food in this study used BR-1 chicken feed produced by PT. Charoen Pokphand. As a pre-treatment adjustment the chicken is maintained 1 week with basal feed. Furthermore, chickens began to be treated by supplementation of moringa leaves, purwoceng and the mixture. On the 7th day after treatment, semen begins to be taken and tested. Semen collection is done every 3 days with the amount of 3 times the taking. The observed variables were semen volume per ejaculation, ejaculatory spermatozoa count (cells/ml), percentage of living sperm, motility, mass movement, color, viscosity and pH of semen. Results from semen volume and sperm count, motility and percentage of living sperm were analyzed with variance analysis using the spss series 25 program, while viscosity, color and pH were reported in a descriptive manner. From the results of observations it can be concluded that the synergistic effect between moringa leaf extract and purwoceng extract only occurs in the increase in the concentration of spermatozoa, but does not occur in other fractions. Supplementation of moringa leaf extract and its combination with purwoceng extract can increase the production and quality of chicken semen, but the influence of moringa leaf extract is more dominant than purwoceng extract. Keywords: Rural Chicken, Moringa oleifera, purwoceng (Pimpinella alpine Molk, semen quality

PRODUCTIVITY AND FRESH SEMEN CHARACTERISTICS OF SIMMENTAL BULL DIFFERENT AGES

This study aimed to determine the effect of age on bulls’ productivity and fresh semen characteristics of Simmental bull in Indonesia. A total of 1071 data of semen collection and production from four age groups (two years old (yo), four yo, ≥ 10 yo with high semen rejection (≥10 HR), and ≥ 10 yo with low semen rejection (≥10 LR) were used in this study to evaluate the productivity and characteristics of fresh semen. The results showed that the pre-freezing and post-freezing semen rejection rate of ≥10 HR group was higher (P0.05) than the other groups. The four yo group had the percentage of second semen ejaculation each collection was higher (P0.05) than the other groups. Furthermore, semen volume, sperm concentration, and total sperm concentration significantly increased (P0.05) until four yo and then decreased (P0.05) in ≥ 10 yo groups. The ≥10 HR group had the volume and total sperm concentration significantly different (P0.05) with a group of ≥10 LR. Total sperm motility, individual motility, and mass movement were lower (P0.05) in ≥10 HR than the other groups. In conclusion, age differences of bulls can affect the productivity and characteristics of fresh semen.

155 Effects of Ad Libitum or Restricted Feeding from 140 to 200 Days of Age on Removal Rate and Semen Production of PIC 800 Boars

Abstract Our objective was to determine the effects of ad libitum or restricted feeding PIC 800 boars from 140 to 200 d of age on removal rate and semen production. A total of 206 boars (141±1.5 d of age, 115±1.9 kg of body weight) were randomly allotted to 1 of 2 treatments that consisted of ad libitum feeding in pens (n = 119, 1.16 square meter floor space per boar) and restricted feeding with 2.3 kg/d in crates (n = 87, 1.05 square meter floor space per boar). All boars were fed a common diet that was formulated to have 2300 Kcal of NE/kg and 0.61% of standardized ileal digestible lysine. The 2 different feeding regimens were applied for approximately 58 d, with boars being individually weighed at approximately 140 and 200 d of age. Boars were then shipped to commercial boar studs where the removal and semen production data were collected. Data were analyzed using a generalized linear mixed model in R, and individual boar was considered the experimental unit. The feed intake of ad libitum fed boars were predicted to be 3.6 kg/d according to previously published models (Lu et al., 2021). At 200 d of age, restricted fed boars had reduced final body weight (143 and 186 kg, P &amp;lt; 0.001) and average daily gain (492 and 1,212 g/d, &amp;lt; 0.001) compared with those fed ad libitum. By d 450 of age, boars that were restricted fed had improved survival probability (78% and 56%, P = 0.002), and reduced removal probability due to structure reasons (9% and 26%, P = 0.017). The probability of the collected semen to be used was not affected by treatment (98.1 and 98.9%, P = 0.112). In the current experiment, restricted feeding from 140 to 200 d of age reduced growth rate of boars, increased their subsequent survival probability, but did not impact semen production.

Serum Nerve Growth Factor Levels as a Predictor of Bull Candidate Semen Quality of Madura Cattle.

Madura cattle are the germplasm of native cattle on the verge of extinction because of crossbreeding. Therefore, the present study was aimed to determine the serum nerve growth factor (NGF) concentration as a predictor of fresh ejaculate fertility parameters in Madura bull candidates. Eleven Madura bull candidates used for frozen semen production were selected for the study. Blood samples were collected using a vacutainer from the jugular vein for analyzing serum NGF and testosterone levels. Meanwhile, semen collection was conducted using an artificial vagina for sperm motility, viability, and concentration assessment. Data were analyzed to determine the correlation among variables and the linear regression of NGF concentration to other significant variables. The result showed that NGF had a significant correlation (p < 0.05) with testosterone levels, sperm motility, viability, and concentration. A significant correlation was observed between testosterone levels, sperm concentration, and sperm viability. The regression equation among significantly correlated variables was determined. For artificial insemination, suitable bull ejaculates for obtaining frozen semen should reach at least 2.12 ng/mL of NGF levels, with sperm viability, sperm concentration, and testosterone levels of more than 78.63%, 1,462.177 million/mL ejaculate, and 25.67 ng/mL, respectively. This is the first study to identify NGF as a predictor of male fertility in bull candidates of Madura cattle. Therefore, NGF levels could be used as a marker of male fertility in Madura bull cattle candidates. Thus, based on the minimum NGF levels, the ejaculate of Madura bull candidate that meets the requirements for frozen semen production could predict fertility.

Varicocele: An Endocrinological Perspective.

Varicocele affects 15% of male population but it is more frequently identified in patients searching medical care for infertility. The impact of varicocele on semen production and fertility is known, but the relationship between clinical varicocele and impaired hormonal production is not clear. In published literature there are some studies regarding hormonal alterations in patients with varicocele but no review in which all the hormonal findings are explained. The aim of this review is to evaluate, by most common search engine, what is known about hormonal alterations in varicocele-bearing patients, to verify if a cause-effect relationship is documented and to give a useful contribution to in clinical management of this kind of patients. We found contradictory results about hormonal status from literature. Some studies confirmed a decrease of testosterone levels and higher FSH and LH levels that normalize after varicocelectomy, others found lower than normal levels of dihydrotestosterone due to decreased activity of epididymal 5-α-reductase. Lower circulating Anti-Müllerian Hormone levels, accompanied by a decreased Inhibin-B level, were reported as indicators of the decreased Sertoli cells function in varicocele-bearing adult patients. The finding of higher basal 17-OH-progesterone concentrations in patients with varicocele was explained by some authors with a testicular C-17,20-lyase deficiency. There is no doubt that varicocele could led to hormonal alterations. This review proposes that the impaired free sexual steroid levels are the result of a slight, deep-rooted defect in the testes of a certain amount of men with varicocele but further multicentre, randomized controlled studies remain mandatory to better clarify the hormonal features of patients with varicocele and to assess the utility of hormonal evaluation for establishing the duration of varicocele and for better identifying patients who need surgical correction.

Science-based quality control in boar semen production.

The ever-increasing understanding of sperm physiology, combined with innovative technical advances, continuously furthers the development of boar semen production management. These improvements pave the way for the future implementation of modified quality assurance concepts. This review provides an overview of current trends and new approaches in boar semen production, focusing on: the improvement of hygienic standards, alternatives to the use of antibiotics including the application of cold temperature storage and the utilization of antimicrobial additives, as well as the implementation of new quality control tools. Furthermore, the influence of dilution and temperature management, as well as new possibilities for an improvement of boar semen shipping and storage conditions are reviewed.

Characteristics of fresh and frozen semen of Red Chittagong Cattle

Semen production from breeding bulls used in Artificial Insemination (AI) program is of great importance in cattle breeding. Good quality semen has positive effect on the fertility of cows and heifers. The aim of this study was to evaluate the quality and assessed as the freezing ability of Red Chittagong Cattle (RCC) bull with fresh-diluted semen and frozen semen. The parameters of semen characteristics included were volume per ejaculate (ml), percentage of mass motility, normal and abnormal sperm, and sperm concentration (million/ml). The highest mass motility was found in bull ID No. 4 and the lowest in bull ID No. 1 but the highest sperm concentration was found in bull ID No. 3 with lowest in bull ID No. 2 in fresh semen. Highly significant (p&lt;0.001) positive correlation was found between mass motility and sperm concentration in bulls of ID No. 3 and 4, a negative significant (p&lt;0.05) correlation was found between mass motility and normal sperm percentage. Two freezing techniques were followed in frozen semen production: Cork sheet freezing and Cryobath freezing with two freezing times 15 and 30 minutes were also applied. Variations in the motility of frozen semen by Cork sheet freezing with two different times were found significant (p&lt;0.05) between bulls. Furthermore, highly significant (p&lt;0.01) difference of motility by Cryobath freezing was found between the bulls. The highest motility after both 15 and 30 minutes Cork sheet freezing and Cryobath freezing was found in bull ID No. 4 and lowest in bull ID No. 3. In the present study, variability in the potentiality of bulls (semen volume and sperm concentration) was observed and found lower than crossbred bulls due to small size of Red Chittagong, an indigenous zebu cattle of Bangladesh. Bangladesh Journal of Animal Science. 51(1):25-30

Pregnancy and calving rates improved using modified swim-up method for buffalo semen sexing.

Present study aimed to evaluate field fertility rate and calf sex ratio of Nili Ravi buffalo semen sexed through modified swim-up method (Animal Reproduction Science, 182, 2017, 69). For this purpose, five mature Nili-Ravi buffalo bulls kept at semen production unit, Qadirabad, Pakistan, were selected. Two consecutive ejaculates per week were collected with artificial vaginą for 3weeks. Qualified semen ejaculates were pooled and divided into two aliquots. The first aliquot was processed by routine procedure (control), whereas the second was processed by modified swim-up technique. After separation, semen was diluted in tris-citric acid extender and cryopreserved using standard techniques. Sexed semen was evaluated for fertility trials during peak breeding season. Artificially inseminated animals were examined for pregnancy rate through rectal palpation at least 3months after insemination under field conditions. Calving ratio of female and male calves were recoded after Parturition. The fertility rate was higher (p<.05) in X-sorted sperm (70%) as compared with control (47%). The female calf ratio was higher (p<.05) in X-sorted sperm (78.58%) compared with control (53.3%). In Conclusion, conception rate and production of female calf were significantly higher with sexed semen separated through modified swim-up method compared with unsexed control.

The Use of Animal's Body, Scrotal Temperature and Motion Monitoring in Evaluating Boar Semen Production Capacity.

Simple SummaryThe evaluation of male animals’ fertilizing capacity is based on laboratory-performed tests, as well as on the in vivo and in vitro reproductive outcome. Boar fertility is strongly associated with a pig farm’s financial status and income. The scientific community attempts to increase the predictive reliability of male fertility to ensure the profitability of the pig industry. In this direction, a different approach, using biomedical thermal and motion sensors, is utilized. This study investigates the correlation of collected data by biomedical sensors with variables well known as their predictable value semen quality. Strong correlations are revealed, encouraging the further application of biomedical methods in the assessment of boars’ fertilizing ability.Biomedical measurements by specialized technological equipment have been used in farm animals to collect information about nutrition, behavior and welfare. This study investigates the relation of semen quality (CASA analysis, viability, morphology, membrane biochemical activity and DNA fragmentation) with boar behavior during ejaculation. Sensors were placed on the boar’s body. Movement features were collected using an inertial measurement unit (IMU), comprising an accelerometer, a gyroscope and a magnetometer. Boar, scrotal and dummy temperatures were measured by an infrared (IR) camera and an IR thermometer, while the face salivation of the boar was recorded by a moisture meter (also based on IR technology). All signals and images were logged on a mobile device (smartphone or tablet) using a Bluetooth connection and then transferred wirelessly to the cloud. The data files were then processed using scripts in MATLAB 2021a (MathWorks, Natick, Massachusetts) to derive the necessary indices. Ninety-four ejaculates from five boars were analyzed in this study. The statistical analysis was performed in the Statistics and Machine Learning Toolbox of MATLAB 2021a using a linear mixed effects model. Significant and strong negative correlations (R2 > 0.5, p ≤ 0.05) were observed between boar, dummy and scrotal temperature with the progressive, rapid and slow movement of spermatozoa, VCL (curvilinear velocity), VSL (straight line velocity) and ALH (amplitude of lateral head displacement) kinematics. The volume of the ejaculate was correlated with the scrotal and dummy temperature. Dummy’s temperature was negatively correlated with BCF (beat/cross-frequency), viability and total time of ejaculation, while it was positively correlated with abnormal morphology. Body temperature was negatively correlated with BCF. Positive correlations were noticed between VAP (average path velocity) and total time of ejaculation with body acceleration features, as well as between the overall dynamic body acceleration (ODBA) and total time of ejaculation. In conclusion, the use of biomedical sensors can support the evaluation of boar sperm production capacity, providing valuable information about semen quality.

Candidate Genes in Bull Semen Production Traits: An Information Approach Review.

Semen quality plays a crucial role in the successful implementation of breeding programs, especially where artificial insemination (AI) is practiced. Bulls with good semen traits have good fertility and can produce a volume of high semen per ejaculation. The aim of this review is to use an information approach to highlight candidate genes and their relation to bull semen production traits. The use of genome-wide association studies (GWAS) has been demonstrated to be successful in identifying genomic regions and individual variations associated with production traits. Studies have reported over 40 genes associated with semen traits using Illumina BeadChip single-nucleotide polymorphism (SNPs).

Dietary Fibre Supplementation Improves Semen Production by Increasing Leydig Cells and Testosterone Synthesis in a Growing Boar Model.

Testicular development is imperative to spermatogenesis, and pre-puberty is the key period for testis development. This study, therefore, investigated the effects of fibre supplementation on testis development and its possible mechanism in a growing boar model. Thirty Yorkshire boars were randomly divided into a control group (Control) and a fibre group (Fibre) from day 0 to 90 after weaning, with three pigs per pen and five pens per treatment. Blood and testes were collected for analysis. Dietary fibre supplementation had no significant effect on growth performance, testicular volume, or libido but increased the semen production of boars. Boars fed with fibre had lower serum cholesterol (CHO) and low-density lipoprotein (LDL) levels compared to those on the Control diet; however, testicular CHO, triglyceride (TG), and LDL concentration in the Fibre group were significantly higher than the Control group (P < 0.01). Testicular histological analysis showed that seminiferous tubules and testicular germ cells of 120-day-old boars were densely arranged in the Fibre group, and the number of Leydig cells was significantly higher than that of the Control group (P < 0.001). Furthermore, the diet supplemented with fibre significantly decreased leptin, leptin receptor (Leptor), and luteinising hormone (LH) concentrations in boar serum (P < 0.05), whereas follicle-stimulating hormone (FSH) and testosterone concentrations were significantly increased (P < 0.05). Meanwhile, the expression of AMH, AMHR2, and SYCP3 genes related to proliferation and differentiation, and hormone-related genes STAR and SOCS3, were significantly up-regulated (P < 0.05). OCCLUDIN expression was up-regulated, whereas CDH2 expression was down-regulated. In conclusion, increased fibre intake during the pre-puberty period in growing boar is crucial for Leydig cell proliferation, up-regulating the expression of genes related to hormone synthesis and thereby promoting the secretion of testosterone and semen production.

Heritabilities and genetic correlations between young bulls and mature bulls for semen production traits in Japanese Black cattle

Heritabilities and genetic correlations between young bulls and mature bulls for semen production traits in Japanese Black cattle

Heritability and genetic correlation estimates of semen production traits with litter traits and pork production traits in purebred Duroc pigs.

We estimated heritabilities of semen production traits and their genetic correlations with litter traits and pork production traits in purebred Duroc pigs. Semen production traits were semen volume, sperm concentration, proportion of morphologically normal sperms, total number of sperm, and total number of morphologically normal sperm. Litter traits at farrowing were total number born, number born alive, number stillborn, total litter weight at birth, mean litter weight at birth, and piglet survival rate at birth. Litter traits at weaning were litter size at weaning, total litter weight at weaning, mean litter weight at weaning, and piglet survival rate from birth to weaning. Pork production traits were average daily gain, backfat thickness, and loin muscle area. We analyzed 45,913 semen collection records of 896 boars, 6,950 farrowing performance records of 1,400 sows, 2,237 weaning performance records of 586 sows, and individual growth performance records of 9,550 animals measured at approximately 5 mo of age. Heritabilities were estimated using a single-trait animal model. Genetic correlations were estimated using a 2-trait animal model. Estimated heritabilities of semen production traits ranged from 0.20 for sperm concentration to 0.29 for semen volume and were equal to or higher than those of litter traits, ranging from 0.06 for number stillborn and piglet survival rate at birth to 0.25 for mean litter weight at birth, but lower than those of pork production traits, ranging from 0.50 for average daily gain to 0.63 for backfat thickness. In many cases, the absolute values of estimated genetic correlations between semen production traits and other traits were smaller than 0.3. These estimated genetic parameters provide useful information for establishing a comprehensive pig breeding scheme.