Number Of Ejaculations Research Articles

Genetic correlations between body weight, daily weight gain, and semen characteristic traits in young Norwegian Red bulls

The aim of this study was to estimate genetic parameters for body weight (BW) at 150 d (Bw_150d), and 330 d (Bw_330d) of age and average daily weight gain (Dwg), and to estimate genetic correlations between these traits and semen characteristic traits: volume; concentration (Conc); motility in fresh, 24-h, and 48-h samples (Mot0h, Mot24h, Mot48h); and sperm defects. Data were collected at the performance test station of young Norwegian Red bulls from 2002 to 2012, before selection of bulls for artificial insemination. The weight and growth data consisted of observations for 3,209 bulls, and andrology information was available for up to 2,034 of these bulls. Genetic parameters were estimated using linear animal models. Models for BW and growth traits included the group and year the bull left the station and the pen they occupied during weighing (group-year-pen) and parity of their dam as fixed effects. Models for andrology traits had group-year, age in months (11 to 15), and the interaction between ejaculate number and days since previous collection included as fixed effects. Estimated heritability was 0.14 for Bw_150d, 0.26 for Bw_330d, and 0.34 for Dwg; the estimated genetic correlations among these traits were all favorable. Both BW traits correlated favorably with all the semen characteristic traits (0.20 to 0.76), whereas Dwg was favorably correlated with volume, Mot24h, Mot48h, and sperm defects, and unfavorably correlated with Conc (-0.25) and Mot0h (-0.53). Our results indicate that the genetic correlations between weight and growth traits and semen characteristics depend on the age of the bulls. Although most genetic correlations were favorable, selection for higher daily weight gain between 150 and 330 d might explain the slight negative genetic trends observed for semen characteristics in young Norwegian Red bulls.

Androgenic Effect and Phytochimie of the Bark of Trunk of Buchholzia coriacea Engl. (Capparidaceae)

The testosterone is the main androgen produced by the testes among the males. Her absence is responsible for erectile dysfunction and the loss of the sexual performance. The aim of the present study is to evaluate the androgenic effect and to determine the profile phytochemestry of the barks of trunk of B. coriacea. Fifteen days after the castration, the animals left in group and, received the aqueous extract of B. coriacea (100, 250 and 500 mg/kg, p.o). The sexual parameters (mounts sexual, number of erections, number of ejaculations and the time of latency) have been valued, and compared, to the witnesses groups: water distilled (0,5 ml/100 mg, p.o) and Enanthate of testosterone (1 mg/mL, i.m). The dosage of the testosterone has been achieved by the technic of ELYSA analysis. The determination of the chemical families has been achieved by the technique of coloration in tubes. The aqueous extract of B. coriacea (100,250 and 500 mg/kg, p.o) has an effect androgenic because managed daily during 15 days, it provokes an increase of the rate plasmatic of the testosterone and the bodily weight of the rats, maintains the sexual parameters among the castrated rat, extract the number of ejaculations. The barks of trunk of B. coriacea would contain the stérols, the flavonoides, the saponosids that could be responsible for the sexual effects and androgénic observed. The aqueous extract of the plant would possess the properties androgenic would be to advise the patients presenting problems of masculine barrenness. 
 Keywords: Androgen - Phytochimie - Buchholzia - coriacea

Influence of the interaction between cysticercosis and obesity on rabbit behavior and productive parameters

Parasites induce behavioral changes in the host and obesity is a health problem affecting different animal species. Cysticercosis caused by Taenia pisiformis affects some behavior of rabbits and reproductive behavior of does. Rabbits do not escape from metabolic disorders, being long-live animals useful in breeding, research and companion animals. Here, we addressed the interaction between parasitosis and obesity, and studied how these conditions or the comorbidity affect behavioral and productive parameters in bucks infected with 3000 T. pisiformis eggs. We found that the chronic infection reduced locomotor activity by 28.5% in obese, 18.5% in infected and 47% in obese-infected group (comorbid). The exploratory activity reduced by 42% in obese, 48% in infected and 68% in comorbid rabbits (P ≤ 0.001). Chinning was not affected by obesity, while infection decreased it by 25%. Behavioral reproductive parameters like response time, the mount latency and number of ejaculates were affected by infection and obesity. Furthermore, obesity seems to increase the parasite load promoting the formation of liver granulomas (16% granulomas compared with normal weight), with a higher number of cysticerci in obese animals (86% more than normal weight). Infection decreases body weight, body mass index and the zoometric index BW/LV in obese and normal weight rabbits. In conclusion, infection with T. pisiformis altered behavioral and productive parameters, and obesity magnifies the impact caused by the infection. Also, obesity leads to major susceptibility to infection with T. pisiformis.

Genetic analysis of semen characteristic traits in young Norwegian Red bulls

The aim of this study was to estimate genetic parameters and genetic trends for male fertility in Norwegian Red bulls. We analyzed data on semen characteristics traits collected at the performance test station of young bulls from 1994 to 2016, in an andrology test used to ensure acceptable semen quality before being selected as an artificial insemination bull. Traits included were volume, concentration, and motility (percentage of moving sperm cells) in fresh samples and after storing for 24 and 48 h, and sperm defects. The data consisted of 14,972 ejaculates from 3,927 young (11-15 mo) Norwegian Red bulls. Genetic parameters were estimated using bivariate linear animal models that included age in months, group-year, and collection-group (main effect of the interaction between ejaculate number and interval between collections) as fixed effects, and test-day and additive genetic and permanent environment effect of the bull as random effects. Considerable genetic coefficients of variation were found for concentration and volume, with lower values for motility. Estimated heritabilities ranged from 0.02 and 0.03 (for sperm defects and motility in fresh samples) to 0.14 (volume and concentration measured on a continuous scale). All estimated genetic correlations were favorable, but the genetic correlations between volume and concentration and volume and sperm defects were not significantly different from zero. The genetic correlations between concentration and motility traits ranged from 0.53 to 0.83, and those between volume and the motility traits were between 0.24 and 0.57. All traits showed a slightly unfavorable genetic trend. Our results indicate that selection of bulls with better sperm quality is possible.

A non-invasive method for semen collection and evaluation in small and median size lizards.

The aim of this study was to develop a non-invasive procedure to stimulate ejaculation in median and small lizards for semen collection. After semen collection, we applied a battery of tests to assess the motility (wave and progressive), viability (eosin-nigrosin stain), morphology (normal/abnormal), sperm concentration and ejaculate number, seminal volume and colour. We obtained this fluid from all males of the four species of sceloporine lizards (n=30) and one species of Mexican horned lizards (n=7). We found that semen from all males had a liquid-like consistency and a milky-white appearance. Ejaculate volume and sperm concentration varied among the males and the species studied. We also observed that although the mobility, viability and normal sperm morphology showed a wide variability, their average value in each species was high. We conclude that "genital papilla pressure" was an efficient and non-invasive semen obtaining method for small- and medium-sized lizards that does not imply damage to donors and could be used in other lizard species.

SOME BIOLOGICAL AND ECONOMIC VALUABLE FEATURES OF THE RED CATTLE OF DIFFERENT ORIGIN IN THE ALTAI TERRITORY

The paper characterizes 52 producers of red steppe, 49 - red Danish and 169 Angler bulls of “Barnaulskoye” enterprise in terms of erythrocyte antigen occurrence. The authors used 53 antiserums in order to determine erythrocytic antigens of 9 genetic systems. The highest frequency observed was F antigen frequency equal to 0.976-1.000. This gene was not observed in one servicing red steppe bull and four servicing Angler bulls. All red Danish bulls had F allele in a homo- or heterozygous state. The concentration of antigens A2, B2, O1, Y2, G’, Q’ (system B), C1, C2, E, R2, W, X2 (system C), H’ (system S) in the red bulls was high and equal to 0.249-0.592. The frequency of erythrocytic antigens B1, I1, P2, T1, T2, Y1, I’, D’, J2’, P1’, B” (B), R1 (C), J (J), S2, U and H” (S) was the lowest at 0-0.122. All 53 blood factors were observed in Angler cattle, but no antigens B1, P2, R1, U и B1, Y1, B” were observed in the red steppe and red Danish cattle. There are no significant differences observed in genetic similarity among three red breeds; the index of genetic similarity are 0.9211-0.9307, which indicates a high relationship among them. The highest number of ejaculates and native sperm was obtained from Angler servicing bulls, the excess over other breeds was 11.9-13.9 and 15.1-42.8%. Red steppe bulls were characterized by lowest amount of ejaculate and less bioproducts for cryopreservation were received from them. The total breeding efficiency of cows with red steppe bull sperm was 85.1%, the superiority over Danish and Angler red cattle was 7.1-11.5%.

Effect of early development on semen parameters and lifespan of rabbit males selected by high growth rate

Life history theory suggests that different body development dynamics may influence survival and future reproductive performance of organisms. The present work studied how these dynamics could influence seminal traits and lifespan of rabbit males selected for growth rate and intended for AI. To achieve this goal, a total of 550 rabbit males were controlled from birth, evaluated both during the testing phase (four consecutive weeks after reaching 147 days of life) and the productive phase (377 of them from the end of the testing phase until 2 years of life). In order to obtain individuals with different body development dynamics, we pre-selected males based on their live weight (LW) at 0, 28, 63 and 147 days and on their average daily gain (ADG) between each period (0–28, 28–63 and 63–147 days). Libido and main seminal traits (semen volume, motility, concentration, and production, as well as normal apical ridge and abnormalities of spermatozoa) were controlled during the testing phase. Semen volume, motility and concentration were subsequently controlled during the productive phase, as well as the length of the male life, calculated as the number of days a rabbit was present at the farm between age 147 and day of death, culling or censoring; set to 2 years of life). The birth weight, the ADG between 0 and 28 days and between 28 and 63 days were positively related to some seminal parameters measured during the testing phase (semen volume, concentration, production and motility; P < 0.05), while the ADG between 63 and 147 days was negatively related to the seminal productivity throughout the productive life of the males (an increment of 10 g per day on ADG reduced the number of profitable ejaculates by 4.9%; P < 0.05). In addition, a higher growth between 0 and 28 and between 63 and 147 days increased the risk of death or culling of males during the productive phase (P < 0.05). In conclusion, an adequate body development early in life seems to have a positive effect on the degree of sexual maturity with which male rabbits begin their reproductive life, but reaching the reproduction onset with excessive weight can reduce their reproductive performance and lifespan.

Low total motile sperm in transgender women seeking hormone therapy.

This study was undertaken to compare semen quality, hormonal status, and social factors in transgender women seeking fertility preservation with those of fertile cisgender men. Long-range goals are to establish standard practice measures ensuring optimum semen quality for cryopreservation and fertility preservation in transgender women. This is a case-control study carried out at an academic medical center. Cases are transgender women seeking fertility preservation prior to initiation of hormone therapy. Controls are cisgender men recently fathering a child. All participants completed the Depression Anxiety Stress Scales 21 survey and additional survey questions related to personal behaviors. Complete semen analysis was carried out in a clinical andrology laboratory according to WHO guidelines, 5th edition. Serum follicle stimulating hormone, estradiol, and testosterone were measured at the time of semen analysis. Sperm concentration, total sperm per ejaculate, total motile sperm, volume, and normal sperm morphology were significantly lower in transgender females compared with fertile cisgender men. Other measures of semen parameters and hormone concentrations were not different between groups. Survey results indicated transgender women were more likely to have symptoms of depression, anxiety, and stress and utilize tucking and tight undergarments, compared with controls; however, both groups reported similar numbers of ejaculations per week. Although semen parameters were low, cryopreservation of sperm prior to hormone therapy is a viable fertility preservation option for most transgender women. The etiology of the differences in semen parameters is not known. Enhanced education related to personal behaviors or treatment to reduce effects of stressors prior to cryopreservation may improve future fertility potential.

Efficacy of soy-lecithin for replacing egg yolk in tris extender on quality of frozen buck semen

The present study undetaken to find the efficacy of incorporating soy-lecithin in tris extender for replacing egg yolk, a widely used animal component. Pooled ejaculates (40), 10 from each of four bucks maintained at Goat Research Station, Burnihat were used for freezing in tris extender containing 1% and 1.5% soy-lecithin and 20% egg yolk by adopting split sample technique following conventional method. The post thaw sperm motility in 1.5% soy-lecithin-tris extender (60.20±0.45%) was comparable with that of 20% egg yolk-tris (61.20±0.45%), the difference being non-significant. However, the post thaw values for live sperm, intact acrosome and hypo-osmotic swollen sperm were significantly lower in 1.5% soy-lecithin-tris as compared to that in 20% egg yolk-tris. The post thaw values were significantly higher for 1.5% than that for 1% soy-lecithin for all the parameters studied. It could be concluded that 1.5% soy-lecithin-tris extender has similar efficacy with that of 20% egg yolk-tris extender in respect of post thaw sperm motility; however, significantly lower post thaw values for remaining sperm qualities obtained with soy-lecithin in tris-based extender necessitate further trials comprising higher number of ejaculates from more bucks to find a suitable level of soy-lecithin for replacing egg yolk in tris extender for freezing of goat semen.

DISTRIBUTION OF EJACULATES ACCORDING TO THE NUMBER OF SPERMATOZOA IN HOLSTEIN BULLS AGED 6-7

The paper highlights the results of the system analysis carried out in order to explore the primary characteristics of native seed from Holstein servicing bulls of Black-and-White breed aged 6-7 years. The analysis was carried out to rank ejaculates by the total number of spermatozoa. The experiment was carried out at OAO “Moskovskoye on pedigree activities” in 2011 - 2013. The researchers tested 5964 ejaculates, obtained from 17 bulls during three years, in relation to the season. The researchers explored the number of ejaculates (n), defect of the native sperm when taking (%), and the seasonal dynamics of the total number of sperm cells in the ejaculate. The keeping technology, feeding and maintenance, sperm collection, its assessment and cryopreservation was carried out in accordance with the requirements of the “National technology of producing and application of servicing bulls’ sperm “. Ejaculates were distributed into three groups according to the total number of spermatozoa: - up to 3 billion; - 3.1 - 5.0 billion; - 5.1 billion and more. The researchers found out that the number of ejaculates of good quality selected for cryopreservation in the mature reproductive aged bulls (6 - 7 years) is 76% on average with a variability of 73-82%, depending on the season and year of maintenance. The highest number of the ejaculates of good quality was obtained in autumn and it was 82.3%, which is 7-10% higher than that in other seasons (p&lt;0.001). The analysis of ejaculates over a three-year period showed that the first group contained the main mass of ejaculates, where the number of spermatozoa was up to 3 billion. This parameter varied within 40-48% from season to season; the researchers observed the ejaculates that have total number of spermatozoa equal to 3.1 - 5.0 billion were 28.5-33.4%, the ejaculates that have the highest number of spermatozoa (5.1 billion and more) were 23-29%.

Sexual behavior of subordinate, but not dominant, rams increases following observed sexual activity

Sexual performance of rams does not improve after observing hetero-sexual behavior of other rams, as happens in bucks and bulls. This lack of effect might be masked by the positive and negative effects that sexual stimulation could have on dominant or subordinate rams, given that important differences have been found within both categories. Thus, the objective of the present experiment was to determine if rams’ sexual behavior is modified differently in dominant (DOM) and subordinated (SUB) rams after observing the sexual behavior of each other. The dominance relationship of nine dyads of Corriedale rams was determined using a food competition test. Next, each ram was tested in two different situations; a control test (CT), and a test in which the other ram was joined with two estrous ewes in the contiguous pen (visual sexual stimulation test; VSST). Estrous ewes were placed in one pen, and each ram was located first 20 min in the contiguous pen. Then, the ram was moved into the pen with the estrous ewes, staying there for other 20 min. During the CT the ewes remained alone the first 20 min. During the VSST the other ram of the dyad was in the pen with the ewes, but it was taken out before introducing the tested ram. There were no differences in the frequency of any behavior during the 20 first min between DOM or SUB rams. The DOM rams did not modify any behavior according to the type of test. On the other hand, SUB rams increased the number of ejaculations and the ejaculation efficiency (P = 0.04 and 0.03, respectively) when tested after viewing the DOM rams, and tended (P = 0.058) to achieve their 1st ejaculation earlier in VSST test. It was concluded that while visual pre-stimulation of a SUB ram courting and mating estrous ewes had no effect on DOM rams’ sexual behavior, the observation of a DOM ram, enhanced mating behavior of SUB rams. This expands the concept that DOM and SUB rams respond with different strategies to visual stimulation.

Behavioral response is absent under the mating competition in rats (Rattus norvegicus)

Sexually receptive female rats normally copulate with several males during estrus, and multiple paternity is common. Sperm competition is therefore likely to occur. One response to competitive mating is to enhance sperm output per ejaculation and another is to augment the number of ejaculations. The latter alternative requires more intense copulatory behavior. In studies in a seminatural environment we observed that male rats did not modify their behavior according to the intensity of competition, whereas observations from standard observation cages suggested that they do so. In order to further evaluate the potential response to competitive mating, we observed male rats copulating in a pair situation, i.e. one male and one female, and in a situation where three males simultaneously copulated with one female. In addition to sexual behavior, social interactions were quantified. It was found that the males in the multiple male condition prolonged mount and intromission latencies, and displayed a reduced number of mounts. There was no change in the number of preejaculatory intromissions or the ejaculation latency. The multiple mating did not affect non-sexual interactions with the female, whereas the female displayed more nose-offs and rejections when copulating with three males. It is concluded that mating competition does alter the initiation of copulation in the male rat, whereas copulatory behavior, i.e. intromission and ejaculation, remains unchanged.

Evaluation of aphrodisiac activity of ethanol extract of Ganoderma lucidum in male Wistar rats

BackgroundGanoderma lucidum was traditionally used to manage male sexual dysfunction. This study was designed to investigate and establish the traditional aphrodisiac potential of the herb.MethodsAphrodisiac potential was evaluated following the oral administration of two different doses (150 and 300 mg/kg) of ethanol extract of Ganoderma lucidum. Sildenafil citrate (Viagra) and distilled water were used as positive and negative controls respectively. Mounting, intromission and ejaculation frequencies, mating performance, and orientation activities towards females, towards the environment, and towards self were observed. Serum testosterone levels were also evaluated.ResultsThe results of the study show that the extract has significantly increased the mounting behavior and mating performance of the rats. There was also significant increase in the number of intromissions and ejaculations. The rats treated with extract were more interested in female rats as indicated by significant increase in the number of anogenital sniffing and climbing. Serum testosterone levels were also significantly increased in the treatment groups.ConclusionEthanol extract of Ganoderma lucidum possesses aphrodisiac activity in male Wistar rats. The lower dose of 150 mg/kg was more effective in terms of aphrodisiac potential of the extract.

Estrogen imprinting compromises male sexual behavior and affects the number of androgen-receptor-expressing hypothalamic neurons†.

Neonatal exposure to high-dose 17β-estradiol (E2) affects the morphology and physiology of sex and accessory sex organs in the long term. In this study, we examined the effects of E2 imprinting on male sexual behavior, fertility, and the number of androgen receptor (AR)-expressing cells in the hypothalamus. E2-treated males showed copulatory behavior represented by mounts and/or intromissions, demonstrating the preservation of aspects of male behavior. They had slightly increased latency for first intromission and a reduced number of ejaculations, associated with a 50% reduction in the fertility index. AR expression in the hypothalamus was assessed by RT-PCR, western blotting, and immunohistochemistry. Treated rats had a significantly lower ventral prostate (VP) weight, demonstrating the efficacy of the treatment. The AR mRNA and protein content in the hypothalamus of E2-treated animals was reduced to the levels of females. AR-expressing cell counts in the ventromedial, anterior medial preoptic, paraventricular nuclei, and preoptic areas were different from control males, and similar to those of females. In conclusion, E2 imprinting resulted not only in ill-developed sexual organs, but also affected sexual behavior, resulting in a female-type hypothalamus, at least with respect to the abundance of AR mRNA and protein and the number of AR-expressing cells in important regions/tracts.

Pengaruh Lingkungan dan Nilai Ripitabilitas pada Kualitas Semen Sapi Peranakan Ongole Jantan

The aims of this study were to analyze the effect of environmental factors (age of bull, season of collection and frequency of ejaculation) and estimate the repeatability on semen quality of ongole grade bulls. Semen data were collected from Singosari National Artificial Insemination Centre, in Malang District, East Java Province, Indonesia. A total of 1.020 ejaculates collected from three Ongole grade cattle from 2012-2016 were analyzed. Data were analyzed by restricted maximum likelihood (REML) method using the mixed model including the random effect of bull and the fixed effects of age of bull, season of collection, and ejaculate number. The results showed that age of bull and ejaculate number significantly affected all studied variables (P<0.01). Season only affected to sperm motility (P<0.01). Repeatability estimates of semen volume, sperm concentration, total number of sperm and sperm motility were 0.48; 0.42; 0.28; and 0.01, respectively. It was concluded that the age of the bull and frequency of ejaculation significantly affected semen quality of Ongole grade cattle. Repeatabilities for semen quality were low, moderate and high.

Chronic cannabidiol exposure promotes functional impairment in sexual behavior and fertility of male mice

Cannabidiol (CBD) is a potent substance extracted from Cannabis sativa. As it has been suggested that marijuana can affect the reproductive system, we decided to assess the effects of chronic CBD exposure on the male reproductive system in an animal model. 21-day old male Swiss mice received CBD for 34 consecutive days at doses (p.o.) of either 15 or 30 mg/kg, and a control group received sunflower oil. Body weight gain and circulating progesterone concentration did not significantly change in CBD-treated animals. In the sexual behavior analysis, the CBD 15 group presented a delay in performing the first mount and intromission, and a reduced number of mounts and ejaculations. The CBD 30 group showed a 30% reduction in fertility rate and a 23% reduction in the number of litters. Our results indicate that chronic CBD exposure promotes functional impairment of the reproductive system of male Swiss mice.

Sexual behavior and testis morphology in the BACHD rat model.

BackgroundHuntington disease (HD) is an autosomal dominant neurodegenerative disorder caused by a mutation in the huntingtin (HTT) gene, which results in brain neurodegeneration and peripheral pathology affecting different organs including testis. Patients with HD suffer from motor and cognitive impairment, and multiple psychiatric symptoms. Among behavioral abnormalities in HD, sexual disturbances have often been reported, but scarcely investigated in animal models. The BACHD rat model of HD carries the human full-length mutated HTT (mHTT) genomic sequence with 97 CAG-CAA repeats and displays HD-like alterations at neuropathological and behavioral level.ObjectiveThis study aims to phenotype the BACHD rats’ sexual behavior and performance as well as testis morphology because alterations in these aspects have been associated to HD.MethodsTwo rat cohorts at the age of 3 and 7 months were subjected to mating tests to assess different parameters of sexual behavior. Histological analyses for testis morphology were performed in different rat cohorts at 1.5, 7 and 12 months of age whereas immunohistochemical analyses were carried out at 7 and 12 months of age to visualize the presence of mHTT in testicular tissue. Furthermore, western blot analyses were used to assess HTT and mHTT expression levels in striatum and testis at three months of age.ResultsAt 3 months, BACHD rats showed a decreased time exploring the female anogenital area (AGA), decreased latency to mount, increased number of intromissions and ejaculations and enhanced hit rate. At 7 months, all sexual parameters were comparable between genotypes with the exception that BACHD rats explored the AGA less than wild type rats. Testis analyses did not reveal any morphological alteration at any of the examined ages, but showed presence of mHTT limited to Sertoli cells in transgenic rats at both 7 and 12 months. BACHD rat HTT and mHTT expression levels in testis were lower than striatum at 3 months of age.ConclusionsThe testis phenotype in the BACHD rat model does not mimic the changes observed in human HD testis. The altered sexual behavior in BACHD rats at three months of age could be to a certain extent representative of and share common underlying pathways with some of the sexual disturbances in HD patients. Further investigating the biological causes of the sexual phenotype in BACHD rats may therefore contribute to clarifying the mechanisms at the base of sexual behavior changes in HD.

Electrostimulation is an effective and safe method for semen collection in medium-sized lizards

The development of safe and consistent semen collection protocols should be ensured to understand basic sperm parameters of a species. Electroejaculation has been hypothesized and tested to be a safe method to evaluate male reproductive potential in wild animals. However, little is known about semen collection protocols in lizards. Adjusting stimulation to species and body mass is important for efficient semen collection as well as for animal welfare. Tropidurus spinulosus is a good model to adapt electrostimulation; it is a medium-sized lizard species, males have semen during a long period and operative sex ratio is male-biased. We aimed to provide a thorough and safe method for collecting semen samples from this animal model by means of electrostimulation and characterize basic sperm parameters. Mature males of T. spinulosus were captured and their testicular volume was evaluated via portable ultrasound scanning. The lizards were electrostimulated by performing standardized series of stimuli. Semen was obtained successfully in 94% of the males. Samples were contamination-free. Mean sperm number of ejaculates was 2.1 ± 1.8 × 106 spermatozoids. The percentage of motile spermatozoa was 78% and sperm dynamic parameters were: VSL 37.26 ± 7.72 μ/s and VCL 84.26 ± 16.27 μ/s. We observed high variability in testicular volume among males; however, almost all the individuals had sperm. Electrostimulation using protocols adjusted to a medium-sized lizard was an effective semen collection method that allowed us to obtain semen samples with high motility (percentage of motile spermatozoa and sperm velocity).

Influence of bull age, ejaculate number, and season of collection on semen production and sperm motility parameters in Holstein Friesian bulls in a commercial artificial insemination centre.

In the current era of genomic selection, there is an increased demand to collect semen from genomically selected sires at a young age. The objective of this study was to assess the effect of bull age, ejaculate number, and season of collection on semen production (ejaculate volume, sperm concentration, and total sperm number; TSN) and sperm motility (prefreeze and post-thaw total and gross motility) parameters in Holstein Friesian bulls in a commercial artificial insemination (AI) center. The study involved the interrogation of a large dataset collected over a 4-yr period, (n = 8,983 ejaculates; n = 176 Holstein Friesian bulls aged between 9 mo and 8 yr). Bulls aged less than 1 yr had the poorest semen production and sperm motility values for all parameters assessed compared with bulls older than 1 yr (P < 0.01). First ejaculates had greater semen production and greater prefreeze motility values than second consecutive ejaculates (P < 0.01), but despite this, there was no difference in post-thaw motility. When subsequent ejaculates were collected from bulls aged less than 1 yr, semen production and sperm motility did not differ compared with mature bulls. Semen collected in winter was poorest in terms of sperm concentration and TSN, but best in terms of post-thaw motility (P < 0.01). In conclusion, second ejaculates can be collected, particularly from bulls aged less than 1 yr, without a significant decrease in post-thaw sperm motility, thus may be a useful strategy to increase semen availability from young genomically selected AI bulls in high demand.

PIG PRODUCTIVITY UNDER PURE BREEDING AND CROSSBREEDING

For the research the groups were formed by method of analogues based on origin, age, physiological state, live weight. Studying sperm productivity, the number of ejaculates obtained during the year, average volume, concentration, and the total number of spermatozoa in the ejaculate were taken into account and conducted according to conventional techniques using a digital photometer “SDM-30” produced by "Minitüb”. Indicators of economical useful traits of the test animals were calculated according to primary zoo-technical accounting by standard methods of biometric analysis. To determine breeding value of animals by the BLUP method, software developed at the Institute of Pig Breeding "System determining the breeding value of pigs" was used. In carrying out the work, population genetics and mathematical methods were applied for studying of patterns of variability, repeatability, assessment of the genotype of animals.&#x0D; Reproductive quality of the sows was assessed by multiparity (total number of piglets at farrowing), prolificacy (piglet’s weight at birth, kg), milk ability (total weight of litter at 21 days, kg) piglet’s weight at weaning and survival of offspring to weaning. Survival of piglets, homogeneity and uniformity of litter were determined by modified M. D. Berezovsky – D. V. Lomako index and V. P. Kovalenko homogeneity index. Growth and development were controlled by change of individual live weight via weighing. Average daily gain was determined based on the initial and final live weight and number of days between weightings.&#x0D; Dynamics of indicators of growth and development, maternal qualities of sows and sperm productivity and fertility of boars at the purebred animal of initial breeds and live weight and age at 100 kg in the hybrids of first generation were studied. The youngsters obtained at crossbreeding Large White breed of domestic and foreign selection with Landrace had the best indicators of growth and development than the purebred counterparts in all age periods. Higher live weight at weaning at age of 60 days was typical for combination ♀LWE x ♂LE and ♀LE x ♂LWE; it is quite natural, because they had lower average number of piglets at weaning. For maturing volumes of back of the carcass and a well-developed layer of fat should be adjusted to Landrace sows and Large White boars. Fattening of commercial hybrids obtained by this scheme under Ukrainian conditions is advisable to check out at animal’s live weight of 115 ... 120 kg.&#x0D; Significant correlations were proven on the basis of: BLUP index – back fat thickness at the level of the 6-7 thoracic vertebra – -0,221 ± 0,0938 (tr = 2,35), BLUP index – back fat thickness on sacrum – -0,298 ± 0,0898 (tr = 3,31), BLUP index – back fat thickness at the midpoint of the back between the withers and sacrum – -0,239 ± 0,0929 (tr = 2,57), BLUP index – body length – -0,338 ± 0,0873 (tr = 3, 86), BLUP index – multiparity – -0,294 ± 0,0900 (tr = 3,26), BLUP index – total weight of the litter at the date of weaning – -0,233 ± 0,0932 (tr = 2,49). Keeping the selection process towards selection and combination of parental pairs by BLUP method is one of the ways to increase the productive capacity of the animals.&#x0D; According to the research it was found that asymmetry of testes sizes was observed together with individual peculiarities of testes form at the same breeding boars. Testes have physiological asymmetry. Ratio of areas of the left testes to right was Sl/Sr = 1.04, and volumes respectively Vl/Vr = 1.20, on average, left testes by their areas were 2.7% more than the right, and by volumes – 14.6% respectively.&#x0D; Comparing the live weight of boars with weight of their testes does not have a logical pattern. The average weight of testes was 0.14% of the live weight of breeding boars. Total volume of ejaculate on a group of boars was 355,3 ± 16,9 ml. The concentration of sperm in the ejaculate was 64,2 ± 4,6 billion, activity – 8,7 ± 0,2 points. The studies found that boars with greater weight of testes produce sperm with more sperm concentration and that's why more sperms in the ejaculate were obtained from them.&#x0D; Combination of Landrace and Large White breeds is apposite for obtaining precocious pigs with well-developed layer of fat at the 6-7 thoracic vertebra and high level of prolificacy (1,8-1,9 kg).