Sperm-egg penetration in laying breeder flocks: a technique for the prediction of fertility.

1. An experiment was conducted to evaluate indices of fertility including the sperm penetration (SP) assay as a technique for the prediction of fertility. Forty-eight males consisting of White Leghorn (WL), New Hampshire (NH), Iraqi Brown (IBr) and Iraqi Barred (IBa) (12 males each) and 64 WL hens were divided at random into 4 groups of 4 replicates of 3 males and 4 females each. 2. At the beginning of each week semen was collected from males and pooled by breed of male. Hens in each breeding group were inseminated once weekly, by breeding group, for 4 consecutive weeks with pooled semen from WL, NH, IBr and IBa males (WLxWL, NHxWL, IBrxWL and IBaxWL). 3. The differences in percentage of dead sperm, acrosomal abnormalities, mass motility, individual motility and spermatocrit between the experimental breeds demonstrated the superiority of WL and NH males in all these quantitative characters of the semen. On the other hand, WL hens inseminated with spermatozoa from NH males had significantly more sperm-egg penetration (SP) holes than WL hens inseminated with spermatozoa from other breeds of males. The breed of males used for insemination affected fertility, hatchability and embryonic mortality. 4. The highest fertility and hatchability and lowest embryonic mortality were observed in eggs laid by hens inseminated with spermatozoa from WL and NH males in comparison with hens inseminated with spermatozoa from Iraqi males. 5. There was a strong positive correlation between SP values and fertility for WLxWL, NHxWL, IBrxWL and IBaxWL. The correlation for all breeds combined was also significant. In addition, SP was also positively correlated with hatchability and negatively correlated with embryonic mortality.     

Sperm penetration assay as an indicator of bull fertility

To predict the fertility of frozen-thawed bull spermatozoa, a sperm penetration assay (SPA) using zona-free hamster oocytes was optimized, and the assay results were compared with data from field fertility expressed as the non-return rate (NRR). To increase sperm penetration, the spermatozoa were pre-incubated and coincubated with oocytes in media containing various concentrations of heparin (0 to 50 μg/ml). Coincubation with 10 μg/ml heparin showed the highest sperm penetration (P<0.05); it is considered to be the optimized SPA method. Sperm fertility index values obtained from WSPA were significantly correlated with the historic average NRR of 46 bulls (P<0.01). To determine the normal range for SPA, we established the lower limits of the sperm fertility index and set the cut-off value at 2.55, at which point the NRR was more than 70%, using the receiver operating characteristic curve. The overall accuracy for the 46 bulls was 95.7% (44/46) for both the low and high NRR, with a sensitivity of 95.5% (21/22) and a specificity of 95.8%. This protocol would make it easier to discriminate bulls according to their sperm fertilizing ability.     

Mouse bioassay to assess oestrogenic and anti-oestrogenic compounds: hydroxytamoxifen, diethylstilbestrol and genistein

Young intact and adult gonadectomized C3H male and female mice were utilized as bioassay models to detect endocrine disruption chemicals. Animals treated with oestradiol (E) or progesterone (Prog) or E plus Prog were used to assess steroid hormone agonist and antagonist activities of 4-OH-tamoxifen (TAM), diethylstilbestrol (DES) and genistein (GEN) by bioassay. The stimulation or inhibition of mammary growth by TAM depended on sex, the state of animal (intact or gonadectomized), hormonal treatment (Prog, E, E plus Prog) and dose of TAM. TAM stimulated mammary growth in untreated ovariectomized (OV-X) females and in Prog-treated intact males and OV-X females. In intact males, mammary growth was increased by TAM at dose 0.1-1 microg day(-1) and decreased at dose 10 microg day(-1). Mammary growth was inhibited by TAM in Prog-treated intact females and in E or E plus Prog-treated intact and gonadectomized males and females. Uterine weights were increased by TAM in both untreated and treated (E, Prog, E plus Prog) intact and OV-X females; however, seminal vesicle weights were decreased by TAM in both untreated and treated (E, Prog, E plus Prog) intact males. DES alone affected mammary growth (an inverted-U-shaped dose-response curve) both in male and female mice. DES increased uterine weights; however, seminal vesicle weights were decreased. GEN increased mammary and uterine growth in OV-X females, GEN plus Prog stimulated mammary growth in intact males. The results obtained in these studies show clearly that only a bioassay consisting of several endpoints reflective to the mechanism of oestrogen and anti-oestrogen action has the ability to evaluate activities of a molecule.     

Effects of antiepileptic drugs carbamazepine and sodium valproate on fertility of male rats

The effects of carbamazepine and sodium valproate on fertility of male rats were studied. The tested drugs were given orally to male rats for 30 and 60 consecutive days. Mating performance, sex organs weights, semen quality, plasma concentrations of sexual hormones as well as histopathological findings were the criteria used to evaluate the reproductive efficiency of treated males. Oral administration of carbamazepine and sodium valproate for 30 and 60 consecutive days significantly decreased the testicular weight, sperm cell concentration, live sperms and percentage of progressively motile spermatozoa. Both drugs significantly increased the percentage of morphologically abnormal spermatozoa. A decrease in plasma testosterone, FSH and LH and an increase in prolactin levels were observed in the treated groups. Histopathological examination showed mild to moderate degenerative changes in the testes of the treated rats while the prostate glands and seminal vesicles appeared normal. A recovery period of 30 days was accompanied by marked changes in the tested parameters towards initial values.     

The effect of fertility control on the transmission of bovine tuberculosis in wild brushtail possums

AIM: To determine the effect of fertility control on the rate of transmission of bovine tuberculosis (Tb), caused by Mycobacterium bovis, in brushtail possums (Trichosurus vulpecula). METHODS: At two study sites with a history of Tb infection in the resident possum population, a sample of adult male and female possums (n=50), determined by palpation to be Tb-free, was surgically sterilised by gonadectomy. A sample of untreated Tb-free male and female possums (n=54) served as controls. Each study site was trapped every 2 months over a 3-year period, and the Tb status of the individuals in the trial assessed. At the conclusion of the trial, all remaining experimental individuals were killed, necropsied and examined for characteristic lesions typical of Tb. The rate of transmission of Tb infection was estimated using the incidence of tuberculous cases in the experimental animals and comparing it between sites, sex and sterilisation treatment. RESULTS: Sterilisation by gonadectomy resulted in a reduction in the rate of transmission of Tb in male possums by 53%, but a corresponding increase in sterilised females for reasons that are still unclear. However, this interaction was statistically weak (p=0.10). When the sexes were combined, there was no overall effect of sterilisation on the rate of transmission of Tb (p=0.43). Sterility treatment notwithstanding, there was a highly significant difference in the rate of transmission between the sexes (p=0.01), being almost one order of magnitude higher in untreated males compared with untreated females. CONCLUSIONS: Although lacking strong statistical support, these results suggest that fertility control that targets endocrine control of fertility may provide some additional benefits for disease control over that achieved by reductions in population density, by reducing the rate of transmission of M. bovis in male possums. However, additional studies are needed to confirm the validity of these results. The large difference in the rate of transmission of M. bovis in untreated males compared with untreated females suggests that transmission of Tb among males may be an important driver of the dynamics of Tb infection in possums.     

The effect of fertility control on the transmission of bovine tuberculosis in wild brushtail possums

AIM: To determine the effect of fertility control on the rate of transmission of bovine tuberculosis (Tb), caused by Mycobacterium bovis, in brushtail possums (Trichosurus vulpecula).

METHODS: At two study sites with a history of Tb infection in the resident possum population, a sample of adult male and female possums (n=50), determined by palpation to be Tb-free, was surgically sterilised by gonadectomy. A sample of untreated Tb-free male and female possums (n=54) served as controls. Each study site was trapped every 2 months over a 3-year period, and the Tb status of the individuals in the trial assessed. At the conclusion of the trial, all remaining experimental individuals were killed, necropsied and examined for characteristic lesions typical of Tb. The rate of transmission of Tb infection was estimated using the incidence of tuberculous cases in the experimental animals and comparing it between sites, sex and sterilisation treatment.

RESULTS: Sterilisation by gonadectomy resulted in a reduction in the rate of transmission of Tb in male possums by 53%, but a corresponding increase in sterilised females for reasons that are still unclear. However, this interaction was statistically weak (p=0.10). When the sexes were combined, there was no overall effect of sterilisation on the rate of transmission of Tb (p=0.43). Sterility treatment notwithstanding, there was a highly significant difference in the rate of transmission between the sexes (p=0.01), being almost one order of magnitude higher in untreated males compared with untreated females.

CONCLUSIONS: Although lacking strong statistical support, these results suggest that fertility control that targets endocrine control of fertility may provide some additional benefits for disease control over that achieved by reductions in population density, by reducing the rate of transmission of M. bovis in male possums. However, additional studies are needed to confirm the validity of these results. The large difference in the rate of transmission of M. bovis in untreated males compared with untreated females suggests that transmission of Tb among males may be an important driver of the dynamics of Tb infection in possums.     

Dam and Sire Effects on Sperm Penetration of the Perivitelline Layer of Eggs Produced by Two Strains of Commercial Turkeys

The reproductive performance of 2 commercial turkey breeder lines was examined using reciprocal crosses between sires and dams of each line. One line had been selected using artificial inseminations performed at biweekly intervals, whereas the second line had been selected using inseminations performed at weekly intervals. The hypothesis was proposed that sires and dams of the 2 lines differ because of different abilities for sperm to penetrate the inner perivitelline layer (IPVL) and fertilize eggs.Fertilized eggs to hatch poults for the experiment were obtained from the primary breeders and were incubated using conditions recommended by the industry. Hens (n = 72) and toms (n = 15) from each strain were identified and reared in preparation for a reproductive cycle using commercially accepted standards. Beginning just prior to the onset of egg production and at weekly intervals thereafter, half of the hens were inseminated with semen from males of the same line, whereas the remaining half received semen from the opposite line. Eggs were collected from the pens daily and set in incubators to determine fertility and embryo survival. At biweekly intervals 3 eggs per pen were used for counting sperm penetration holes in the IPVL. Data were collected for fertility, hatchability, and time that embryos died for each of the pens. Dam and sire affected IPVL penetration independently. A dam by sire interaction influenced fertility, whereas hatchability was affected only by dam. Thus, it is concluded that selection of dam and sires for commercial breeders alters IPVL sperm penetration ability of hens as well as egg-binding ability of sires.     

Recovery of fertility in quinestrol‐treated or diethylstilbestrol‐treated mice: Implications for rodent management

Fertility control is an alternative strategy to traditional culling for the management of rodent pests. Previous studies have demonstrated that quinestrol is a potential contraceptive for male rodents, but the recovery of fertility in quinestrol‐treated rodents has not been evaluated. This study used C57BL/6J mice to evaluate the recovery rate of male fertility after the administration of quinestrol. Diethylstilbestrol (DES), a non‐steroid estrogenic compound, was used for comparison. Different groups of mice were treated with 1 mg/kg quinestrol, 1 mg/kg DES, or castor oil separately for 7 days. These mice were then killed on days 8, 22 and 50 respectively. Our results indicated that the weight of epididymides and seminal vesicles decreased significantly on days 8 and 22 in quinestrol/DES‐treated mice, with extensive histological changes in the seminiferous tubules. Sperm concentrations in the cauda epididymal fluid were significantly reduced on days 8 and 22 in both quinestrol and DES treatment groups and on day 50 for the DES, but not the quinestrol group. Further analysis revealed that DES‐treated mice exhibited a higher proportion of abnormal sperm accumulation in the epididymis, indicating that the normal sperm transportation to the cauda epididymis was blocked. Our results indicate that the anti‐fertility effects on male mice given quinestrol were of shorter duration than for those receiving DES at the dose of 1 mg/kg body weight.     

Effect on fertility of low numbers of fowl spermatozoa inseminated in aqueous diluent or semen components of the fowl and turkey

A study was undertaken to compare the effect on fertility in the fowl of aqueous medium, natural homologous seminal plasma, heterologous turkey seminal plasma and whole turkey semen when whole fowl semen was excessively diluted with these media and inseminated fresh. High dilution with fowl seminal plasma resulted in the best fertility. Dilution with the turkey semen components produced fertility no different from that with aqueous diluent when the dose of spermatozoa was 5 X 5 or 10 X 10(6). The results of this study confirm that 5 X 5 to 10 X 10(6) good quality spermatozoa are sufficient to produce acceptable fertility in weekly inseminations of fresh semen. This enables good quality semen to be highly diluted. However, at high dilution rates there is a need to reconsider the composition of semen diluents, with respect to simulating as yet unknown properties provided by factor(s) in homologous ductus deferens seminal plasma.     

Musculo-skeletal lesions in adult male broiler breeder fowls and their relationships with body weight and fertility at 60 weeks of age

1. Males from three broiler breeder experiments were examined to determine the incidence of musculo-skeletal lesions (destructive cartilage loss, dyschondroplasia and its sequelae, ruptured tendons and ligaments) in birds culled for low fertility and in males surviving to the end of the breeding period. Relationships with body weight and fertility were studied. 2. The incidence of musculo-skeletal lesions in males culled for low fertility was high. 3. In two experiments, high body weights at termination of the breeding period were associated with a raised incidence of musculo-skeletal lesions and lowered fertility. 4. The results support the hypothesis that lack of control of male body weight gain per se is an important cause of declining fertility with age in broiler breeder flocks. There was no evidence that males were obese.     

Effects of the age of male and female broiler breeders on sexual behaviour, fertility and hatchability of eggs

1. The effects of the age of male and female broiler breeders on fertility, hatchability and sexual behaviour were determined in two 2x2 factorial experiments. In the 1st, male and female birds 27 to 29 and 35 to 37 weeks and in the 2nd at 35 to 37 and 55 to 57 weeks of age were compared. 2. Fertility was not affected by the age of the males or females. 3. Early embryo deaths were higher and hatchability of fertile eggs was lower in eggs from females aged 27 to 29 and 55 to 57 weeks compared with eggs from birds aged 35 to 37 weeks. 4. There were no differences in male display behaviours at any age. The number of observed matings were higher in young males 27 to 29 weeks old compared with males 35 to 37 and 55 to 57 weeks of age. There were no detectable differences in the responses of the females to the males at different ages. 5. Plasma testosterone concentration in males increased from 24 to 30 weeks of age and was relatively constant from 36 to 60 weeks. Plasma oestrogen in females was high at 24 and lowest at 30 weeks of age after which it increased. 6. The results suggest that there may be little difference in the fertility of male and female broiler breeders at different ages when body weight is adequately controlled to at least 60 weeks of age.     

Fertility of deep frozen boar spermatozoa at various intervals between insemination and induced ovulation: influence of boars and thawing diluents.

The fertilizing ability of deep frozen boar spermatozoa was assessed after artificial insemination at various intervals after human chorionic gonadotropin (HCG) induced ovulation in gilts. Boar seminal plasma and OLEP were used as thawing diluent agents. The fertilization rates were similar when insemination was performed 2 or 6 hours before the time of estimated ovulation (40 hours post-HCG administration). However, fertility rates markedly declined when insemination was performed earlier than 6 hours before expected ovulation. In inseminations performed 2 hours before ovulation, the fertility rate was higher with specimens treated with boar seminal plasma diluent than with OLEP. As the difference between the time of insemination and that of ovulation increased, the difference in fertilizing ability of spermatozoa from the 2 boars used also increased. The results show that spermatozoa which have a low resistance to freezing-thawing also have a diminished fertile life in the female genital tract.     

The effects of heat stress and sperm quality classification on broiler breeder male fertility and semen ion concentrations

1. The present study was undertaken to determine the effects of heat exposure on fertility, semen quality, and semen ion concentrations of broiler breeders classified on sperm quality index (SQI) before heat stress. 2. Cobb males (108) were individually caged in 6 temperature-controlled rooms. Each room contained an equal number of males from each of the 4 SQI population quartiles as follows: best (B), good (G), fair (F), and poor (P). Three rooms were heated to 35 degrees C, and the other three rooms were maintained at a constant 23 degrees C as controls. For each SQI group in each room, 15 Leghorn hens were artificially inseminated (5 x 10(7) sperm/hen) once a week for 8 weeks for fertility observations. 3. Body weight, sperm concentration, SQI, and fertility of P males were lower than in the other three SQI groups. Body temperature of the top three SQI groups was increased by heat exposure, but body temperature was not altered by heat stress in the P group. Fertility, sperm viability, and SQI of the top three SQI groups, but not the P group, was decreased by heat stress. Seminal plasma K+ of P males was lower than that of B males. However, seminal plasma Ca2+ concentration of P males was higher than that of B males. 4. In conclusion, high ambient temperatures had more impact on semen quality and fertility of males in the top 75% of the SQI population than in males in the bottom 25% of the population. In addition, calcium ions (Ca2+) appear to play a major role in heat stress infertility.     

Determination of cytogenetic markers for biological monitoring in coypu (Myocastor coypu)

Cytogenetic tests are used to assess the influence of physical and chemical factors with potential mutagenic and genotoxic properties on the animal organism. The test results make it possible to eliminate mutagens, as well as helping predict possible genetic consequences in animal cells and assess animal resistance. The aim of this study was to examine, using cytogenetic tests, the spontaneous chromosome and DNA damage in coypu lymphocytes. Four tests: fragile site (FS), bleomycin (BLM), micronucleus, (MN) and comet were used for the first time in coypu cells. The averages with standard deviations obtained in the research were as follows: 3.30 ± 0.80 fragile sites/cell; 0.63 ± 0.80 BLM damage/cell; 6.10 ± 0.53% binucleated cells with MN; and 3.24 ± 0.63% DNA in tail. The present analysis showed high interindividual variation in spontaneous chromosomal and DNA damage levels. In the case of micronucleus, fragile sites, and comet assays, the differences between animals were statistically significant. The data suggest that these assays are sensitive enough to detect some effects on an individual animal and can be proposed as tools for coypu biomonitoring.     

Influence of the Donor Male on the Fertility of Frozen-Thawed Rabbit Sperm after Artificial Insemination of Females of Different Genotypes

In this work, the influence of the donor male on the fertility of cryopreserved rabbit sperm after artificial insemination into females from different genotypes was evaluated. Females belonged to three lines selected for maternal characteristics (A, V and H) and all the possible crosses between them. Sperm from five males from the line selected for one of the maternal characteristics (line V) was frozen individually in a Tris-citric acid-glucose diluent with 1.75 m of DMSO and 0.05 m of sucrose (final concentrations). After artificial insemination of the cryopreserved sperm, fertility rates and prolificacy were similar for all groups of females (56% of fertility rate and 7.2 total born). Significant differences between males were observed for both fertility (p < 0.05) and kindling (p < 0.01) rate. These differences could be because of differences in the freezing resistance of sperm from the different males.     

Influence of boars on the relationship between fertility and post thawing sperm quality of deep frozen boar spermatozoa.

The possibility of selecting boars for deep freezing of spermatozoa was evaluated by tests of frozen-thawed spermatozoa. 20 of 31 ejaculates were used for artificial insemination of 37 gilts. Boar seminal plasma and OLEP were used as thawing diluents. The thermoresistance test and the extracellular concentration of aspartate aminotransferase (ASAT) were used as indicators of fertility. Spermatozoa from 4 boars were utilized. 1 of the boars appeared to be of superior fertility, while the spermatozoa from another was infertile. The latter animal had been used for fresh artificial insemination trials, and had shown higher pregnancy rates than the average. Samples from this boar exhibited the lowest degree of motility after 3 hours storage at 37 degrees C, the greatest relative decrease of motility during the thermoresistance test, the greatest release of ASAT after thawing by OLEP, and greatest relative release of ASAT. These variations were statistically significant (p less than .05). The results show that there is a possibility of detecting boars with spermatozoa with potential low freezability.     

In vitro assessment of semen for the prediction of fertility

The prediction of fertility is a primary goal in the field of reproductive medicine. The aim of the present paper is to describe the value of conventional and modern sperm analysis systems considering the process of fertilization. The classical assessment of motility and morphology enables the rough estimation of semen quality in order to select ejaculates for the use in artificial insemination. Recent methods for sperm diagnosis, such as fluorescent marking for the detection of sperm plasma membrane integrity, the hypoosmotic swelling test, and computer assisted semen analysis allow for the evaluation of a large number of spermatozoa and the assessment of sperm dynamics under in vitro-fertilization conditions. The oocyte penetration test investigates the ability of spermatozoa for capacitation, hyperactivation and acrosome reaction in vitro. The amount of specific seminal plasma proteins is related to fertility and thereby provides an additional semen evaluation method. For the use of a given semen test the specific in vitro condition has to be considered. In addition, the evaluated criteria relevant for the process of fertilization need to be defined. The combination of selected semen tests gives a higher accuracy for the prediction of fertilizing capacity compared with a single test.     

Successful Treatment of Seminal Vesiculitis with Imipenem-Cilastatin in a Stallion

A 7-year-old thoroughbred stallion presented with severe colic, which was resolved surgically. On postsurgical palpation and rectal ultrasonography, the left seminal vesicle was enlarged, the left testicle and epididymis showed signs of inflammation with hydrocele. Antibiotics and anti-inflammatory treatment were administered. Fever and colic syndrome recurred, with severe inflammation of the left testis and epididymis, and unilateral orchiectomy was performed. Histopathological diagnosis confirmed chronic orchioepididymitis, and Klebsiella pneumoniae was identified and typed from all cultures. At breeding soundness examination 2 months after treatment with ceftiofur, K. pneumoniae was again isolated, and cytology revealed degenerated polymorphonuclear cells and red blood cells. Transurethral endoscopic examination was used to locate the infection in the left seminal vesicle, and ticarcillin-clavulanic was locally infused for 10 days. Nevertheless, the pathogen was once again isolated in the ejaculate, and the affected seminal vesicle was again treated locally for 5 consecutive days, using imipenem-cilastatin, a new antibiotic showing high sensitivity. Follow-up breeding soundness examination revealed an improvement in seminal characteristics and no pathogen isolation. Total pregnancy rate (31 of 36; 86%) and first cycle pregnancy rate (18 of 36; 50%) in the last breeding season reached levels similar to those prior to infection (65 of 82; 80% and 47 of 82; 57% respectively), suggesting that local treatment with imipenem-cilastatin in stallions with seminal vesicle infections is effective and, in this case, did not produce any adhesions or other undesirable effects, permitting the stallion to resume breeding with no apparent deleterious effect on fertility despite having only one testicle.     

Influence of Seminal Plasma Antioxidants and Osteopontin on Fertility of the Arabian Horse

This study was designed to investigate enzymatic antioxidants’ activity and nonenzymatic antioxidants’ levels in seminal plasma of stallions and to relate them with season, age, and fertility of stallions. Fifty ejaculates were collected from six healthy Arabian stallions, 4-22 years old. Ejaculates were evaluated by conventional methods. Five milliliters of each semen sample was centrifuged, and the supernatant seminal plasma was stored at −20°C. Five antioxidants, in addition to osteopontin (OPN) and testosterone, were determined in stallion seminal plasma by using commercial enzyme-linked immunosorbent assay kits. Results revealed that uric acid, ascorbic acid, OPN, and testosterone concentrations and glutathione peroxidase (GPx) activity in stallions’ seminal plasma were high (P < .05) during spring. GPx activity was higher (P < .05) in age group B (11-18 years old) than in age group A (4-10 years old). The effect of stallions’ age on GPx activity in the fertility groups was highly significant (P < .01). OPN concentration was highest (P < .05) in age group A. Uric acid and OPN concentrations and GPx activity in stallions’ seminal plasma and percent of sperm motility were higher (P < .05) in fertility group III (>70%) than in fertility group I (<50%). However, ascorbic acid concentration, catalase activity and percentage of sperm abnormalities were lower (P < .05) in fertility group III than in fertility group I. It was concluded that season and stallion age may affect antioxidant defense systems in stallions’ seminal plasma. The impairment of seminal antioxidants and OPN could lead to low fertility.     

Exploring the metabolome of seminal plasma in two different horse types: Light versus draft stallions

The application of the ‘omics’ studies in the field of animal reproduction has been aimed at identifying novel biomarkers of fertility since the last few years. When assessing reproductive efficiency in horses, breed should also be taken into account as it can influence semen quality and fertility. Considering the growing interest in metabolomic analysis to evaluate male fertility, we aimed to investigate the metabolomic profile of seminal plasma in two different horse breeds. Twelve healthy stallions, n.6 American Quarter Horse (AQH) and n.6 Italian Draft Horse (IDH) stallions, regularly used for artificial insemination, were included in the study. Two semen collections, performed 30-day apart, were considered for the assessment of semen parameters including gel-free volume, spermatozoa (spz) concentration, spz progressive motility and seminal plasma analysis by ¹H-NMR.Semen characteristics differed between IDH and AQH (p < .05) as well as the first cycle conception rate that was higher in AQH than IDH (p = .001). Metabolomic analysis quantified 56 molecules in equine seminal plasma, with 11 metabolites showing different concentrations in IDH compared to AQH (p < .05).This study provided evidence of differences in seminal plasma metabolites' concentrations between studied horse types, highlighting specific metabolomic fingerprints characterizing AQH and IDH sperm.