The Usefulness of Sexual Behaviour Assessment at the Beginning of Service to Predict the Suitability of Boars for Artificial Insemination.

Parameters of sexual activity were determined in 49 young boars used for artificial insemination, four times at three-month intervals. The parameters included the time from entering the arena until mounting the phantom; the time from mounting the phantom until achieving erection; the time from achieving full erection until the start of ejaculation; duration of ejaculation; and the number of times the boar mounted the phantom. Characteristics of the ejaculates were also assessed. The libido parameter associated with the greatest efficacy of artificial insemination was the effectiveness of artificial insemination service, the time from entering the arena until the start of ejaculation. The significance of this trait for predicting ejaculation performance was analysed. The libido characteristics were classified into three categories: boars with a short reaction time to the phantom, boars with an intermediate reaction time, and boars with a long reaction time. For these groups, the characteristics of ejaculates collected at the start of the period during which ejaculates were collected and after three, six and nine months were determined. The sexual experience of boars was not associated with the expression of sexual behaviour because young boars during their first three months of ejaculate collections required less time to initiate ejaculation. The ejaculates with the greatest utility were obtained after six months of service. These ejaculates had the largest volume (255.22 mL), and the most insemination doses could be prepared from these ejaculates. On average, more than 23 insemination doses were prepared from ejaculates collected after six months of semen collections, which is about four doses more than from ejaculates collected at the start of artificial insemination service (p < 0.01).The time from entering the arena to beginning ejaculation can be used to predict a boar's future libido. A relationship was shown between the level of libido and ejaculate characteristics. The ejaculates of the boars which needed the longest time to begin ejaculation at the start of semen collections had the greatest sperm concentration and number. In group 3, the boars'ejaculates contained about 6-9 × 109 more sperm than the ejaculates of boars from group 1. After six months of the experimental period, the difference was nearly 15 × 109 sperm (p < 0.05), and after nine months, it exceeded 22 × 109 sperm (p < 0.01).

Effects of breed and ejaculate volume on sperm morphology and semen parameters of boars.

The aim of the study was to determine the relation between the semen quality, frequency of sperm defects, sperm dimensions and shape, and the ejaculate volume of Large White and Landrace boars. A total of 648 ejaculates collected from 31 Large White and 30 Landrace boars were divided into three groups according to the criterion of the ejaculate volume. In this study Landrace boars produced ejaculates with higher volume, sperm concentration, and total numbers of spermatozoa than Large White boars. Landrace boars also showed a lower frequency of sperm with morphological abnormalities (P < 0.05). Landrace boars sperm had larger heads, which were by 0.15 µm longer, and by a larger perimeter and area (P < 0.05). Landrace boar spermatozoa also had a longer flagellum and were generally larger and by 2.07 µm longer than Large White boar sperm (P < 0.05). Significant differences were also found in the shape of sperm of the two breeds (P < 0.05). Landrace boars sperm had more elongated heads, and the ratio of head size to flagellum length was lower than in Large White boars sperm (P < 0.05). Sperm from ejaculates with low volume had a shorter flagellum and a greater head length/flagellum length ratio than sperm from medium- and high-volume ejaculates (P < 0.05).

Gene promoter polymorphisms in boar spermatozoa differing in freezability.

Single nucleotide polymorphisms (SNPs) in the 5'-flanking regulatory regions of genes could affect their expression levels. This is a follow-up study aimed to identify polymorphic variants in the 5'-flanking regulatory regions of genes expressed in boar spermatozoa, and to predict the interactions of such variants with transcription factors (TFs) on the gene promoter activity, using bioinformatics. Five and six boars were classified as having good and poor semen freezability (GSF and PSF, respectively) according to post-thaw (PT) assessment of sperm motility and membrane integrity characteristics. The 5'-flanking region sequences of the 14 genes (FOS, NFATC3, EAF2, FGF-14, BAMBI, RAB33B, CKS2, LARS2, SLC25A16, ACADM, CPT2, CCT3, DTD2 and CCDC85A) were PCR amplified and analyzed by Sanger sequencing method. A total of 32 polymorphic variants were identified in the 5'-flanking regions of the genes, including 4 insertion/deletion (indel) polymorphisms, and 8 unknown (novel) SNPs. Multiple sequence alignment analysis revealed a 26-bp indel variant in the 5'-flanking region of the LARS2 gene, which showed greater protein expression in spermatozoa from boars of the PSF group. It was found that 17 polymorphic variants, observed in the differentially expressed (DE) genes, showed significant allele frequency differences between the GSF and PSF groups. Polymorphic variants in the 5'-flanking regulatory regions of the genes contributed to the decrease or increase in the binding affinity for different testis-specific TFs, such as SMAD1, NF-1, FOXMI, RXRA, STAT4 and C/EBPß. This study provides more insights into the mechanisms responsible for variations in transcriptional activity in promoters of genes expressed in boar spermatozoa. The allelic variants are promising genetic markers for predicting the freezability of boar spermatozoa.

Heterosis for morphometric characteristics of sperm cells from Duroc x Pietrain crossbred boars.

Morphometric studies of spermatozoa were conducted on 30 ejaculates collected from 15 boars represented by five Duroc boars, five Pietrain boars and five Duroc x Pietrain crossbred boars. Spermatozoa were stained using two methods: eosin-nigrosin and eosin-gentian. Values for morphometric measurements of sperm cells including head length, head width, head area, head perimeter, tail length and total sperm cell length were collected, and indices characterizing sperm cell morphological structure were calculated. The effects of heterosis on dimensions and shape of sperm cells from Duroc x Pietrain boars were evaluated. The effects of genetic effects on sperm head dimensions and shape were determined. Duroc x Pietrain crossbred boars produced spermatozoa with larger heads than purebred Duroc and Pietrain boars. The heads of sperm cells from crossbred boars were more rounded in shape, whereas sperm heads from purebred boars were more elongated. There were marked effects of heterosis on sperm head size and shape. Spermatozoa from Duroc boars also had larger and more rounded heads and longer tails than sperm cells from Pietrain boars. In addition, staining method affected the outcome from evaluation of heterosis on dimensions and shape of sperm cells. There were larger heterotic effects based on morphometric measurements of heads of spermatozoa stained using the eosin-nigrosin method than with use of the eosin-gentian dye technique.

Assessment of chosen semen characteristics of two colour morphs of the Arctic fox Alopex lagopus L.

The aim of the study was to evaluate semen quality in the two most popular colour morphs of the Arctic fox Alopex lagopus L., blue and white, based on ejaculate parameters, acrosin activity and analysis of sperm morphology. The research material consisted of ejaculates collected once by manual stimulation from 20 one-year-old male Arctic foxes (10 individuals of the blue morph and 10 of the white morph). Ejaculates were evaluated in terms of volume, sperm concentration, total number of spermatozoa and the percentage of spermatozoa with major and minor defects. The study revealed that male blue Arctic foxes produce ejaculates with much higher concentration (148.75 × 106 /ml) and total number of spermatozoa (98.16 × 106 ) compared to white Arctic foxes (42.88 × 106 /ml and 35.2 × 106 respectively). The level of acrosin activity from white foxes seemed to be higher compared to blue foxes but the difference was not statistically confirmed. Semen from Arctic foxes is characterized by high inter-individual variability in sperm morphology. The frequency of morphological changes in sperm from Arctic foxes does not significantly depend on ejaculate volume, sperm concentration or the total number of spermatozoa in the ejaculate, but is associated with acrosin activity.

Dependence of Sperm Morphology and Ejaculate Characteristics on Sperm Concentration in the Ejaculates of Hypor Boars.

INTRODUCTION: Determination of sperm concentration and morphology in ejaculate is essential in evaluating fertility. Sperm shape and dimensions may depend on their concentration in ejaculate. The aim of the study was to evaluate the dependence of Hypor boar morphological and morphometric sperm characteristics on concentration in ejaculate. MATERIAL AND METHODS: The study was conducted on 120 ejaculates from 12 Hypor boars. Depending on sperm concentration, they were put into three groups: low, medium, and high. Ejaculate sperm concentration was determined with the photometric method. Slides were prepared from semen samples which were evaluated for the morphology of spermatozoa. The preparations for morphological analyses were by the eosin-gentian staining method. RESULTS: As the sperm concentration in the ejaculate increased, the length, perimeter, and area of the sperm heads also did. In the ejaculates with higher sperm concentration the sperm heads were rounder. The ratios of head dimensions to tail length or total length were the highest in the sperm from ejaculates with the highest concentrations. The highest percentage of morphologically abnormal sperm was noted in ejaculates with low concentrations. CONCLUSION: The dimensions and shape of sperm depend on the sperm concentration in the ejaculate. In ejaculates with the highest concentrations, the sperm have larger dimensions. Sperm concentration affects the frequency of morphological anomalies in the spermatozoa.

Ejaculate Traits and Sperm Morphology Depending on Ejaculate Volume in Duroc Boars.

INTRODUCTION: The aim of this study was to evaluate the dependence between ejaculate traits, sperm morphology, and ejaculate volume in Duroc boars. MATERIAL AND METHODS: The analysis involved 121 ejaculates collected from 12 Duroc boars kept in three artificial insemination centres located in central Poland. Ejaculates were collected manually at one-month intervals, over a period of 10 months. At least 10 ejaculates were collected from each boar. The material was divided by ejaculate volume and each ejaculate was assigned to one of three volume groups: 160 mL and lower, 161-200 mL, and 201 mL and higher. The ejaculates were assessed to identify the basic physical traits and determine the incidence of morphological abnormalities in the spermatozoa, specifying major and minor abnormalities. Furthermore, the morphological structure indices for the spermatozoa were also calculated. RESULTS: In large-volume ejaculates, spermatozoa were more elongated in shape, their heads were more elongated and had the largest flagella. With an increase in the ejaculate volume, sperm concentration in the ejaculate decreased. Moreover, while the total number of sperm in the ejaculate increased, the number of insemination doses obtained from a single ejaculate were higher. CONCLUSION: The volume of ejaculate has little impact on the occurrence of morphological abnormalities and the size of sperm cells. Ejaculate volume is important for the shape of the sperm cells.

Application of Two Staining Methods for Sperm Morphometric Evaluation in Domestic Pigs.

INTRODUCTION: The effect of two smear staining methods on the dimensions and shape of sperm cells in the semen of domestic pigs was evaluated. MATERIAL AND METHODS: The studies were carried out on 30 ejaculates collected from 15 boars, which included five Duroc boars, five Pietrain boars, and five hybrid Duroc × Pietrain boars. Each ejaculate was next sampled to make two microscopic slides, of which one was stained with eosin-nigrosin and the other with eosin-gentian dye. In total, 600 measurements of sperm cells were made. Each sperm was measured for the following morphometric parameters: head length, head width, head area, head perimeter, tail length, and the total sperm length. RESULTS: Sperms measured on slides stained with eosin-nigrosin showed lower dimensions as compared with those stained with the eosin-gentian dye method. Sperm stained with eosin-nigrosin had shorter and narrower heads than sperm stained with eosin-gentian dye. The method of staining, therefore, affected not only the dimensions of the sperm, but also the proportions of the dimensions defining the shape of the sperm. CONCLUSIONS: The size and shape parameters in porcine sperm may take on different values depending on the method of semen staining. Sperm cells stained with eosin-nigrosin are smaller than the sperm stained with eosin-gentian dye. The sensitivity of the sperm to the type of dye used for the fixation may be associated with genetic factors.

The effect of sperm concentration in the ejaculate on morphological traits of bull spermatozoa.

Experiments were performed on 75 ejaculates obtained from 19 bulls representing different cattle breeds used at the Masovian Centre for Animal Breeding and Reproduction in Lowicz. Fresh ejaculates were measured in respect to their volume and sperm count in the ejaculates was determined. The ejaculates were classified based on the criterion of sperm concentration and divided into five groups. Sperm morphometric measurements were taken from each bull and assessment of semen morphology was done on the basis of examination under a microscope using preparations made from fresh ejaculates. For each slide, morphometric measurements were taken of 15 randomly selected spermatozoa characterised by normal morphology and well visible under the microscope. Additionally, in each preparation morphometry of 500 spermatozoa was evaluated, numbers of spermatozoa with normal morphology and morphological abnormalities were recorded and these were categorized into spermatozoa with major and minor defects. An insignificant correlation was observed between the sperm concentration in the ejaculate and morphological traits, dimensions and shapes of bull spermatozoa. The less concentrated ejaculates contained spermatozoa with a slightly larger head circumference and a more elongated head shape in comparison with the spermatozoa in the more concentrated ejaculates. The highest frequency of morphologically malformed spermatozoa, both in the case of primary and secondary alterations, was observed in ejaculates with sperm concentration of no more than 1000 x 10(3)/mm3.

An assessment of the breeding maturity of insemination boars based on ejaculate quality changes.

We examined the sexual development and insemination capability of boars representing five breeds used at Polish sow insemination stations. The speed of attaining full breeding maturity by the boars and their insemination usefulness was assessed based on the results of experiments analysing age-related changes in the physical characteristics of the ejaculates. Directly after sampling, the ejaculates were analysed for the following physical parameters: ejaculate volume, sperm concentration and the percentage of progressively motile spermatozoa per ejaculate. The total number of spermatozoa in the ejaculates and the number of insemination doses obtained from one ejaculate were calculated using SYSTEM SUL v. 6.1 software. The sexual development of boars continues during insemination use, leading to improved ejaculatory performance. The physical parameters of the ejaculate change along with the age of the boar. The Duroc and Hampshire boars represent a pattern of sexual development that is different from that of the PLW, PL and Pietrain males, with an evident earlier termination of growth. The American boars (Duroc and Hampshire) acquire top ejaculatory performance approximately 6 months earlier.

Morphometrical characteristics of spermatozoa in Polish Landrace boars with regard to the number of spermatozoa in an ejaculate.

Ejaculates (n=344) were collected from 35 Polish Landrace boars. The ejaculates were assigned to one of four groups according to the total number of spermatozoa in an ejaculate. Morphometrical measurements of spermatozoa with proper morphology were performed. Spermatozoa with smaller head length and head area were found in ejaculates with the greatest total sperm number (more than 120 x 10(9) spermatozoa) than in ejaculates with total number of spermatozoa of 70-90 x 10(9). The results of the present study suggest that the number of spermatozoa in an ejaculate influences morphometrical characteristics of the spermatozoa in Polish Landrace boars.

Evaluation of males spermiogram in domestic pigs.

A microscopic assessment was used to estimate sperm morphological structure in 405 ejaculates from 70 boars according to Blom classification. The classification of spermiogram quality according to a new 6-degree scale was also established. We found, that male spermiograms in domestic pigs were characterized by a large variability both between and within breeds. The estimation of semen quality, only with regard to the mean frequency of occurrence of particular morphological forms of spermatozoa, was not effective for evaluation of individual boar or group of boars. However, the method was effective to evaluate individual ejaculates. The quality classification of the spermiogram enabled to evaluate usefulness of ejaculates graded as good and average for insemination.

Sperm morphology of cattle and domestic pigs.

Sperm morphology was evaluated (using Blom classification) in 44 ejaculates of 11 bulls and 44 ejaculates of 11 boars. Significant differences in sperm morphology were found between bulls and boars. In addition, the correlations between frequency of morphological changes and morphometrical traits of boar spermatozoa were demonstrated. More morphological anomalies of spermatozoa were recorded in ejaculates containing longer spermatozoa.

The effect of age on the morphometric sperm traits of domestic pigs (Sus scrofa domestica).

The experiment was conducted using 20 male domestic pigs, which were in 2 (equal-sized) age groups: under 14 months old and over 18 months old. At least 5 ejaculates from each male were taken, and in each ejaculate, morphometric measurements of 50 spermatozoa were made. The measured parameters were head area, head length and width, and flagellum length. For each ejaculate, the basic physical traits and the frequency of occurrence of developmental anomalies of the spermatozoa were examined. It was found that sperm dimensions tended to increase along with the boars' age. Considerable and statistical differences in head area and flagellum length were proved. Spermatozoa collected from older boars (above 18 months of age) had a head area larger by 0.49 microm(2)(P< or = 0.01) and a flagellum longer by 0.67 microm (P< or =0.01) than spermatozoa collected from younger boars (under 14 months of age). The differences in head length and width between the spermatozoa of the tested boars were considerably smaller and were not statistically provable. Significant correlations between the head area of spermatozoa and the head length (r = 0.56, P< or =0.05) and head width (r = 0.36, P< or =0.05) were found. However, the head length was not significantly directly correlated with its width (r = 0.18, P< or =0.05), and flagellum length was negatively correlated with spermatozoan head width (r = -0.71, P< or =0.05). Slight correlations between the morphometric traits of the sperm and the physical traits of the ejaculates (r = -0.11 to 0.16) were found, although in most cases, the correlations were not statistically provable.