Polish Landrace Boars Research Articles

Long non-coding RNA variability in porcine skeletal muscle.

Recently, numerous studies including various tissues have been carried out on long non-coding RNAs (lncRNAs), but still, its variability has not yet been fully understood. In this study, we characterised the inter-individual variability of lncRNAs in pigs, in the context of number, length and expression. Transcriptomes collected from muscle tissue belonging to six Polish Landrace boars (PL1-PL6), including half-brothers (PL1-PL3), were investigated using bioinformatics (lncRNA identification and functional analysis) and statistical (lncRNA variability) methods. The number of lncRNA ranged from 1289 to 3500 per animal, and the total number of common lncRNAs among all boars was 232. The number, length and expression of lncRNAs significantly varied between individuals, and no consistent pattern has been found between pairs of half-brothers. In detail, PL5 exhibits lower expression than the others, while PL4 has significantly higher expression than PL2-PL3 and PL5-PL6. Noteworthy, comparing the inter-individual variability of lncRNA and mRNA expression, they exhibited concordant patterns. The enrichment analysis for common lncRNA target genes determined a variety of biological processes that play fundamental roles in cell biology, and they were mostly related to whole-body homeostasis maintenance, energy and protein synthesis as well as dynamics of multiple nucleoprotein complexes. The high variability of lncRNA landscape in the porcine genome has been revealed in this study. The inter-individual differences have been found in the context of three aspects: the number, length and expression of lncRNAs, which contribute to a better understanding of its complex nature.

Dependence of the frequency of sperm defects and dimensions on sperm motility in ejaculates of Polish Landrace boars

An attempt was made to determine the dependence of the frequency of sperm defects and dimensions on sperm motility in ejaculates of Polish Landrace boars. The study was conducted on 393 ejaculates collected from 33 Polish Landrace boars. Ejaculates were grouped according to the percentage of sperm with progressive motility, distinguishing ejaculates in which the percentage of motile sperm was 70% and 80%. In each ejaculate, the frequency of morphological changes in the sperm was determined and morphometric measurements of the sperm were made. Ejaculates with a higher proportion of sperm with progressive motility were found to contain more sperm. The ejaculate volume and sperm concentration in the ejaculate were not found to be directly associated with sperm motility. The frequency of primary defects was linked to sperm motility. Ejaculates with higher sperm motility contained fewer sperm with primary defects. The frequency of minor morphological changes, however, shows no significant dependence on sperm motility in the ejaculate. The primary morphological sperm defects most often found in ejaculates are a proximal droplet and the Dag defect. Both of these morphological forms are more common in ejaculates with lower sperm motility. The most common secondary sperm defects include sperm with a simple bent tail, sperm with a free normal head, and sperm with a distal droplet. These defects were not found to depend on sperm motility in the ejaculate. Sperm cells in ejaculates with greater sperm motility had slightly larger dimensions than sperm in ejaculates with lower sperm motility. Ejaculates with higher sperm motility are preferable for use in practice, not only because more insemination portions can be prepared from them, but also due to the lower frequency of primary defects.

Dependence of physical characteristics of ejaculate of Polish Landrace boars on the time interval between successive ejaculate collections

The aim of the research was to determine the dependence of physical properties of boar ejaculates on the time interval between successive ejaculate collections. The material for the study comprised 1954 ejaculates collected manually from boars used for artificial insemination. For all ejaculates, the ejaculate volume, sperm concentration, percentage of motile spermatozoa, and number of spermatozoa in the ejaculate were determined, and the number of insemination doses per ejaculate was calculated. The boars’ suitability for artificial insemination was evaluated taking into account the effect of the time passed between ejaculate collections. The ejaculate volume and the concentration and number of sperm in the ejaculate were shown to increase with the time elapsed since the previous ejaculate. The number of insemination doses obtained per ejaculate increased as well. Ejaculates with a high sperm count were obtained when the ejaculation frequency was no more than every 4 days. The percentage of spermatozoa with progressive motility increased with the time elapsed since the collection of the previous ejaculate, but only up to 4 days. Further decreases in ejaculation frequency no longer resulted in increased sperm motility.

Effect of boar ejaculate fraction, extender type and time of storage on quality of spermatozoa.

The aim of this study was to investigate the effect the sperm-rich fraction (F1) and the post-F1 fraction (F2) on the quality of boar spermatozoa stored in a liquid state. Ejaculates were collected from three Polish Landrace boars. Each ejaculate fraction was diluted with BTS short-term extender and Safe-Cell Plus (SCP) long-term extender and stored for seven days (D1-D7) at 17°C. Analyses included sperm motility parameters, normal apical ridge (NAR) acrosomes and plasma membrane integrity (PMI). Prior to the dilution of fractions, marked changes (p<0.05) were noted between F1 and F2 in progressive motility (PMOT), velocity average pathway (VAP) and velocity straight line (VCL). After the ejaculate was diluted, the type of fraction and type of extender significantly affected (p<0.05) PMOT, being markedly higher (p<0.05) for F1 extended in BTS. No marked changes (p<0.05) were observed between F1 and F2 extended in SCP for any of the analyzed sperm quality parameters during seven days of storage. Significantly higher (p<0.05) values of sperm quality parameters were noted in F1 compared with F2 for BTS on D7 of storage. The results of the four-way ANOVA analysis indicate that boar, fraction of ejaculate, extender type and day of storage had significant effects on the quality of boar stored spermatozoa. The F1 was characterised by higher quality of spermatozoa during storage in comparison with F2 in the short-term extender. Using the long-term extender containing the proteins allowed for a better application of F2, which could be important for the pig industry.

Cechy fizyczne ejakulatu knur�w inseminacyjnych w zaleznosci od uplywu czasu miedzy pobraniami kolejnymi ejakulat�w

The ejaculate characteristics of Polish Landrace boars showed a significant correlation with the intervals between the successive ejaculate collections. The effect of insemination use intensity was however varied. Rising frequency of ejaculate collection led to a systematic and fairly even fall in ejaculate volume. Ejaculate sperm concentration remained at a relatively high level when ejaculates were collected with a frequency of 7 to 3 days but further shortening of the interval between the successive collections led to a drastic decrease in sperm concentration. An increase in ejaculate collection frequency to every four and fewer days resulted in a significant decrease in the number of spermatozoa present in the produced ejaculates and a concomitant decrease in the number of insemination doses prepared from these ejaculates, with an escalation of such changes.

Boar sperm quality in relation to presence of sp32-like protein in spermatozoa - preliminary studies

Abstract The aim of the study was to analyse sperm proteomes of ejaculates from Polish Large White (PLW) and Polish Landrace (PL) boars and to identify differences which putatively influence semen quality. Spermatozoa protein profiles were analysed by electrophoretic methods followed by selected techniques to evaluate semen quality on the following factors: sperm motility, lipid peroxidation levels (MDA production), ATP content, activities of superoxide dismutase (SOD) and catalase (CAT), total antioxidant status (TAS), and total oxidant status (TOS) of seminal plasma. A protein with an estimated molecular weight of 30 kDa was found in spermatozoa of selected ejaculates. Mass spectrometry demonstrated that this polypeptide is most similar to proacrosin binding protein (sp32). The presence of the protein was more frequently observed in sperm extracts obtained in spring-summer period. Ejaculates containing sp32-like protein demonstrated significantly higher spermatozoa motility, lower inhibition of MDA production by seminal plasma, and higher SOD activity in seminal plasma. Boar semen which included sp32-like protein also demonstrated lower ATP levels in spermatozoa as well as higher TAS and lower TOS of seminal plasma, though the differences were not statistically significant. Ejaculates from PLW boars, with sp32-like protein present in sperm, were characterised by significantly higher sperm motility, lower ATP content in spermatozoa, and higher TAS of seminal plasma. The diminished parameters of semen quality were observed in ejaculates from PL boars that also contained the discussed protein, but the differences were not statistically significant. These findings suggest that the presence of sp32-like protein in boar spermatozoa could influence semen quality

Storage temperature of boar semen and its relationship to changes in sperm plasma membrane integrity, mitochondrial membrane potential, and oxidoreductive capability

The aim of this study was to analyze changes in sperm plasma membrane integrity, mitochondrial activity, and extracellular environment during storage of boar semen at 5 °C, 16 °C, and 25 °C for 10 days. Progressive sperm motility, plasma membrane integrity (SYBR-14/PI-test and HOS test), aspartate aminotransferase (AAT), and mitochondrial activity (JC-1-test and NADH-dependent NBT assay), as well as pH and osmolality were assessed in nine ejaculates of Polish Landrace boars. The plasma membrane integrity of the semen stored at 5 °C was similar to that of the semen stored at 16 °C and 25 °C; however, an increase in AAT activity of the semen stored at 5 °C revealed sperm membrane disorders as early as day 2. Significant differences in the progressive motility of the semen stored at 5 °C and 16 °C were observed at each of the evaluation times. This reduced motility was consistent with decreased sperm mitochondrial transmembrane potential and oxidoreductive capability. We inferred that the cooling of boar semen to 5 °C increases the permeability of the sperm plasma membrane, which may not be revealed by SYBR-14/PI staining or HOS testing. The loss of boar sperm motility that occurs during hypothermic liquid preservation may be connected with alterations in the plasma membrane stability and disorders of mitochondrial transmembrane potential and oxidoreductive capability.

WPŁYW SEZONU URODZENIA I SEZONU EKSPLOATACJI ROZPŁODOWEJ KNURÓW RASY POLSKA BIAŁA ZWISŁOUCHA NA WYNIKI ROZRODU

The effectiveness of breeding boars in insemination depends mainly on the skill of optimal use of their reproductive potential. Nevertheless, their semen is highly variable in its quality and physical characteristics, which makes it difficult to organise semen production for artificial insemination purposes. The present study contains an analysis of semen collected from Polish Landrace breed boars - the most popular pigs bred in Poland. It demonstrates that there is a statistically significant interaction between season of birth and reproductive season of Polish Landrace boars. What is more, it proves that these significant differences between reproductive performances of boars are closely connected to their breeding season and seasons of their birth and life. The results also illustrate how to improve organisation of insemination centres and make them better financially efficient.

Correlation of frequency of spermatozoa morphological alterations with sperm concentration in ejaculates of Polish Landrace boars

The experiments were performed on 448 ejaculates obtained from 41 Polish Landrace boars. Ejaculates collected from each boar at one-month intervals for approximately 10 months were analysed. Sperm morphometric measurements were taken from each boar and assessment of semen morphology was done on the basis of examination under a microscope of preparations made from fresh ejaculates. The ejaculates were classified based on the criterion of sperm concentration and divided into three groups. An attempt was made in the present study to assess the correlation of ejaculate parameters, morphological sperm alteration incidence and morphometric sperm parameters with the sperm concentration in ejaculates of Polish Landrace boars. It should be stated that morphometric traits of spermatozoa are related to sperm concentration. The spermatozoa in concentrated ejaculates had smaller heads than the spermatozoa in the ejaculates with lower sperm concentrations. This can mean that the high fertility of males that produce highly concentrated semen does not only result from a high sperm concentration, but also from the fact that the spermatozoa in such ejaculates have smaller heads. The highest frequency of morphologically well-formed spermatozoa was identified in ejaculates with the sperm concentration ranging from 400 to 500 thousand/mm3.

Effect of oxytocin treatment on the reproductive performance of sows after artificial insemination with liquid semen

This study was designed to evaluate the effect of oxytocin treatment at the time of insemination on fertility and prolificacy of sows during the summer season (July and September). The study included 107 Polish Large White × Polish Landrace sows divided into 3 groups: C, control (without oxytocin); I, experimental (5 IU oxytocin administrated intramuscularly per sow, 2 min before insemination); and II, experimental (5 IU of oxytocin added into a 100-mL seminal dose, at the time of insemination). Semen was collected from 11 boars: 2 Polish Large White, 5 Polish Landrace, and 4 Duroc × Pietrain. The highest farrowing rate was obtained in group II at 94.4%. Compared with groups C at 63.9% and I at 71.43%, the demonstrated differences were statistically significant (P ≤ 0.01). The interaction between oxytocin and the breed of boar was also demonstrated. The highest significant differences were observed for Polish Landrace boars semen from group II compared with that of group C (P =

Concentrations of oestrogens in blood plasma and seminal plasma of boars during the postpuberal period

Concentrations of oestrogens in the blood plasma and seminal plasma of mature boars are high. However, little is known about their concentrations after reaching sexual maturity. The aim of this study was to determine the concentration of oestrogens in blood plasma and seminal plasma of boars during the postpuberal period. Free and conjugated oestrone and oestradiol-17beta were determined by radioimmunoassay in blood from the testicular vein and artery, and peripheral circulation as well as in seminal plasma collected from 18 Polish Landrace boars. The animals were divided into three groups (n = 6) according to age (8, 12 and 16 months, respectively). Oestrone was predominant free and conjugated oestrogen. The highest values of oestrogens were measured in the testicular vein (p < or = 0.05). The concentrations of oestrogens in seminal plasma did not differ from those found in the peripheral circulation. An age-dependent increase in levels of all four oestrogens (p < or = 0.05) was observed. This can be associated with biochemical maturation of the reproductive system during the postpuberal period.

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.

A note on associations between polymorphism within the 2,4-dienoyl-CoA reductase gene (&lt;i&gt;DECR1&lt;/i&gt;) and growth rate of Polish Landrace boars

The V54L missense mutation within the DECR1 gene, which encodes a mitochondrial 2,4- dienoylCoA reductase, was investigated to determine whether this polymorphism is associated with growth rate (daily gains), meat content and selection index in Polish Landrace boars kept under uniform feeding and environmental conditions (one herd). The genotype of 334 boars was determined by PCRRFLP, identifying 112, 162, and 60 boars bearing genotypes CC, CG and GG, respectively. Statistical analysis was carried out by the General Linear Model (GLM) procedure, including fi xed effects of DECR1 genotype, sire, and birth season. Signifi cant differences (P<0.01) between boars with CC and GG genotypes were found. Boars with genotype CC showed the highest daily gains (860.7 g ± 46.3), in comparison with boars bearing the GG genotype (841.7 g ± 53.6). The current fi ndings support the hypothesis that DECR1 V54L polymorphism is a promising marker of growth rate in pigs.