Individual and seasonal variations in the quality of fractionated boar ejaculates.

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.

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Application of two staining methods for sperm morphometric evaluation in domestic pigs

The aim of this study was to compare ejaculates of Duroc and Pietrain boars in terms of sperm morphology characteristics. Analysis was performed on 116 ejaculates collected from 6 Duroc boars and 9 Pietrain boars. The boars selected for examination were young and at the beginning of their reproductive utilization. Ejaculates were collected at monthly intervals over the period of 10 months. Microscopic slides were prepared immediately after collection of ejaculates. The slides were examined to assess the frequency of morphological abnormalities. Moreover, morphometric measurements were taken from 15 randomly selected morphologically normal spermatozoa. Also, conventional evaluation of ejaculates was made following methods used at Polish sow insemination centres. Differences were found in the dimensions and shape between Duroc and Pietrain spermatozoa. Pietrain spermatozoa were characterised by significantly smaller head perimeter compared with Duroc (P ≤ 0.01). Moreover, Pietrain spermatozoa tails were by 0.8 μm longer (P ≤ 0.01), and their total sperm length was greater by 0.5 μm compared to Duroc (P ≤ 0.05) sperm. The volume of Duroc ejaculates was lower but their sperm concentration was greater. The results of the present study contribute to scientific progress as they demonstrate differences in sperm size between boars of different breeds, which may be reflected in different reproductive performances of the boars. Pigs, purebreed, ejaculate, morphometry

https://actavet.vfu.cz/media/pdf/avb_2012081020195.pdf

Comparative analysis of Duroc and Pietrain boar sperm morphology

 The study was performed on 4 609 ejaculates obtained from 32 boars, including 14 purebred and 18 two-breed crosses The ejaculates were collected manually every 4–5 days The study involved ejaculates collected from each boar from the first day of its insemination use until the day of semen depletion Each ejaculate was assessed for the following physical parameters: ejaculate volume, sperm concentration, percentage of spermatozoa with correct motility, total sperm count per ejaculate and number of insemination doses obtained from one ejaculate The effect of heterosis was calculated on the physical parameters of the boar crosses ejaculates in relation to the mean value of a given parameter for the parent breeds Positive and well pronounced heterosis effects were identified in the majority of the physical ejaculate parameters of the cross boars for all the cross-breeding variants A negative effect of heterosis was only identified in the ejaculate sperm concentration of the Hampshire × Pietrain crosses The highest ejaculatory efficiency was identified in the hybrids produced on the basis of the Hampshire breed These breeders were also found to feature significant heterosis effects on ejaculate volume, total ejaculate sperm count and number of insemination doses prepared from one ejaculate

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Assessment of the effect of heterosis on semen parameters of two-breed crosses of Duroc, Hampshire and Pietrain boars

The objective of this study was to evaluate the effects of season, natural photoperiod, and room temperature at the housing facility on boar semen characteristics in Uruguay (34o66'S; 56o29'W). For this purpose, 117 ejaculates, obtained from eight adult males collected through 12 consecutive months, were assessed for sperm viability, DNA integrity, abnormalities (total, primary, and secondary), ejaculate volume, and sperm concentration. Viability, total and primary abnormalities, volume, and sperm concentration were affected by season. Sperm viability, volume, and sperm concentration were affected by natural photoperiod. In general, autumn and the decreasing photoperiod had a negative impact on most of the semen characteristics, except for volume. Housing temperature did not affect semen characteristics. In boars living in temperate climates, semen quality is negatively affected during autumn and is related to photoperiod changes; however, the effects of temperature changes in housingdo not affect these seminal characteristics. In this scenario, seasonal differences in semen quality may have a negative effect on sow fertilization. Consequently, semen quality control especially during autumn is imperative for the best boar selection to be used for insemination purposes. Seasonal differences in semen quality may have a negative effect on sow reproductive performance. This issue will be addressed in a future investigation.

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Seasonal variation in sperm characteristics of boars in southern Uruguay

The experimental material consisted of 12,285 ejaculates obtained from 93 boars, including 18 Duroc boars, 30 Pietrain boars, 24 ♀Duroc x ♂Pietrain crossbreds and 21 ♀Pietrain x ♂Duroc crossbreds. The boars were utilised for at least 6 months and qualified for insemination from January 1, 1992 to December 31, 2007. Each ejaculate was assessed using standard methods for the following physical traits: volume, sperm concentration, spermatozoon motility, total number of spermatozoa, and number of insemination doses per ejaculate. The data obtained were classified into 12 sub-groups consisting of ejaculates collected in successive months. Ejaculates collected in the summer months had less spermatozoa than in the autumn and winter period. Ejaculates collected in the summer (mainly in July) yielded the least amount of insemination doses. Ejaculates of both types of crossbreds were characterised by greater spermatozoon motility compared with purebred boars, irrespective of the month of ejaculate collection.

Effect of seasonal factors on the ejaculate properties of crossbred duroc x pietrain and pietrain x duroc boars as well as purebred duroc and pietrain boars

The study was carried out on 1913 ejaculates collected from 51 Landrace boars. The ejaculates were collected manually. The study included all ejaculates collected by one artificial insemination station over a span of 12 consecutive months. The ejaculates were subjected to the standard analysis which involved: ejaculate volume, sperm concentration, percentage of progressive motility spermatozoa, total number of spermatozoa, and number of artificial insemination doses per ejaculate. Temperature, relative air humidity, and atmospheric pressure in the piggery were monitored during the semen collections. The resulting data were grouped by air temperature, humidity and pressure, and analyzed. It has been found that the microclimate in the place of semen collection may affect the quality of the collected semen. This effect is varied; temperature, humidity and atmospheric pressure act differently in relation to the semen traits. Temperature and atmospheric pressure have an effect on sperm concentration. Ejaculates with the highest sperm concentrations were collected at the lowest measured temperatures (10°C and lower) as well as with the lowest relative air humidity. Sperm motility revealed a strict and oriented relationship with both temperature and humidity, but also with atmospheric pressure. Semen collected at the lowest air humidity (50% and lower) and at the lowest observed atmospheric pressure (below 900 hPa) contained the most sperm. The highest number of artificial insemination doses are produced from ejaculates collected in such conditions.

D. Kowalewski

Papers

Effect of seasonal factors on the ejaculate properties of crossbred duroc x pietrain and pietrain x duroc boars as well as purebred duroc and pietrain boars

Effect of piggery microclimate on ejaculate performance of artificial insemination boars.

Jakość nasienia knurów ras wbp, pbz, duroc i pietrain w poszczególnych miesiącach roku