Comparative assessment of reproductive capacity of boar-sires dependingon the breed and season

Abstract

The article highlights the results of the reproductive capacity of different breeds of boar sires in the farms of east- ern, southern, and central regions of
Ukraine in dynamics over three years are given. It represented the influenceof the year's season on sperm quality by estimating the ejaculate volume,
concentration, and motility of sperm of boars-sires of the different breeds and their hybrids. Data were also calculated on the culling of ejaculates of boar
sires of various breeds for the years 2019–2021 in the dynamics. In a comparative aspect, the indicators were analyzed by the following genotypes: Large
White, Ukrainian Meat, Landrace, Duroc, Yorkshire, and syntheticline Makster. The reproductive capacity of boars was within the limits of the indicators
for the elite and first clas- ses. However, specific differences were observed between boars of different breeds, which were constant and took place during
the three studied years. The difference in the concentration of sperm in the ejaculates of the UkrainianMeat breed gradually decreased starting from
2019 and was the smallest in 2021. The highest ejaculate volumewas found in boars of the Ukrainian meat breed (310.9 ± 113.2 cm3
), and the sperm
concentration was the highest in boar sires of the Large White breed (215.7 ± 83.5 million/cm3
). On the other side, hybrids of the Large White breed had
low indicators compared to other groups of animals (Large White × Yorkshire – 184.2 ± 68.5 mil- lion/cm3
, Large White × Makster – 189.0 ± 59.7
million/cm3
). Sperm motility did not undergo significant breed differences: the average annual indicator of motility was 7.6 ± 0.09 points, and it was the
highest in the winter period (8.6 ± 0.11 points), however, for the established variances; the dilution was used 1.65–3.58 times and a high percentage of
unusable sperm (15.4–29.4 % of the total amount) was established in a large number of sam- ples. According to the results of the annual analysis of the
sperm production of boars, a high degree of culling of ejaculates was established for various reasons (high level of sperm agglutination (52.3–74.0 %), low
concentration of germ cells (14.5–29.8 %), presence of foreign impurities (5,8–12.4 %). The highest percentage of culling was insummer (20.3 %). Thus, the
obtained results showed the breed and seasonal characteristics of the reproductive capacity of breeding boars