Relationship between pre-pubertal biometrical measures and sperm parameters for the selection of high genetic merit pure and crossbred boars

Differential impact of the kinase inhibitors ruxolitinib and ceritinib on porcine sperm in vitro

Small-molecule protein kinase inhibitors are applied for the medical treatment of several diseases (Roskoski Jr, 2016). Given the increasing use of these molecules, particularly in cancer therapy, their influence on sperm is of great importance for a better understanding of the presumed effects on the reproductive potential and fertility of male patients. Therefore, we investigated the influence of the small-molecule kinase inhibitors ruxolitinib and ceritinib on porcine sperm in vitro. Porcine sperm were employed as a substitute for mammalian, especially human sperm, as they are available in large quantities in reproducible quality. Under all conditions, ceritinib at a molar drug/lipid ratio of 1:10 had adverse effects on sperm motility, viability and membrane integrity, while ruxolitinib at highest concentrations showed no or only weak effects on motility parameters. The massive merocyanine 540 binding in all dead and most viable ceritinib treated cells already after a short-term incubation at 38°C qualifies the disturbance of membrane lipid order as the most likely cause for the observed decrease in motility and viability. Therefore, possible damage to human sperm must be considered when administering ceritinib. The attempt to investigate a kinase-mediated influence of the inhibitors on capacitation and acrosome reaction failed because even the low concentration of the solvent DMSO interfered with this function. To test effects of small-molecule kinase inhibitor on selected properties of living cells, porcine sperm has proven to be a useful in vitro model.

Selection and direct biomarkers of reproductive capacity of breeding boars

Efficient management of pig reproduction is paramount for the sustainability and productivity of the global pork industry. Modern artificial insemination (AI) breeding programs have greatly benefited from the integration of advanced selection methods and biomarkers to enhance the reproductive performance of boars. While traditional selection methods have relied soley on boar phenotype, such as growth rate and conformation, modern pig breeding has shifted more and more toward molecular and genetic tools, which are still complemented by phenotypic traits. These methods encompass genomics, transcriptomics, and proteomics. Biomarkers serve as critical indicators of boar reproductive capacity. They can help to identify individuals with superior fertility and aid in the early identification of potential fertility issues, allowing for proactive management strategies. This review summarizes current knowledge of various biomarkers associated with semen quality, sperm function, and overall reproductive fitness in boars. Furthermore, we explore advanced technologies and their potential applications in uncovering novel selection methods and biomarkers for predicting boar fertility. A comprehensive understanding of selection criteria and biomarkers governing boar reproductive capacity is essential for developing effective breeding programs to enhance swine reproductive performance.

Relationship between pubertal testicular ultrasonographic evaluation and future reproductive performance potential in Piétrain boars

New ways of predicting sperm quality and output performance in young artificial insemination (AI) boars are important for breeding companies to ensure that the pubertal boars delivered to the AI studs have a high chance of meeting minimum quality standards to be used for insemination and therewith dissemination of desirable characteristics. The aim of the current study was to characterize the testicular development of 218 pubertal Piétrain boars (Line 408, Pig Improvement Company) to identify traits with predictable characteristics relative to their sperm quality as an adult AI boar. Scrotum, testes and epididymis were examined ultrasonographically at day (d) 100 (on-test) and 170 (off-test) followed by a computer-assisted grayscale analysis (GSA). Over the test period, paired testicular volume increased 7.3-fold from 22.7 ± 10.8 cm³ to 166.6 ± 62.2 cm³. The right testis was significantly (P = 0.014) larger than the left one at the off-test. Based on the sperm quality (ejaculate volume, sperm concentration, total sperm number, morphologically abnormal sperm and total sperm motility at day 3 of semen storage), 82.11% (n = 179) of the boars were classified as "productive" boars. These boars had a significantly (P = 0.039) larger paired testicular volume than "non-productive" boars (45.9 ± 19.9 cm³vs. 38.5 ± 12.6 cm³) at the on-test. For the right testis at on-test, significant differences for the standard deviation of mean gray value (P = 0.022), area under the curve (P = 0.004) and mean gradient value (GRAD, P = 0.030) regarding the future sperm production capacity (SPC) were shown. At off-test, there was a significant difference for minimum gray value (MIN GV, P = 0.003) and mean gray value (P = 0.001) related to SPC. To find SPC related cut-off values for GSA data, a two segmental non-linear regression analysis was carried out indicating breakpoints for GRAD ≥12 and MIN GV ≥ 40 for boars with low SPC. Off-test boars with MIN GV ≥ 40 showed a 2.4 higher risk to display low SPC (Odds ratio = 2.4 [1.1, 5.4]; P = 0.024). The results may enable breeding companies to include new sperm quality associated traits in their boar testing and selection programs.