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.

Effects of vibrations during boar semen transport: Low-temperature transport as a new management tool.

Transport-related vibrations (TV) compromise the quality of conventionally stored (17 °C) boar semen, but knowledge about TV effects after 5 °C transport is insufficient. This study evaluates the effects of TV after novel 5 °C transport compared to a 17 °C control. Ejaculates of 18 fertile Piétrain boars, diluted in a split sample procedure using Androstar Premium® (AP, 5 °C storage) or Beltsville Thawing Solution (BTS, 17 °C storage), were subjected to transport simulation using a laboratory shaker IKA MTS 4. The timing was set according to the respective processing protocols: for 17 °C BTS samples, TV simulation was performed the day of collection, 5 °C AP samples were subjected to TV the day after collection following completion of the established cooling curve to 5 °C. Six samples per ejaculate were exposed to different TV durations (0 h, 3 h, or 6 h) to evaluate the effect on sperm quality (progressive motility (PM), thermo-resistance test (30 and 300 min incubation at 38 °C (TRT30/TRT300)), mitochondrial activity (MITO), plasma membrane and acrosome integrity (PMAI)). Generalized linear mixed models revealed TV (P = 0.021) and storage time (P < 0.001) dependent declines in PM. Direct, pairwise comparisons revealed that 5 °C samples are not affected by TV (P(3 h vs. 6 h transport) = 1.0; P(0 h vs. 6 h transport) = 1.0). They therefore showed superior quality maintenance after TV compared to 17 °C samples (P(3 h vs. 6 h transport) = 0.025; P(0 h vs. 6 h transport) < 0.001). Concluding, low-temperature transport is possible without significant semen quality loss and with better quality maintenance than standard transport.

Analysis of artificial insemination center management factors that contribute to sperm parameters and boar longevity with a major focus on PGF2α treatment.

Artificial insemination (AI) centers' economic profitability is directly impacted by the amount of high-quality sperm doses. Many internal and external factors contribute to the quality of ejaculates. To enhance the libido and to reduce the time that is required to train boars for semen collection, prostaglandin products are used routinely at AI centers. The objectives of this study were to analyze sperm parameters of 40,765 ejaculates and the survival of 406 PGF2α-treated and 417 untreated AI boars of five breeds (Duroc [DU], Large White [LW], Landrace [LR], Pietrain [PI], and Large White Sire Line [LS]). Data were assessed in one AI center in Switzerland from 2018 to 2022 and sperm parameters were determined by computer-assisted sperm analysis immediately after semen collection. For further calculations, the ejaculates were divided into four groups depending on the boar's age at semen collection day: 7 to 11, 12 to 18, 19 to 24, and 25 to 87 mo. Along with the boar age, breed, season, and semen collection frequency even the treatment with PGF2α had significant influence on sperm parameters. Overall, 19.5% ejaculates were collected after PGF2α treatment. For every age and breed group, higher ejaculate volume was found for untreated boars than for PGF2α-treated boars (P < 0.001). Higher values for total and progressive sperm motility, total sperm number, and the proportion of morphologically normal sperm were observed in untreated boars across several age and breed groups. Only for sperm concentration, higher values were found for treated boars older than 11 mo (P < 0.001) and the breeds DU, LW, and LR (P < 0.001). The chance of ejaculates being rejected for AI purposes because of low sperm quality was 21% greater for treated boars. There was no difference in survival between treated and untreated boars. The hazard for boar removal increased with decreasing age at first semen collection and decreasing semen collection frequency. The results reveal better sperm quality for untreated boars than for PGF2α-treated boars, which might indicate that the underlying fertility of boars necessitating treatment is inferior compared to boars that can be collected without further treatment. Therefore, AI boar stations that are aiming to reduce PGF2α treatment should pay special attention to high libido and fertility of young prospective AI boars.

In many artificial insemination (AI) centers, prostaglandin products are used routinely to enhance the mounting behavior of boars with libido problems and to expedite the training of young boars to mount an artificial sow and allow semen collection. Recent studies examining the influence of prostaglandin-F2α (PGF2α) on sperm quality are still rare and present low sample sizes and diverse results. The aim of this study was to analyze AI center management factors that affect boar longevity and sperm parameters with a main focus on PGF2α treatment. The analysis compares sperm parameters of 40,765 ejaculates and the longevity of 823 PGF2α-treated and untreated AI boars based on 4 yr of data. Sperm parameters were assembled by computer-assisted sperm analysis. The results revealed that not only boar age, breed, semen collection technician, season, and the monthly collection frequency contributed significantly to the sperm parameters, but also the treatment with PGF2α. While we found at least greater values for ejaculate volume, total sperm number, and total and progressive motility for untreated boars, the longevity at AI center was not affected by PGF2α treatment. Rather, the boar's age at first semen collection session and the semen collection frequency had significant influence on the survival time of AI boars.

Lifetime and removal reasons for Pietrain boars in European AI centers: a retrospective analysis.

Currently, artificial insemination (AI) is the most common reproductive method used in swine production. The economic profitability of AI centers is closely linked to a boar's retention rate and the purchase of replacement boars. The objectives of this study were to examine data of selection process and lifetime of a total of 6,496 purebred Pietrain AI boars and to analyze the frequency and reasons of removal in eight European countries. Data were obtained from two German boar multiplication farms as well as 53 AI centers from 2018 to 2022. The retention time was analyzed from the selection process until replacement and to the end of the examination, respectively. The selection process of the boars took place at 168 ±â€…5 (mean ±â€…SD) days of age. For further calculations, the removal reasons were divided into nine groups: breeding (BR), died (DI), euthanasia (EU), health (HE), genetics (GE), low libido (LI), sperm quality (SQ), structure (ST), and other (OT). Overall, 56.1% of the examined boars were removed, with 17.5% being removed within the same year they entered the AI center. The annual removal rate for the 53 AI centers averaged 42.4%. The most frequent removal reason was low SQ (45.1%), followed by genetics (28.6%) and low libido (10.6%). The highest relative frequency of removals was observed for an age of 2 yr (34.0%). The highest removal risk was calculated for boars in Czech AI centers (P < 0.001), while the lowest removal risk occurred in Dutch (P = 0.006) and Portuguese AI centers (P = 0.01). The comparison of removal groups revealed, inter alia, higher body weight at selection process for the BR group (117.9 ±â€…9.0 kg) and longer quarantine periods for LI group (45.9 ±â€…17.6 d). Boars in the GE group were characterized by the oldest age at removal (934.0 ±â€…272.8 d) and longest period of exploitation (672.5 ±â€…266.8 d). The results could be helpful to detect the most common reasons for production failure of AI Pietrain boars and beneficial for establishing an economical removal policy in AI centers and for improving boar management through problem-based selection in boar multiplication farms.

Unsurprisingly, the removal of boars from artificial insemination (AI) centers affects the centers' economic performance and production efficiency. An analysis of reasons for removal is beneficial for an optimal removal policy and can help detect health problems that could be occurring in the herd. The aim of this study was to analyze data of selection process and removal, lifetime and removal reasons of 6,496 Pietrain boars in 53 European AI centers. The most common reason for boar removal was poor sperm quality, followed by genetics and low libido. The highest retention rate with increasing age was calculated for boars removed due to genetics, whereas boars removed because of low libido were characterized by the lowest probability to remain in the herd. Hazard analysis indicates that the removal risk for boars is influenced by the production process and differs between European countries.

Antibody-guided in vivo imaging of Aspergillus fumigatus lung infections during antifungal azole treatment.

Invasive pulmonary aspergillosis (IPA) is a life-threatening lung disease of immunocompromised humans, caused by the opportunistic fungal pathogen Aspergillus fumigatus. Inadequacies in current diagnostic procedures mean that early diagnosis of the disease, critical to patient survival, remains a major clinical challenge, and is leading to the empiric use of antifungal drugs and emergence of azole resistance. A non-invasive procedure that allows both unambiguous detection of IPA and its response to azole treatment is therefore needed. Here, we show that a humanised Aspergillus-specific monoclonal antibody, dual labelled with a radionuclide and fluorophore, can be used in immunoPET/MRI in vivo in a neutropenic mouse model and 3D light sheet fluorescence microscopy ex vivo in the infected mouse lungs to quantify early A. fumigatus lung infections and to monitor the efficacy of azole therapy. Our antibody-guided approach reveals that early drug intervention is critical to prevent complete invasion of the lungs by the fungus, and demonstrates the power of molecular imaging as a non-invasive procedure for tracking IPA in vivo.

A network of trans-cortical capillaries as mainstay for blood circulation in long bones.

Closed circulatory systems (CCS) underlie the function of vertebrate organs, but in long bones their structure is unclear, although they constitute the exit route for bone marrow (BM) leukocytes. To understand neutrophil emigration from BM, we studied the vascular system of murine long bones. Here we show that hundreds of capillaries originate in BM, cross murine cortical bone perpendicularly along the shaft and connect to the periosteal circulation. Structures similar to these trans-cortical-vessels (TCVs) also exist in human limb bones. TCVs express arterial or venous markers and transport neutrophils. Furthermore, over 80% arterial and 59% venous blood passes through TCVs. Genetic and drug-mediated modulation of osteoclast count and activity leads to substantial changes in TCV numbers. In a murine model of chronic arthritic bone inflammation, new TCVs develop within weeks. Our data indicate that TCVs are a central component of the CCS in long bones and may represent an important route for immune cell export from the BM.

Beware the intruder: Real time observation of infiltrated neutrophils and neutrophil-Microglia interaction during stroke in vivo.

Inflammation plays an important role in the pathogenesis of ischemic stroke including an acute and prolonged inflammatory process. The role of neutrophil granulocytes as first driver of the immune reaction from the blood site is under debate due to controversial findings. In bone marrow chimeric mice we were able to study the dynamics of tdTomato-expressing neutrophils and GFP-expressing microglia after photothrombosis using intravital two-photon microscopy. We demonstrate the infiltration of neutrophils into the brain parenchyma and confirm a long-lasting contact between neutrophils and microglia as well as an uptake of neutrophils by microglia clearing the brain from peripheral immune cells.