Serum Of Boars Research Articles

Detection of Porcine Circovirus Type 3 in Serum, Semen, Oral Fluid, and Preputial Fluid Samples of Boars.

Porcine circovirus type 3 (PCV3) is commonly associated with clinical symptoms such as porcine dermatitis and nephropathy syndrome (PDNS)-like lesions, respiratory signs, and reproductive disorders. This study aimed to investigate the epidemiology of PCV3 in a boar stud. The objectives were to detect PCV3 in semen, as well as matched serum, oral fluid, and preputial fluid samples from adult boars using quantitative polymerase chain reaction (qPCR), analyze PCV3-IgG antibody data, and genetically characterize a positive sample. A total of 112 samples from 28 boars were collected from a large-scale pig farm in Guangxi, China. The qPCR results showed that the PCV3 DNA was not detected in semen, with a positive rate of 0% (0/28), while it was detected in serum (3.57%-1/28), oral fluid (64.28%-18/28), and preputial fluid (46.4%-13/28). The seropositivity rate of PCV3-IgG in serum was 82.14% (23/28) according to the indirect enzyme-linked immunosorbent serologic assay (ELISA) results. Phylogenetic analysis revealed that one of the PCV3 isolates belonged to the PCV3c clades. This is the first report of PCV3 detection in preputial fluid from boars. The results suggest that PCV3 is transmitted among boars on pig farms and exhibits epidemic characteristics.

Assessment of the influence of N-acetylcysteine in vivo on sperm quality and hormone balance in boars

The substantiation of the use of antioxidant compounds to correct the reproductive capacity of males is an urgent problem of modern reproductive science. Some amino acids have pronounced antioxidant properties, including N-acetylcysteine (NAC). The work aimed to determine the effect of oral administration of NAC on sperm quality and hormonal balance in infertile boars. According to the results of andrological dispensation, three groups of animals were formed – I experimental groups (n = 5) and II (n = 5), with reduced reproductive capacity, and control (n = 5) with total reproductive capacity. The animals of the experimental groups were orally administered NAC at a dose of 75 mg/kg body weight (test I) and 50 mg/kg body weight (test II) for 30 days. With the introduction of different doses of NAC, an improvement in the quality of the ejaculates of the boars of the experimental groups was observed. In I experimental group, on the 120th day of the experiment, a probable increase in motility by 35.5 %, ejaculate volume by 8.7 %, and concentration by 5.1 % were established (P ˂ 0.05). On the other hand, the content of spermatozoa with morphological abnormalities probably decreased (by 22.7 %, P ˂ 0.01). Similar changes were obtained in boars of the II experimental group – the number of morphologically abnormal cells probably decreased – on the 90th and 120th day of the study by 17.7 % (P ˂ 0.05) and 24.7 % (P ˂ 0.01), respectively. Sperm motility and ejaculate volume increased significantly – by 28.1 % (P ˂ 0.01) and 7.9 % (P ˂ 0.05). The use of NAC contributed to the normalization of the endocrine function of the gonads, as a result of which an increase in the level of total testosterone in the blood serum of boars – an experimental group I was established by 16.3 % (P ˂ 0.05) on the 30th day of the study and by 33.7 % (P ˂ 0.001) on the 45th day. Similar changes were obtained in the animals of the II experimental group – an increase in testosterone level by 13.8 % and 29.8 % on the 30th and 45th day of the experiment, respectively (P ˂ 0.05–0.01). The estradiol level tended to decrease on the 30th day of the study. In contrast, on the 45th day, it was significantly lower than before administration by 13.6 % and 12.3 % in animals of I and II experimental groups, respectively (P ˂ 0.05). Testosterone-estradiol ratio up to 7.4–8.2 units on the 45th day of the study, which indicated the normalization of the balance of sex hormones in the body of boars. The obtained results recommend NAC as an effective means of correcting infertility in boars.

Virological and Histopathological Findings in Boars Naturally Infected With Porcine Reproductive and Respiratory Syndrome Virus Type 1.

Major geographical transmission of porcine reproductive and respiratory syndrome virus (PRRSV) occurs via semen when a boar stud is infected. This happened in Denmark in 2019, providing an opportunity to compare previous experimental PRRSV boar studies with natural PRRSV-1 infection in boars. The aim of this study was to investigate the association between the presence of PRRSV RNA in serum, semen, testicles, and epididymis of boars naturally infected with PRRSV and to describe the histological lesions in the testes and epididymis combined with direct visualisation of PRRSV-infected cells by immunohistochemical staining (IHC). The exact timing of infection of each boar was not determined, but based on serology the boars were divided into two groups: acute and late infections. All boars included were sampled the same day. In this study, 35 boars and 10 healthy boars from another PRRSV-negative boar stud were included as histological controls. PRRSV RNA was found most often in serum (51%) and least frequently in semen (22%) and was more often detected in the reproductive tract in the acute phase of infection (p < 0.0001; RR: 2.58). Mononuclear cells and multinuclear giant cells were present in the adluminal compartment of the testis and epididymis in PRRSV-infected boars, but not in control boars (p < 0.05), which supports the hypothesis that macrophages are involved in the venereal spread of the virus.

Evaluation of mineral metabolism of immunocorrected boars during castration

The article presents data on the effect of castration on changes in indicators reflecting mineral metabolism. The work was performed on 14 boars (aged 5 months) divided into two groups ‒ control and experimental ones (n = 7 in each). Before castration by an open method, all animals were intramuscularly injected with ketoject; and in the postoperative period, medical support consisted of repeated use of the abovementioned drug, as well as cobactan and hipratopic. The boars of the experimental group were additionally injected with thymogen. Blood sampling was performed before the surgery, on the 14th and 30th day after it, the serum was obtained using the conventional method. The content of calcium, phosphorus, sodium, potassium, chlorine, magnesium was evaluated.It was found that the indicators of sodium, potassium, chlorine and magnesium before castration of boars were within the physiological norm in both groups, while the indicators of both calcium and phosphorus exceeded physiological norm in the control and experimental groups by 1.46 ‒ 1.51 and 1.14 ‒ 1.22 times, respectively.Further dynamics of calcium and phosphorus was accompanied (in the catabolic phase) by hypocalcemia, a decrease in the level of phosphorus to reference values, in the anabolic phase by normalization of the calcium content against the background of a slight excess increase in phosphorus.The use of thymogen in the experimental group contributed to a decrease in the intensity of changes on the 14th day and normalization of calcium and phosphorus on the 30th day. There were no significant fluctuations in the dynamics of sodium and chlorine. Potassium levels in both groups in the catabolic phase exceeded both the initial and standard values (mostly in the control), in the anabolic phase this trend persisted in relation to the control against the background of normalization in the experimental group. The content of magnesium in the blood serum of boars was characterized by positive dynamics: indicators were below the norm before castration, the reference values were subsequently noted in the control group on the 14th day, in the experimental group ‒ on the 30th. The presented research results indicate that the protective effect of thymogen in optimizing mineral metabolism during castration of boars is mainly realized at the level of calcium and phosphorus dynamics.

Detection of porcine circovirus type 3 DNA in serum and semen samples of boars from a German boar stud

Porcine circovirus type 3 (PCV3) is regularly reported in association with various clinical presentations, including porcine dermatitis and nephropathy syndrome (PDNS)-like lesions, respiratory signs, congenital tremor, and reproductive disorders. To investigate the epidemiology of PCV3 in a boar stud, we analysed fresh boar semen and matching sera from 181 boars from a German stud supplying semen for artificial insemination (AI) to approximately 740 breeder farms for PCV3 DNA. PCV3 DNA was detected in 1.7% semen samples and 24.3% sera. Spearman rho correlation demonstrated a significant positive correlation between boar age and quantitative DNA (by PCR quantification cycles [Cq] values) in serum samples (r = 0.636; P < 0.001). Sera from boars up to 12 months of age had higher viral loads (P < 0.001) and were PCV3-positive significantly more often (P < 0.01) than older boars. Detection of PCV3 DNA was not associated with breed (P> 0.05). PCV3 DNA was detected sporadically in fresh boar semen. Based on the assumption that processing fresh semen reduces viral load in semen used for AI, it is likely that the risk of sexual transmission of PCV3 during AI in is low. However, young boars may contribute to the maintenance of PCV3 infection in boar studs.

THE USE OF GADOLINIUM ORTHOVANADATE NANOPARTICLES FOR THE CORRECTION OF REPRODUCTIVE ABILITY IN BOARS UNDER OXIDATIVE STRESS

The search for effective and safe means of correcting male hypofertility is an urgent problem of modern reproductology. Researchers have proved the possibility of the use of nanoparticles based on oxides of rare earth elements for the treatment of disorders of male reproductive function. We investigated the effectiveness of the use of gadolinium orthovanadate nanoparticles activated by europium the size of which was 25×8 nm in the dose of 0,0125 mg per kg of live weight to correct reproductive ability decrease in boars under oxidative stress. After 14 days of hydrosol nanoparticles administration we established experimentally the dynamics of the content markers of oxidative stress and stable metabolites in the Nitrogen oxide cycle, and also determined the changes in sperm quality indicators. Thus, diene conjugates concentration in the blood serum of boars on the 15 th day tended to decrease, and on the 30 th day of the study was lower by 9,4 % compared to the group of animals before administration. At the same time the amount of thiobarbiturate-active products decreased on the 15 th day of the study by 24,7 %, and on the 30 th day – by 48,2 %, which indicates the normalization of oxidative processes in males. We noted positive changes in the system of the Nitrogen oxide cycle, the content of stable metabolites on the 15 th day was lower than in animals before administration by 25,2 %, and on the 30 th day – by 42,6 %. At the same time, we observed an improvement in the quality of boar sperm, especially motility and the number of motile sperm in the ejaculate increased by 42,9 % and 57,1 % on the 60 th day and by 95,2 % and 1,48 times on the 90 th the day of the study, respectively. In this case, the volume of ejaculate, sperm concentration and sperm content with morphological anomalies with the introduction of nanoparticles normalized and almost reached the values of the control group. The researchers are interested in further elucidating the effect of correction of reduced reproductive ability in boars under oxidative stress with gadolinium orthovanadate nanoparticles on hormonal background and the state of enzymatic and non-enzymatic systems of antioxidant protection. Keywords: sperm quality, prooxidant-antioxidant system, peroxidation, oxidative stress markers, the Nitrogen oxide cycle, nanomaterials

Salmonella seroprevalence in wild boar from Southeast Spain depends on host population density

Salmonellosis is the second most prevalent zoonosis in Europe and it has considerable economic and health implications for its monitoring and control as well as being among the most prevalent pathogens on livestock farms. The wild boar (Sus scrofa) has been identified as a competent host and spreader of Salmonella spp. There has been a significant increase in wild boar population in Europe in recent decades, and it is even present in urban areas. This study evaluates the spatial distribution of the seroprevalence of Salmonella spp. in wild boar from Murcia (Southeast Spain) and its relationship with host-related risk factors (sex, age, location and density). The presence of antibodies against S. Typhimurium and Choleraesuis in 269 serum of wild boars hunted in Murcia between 2015 and 2019 were analyzed using a commercial ELISA test (PrioCHECK porcine Salmonella kit). The seroprevalence were spatially distributed using Kernel function, and wild boar density using Gaussian kernel estimates (spatialEco version 1.1.1). The risk function was estimated as the ratio between the intensity of positive samples and the wild boar density The overall seroprevalence was 19.3% (IC95% 16.9–21.8), showing a significant spatial aggregation. The highest seroprevalence detected was 51.8% (IC95% 42.2–61.5) in a specific area with high risk of infection (76–100%) and was related to the wild boar density. Only marginal differences were detected for sex and age. The use of ELISA combined with QGIS (version 3.6.0) has allowed the identification of areas of Salmonella occurrence associated with high density as risk factor.

Изменение суммарного количества водорастворимых антиоксидантов в сыворотке крови хряков дюрок в зависимости от длительности их откорма

The influence of fattening conditions on the digestive and metabolic processes in animals is actively studied to increase the production of animal food. The aim of the study was to estimate the total amount of water-soluble antioxidants in the blood serum of Duroc boars depending on the duration of fattening. Experiments were conducted on 102 animals to confirm the results of laboratory studies, as well as determination of the total antioxidant activity of pig blood serum by amperometric method. For the first time, a significant difference in antioxidant activity was found in blood samples of Duroc boars with the duration of their fattening from 81 to 101 days.

Metabolic profile and content of the connective tissues’ biopolymers in the blood serum of service boars at the different regime of reproductive loading

It is necessary to carry out not only the evaluation of sexual activity of breeder boars and the quality of their sperm, but carefully investigate the metabolic status by laboratory methods during the medical examination. It helps to determine the optimal parameters for the implementation of the reproductive potential of the breeder boars. Biochemical methods of research can establish imbalance in metabolism, the nature and localization of cytolytic processes by the degree of enzymes activity in serum. However, in order to detect inflammatory or destructive changes in the connective tissue structures, in particular the musculoskeletal system, the most informative indexes will be biopolymers of the connective tissue – glycoproteins and proteoglycans. The results of a complex examination of clinically healthy breeder boars with different regime of their production use, which includes an extended set of biochemical tests with the determination of glycoprotein, chondroitin sulfate, total glycosaminoglycans and their fractions, are presented in this paper. It was found that the level of such parameters as the total protein and its fractions, urea, aspartate and alanine aminotransferase activity, and the MB fraction of creatine phosphokinase did not have any significant differences. For breeder boars that were used in reproductive events irregularly (group I), there was an indicative higher level of creatinine and glycosaminoglycans. In animals with regular use as the herd (group II), the level of creatinine and fractions of glycosaminoglycans (GAG) was lower, but there was an increasing in cholesterol, β-lipoproteins, and activity of total creatine phosphokinase. The probable difference in these indicators can be explained by the difference in the intensity of the energy metabolism processes in muscle tissue. Indeed, during long-term hard work of skeletal muscles, not only glycogen stores are used, but also the use of lipids is of great importance. In addition, the raising of cholesterol and β-lipoproteins may be due to their active involvement in the synthesis of steroid hormones. Increasing the activity of total creatine phosphokinase in blood serum of animals with the intensive use in technology probably is the evidence of severe physical activity and the development of destructive processes in muscle tissue (hyperenzymemia is detected in early stages of myopathy). The absence of the most inflammatory processes was evidenced by the unchanged level of serum glycoproteins, which are known as the acute phase tests. Differences in the parameters of the state of connective tissue were determined at the levels of general GAG, their I and III fractions (chondroitin-6-sulfate and heparan sulfate, respectively). In the first group of boars, there was a higher level of I fraction of GAG, that indicated a significant load on the joints' cartilages and the gradual development of destructive processes in them. About the III fraction of GAG, an increasing of their blood content could indicate the reaction of the vascular flow, changes in ventilation of the lungs, the course of anti-inflammatory processes in animals with the appearance of intense physical activity.

Novel and differentially abundant microRNAs in sperm cells, seminal plasma, and serum of boars due to porcine reproduction and respiratory syndrome virus infection

The objectives of this study were to identify and determine relative abundance of miRNAs in boar sperm, seminal plasma (SP), and serum pre- and post-viral infection. Functional enrichment analyses on predicted targets of miRNAs of interest were performed. Boars (n = 6) were inoculated with porcine reproductive and respiratory syndrome virus (PRRSv) strain 1-8-4 (Day 0). Semen and serum were collected on Day -2 and 6. Sperm and SP were separated and aliquots were flash frozen and stored at −80 °C. Serum was frozen and stored at −80 °C. Total RNA was isolated from sperm and SP samples and subjected to RNA sequencing. Microarray analysis was performed using the Day -2 and 6 RNA samples from serum, sperm and SP. Potential miRNA targets were predicted using miRanda 3.3a and targets were then analyzed for enrichment of Gene Ontology) and InterPro terms and were considered to be enriched if P < 0.01 using the Bonferroni correction. Microarray analyses resulted in 83, 13, and 10 miRNAs with differences in abundances in sperm, serum, and SP, respectively, when comparing Day -2 and 6. Results from enrichment analyses indicated that the predicted targets of 35, nine, and five miRNAs with differences in abundances for sperm, SP, and serum, respectively, that have functions and/or conserved protein domains that are enriched when compared to the pig genome. Enriched terms for P2X purinoceptors were identified for sperm, SP and serum. Enriched terms for cell adhesion were identified for sperm and serum transcripts. Enriched terms for cell signaling were identified for sperm and SP transcripts.

Lactate dehydrogenase as a possible indicator of reproductive capacity of boars

The aim of this study was to determine the activity of lactate dehydrogenase (LDH) and its isoenzymes in the blood serum and seminal plasma of boars from the breeding and insemination centre with regard to their age. Significant quantitative differences in the presence of isoenzymes between blood serum and seminal plasma were recorded. Isoenzyme LDH-C4 in the seminal plasma of breeding boars of both groups was identified in the position between the third and fourth fraction of LDH, although boars from the breeding centre showed significantly lower concentrations. Refrigeration had a negative influence on the activity of LDH isoenzymes in the blood serum after 7 days and in seminal plasma after 3 days of storage. The work extends the knowledge in an insufficiently examined field of veterinary medicine: the distribution and physiological function of LDH in boars focusing on isoenzyme LDH-C4 in seminal plasma.

High levels of ochratoxin A in blood serum and kidneys of wild boars Sus scrofa in Poland

The aim of our study was to evaluate the ochratoxin A (OTA) concentration in the blood serum and kidneys of wild boars Sus scrofa in two consecutive years. We took samples from wild boars hunted in five regions of northwestern Poland during November and December 2006 (N = 39) and throughout 2007 (N = 62). The body weight of the animals ranged from 35 to 100 kg. As a control, we used 20 pigs Sus scrofa domestica of an average body weight of 100 kg. We extracted the OTA and then purified it on immunoaffinity columns. The amount of OTA was determined using HPLC‐FLD. The OTA concentration varied among individual animals, some of which had extremely high levels in their blood serum (1,170 ng/ml) and kidneys (97 ng/g). The 2006 average OTA concentration in the serum was similar to the average found in 2007 (6.15 ng/ml and 5.91 ng/ml, respectively). In 2006, the concentration of OTA in the serum of wild boars was &gt; 3 times higher than the concentration found in the serum of pigs. We detected a higher level of OTA in the kidneys of wild boars in both 2006 (1.77 ng/g) and 2007 (2.34 ng/g) than the levels present in the kidneys of pigs (0.59 ng/g). In conclusion, the content of OTA in the serum and kidneys of wild boars changed with year and region. The OTA levels in wild boars from certain regions were much higher than in other regions, and such high levels may cause nephropathy in wild boars and thus pose a possible threat to consumers.

Immunoglobulin changes in boars exposed to administration of levamisole and exogenous adrenocorticotropic hormone

The objective of this paper is to determine the effect of levamisole (LEV) immunoglobulin concentration in the serum of boars exposed to three-day stress induced by the adrenocorticotropic hormone (ACTH). Boars were assigned to four groups (n=7). The first group received LEV for three days (2.5 mg/kg BW), the second group received ACTH (10 g/kg BW) for three days and the third group received LEV for three consecutive days and ACTH on the three following days (2.5 mg/kg BW ; ACTH 10 g/kg BW). The control group received saline solution (1 mL) during the experiment (six days). Concentrations of total protein, globulin, albumin and immunoglobulin concentration (IgG, IgA and IgM) were determined during levamisole, ACTH and levamisole + ACTH combined treatment administration, and during the 16-day post- administration period. Total protein levels were significantly increased during the stress period and over the next sixteen days (p0.01 to p0.0001, respectively) in the ACTH group of boars. However, total protein levels were significantly elevated in the LEV+ACTH group on day 1 and 2 of ACTH injection (p0.05 and p0.001) and on day 5 and the last day of measurement (p0.001 and p0.01). However, the three-day administration of levamisole (LEV) stimulated a statistically significant increase of protein concentrations compared to control values after levamisole treatment, on days 2 and on days 11, 15 and 24 (p0.01, all). Levels of serum albumin were not affected with levamisole or ACTH treatment. According to determined total protein concentrations, globulin concentrations were significantly increased throughout and after the ACTH treatment in the second group (p0.01 to p0.0001, respectively). Also, globulin concentrations were significantly elevated in the LEV+ACTH group throughout the three-day ACTH treatment and in the 16-day post-administration period (p0.05 to p0.01, respectively). The three-day levamisole administration resulted in an increase of globuline concentrations (LEV). However, there were no statistically significant differences in comparison to control pigs. ACTH treatment significantly elevated serum IgG concentration during the stress period (p0.001 to p0.0001, respectively) and over the next 16 days (p0.01 to p0.0001, respectively). However, in the LEV+ACTH group of boars, IgG levels were significantly elevated on days 1 and 3 of ACTH injection (p0.05 and p0.01) and days 1 and 5 in the post-treatment period (p0.01 and p0.05). Administration of levamisole (LEV) had no significant impact on IgG levels compared to the control boar group. However, a statistically significant increase in IgA concentrations in boars treated with levamisole (LEV) was determined on day 2 (p0.02) and day 11 (p0.05) after administration of levamisole compared to animals of the LEV+ACTH group. Furthermore, boars receiving levamisole before stress induction (LEV+ACTH) on day 5 after stress induction had IgM concentrations statistically significantly higher (p0.05) than animals treated only with ACTH. These results show that levamisole may stimulate the immune system in swine and immunoglobulin in the serum of boars exposed to stress.

Prevalence of Actinobacillus pleuropneumoniae Infection in Hunted Wild Boars (Sus scrofa) in Germany

Actinobacillus pleuropneumoniae is an important pathogen of the porcine respiratory tract. Subclinically and chronically infected pigs may enter a permanent carrier state, harboring A. pleuropneumoniae in lungs or tonsils. Despite the enormous role of A. pleuropneumoniae in domestic swine production, no published data about prevalence and distribution of A. pleuropneumoniae infections in wild boars (Sus scrofa) are available. Antibodies against A. pleuropneumoniae have been detected in serum of wild boars from Slovenia. The aim of the present study was to evaluate A. pleuropneumoniae infection status in wild boars in Germany. Tissue samples from lungs and tonsils of 531 wild boars from 52 hunts during the hunting seasons 2004-05 to 2006-07 were examined for A. pleuropneumoniae by polymerase chain reaction (PCR). Although gross pathologic lesions typical for pleuropneumonia were not detected, 35.8% of the wild boars were PCR-positive. Tonsils were involved in 94.3% and lungs in 15.5%. Actinobacillus pleuropneumoniae infection prevalence increased with age and body weight. Further research is needed to understand the involvement of different A. pleuropneumoniae serotypes and to understand the interrelationship of A. pleuropneumoniae infection between wild boars and domestic pigs.

Detection of porcine reproductive and respiratory syndrome virus in semen and serum of boars during the first six days after inoculation

Objectives: To determine, during the first 6 days post inoculation, when porcine reproductive and respiratory syndrome virus (PRRSV) can be detected in serum or semen by polymerase chain reaction (PCR); the impact of pooling on detection of PRRSV by PCR; and the possible association between rectal temperature and detection of PRRSV in serum by PCR. Materials and methods: Forty mature boars (four groups of 10) were inoculated intranasally with PRRSV variant MN 30-100. Serum and semen samples were collected on a rotating basis from one group every 12 hours for 6 days and tested for PRRSV by PCR. Rectal temperatures were recorded for all 40 boars at 12-hour intervals. Results: Serum samples became PCR-positive before semen samples. During the first 6 days after inoculation, serum was PRRSV-positive in 36 of 40 boars, and semen was PRRSV-positive in four of 40 boars. Median time to detection was 36 and 72 hours for nested PCR and Taqman PCR, respectively. Results were inconsistent when a positive semen sample was pooled with negative semen. Elevated rectal temperature was not associated with PCR-positive serum or semen results. Implications: Under the conditions of this study, PCR is more sensitive and detects PRRSV-infected boars earlier in serum than in semen. Pooling of positive semen samples provides variable PCR results. Rectal temperatures are not correlated with PCR-positive results. Sampling techniques are needed to more easily obtain serum samples for PCR from boars once or twice weekly at the time of semen collection.

Persistence of Porcine Reproductive and Respiratory Syndrome Virus in Serum and Semen of Adult Boars

Four seronegative adult boars were intranasally inoculated with porcine reproductive and respiratory syndrome virus (PRRSV) isolate VR-2332. Serum and semen were collected 2-3 times weekly for over 100 days postinoculation (DPI). Serum samples were assayed for PRRSV by virus isolation (VI) and a polymerase chain reaction (PCR) and screened for antibodies to PRRSV using the indirect fluorescent antibody (IFA) and virus neutralization (VN) tests. Semen was assayed for PRRSV RNA by PCR. Virus and viral RNA was detected in the serum of all boars within 1 DPI by Vi and/or PCR. However, VI results indicated that viremia was transient and occurred from 1 to 9 DPI. Viral RNA was detected in serum from 1 to 31 DPI. In the acute stage of the infection, PRRSV RNA was detected in serum by PCR prior to the presence of viral RNA in semen. The PRRSV RNA was detected in semen as early as 3 DPI and persisted for 25 DPI in 2 of the boars and 56 and 92 DPI in the remaining 2 boars. Detection of PRRSV RNA in semen occurred 2-8 and 28-35 days prior to the detection of antibodies by IFA and VN, respectively. PRRSV was isolated from the bulbourethral gland of the boar that shed viral RNA in semen for 92 DPI. These results suggest that PRRSV RNA can be detected by PCR in boar serum and semen, and may persist for variable periods of time. Viremia and the serologic status of the boar are not adequate indicators of when PRRSV or PRRSV RNA is being shed in the semen. Preliminary findings also indicated that neither shipping stress nor reinoculation with homologous PRRSV resulted in viremia or viral RNA shedding in semen.

Boar Seminal Vesicles Secrete Arylsulfatases into Seminal Plasma: Evidence That Desulfation of Seminolipid Occurs Only after Ejaculatio1

The presence and composition of arylsulfatases in secretions of various glands of the boar genital tract were studied. Arylsulfatase A was present in seminal plasma but not in extracellular fluids of the testis and epididymis nor in blood serum of boars. On the other hand, arylsulfatase B was present in both seminal plasma and extracellular fluids of the testis but was completely resorbed in the epididymis. The acrosomal arylsulfatase A did not leak out of spermatozoa before ejaculation. We conclude that arylsulfatases A and B present in seminal plasma are secreted by the seminal vesicles, for three reasons: 1) secretions from seminal vesicles contained 2.3-fold higher arylsulfatase activities than did those from seminal plasma, but had an identical composition; 2) cauda epididymal fluids did not contain arylsulfatase; and 3) other accessory glands of the boar genital tract did not secrete arylsulfatase. When intact boar spermatozoa were incubated with arylsulfatase A, complete desulfation of seminolipid was observed. The most important arguments favoring our hypothesis that desulfation of seminolipid does not start before ejaculation are the following: 1) desulfoseminolipid is not detectable in epididymal or freshly ejaculated sperm samples; 2) the acrosomal arylsulfatase A cannot desulfate seminolipid present at the surface of the plasma membrane of intact spermatozoa because of its intracellular localization; 3) extracellular arylsulfatase A is stored in seminal vesicles and thus can interact with spermatozoa during and after ejaculation.

Testicular Function in Boars Exposed to Elevated Ambient Temperature1

Pituitary-testicular function was examined in yearling boars exposed to 23 ± 1#{176}C (control) or 34.5 ± 1#{176}C for 8 h and 31 ± 1#{176}C for 16 h during each 24 h period (heat stressed). Plasma testosterone and immunoreactive LI concentrations were monitored throughout treatment and testes were removed after 13 weeks to quantify spermatogenesis and assess steroidogenesis by measuring the incorporation of E1�l 4C1 acetate into selected L� 4C1 androgens by slices of testicular tissue incubated in vitro. Plasma testosterone and LI concentrations were similar when control and heat stressed boars were bled infrequently during treatment. However, heat stress significantly altered androgen biosynthesis in vitro as evidenced by decreased amounts of II Cl associated with androstenedione, testosterone and dihydrotestosterone and increases in androsterone and androstanediol. Addition of LH and FSH to testicular incubates markedly enhanced the amount of (1-’ 4CI acetate incorporated into 1l 4C1 androgens but further differences between control and heat stressed boars were not apparent. In another experiment, plasma testosterone was quantified in the serum of boars every 30 mm for 12 h on Days 0, 7 and 14 during exposure to 23 ± 1#{176}C (control) or 34.5 ± 1#{176}C (heat stressed). Serum testosterone was reduced (P(0.10) after 7 days of heat stress. Elevated ambient temperature for 90 days significantly reduced the number of young spermatids in round cross sections of seminiferous tubules at stage 1 of the cycle of the seminiferous epithelium but failed to affect the number of type A spermatogonia or preleptotene and pachytene spermatocytes. The results demonstrate that heat stress can exert a transitory decline in plasma

436. Determination of 5α-androst-16-en-3-one (boar taint steroid) by radioimmunoassay in fatty tissue and serum of normal and active-immunized boars

436. Determination of 5α-androst-16-en-3-one (boar taint steroid) by radioimmunoassay in fatty tissue and serum of normal and active-immunized boars