The use of ultrasonography in the reproductive evaluation of boars

The objective was to study the use of ultrasound as a complementary test in the breeding soundness evaluation in male pigs and study the pattern of echogenicity of the testicular parenchyma in boars of different racial groups. Twenty‐six adult boars from four different racial groups were used, 10 from the Piau breed (group 1), four from the commercial and finishing group (group 2), six Pietrain breed (group 3) and six from the Duroc breed (group 4). All animals were evaluated for breeding soundness evaluation and the ultrasound examination of the testicles. The groups of animals that were evaluated showed no difference in the main semen parameters that were evaluated, except for the sperm volume, concentration of the ejaculated sperm and the supravital staining; the lowest figures were for the animals from the Piau breed (group 1). In relation to the testicular biometrics, Duroc animals (group 4) had a greater scrotal width compared to the other groups. But when we assessed the intensity of pixels of the testicles, there was a difference between groups. The groups 2 (finishing animals), 3 (Pietrain) and 4 had no difference between themselves. Group 3 had greater pixel intensity in relation to group 1. Of the 26 animals studied, five showed an abnormality during ultrasound evaluation, like hydrocele, hyperechoic mass in the testicular parenchyma, cyst in the head of the epididymis and the presence of fluid in the head and tail of the epididymis. The various animal groups studied did not differ in the principal reproductive parameters evaluated, showing that despite the great variability of reproductive traits between breeds and within the same breed, the breeding soundness evaluation, the more complete it is, is essential for the selection of breeders and the ultrasonography of the reproductive system becomes an important addition in this examination.     

Serologic and molecular survey for major viral pathogens in grazing hybrid wild boars in Northeast China

Hybrid wild boar husbandry is an important component of livestock production in Northeast China. However, the current disease situation of these animals is largely unknown due to a lack of disease surveillance. The present study was conducted to determine the prevalence of several important viral diseases in the hybrid wild boar population of Northeast China. Between September 2015 to December 2016, 169 blood and 61 tissue samples were collected from apparently healthy hybrid wild boars from farms in Jilin, Inner Mongolia and Heilongjiang provinces. ELISA detected serum antibodies against classical swine fever virus(CSFV), porcine reproductive and respiratory syndrome virus(PRRSV), pseudorabies virus(PRV), porcine circovirus type 2(PCV2) and Japanese encephalitis virus(JEV), but not against African swine fever virus(ASFV), with PCV2 having the highest seropositive rate(87.2–100% in different farms). RT-PCR or PCR performed on the processed samples detected only PCV2, with 33.1%(56/169) of blood samples and 32.8%(20/61) of spleen samples being positive, respectively, indicating widespread PCV2 infection in hybrid wild boars. Phylogenetic analysis of 15 PCV2 ORF2 sequences showed that they belong to genotypes PCV2a, PCV2b and PCV2d, with nucleotide and deduced amino acid homologies of 88.5–100% and 88.1–100%, respectively.     

Genomic analysis of influenza A virus from captive wild boars in Brazil reveals a human-like H1N2 influenza virus

Influenza is a viral disease that affects human and several animal species. In Brazil, H1N1, H3N2 and 2009 pandemic H1N1 A(H1N1)pdm09 influenza A viruses (IAV) circulate in domestic swine herds. Wild boars are also susceptible to IAV infection but in Brazil until this moment there are no reports of IAV infection in wild boars or in captive wild boars populations. Herein the occurrence of IAV in captive wild boars with the presence of lung consolidation lesions during slaughter was investigated. Lung samples were screened by RT-PCR for IAV detection. IAV positive samples were further analyzed by quantitative real-time PCR (qRRT-PCR), virus isolation, genomic sequencing, histopathology and immunohistochemistry (IHC). Eleven out of 60 lungs (18.3%) were positive for IAV by RT-PCR and seven out of the eleven were also positive for A(H1N1)pdm09 by qRRT-PCR. Chronic diffuse bronchopneumonia was observed in all samples and IHC analysis was negative for influenza A antigen. Full genes segments of H1N2 IAV were sequenced using Illumina's genome analyzer platform (MiSeq). The genomic analysis revealed that the HA and NA genes clustered with IAVs of the human lineage and the six internal genes were derived from the H1N1pdm09 IAV. This is the first report of a reassortant human-like H1N2 influenza virus infection in captive wild boars in Brazil and indicates the need to monitor IAV evolution in Suidae populations.     

Seroprevalence of Hepatitis E Virus in Domestic Pigs and Wild Boars in Switzerland

Hepatitis E is considered an emerging human viral disease in industrialized countries. Studies from Switzerland report a human seroprevalence of hepatitis E virus (HEV) of 2.6–21%, a range lower than in adjacent European countries. The aim of this study was to determine whether HEV seroprevalence in domestic pigs and wild boars is also lower in Switzerland and whether it is increasing and thus indicating that this zoonotic viral infection is emerging. Serum samples collected from 2,001 pigs in 2006 and 2011 and from 303 wild boars from 2008 to 2012 were analysed by ELISA for the presence of HEV‐specific antibodies. Overall HEV seroprevalence was 58.1% in domestic pigs and 12.5% in wild boars. Prevalence in domestic pigs was significantly higher in 2006 than in 2011. In conclusion, HEV seroprevalence in domestic pigs and wild boars in Switzerland is comparable with the seroprevalence in other countries and not increasing. Therefore, prevalence of HEV in humans must be related to other factors than prevalence in pigs or wild boars.     

Estimation of Genetic Parameters and Analysis of Season Effects and Age Effects for Semen Traits in Landrace Boars

The purpose of this study was to estimate the genetic parameters of semen traits of Landrace boars in South China and to analyze the influence of the age and season of semen collection on semen traits, so as to provide theoretical basis for formulating reasonable boar breeding program. The Asreml-R was used to analyze the 107 221 semen data of 1 605 Landrace boars from 2 AI stations in Southern China, the single-trait repeatability animal model was used to estimate the variance components, heritability and repeatability of each semen traits, two-trait repeatability animal model was used to estimate genetic correlation and phenotypic correlation of semen volume, semen density, sperm motility and percentage of abnormal sperm. The general linear model of R language program was used to analyze the influence of age and season of semen collection on semen traits. The results showed that the semen volume and percentage of abnormal sperm had medium heritability (0.23 and 0.38), and the variation coefficient of percentage of abnormal sperm was 85.42%, while the other traits had low heritability (0.07-0.19). Semen volume-semen density and sperm motility-percentage of abnormal sperm had extremely significantly negative genetic correlation(-0.77 and -0.90, respectively). Semen density-sperm motility showed extremely significantly positive genetic correlation (0.50). The influence of the age of semen collection on semen traits was significant(P<0.05). After boars reached sexual maturity, semen volume showed a significant increase, semen density and percentage of abnormal sperm showed a general decrease, and total sperm number and functional sperm number were significantly higher in the 13-18-month of age group than those in the other groups (P<0.05). The semen density was the highest in spring, and the total sperm number and functional sperm number were significantly higher in autumn and winter than those in spring and summer (P<0.05). In conclusion, the semen volume and percentage of abnormal sperm of Landrace boars can be selected as candidate traits. In the boar production management, boar whose semen production after 36 months of age decline, will be considered to update. Boar semen quality was significantly higher in autumn and winter than those in spring and summer. It is suggested that cooling work should be done in advance in Southern China in summer.     

长生公猪维持能量需要的研究

用6头约克夏和10头汉普夏、杜洛克、丹麦伦德瑞斯共36头小公猪,在其20—100kg 生长阶段内分期进行氮—碳平衔试验和呼吸测热试验各180头次。结果表明,生长公猪每千克代谢体重(W~(0.75))所需的维持能量与体重的一定的幂的倒数成比例。当代谢能转化为体蛋白质能和体脂肪能的效率[k_p和k_f]为0.60和0.80,0.68和0.75,0.56和0.74时,每千克代谢体重所需的维持能量分别为1131W~(-0.20),1307W~(-0.23)和1235W~(-0.25)千焦代谢能或1173W~(-0.20),1356W~(-0.23)和1281W~(-0.25)千焦消化能。建议用 ME_m,KJ/W~(0.75),kg=1307W~(-0.23),kg 作为生长公猪维持需要的公式。     

Effect of ammonium‐iron‐hexa‐cyanoferrate and of the covariates age,gender, weight,season and calendar time on radiocaesium contamination of wild boars living in the wild in Bavaria

Feed with Ammonium‐iron‐hexa‐cyanoferrate (AFCF; 1250 mg AFCF/kg) was fed between March 2009 and March 2011 to wild boars in a territory of 4.5 km² (experimental group, EXP). One hundred and forty similar territories in the same county (500 km², spruce forest, agriculture) served as control (CON). Data for comparison from all territories were available from March 2005 to March 2011. Wild boars could move between, into and from the territories. Lean skeletal muscle meat (500 g) of all wild boars that were killed by humans (hunting and traffic accidents) was investigated for gamma‐radiation from ¹³⁷Cs with a becquerel monitor with a sodium iodide scintillator crystal (range of detection 20–9999 Bq/kg). The wild boars were weighed, and gender and age were determined. For the analyses of effects, multivariable regression models were fitted with the ¹³⁷Cs concentration as response variable. There was a significant difference between the ¹³⁷Cs contamination of wild boars from CON (563 ± 932 Bq/kg meat, n = 1253) and EXP (236 ± 276 Bq/kg meat; n = 45). ¹³⁷Cs contamination decreased with increasing body weight by ?5 Bq/kg meat/kg body weight increase (p < 0.05). Females had higher Bq measurements than males (by +80 Bq/kg meat, p < 0.05). Piglets were lower than adults, but turn‐coats higher. From November to May, contamination was higher (by +500 to +600 Bq/kg meat, p < 0.05) than during the rest of the year. In 2010, contamination was higher (by +200 to + 300 Bq/kg meat, p < 0.05) in comparison with the other years under observation. When all covariates were controlled for, the effect of AFCF was highly significant. Interaction analyses showed that the intervention decreased ¹³⁷Cs contamination by ?500 Bq/kg meat during November to May and by ?200 Bq/kg meat during the rest of the year. In summary, AFCF feeding reduces ¹³⁷Cs contamination of wild boars living in the wild significantly, particularly during the season from November to May.     

Genetic diversity and antibiotic susceptibility of Staphylococcus aureus isolates from wild boars

We here report the occurrence of S. aureus in wild boars and characterize isolates genotypically and phenotypically in order to get knowledge about the occurrence of clonal lineages and genotypes in free-living wild animals. Forty-one S. aureus isolates obtained from 111 wild boars hunted in Lower Saxony, Germany, were investigated and compared to human and livestock isolates. The S. aureus belonged to multilocus sequence types ST1, ST7, ST30, ST133, ST425, ST804, ST890 and to the new ST3237, ST3238, ST3255 and ST3369. The livestock associated CC398-MRSA lineage, however, was not found. In addition to well-known spa types, the new types t14999, t15000, t15001 and t15002 were detected. Macrorestriction analysis revealed a variety of different SmaI fragment patterns. Most isolates were susceptible to all antimicrobials tested, including methicillin, and resistance was detected only to ampicillin, penicillin and erythromycin. PCR analysis confirmed the presence of staphylococcal enterotoxin genes (seh) in all t127-ST1 isolates. A high degree of genetic diversity was detected with many spa types and clonal lineages previously reported in humans and livestock animals.