Quality and microbiologic contamination of seminal material prepared in farm [swine; Lombardy]

artificial insemination biological contamination boars calidad cell culture coltura di cellule contamination biologique contaminazione biologica culture de cellule diagnosi di laboratorio diagnostic de laboratoire encuestas sobre explotaciones escherichia coli espermatozoo farm surveys higiene veterinaria identification identificazione igiene veterinaria indagini su aziende agricole laboratory diagnosis lombardia lombardie lombardy malformation malformations malformazioni proteus mirabilis pseudomonas aeruginosa quality qualità semen sperma spermatozoa spermatozoi sperme streptococcus faecalis verraco verrat verri veterinary hygiene