Total Aseptization of Boar Semen, to Increase the Biosecurity of Reproduction in Swine

Abstract

The aim of the study was to establish the complete microbiological profile of boar semen (Sus scrofa domesticus) and to choose the most effective antiseptic measures in order to control and optimize AI reproduction in pig farms. One hundred and one semen samples were collected and analyzed from several pig farms. The microbiological profile of ejaculates was determined by evaluating the degree of contamination of fresh semen and after dilution with specific extenders. The bacterial and fungal load of fresh boar semen recorded an average value of 82.41/0.149 × 103 CFU/mL, while after diluting the ejaculates the contamination value was 0.354/0.140 × 103 CFU/mL. Twenty-four germs (15 bacterial and 9 fungal species) were isolated, the most common being Candida parapsilosis/sake (92%) and Escherichia coli (81.2%). Modification of the sperm collection protocol (HPBC) reduced contamination in raw sperm by 49.85% in bacteria (significant (p < 0.00001) and by 9.67% in fungi (non-significant (p < 0.111491). The load in bacteria and filamentous fungi can be controllable, but not in levuras fungi. Some fluconazole-added extenders (12.5 mg%), ensure fungal aseptization, and even an increase in sperm progressivity (8.39%) for at least a 12 h shelf life after dilution. Validation of sperm aseptization was done by maintaining sow fecundity unchanged after AI (insignificant p > 0.05).

Investigating the need for antibiotic supplementation to the extender used for semen cryopreservation in collared peccaries

“…Regarding bacterial contamination in peccary fresh ejaculates, we found values >1 x 10 6 CFU/mL, which are into the normal range previously described for the species as 0.04 to 2.2 x 10 6 CFU/mL (3). It is difficult to compare these findings with those reported for other species, as even in boars there is no consensus regarding the number of bacteria found in fresh ejaculates, which can vary from just 0.08 10 6 CFU/mL (16) to 370 x 10 6 CFU/mL (17). In fact, semen collection in farm animals is not a sterile procedure, with some bacterial flora contaminating the semen (16), but the adoption of adequate sanitary practices can help to reduce sample contamination.…”

Candida Genus Maximum Incidence in Boar Semen Even after Preservation, Is It Not a Risk for AI though?

“…After qualitative microbiological examinations, it was reconfirmed that boar semen had a variable degree of bacterial and fungal contamination. Numerous studies have highlighted the bacterial contamination [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 9 , 37 ] of boar semen and its negative effects, both in terms of the number of germs (LogCFU) and their typing [ 11 , 13 , 20 ]. In general, when talking about the contamination of boar semen and its quality in preservation, attention is directed toward the bacterial one.…”

“…Similar to G. Althouse (2005), who introduced the term “bacteriospermia” for fresh and diluted semen, Ș. Ciornei (2021) introduced the term “mycospermia”, referring to the fungal contamination of boar semen [ 9 ]. Boar semen, unlike the sperm production of other males, is usually used diluted in liquid and stored at a relatively controlled temperature (between 14 and 18 °C).…”

“…Isolated publications have aimed at a complete asepticization of boar semen; therefore, Ciornei S. et al (2021) identified the main elements of risk in bacterial and fungal contamination of semen and limited the degree of contamination by implementing hygiene protocols and the biosecurity of sperm collection (HPBC) [ 9 ].…”

“…Colloidal centrifugation of the semen separates sperm from most bacteria, but it is not known exactly if this also applies to yeast. However, strict attention to hygiene should take placed at all stages of semen collection and processing [ 4 , 8 , 9 ].…”