Artificial insemination of boar semen doses prepared with a lowdensity colloid under field conditions

Athina Basioura¹Ioannis Tsakmakidis¹Jane Morrell^2*Theodoros Ntallaris²

• ¹Aristotle University of Thessaloniki, Thessaloniki, Central Macedonia, Greece
• ²Swedish University of Agricultural Sciences, Uppsala, Sweden

Ejaculate contamination with bacteria during semen collection is inevitable in practice and antibiotics are a constituent of semen extenders, although bacterial resistance to antibiotics is a serious problem. The present study investigated the effect of preparing semen by centrifugation through a low density colloid during preparation of semen doses under field conditions as an alternative to adding antibiotics. Five ejaculates from 4 boars were each divided into two aliquots: control semen doses (extended with a commercial Beltsville Thawing Solution with antibiotics; 30 × 10⁶ spermatozoa/mL) and treated semen doses [processed with Porcicoll (300×g; 20 min); sperm pellet was re-suspended in Beltsville Thawing Solution without antibiotics; 30×10⁶ spermatozoa/mL]. Computer assisted sperm analyzer (CASA) motility and kinematic variables were assessed for control and treated semen doses. Sows were divided into two groups and inseminated with either control or treated semen doses. In the second round, after weaning the litters from the first round, the sows of control group were inseminated with treated semen doses and those of treated group with control semen doses. For all groups, pregnancy rate, farrowing rate, litter size, number of live born and weaned piglets were recorded. No differences (p > 0.05) between control and treated semen doses or between rounds were observed for all CASA motility and kinematic variables. The pregnancy (p = 0.0271) and farrowing (p = 0.046) rates were higher in sows of control than treated group. No differences were observed for litter size, number of live born and weaned piglets (p > 0.05) between the control and treated groups, and the farrowing rates were the same for the sows in both rounds. Under the current experimental conditions, sperm quality was not impaired by treatment with Porcicoll. An interesting finding is the ability of the sows to become pregnant again after insemination with semen doses without antibiotics, with no effect on reproductive output. In conclusion, artificial insemination with boar semen doses processed by Porcicoll, fulfilling the modern requirements for alternatives to antibiotics, could be a promising state-of-the-art product.