Evaluation of Vaginal Infusion with Ampicillin on Incidence of Pelvic Organ Prolapse in Late Gestation Sows.

Within the last decade, increased sow mortality resulting from pelvic organ prolapse (POP) has become a growing concern in the swine industry. Despite being widely acknowledged as a prevailing sow welfare and production issue, mitigation strategies are lacking. Previous studies have demonstrated changes in the vaginal microbiome are associated with increased risk for POP during late gestation. Therefore, the vaginal microbiome represents a potential target for prevention strategies. The objective of the current study was to evaluate effects of vaginal infusion using ampicillin on POP incidence. We hypothesized that altering the vaginal microbiome through the use of antibiotics would reduce POP risk during late gestation. Ampicillin was infused into the vagina at two timepoints during late gestation. The first dose (10 mL at 200 mg/mL) was administered approximately three weeks prior to farrowing followed by a second, equivalent dose at approximately three days pre-farrowing. Sows were randomly assigned to treated (TRT; n = 824) and non-treated (CON; n = 739) groups based on gestation pen. Eighty-seven percent of sows in the TRT group received both infusions of ampicillin. At gestation week 15, sows (n = 1076) were evaluated for prolapse risk using a 3-point perineal scoring system. Briefly, a perineal score (PS) of 1 (PS1) presumes little to no risk of prolapse, a PS of 2 (PS2) presumes moderate risk of POP, and a PS of 3 (PS3) presumes high risk of prolapse. From the 1,076 sows assigned a PS, 46.5%, 49.7% and 3.8% of sows were scored PS1, PS2, or PS3, respectively. Ampicillin treatment did not affect PS (P = 0.20) during late gestation, with 45.6%, 51.6% and 2.8% of CON sows and 47.2%, 48.1% and 4.7% of TRT sows scoring a PS1, PS2, or PS3, respectively. Additionally, treatment did not affect POP incidence (P = 0.74), with 4.5% of CON sows and 4.7% of TRT sows subsequently experiencing POP. When evaluating litter characteristics, ampicillin treatment did not affect number of total born, liveborn, or stillborn piglets (P = 0.54). However, an effect of PS was observed on total born and stillborn piglets (P ≤ 0.01), and a tendency to effect number of liveborn piglets (P = 0.06). Sows assigned a PS3 during late gestation had fewer piglets born alive, presumably due to the increased number of stillborn piglets. Additionally, PS3 sows had 1 more total piglet on average within their litters compared with PS1 assigned sows (P = 0.01). In conclusion, vaginal infusion of ampicillin had no effect on PS, POP incidence or litter characteristics, but PS did have an effect on the number of piglets born alive. This project was supported by the National Pork Board and the Foundation for Food and Agriculture Research. [ABSTRACT FROM AUTHOR]