This study investigated the effectiveness of a floating cover made of multiple floating balls in reducing hydrogen sulfide (H₂S) emissions from a swine nursery slurry pit, which was pre-filled with aerobically treated slurry to 30% volume. H₂S emissions were monitored across two phases: a non-rearing period and an 8-week rearing period. Initially, the cover proved effective, achieving a 49% reduction in area-based H₂S emissions compared to the control during the non-rearing phase. However, a temporary spike in H₂S was observed in the treated group during the first week after pig placement. This increase was likely due to physical agitation of the slurry surface caused by the animals entering the barn. Despite this initial peak and subsequent manure accumulation, the floating cover consistently reduced emissions thereafter. The cover achieved a significant 62% reduction in H₂S emissions (p < 0.05) over the entire rearing period, demonstrating sustained mitigation performance under operational conditions. Importantly, the substantial reduction in H₂S volatilization did not translate into a measurable difference in nursery pig productivity; average daily gain (ADG) was similar between the treatment and control groups (p > 0.05). Overall, the floating cover offers a practical and effective strategy for mitigating H₂S emissions in swine housing. Further field-based studies are recommended to confirm its long-term applicability and effectiveness at a commercial scale under varying operational conditions.