AI success can depend upon sperm quality at collection, sperm age when inseminated, insemination volume, and AI times relative to estrus. However, in addition to these factors, another essential component of AI effectiveness is the number of sperm inseminated. In fact, concentration of sperm inseminated, may actually compensate for many deficiencies involving the technology when using AI, when conditions are less than optimal. Therefore, properly estimating the concentration of the boar ejaculate is critical for efficient boar use and for influencing the effectiveness of the AI technology to optimize farrowing rate (FR) and litter size (LS). Two billion sperm appears to optimize conventional AI for LS and FR when semen that is less than 36 h old, is administered within a