Importance of Sperm Concentration for AI

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 –28 h prior to ovulation1. To further illustrate this, Watson and Behan2 reported that when using conventional AI, 1 billion sperm resulted in lower farrowing rates and smaller litter sizes when compared to 2 or 3 billion sperm, (AI at 0 and 24 h, and semen used within 48 h of collection). However, when bypassing the cervix and much of the uterus with surgical insemination, 1 versus 3 billion had no effect when insemination was performed at < 10 h before ovulation3. Apparently, the importance of sperm concentration used in an AI dose becomes clear when it was reporte