Any factor that interrupts the flow of pigs in a production system will have an adverse effect on profitability. Areas in the production scheme where any through-put interruption can occur need to be identified, says Veteri-narian Tom Fangman, University of Missouri.

He has identified a few critical control-point consid-erations for farrowing rates. The critical-control points that contribute to the farrowing-rate determi-nation (with a range of 75 percent to 87.2 percent) include the following:

1. Conception rate (85 percent to 90 percent.)

2. Seasonal infertility

3. Gestation nutrition

4. Health/abortion influencers, including parvovirus, Leptospirosis, porcine reproductive and respiratory syndrome, swine influenza virus, as well as other bacterial infections.

5. Percent of sows bred by seven days (80 percent to 94.8 percent.) Factors that could affect this include the artificial insemination technician, semen quality, estrus detection, environmental temperature and wean-to-first-service interval (5.2 days). The sow's wean-to-first-service interval is influenced by lactation nutrition, sanitation, parity and health, such as uterine bacteria.