What the Survey Says: Characterization of North American Boar Studs

The seventh quadrennial Boar Stud Managers Conference was held in August 2025 in St. Louis, MO. One survey was completed separately for 62 individual studs represented at the conference. The survey was to characterize boar studs in terms of management practices and other aspects. Most boar studs were built as studs (84%), while remodeling them from another pig barn was the next common answer (13%). Remaining studs (3%) were a combination of the two. Survey results show the average capacity was 411 boars with a range of 100 to 2000 boars and current inventory 341 boars (range of 95 to 1750 boars). A majority of respondents said 90%-100% of their boars were housed in stalls, while the remaining stated 89% or less of their stock were housed in stalls with 4 of those respondents housing no boars in stalls. Automatic semen collection was used on most boars in 43% of studs. The average number of full-time employees per stud was 8 with a range of zero to 50. Studs varied in the proportion of doses prepared for intrauterine insemination with 30% less than 16% of doses, 20% 16-50% of doses, and one quarter each 51-89% and 90-100%. Average annual cull rate for boars was 62% (range of 25% to 200%). The most common reason for culling (40%) was for genetic improvement. Semen quality was the next highest culling reason (34%), with lameness/health following at 14%. Additional culling reasons were “other” (6%), age (4%), and semen output (2%). In relation to semen output, respondents were asked about the difference in ejaculate discard rate between the lowest and highest calendar quarters and reported an average of 13% with a range of 0.5% to 60%. Results showed average minimum sperm normal morphology was 71% (range 25% to 80%) while the average minimum acceptable motility was 75% (range 60% to 90%). Tools used for semen analysis and concentration include exclusively CASA (48%); exclusively spectrophotometer (24%); a combination of two or more analysis tools (23%) including, but not limited, to visual assessment, microscope, spectrophotometer, and CASA; and other (5%). The most common extender type used was medium term (48%), with long term extender used slightly less (42%) and a combination of extender length being least common (10%). The average time that survey respondents have worked with pigs was 23 years (range of 2 to 50 years). Individuals were then asked how long they have worked in boar studs with the average result being 18.5 years (range of 2 to 48 years). These findings provide a collective representation of the boar studs present at the 2025 Boar Stud Managers Conference.