Relationships between sow body condition with subsequent reproductive performance

Abstract Text: The objective was to quantify relationships between sow body condition with subsequent reproduction. Sows were measured at breeding (n=1571) and before farrowing (n=887) at a commercial farm. Body condition measures included: a Knauer sow caliper (CS), weight (WT), 10^th rib backfat (BF),10^th rib LM area (LMA) and body condition score (BCS) scored on a 1 to 5 scale by a technician. Sow traits were: number born alive (NBA), litter birth weight (BW), number weaned (NW), piglet survival (PS) which was NW divided by total born, litter weaning weight (WW) and wean-to-conception interval (WCI). Data were analyzed in SAS using PROC GLM. Breeding CS had a curvilinear relationship (P<0.05)  with NBA, BW, NW, PS and WCI with a CS of 15 being optimal for NBA, NW and PS and 14 ideal for BW and WCI. A 1 score increase in breeding BCS decreased (P<0.05) WW by 1.98kg. Breeding BCS had a curvilinear relationship (P<0.05) with NBA, BW, NW, PS and WCI with 3.2 being optimal for NBA, BW, NW and WCI and 3.0 ideal for PS. A 10kg increase in breeding WT decreased (P<0.05) PS and WW by 0.8% and 0.67kg, respectively, and increased (P<0.05) WCI by 0.23 d. A mm increase in breeding BF decreased (P<0.05) NBA, BW and WW by 0.04, 0.06kg and 0.17kg, respectively, and increased (P<0.05) WCI by 0.07d. Breeding LMA had a curvilinear relationship (P<0.05) with PS, with 52.5cm² being optimal. A 1 score increase in farrowing CS decreased (P<0.05) NBA and BW by 0.16 and 0.3kg, respectively. Farrowing CS had a curvilinear relationship (P<0.05) with NW and PS with 15 being optimal. A 1 score increase in farrowing BCS decreased (P<0.05) BW by 0.97kg. Farrowing BCS had a curvilinear relationship (P<0.05) with NW and PS with 3.6 being ideal. A 10kg increase in farrowing WT decreased (P<0.05) NBA and NW by 0.11 and 0.09, respectively. Farrowing WT had a curvilinear relationship (P<0.05) with WW and PS with an adjusted WT of 220 and 210kg, respectively, being ideal. A mm increase in farrowing BF decreased (P<0.05) NBA by 0.03 and a cm² increase in LMA decreased (P<0.05) NBA by 0.04, respectively. Farrowing LMA had a curvilinear relationship (P<0.05) with WCI with 51.6cm² being ideal. Results suggest sow body condition explains variation in subsequent reproductive performance. Producers should use CS or WT instead of a subjective BCS to manage gestating sows and maximize subsequent reproduction. 

Keywords: body condition, reproduction, sow