Effect of Late Gestation Diet and Feeding Level on Changes in Sow Weight and Body Condition

The objective was to determine the effect of diet (LGD) and feeding level (FL) on sow weight (WT) and body condition (BC) in late gestation. Second parity, Landrace × Large White sows (n=61) were housed at the North Carolina Department of Agriculture Tidewater Research Station. On d 104 of gestation, sows were moved to farrowing stalls and randomly allocated by BC caliper score (CS) to one of two corn-soy LGD, gestation (GEST) or lactation (LACT), and one of three FL (1.5, 3.0 or 4.5 kg/d) in a 2×3 factorial design. The LGD were fed until farrowing. The GEST diet contained 2,979 Kcal/kg ME, 0.58 SID lysine and the LACT diet contained 3,322 Kcal/kg ME, 0.99 SID lysine and 2.5% added fat. Sow WT and CS (<12=thin, 12-15=ideal, 15+=fat) were collected on d 104, 112 and at weaning (WEAN). Lactation feed intake (LFI) and wean-to-estrus interval (WEI) were collected. Data analysis was completed in SAS using PROC GLM. Fixed effects included LGD and FL (as a linear term). No LGD × FL interactions were P<0.05. Sow WT and CS traits measured after d 104 of gestation included initial measure as a covariate. Average sow WT at d 104 was 231 kg and did not differ (P>0.05) between treatments. Sow WT at d 104, 112 and WEAN did not differ (P<0.05) between LGD. Yet at d 112 of gestation, sows fed LACT had greater (P<0.05) CS than those fed GEST (15.25 vs. 14.73). At WEAN sows fed LACT had similar (P>0.05) CS to GEST (12.22 vs. 11.88, respectively). Sows fed LACT had similar (P>0.05) LFI and WEI to those fed GEST. One kg/d increase in late gestation FL increased (P<0.01) sow WT and CS on d 112 by 5.04 kg and 0.41, respectively. One kg increase in late gestation FL increased (P<0.05) sow WT loss during lactation by 2.84 kg but not (P>0.05) CS loss. Yet overall, one kg/d increase in late gestation FL tended (P=0.08) to increase sow WEAN WT by 2.18 kg and improved (P<0.05) WEAN CS by 0.38. Increased gestation FL did not impact (P>0.05) LFI or WEI. Results indicate feeding LACT in late gestation improved sow CS at farrowing, but did not increase sow WT. Increased FL the last 10 d of gestation increased late gestation WT gain, did not impair LFI, tended to increase sow WEAN WT and increased sow CS at farrowing and at WEAN.