An increased feed intake during early pregnancy improves sow body weight recovery and increases litter size in young sows

This study evaluated the effect of feeding level and protein content in feed in first- and second-parity sows during the first month of gestation on sow BW recovery, farrowing rate, and litter size during the first month of gestation. From d 3 to d 32 after first insemination, sows were fed either 2.5 kg/d of a standard gestation diet (Control, n = 49), or 3.25 kg/d (+ 30%) of a standard gestation diet (Plus Feed, n = 47), or 2.5 kg/d of a gestation diet with 30% greater level of ileal digestible AA (Plus Protein, n = 49). Feed intake during the experimental period was 29% greater for Plus Feed sows compared with Control and Plus Protein sows (93 vs. 72 kg, P <0.05). Plus feed sows gained 10 kg more BW during the experimental period compared with Control and Plus Protein sows (24.2 ± 1.2 vs. 15.5 ± 1.2 and 16.9 ± 1.2 kg, respectively, P <0.001). Backfat gain and loin muscle depth gain were not affected by treatment (P = 0.56 and P = 0.37, respectively). Farrowing rate was lesser, though not significantly, for Plus Feed sows compared with Control and Plus Protein sows (76.6% vs. 89.8% and 89.8%, respectively, P = 0.16). Litter size, however, was larger for the Plus Feed sows (15.2 ± 0.5 total born) compared with the Control and Plus Protein sows (13.2 ± 0.4 and 13.6 ± 0.4 total born, respectively, P = 0.006). Piglet birth weight was not different among treatments (P = 0.65). For both first- and second-parity sows, the Plus Feed treatment showed similar effects on BW gain, farrowing rate, and litter size. In conclusion, an increased feed intake (+ 30%) during the first month of gestation improved sow BW recovery and increased litter size but did not significantly affect farrowing rate in the subsequent parity. Feeding a 30% greater level of ileal digestible AA during the same period did not improve sow recovery or reproductive performance in subsequent parity