Effects of Phase Feeding Gestating and Lactating Sows

Effects of phase feeding gestating and lactating sows on reproduction performance, piglet robustness at birth and post-weaning

Funded by the Pork Checkoff

Samuel Kofi Baidoo, Associate Professor

Southern research and Outreach Center, University of Minnesota, Waseca, MN 56093



Effect of phase feeding versus conventional feeding was investigated on sow reproductive performance for two successive parities. A total of 240 mixed parity (1-7) sows were assigned to two dietary treatments on the week of insemination. Sows were blocked by parity and had similar body weight (BW) and backfat (BF). The phase-fed sows (n = 121, BW = 227.0 ± 3.6 kg, BF = 16.5 ± 0.7 mm) received 0.4%, 0.57% and 0.7 % SID lysine diets in three different periods 1(d0 (breeding) – d35), 2 (d35- d70) and 3 (d70 – d109), respectively during gestation. The control sows (n = 120, BW = 227.7 ± 3.5 kg, BF =16.3 ± 0.7 mm) were fed a 0.57% SID lysine diet throughout gestation. Sows were moved to farrowing crates on d109 and assigned two different feeding regimens in a 2 x 2 factorial arrangement. Sows were fed a conventional lactation diet (1.0% standard ileal digestible (SID) lysine throughout lactation throughout lactation or test diets (SID lysine 0.8%, 1.0%, and 1.2%) for phases 1(d 0-6), 2(d 7-12) and 3 (d 13 – weaning) respectively. The sows on phase feeding regimens and on control regimen received control diets during successive gestation and lactation periods. Ratios of lysine to other amino acids for sows of mixed parity were according to NRC (2012) and kept similar across all dietary treatments. Sow BW and BF were measured during the start and end of each period. Number of piglets born live, still-born, mummies; number weaned; litter weights, and wean-to-estrus interval was recorded. Serum samples collected at the start and end of first gestation and lactation were analyzed for serum amino acids concentration.

Feeding low lysine diet in first phase (d0 – d35) of gestation did not affect (P = 0.227) the BW and BF changes in sow for that period. There was no effect (P> 0.05) of dietary treatments on sow body condition during both reproductive cycle. Total born, born alive, number weaned, number of mummies, stillborn and low viable piglets were not affected (P> 0.05) by dietary treatments. Litter weight gain and litter weight for each phases were not different (P> 0.05) among dietary treatments. Sows phase fed in the previous gestation and fed control diet in the previous lactation had 1 to 1.5 more (< 0.05) piglets born alive in the subsequent parity than sows that were phase fed in the previous lactation period regardless of feeding regime in the previous gestation period. Principal component analysis of serum amino acid data revealed time-dependent difference (d0 vs d109 in gestation, d8 vs d18 in lactation). Also differences between gestation and lactation samples were also observed. However, the effects of phase feeding were not apparent.

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