The effects of phase feeding lysine during gestation on piglet vigor and sow reproductive performance

The effects of phase feeding Lys during gestation on sow reproductive performance and piglet vigor were evaluated. Females (n=45) were blocked by parity and randomly allotted to one of 3 feeding regimens: 12 g SID Lys/d (Control), 12 g SID Lys/d d2 - 89 and 17 g SID Lys/d d90 - 110 d of gestation (PF 1) and 10, 8.5, and 7 g SID Lys/d d2 - 89 for gilts, parity 1 and parity 2+, respectively and 17 g SID Lys/d d90 - 110 d of gestation (PF 2). Dietary energy and essential AA:Lys met NRC recommendations. Sow reproductive performance was defined as litter characteristics at birth and piglet vigor as cord cortisol and immunocrit at d2 of age from 6 and 4 piglets/litter, respectively. Data were analyzed as a randomized complete block with sow(block) as the random variable and means separation using Tukey's adjustment. Maternal Lys intake had no impact on total born, liveborn (Con:13.9 +/- 0.7, PF1:12.8 +/- 0.8, PF2:12.5 +/- 0.7), stillborn, or mummies. Piglet birth weight was lower (P=0.01) in PF2 litters (1.26 +/- 0.03 kg) than Con (1.32 +/- 0.03 kg) and PF1 (1.38 +/- 0.03 kg). Gestation Lys intake did not affect serum immunocrit levels in piglets. Heavy piglets (>1.4 kg at birth; 0.184 +/- 0.01) had 12% greater immunocrit value than light piglets (<= 1.0 kg at birth; 0.163 +/- 0.01). Cord cortisol levels did not differ by maternal treatment. In a single gestation, phase feeding Lys intake had minimal impact on litter characteristics or vigor at birth.