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Effect of altered lysine : energy ratio during gestation on wean pig growth performance
To determine the effects of altering dietary Lysine: energy ratio in gilt diets during gestation on wean pig performance, a total of 51 gilts were randomly assigned to 3 feeding regimens: Control, 2.21 kg/d from breeding to d 112 (1.93 g Lys/Kcal ME; 3276 Kcal ME/kg); Bump feeding (Bump-f), the control diet at 2.21 kg/d from breeding to d 89 and 2.61 kg/d from d 90 to 112; Phase feeding (Phase-f ), 2.21 kg/d from breeding to d 89 (1.81 g Lys/Kcal ME; 3275 Kcal ME/kg) and 2.61 kg/d from d 90 to 112 (2.46 g Lys/Kcal ME; 3290 Kcal ME/kg). During lactation sows received the same diet (3368 Kcal ME/kg, 0.88 % SID Lys). Thirty nine sows successfully farrowed at least 7 piglets and remained in the study (Control n=9, Bump-f n=13, Phase-f n=14 sows). Litters were equalized to 10 piglets within 72 hours of birth by cross fostering within the same treatment. At weaning (20 ± 2 d), 8 pigs/sow were placed into 2 pens such that initial BW variation was <10%/pen. All pigs received a commercial pig starter crumble diet for the first week post-weaning and an early grower mash diet in weeks 2, 3 and 4. Feed intake and BW were measured weekly. Data were analyzed using the Proc MIXED procedure in SAS. Maternal diet did not affect average BW at weaning (6.2 ± 0.2 kg) or the post-weaning growth performance. Final BW was 14.9 ± 0.5 kg and overall ADG, ADFI and gain: feed from weaning until d 47 was 321 ± 15 g/d, 467 ± 18 g/d, and 0.690 ± 0.020 g/d, respectively. During the transition from crumble diet to mash diet, all pigs suffered a setback in daily gain (-66.1, -26.1, and -17.5 ± 26.92 g/d in Control, Bump-f, and Phase-f pigs, respectively) but this was not affected by maternal feeding regimen in gestation. There was an increase (P < 0.001) in ADG and ADFI and a decrease (P < 0.001) in gain: feed over the 4 week post-wean period but gain: feed was not different between weeks 3 and 4. In gilts, constant feeding, bump feeding or bump feeding with altered lysine: energy during gestation may result in equivalent piglet growth performance in the first 4 weeks post-wean.
Keywords: Lysine, Phase-feeding, Bump-feeding