Kloostra Vanessa, Farmer Chantal, Huber Lee-Anne
Department of Animal Biosciences, University of Guelph, Guelph, ON, CanadaN1G 2W1.
Agriculture and Agri-Food Canada, Sherbrooke Research and Development Centre, Sherbrooke, QC, CanadaJ1M 0C8.
J Anim Sci. 2025 Jan 4;103. doi: 10.1093/jas/skaf271.
One hundred fifty-two gestating primiparous sows were used to determine the standardized ileal digestible (SID) Lys (protein) intake in late gestation necessary to maximize whole-body N retention, piglet birth weight, and subsequent milk yield. On day 90 of gestation, primiparous sows were assigned to 1 of the 7 isoenergetic diets with equally spaced and increasing SID Lys (protein) contents using primarily soybean meal to supply additional Lys [70% to 160% of NRC-NRC-(2012) estimated requirements; 13.3 to 30.5 g SID Lys per day; n = ~ 21]. An N-balance was completed between days 105 and 108 of gestation. After farrowing, all sows received a standard lactation diet until weaning (day 20 ± 1). Using the Bayesian information criteria to assess best fit, the linear broken-line model was selected to determine optimal SID Lys (protein) intakes. Sow BW gain in late gestation increased, and BW loss in the subsequent lactation tended to increase with increasing SID Lys (protein) intake in late gestation (linear; P < 0.001 and P = 0.086, respectively). The gain in backfat depth during late gestation tended to decrease with increasing SID Lys (protein) intake (linear; P = 0.067), but backfat depth loss during the subsequent lactation was not influenced by SID Lys (protein) intake in late gestation. The N intake, excretion, and whole-body retention (N intake-N output in urine and feces) increased with increasing SID Lys (protein) intake (linear; P < 0.0001). Whole-body N retention was maximized at an SID Lys intake of 22.0 g/d during late gestation (115% of NRC-estimated requirements). Litter size and the number of stillborns per litter were not affected by dietary treatment, but piglet birthweight increased and then decreased with increasing SID Lys (protein) intake (quadratic; P < 0.01) and was maximized at an SID Lys intake of 22.0 g/d during late gestation. Estimated milk yield in the subsequent lactation increased (linear; P < 0.05) and litter growth rate tended to increase (linear; P = 0.057) with SID Lys (protein) intake in late gestation. Estimated milk yield was maximized at an SID Lys intake of 22.7 g/d during late gestation (119% of NRC-estimated requirements). Therefore, SID Lys intake in late gestating primiparous sows should be increased by 15% above current recommendations to maximize whole-body N retention in late gestation and piglet birth weight, and by 19% to maximize milk yield in the subsequent lactation.
152头妊娠初产母猪用于确定妊娠后期使全身氮保留、仔猪出生体重和随后的产奶量最大化所需的标准化回肠可消化（SID）赖氨酸（蛋白质）摄入量。在妊娠第90天，初产母猪被分配到7种等能量日粮中的1种，这些日粮的SID赖氨酸（蛋白质）含量等间距增加，主要使用豆粕来提供额外的赖氨酸[为NRC - NRC -（2012）估计需求量的70%至160%；每天13.3至30.5克SID赖氨酸；n =约21]。在妊娠第105天至108天期间完成氮平衡测定。分娩后，所有母猪在断奶（第20±1天）前接受标准泌乳日粮。使用贝叶斯信息准则评估最佳拟合，选择线性折线模型来确定最佳SID赖氨酸（蛋白质）摄入量。随着妊娠后期SID赖氨酸（蛋白质）摄入量增加，妊娠后期母猪体重增加，随后泌乳期体重损失有增加趋势（线性；分别为P < 0.001和P = 0.086）。随着妊娠后期SID赖氨酸（蛋白质）摄入量增加，妊娠后期背膘厚度增加趋势减弱（线性；P = 0.067），但随后泌乳期背膘厚度损失不受妊娠后期SID赖氨酸（蛋白质）摄入量影响。随着SID赖氨酸（蛋白质）摄入量增加，氮摄入量、排泄量和全身保留量（氮摄入量 - 尿液和粪便中的氮排出量）增加（线性；P < 0.0001）。妊娠后期SID赖氨酸摄入量为22.0克/天时，全身氮保留量最大化（为NRC估计需求量的115%）。窝产仔数和每窝死胎数不受日粮处理影响，但仔猪出生体重随着SID赖氨酸（蛋白质）摄入量增加先增加后降低（二次曲线；P < 0.01），在妊娠后期SID赖氨酸摄入量为22.0克/天时最大化。随着妊娠后期SID赖氨酸（蛋白质）摄入量增加，随后泌乳期的估计产奶量增加（线性；P < 0.05），窝生长率有增加趋势（线性；P = 0.057）。妊娠后期SID赖氨酸摄入量为22.7克/天时，估计产奶量最大化（为NRC估计需求量的119%）。因此，妊娠后期初产母猪的SID赖氨酸摄入量应比当前建议量增加15%，以最大化妊娠后期全身氮保留和仔猪出生体重；增加19%以最大化随后泌乳期的产奶量。
