摘要
【Abstract】 Fifty-five primiparous sows were recruited to evaluate the effect of increasing standardized ileal digestible (SID) Lys-to-net energy (NE) ratios on primiparous sow maternal nitrogen retention, milk nitrogen output, and piglet growth performance during each week of lactation. Sows were assigned to one of five diets with equally spaced and increasing SID Lys-to-NE ratios between 2.85 and 5.51 g SID Lys/Mcal NE. The intermediate ratios were achieved by blending the two extreme diets in varying proportions using a feeding system with feed blending capabilities and were provided to sows immediately after farrowing and until weaning (d 24 ± 1). Nitrogen (N) balances were conducted between days 4 and 7 (week 1), 12 and 15 (week 2), and 20 and 23 (week 3) with total urine and fecal grab sampling occurring during each N balance period. Linear (LBL) and quadratic broken-line and polynomial quadratic models were used to determine the optimum dietary Lys-to-NE ratios for maternal N retention in each week of lactation. The Bayesian information criterion was used to assess best fit. Dietary feeding program did not influence sow average daily feed intake in lactation, piglet average daily gain and body weight at weaning, or milk N output during any nitrogen balance period. Sows fed increasing SID Lys-to-NE ratios lost less body weight and backfat by the end of lactation (linear; P < 0.05). Sow N intake, N excretion, whole-body N retention (N intake – N excretion in urine and feces), and maternal N retention (whole-body N retention – milk N output) increased as dietary SID Lys-to NE ratio increased within each N balance period (linear; P < 0.05). The LBL model showed the optimal SID Lys-to-NE ratio for maternal N retention was out of the range of the dietary treatments for week one, but maternal N retention was optimized at 4.74 and 4.85 g SID Lys/Mcal NE in weeks two and three, respectively. Therefore, a dynamic SID Lys-to-NE ratio during each week of lactation could be implemented to enhance maternal N retention of primiparous sows.
摘要译文
【摘要】募集了五十五个产头母猪，以评估增加标准化的回肠消化不良（SID）Lys-NET能量（NE）比率对哺乳期每周哺乳期在哺乳期的每周的产母氮的保留，牛奶氮输出和小猪生长效果。母猪被分配给五个饮食中的一种，其间距且SID Lys-ne比率增加了2.85至5.51 g Sid Lys/McAl NE。通过使用饲料混合能力将两种极端饮食混合成不同比例，可以实现中间比，并在饲养后立即提供给母猪，直到断奶（D 24±1）。在第4至第7（第1周），第12和15（第2周）以及20和23（第3周）之间进行了氮（N）平衡，在每个N余额期间进行总尿液和粪便抓取抽样。线性（LBL）和二次断裂线和多项式二次模型用于确定在哺乳期每周保持母体N保留的最佳饮食Lys-ne比率。贝叶斯信息标准用于评估最佳拟合度。饮食喂养计划不会影响母猪在哺乳期的平均每日饲料摄入量，在断奶时的平均每日增益和体重，或在任何氮平衡期内产量的牛奶N产量。在哺乳期结束时，喂养增加的SID LYS与NE比率的母猪减少了体重和背脂力（线性； P <0.05）。随着饮食中的SID SID SID LYS与NE的比例增加，SOW N摄入量，N排泄，全身N保留（N摄入量 - N摄入量）以及母体N保留率（全身N保留 - 牛奶N输出）在每个N平衡周期内增加（线性；线性； P <0.05）。LBL模型显示，母体N保留率的最佳SID LYS与NE的比率超出了第一周的饮食处理范围，但是在第二和第三周中，母体N保留率分别在4.74和4.74和4.85 g SID LYS/MCAL NE中优化。因此，可以在泌乳的每个星期内实施动态的SID LYS与NE比率，以增强产妇的n保留。
Nicole L Gregory [1];Lee-Anne Huber [2];. The standardized ileal digestible lysine-to-net energy ratio in the diets of lactating primiparous sows to optimize maternal nitrogen retention is dynamic but does not impact piglet performance[J]. Journal of Animal Science, 2025,103