Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada.
J Anim Sci. 2020 May 1;98(5). doi: 10.1093/jas/skaa124.
This study was conducted to investigate the effects of dietary complexity and l-Thr supplementation on energy and nutrient utilization in nursery pigs. Thirty-two nursery pigs (7.23 ± 0.48 kg) were randomly assigned to a 2 × 2 factorial treatment arrangement based on diet complexity (complex vs. simple) with different levels of l-Thr supplementation. The complex diet contained animal protein sources (e.g., fish meal and plasma) and a dairy product (e.g., dried whey) to mimic a conventional nursery diet. The simple diet was formulated with corn, wheat, and soybean meal. Both diets were supplemented with l-Thr to contain either 100% or 115% (SUP Thr) of the estimated standardized ileal digestible Thr requirement for 9 kg body weight pigs (NRC, 2012). The pigs were individually housed in metabolism crates and fed an experimental diet ad libitum for a 7-d adaptation period and 5 d of total but separate urine and fecal collection. On day 14, all pigs were euthanized to determine body composition. The diet complexity, l-Thr supplementation, and their interactions were considered main effects. Pigs fed the complex diet tended to exhibit greater (P < 0.10) apparent total tract digestibility (ATTD) of ash and urinary energy output than those fed the simple diet. The complex diet had greater (P < 0.05) digestible energy and net energy contents than the simple diet. Furthermore, the complex diet-fed pigs had lower (P < 0.05) plasma urea nitrogen concentration on day 14 than simple diet-fed pigs. The SUP Thr decreased (P < 0.05) ATTD of acid detergent fiber but trended (P < 0.10) toward a decrease in urinary nitrogen (N) output and an increase in N retention and body N mass. In conclusion, the simple diet for nursery pigs had lower digestible and net energy contents than a complex diet. The SUP Thr can improve N utilization and body protein deposition, irrespective of diet complexity.
本研究旨在探究饲粮复杂程度和 l-苏氨酸（l-Thr）添加水平对仔猪能量和养分利用的影响。将 32 头体重为（7.23±0.48）kg 的仔猪随机分为 2×2 因子试验设计，根据饲粮复杂程度（复杂 vs. 简单）和不同水平的 l-Thr 添加分为 2 个处理。复杂饲粮含有动物蛋白源（如鱼粉和血浆）和乳制品（如乳清粉），以模拟传统的仔猪饲粮。简单饲粮由玉米、小麦和豆粕配制而成。2 种饲粮均添加 l-Thr，使其分别满足 9kg 体重猪的估计可消化苏氨酸需要量（NRC，2012）的 100%或 115%（SUP Thr）。仔猪单独饲养在代谢笼中，自由采食试验饲粮适应 7d，然后进行 5d 的尿液和粪便单独收集。第 14 天，所有仔猪处死以测定体组成。饲粮复杂程度、l-Thr 添加及其互作均设为主要效应。与饲喂简单饲粮的仔猪相比，饲喂复杂饲粮的仔猪表现出更高（P＜0.10）的总能表观全肠道消化率（ATTD）和尿能排出量，且复杂饲粮的可消化能和净能含量也高于简单饲粮。此外，饲喂复杂饲粮的仔猪在第 14 天的血浆尿素氮浓度也低于饲喂简单饲粮的仔猪（P＜0.05）。SUP Thr 降低了（P＜0.05）酸性洗涤纤维的 ATTD，但降低了（P＜0.10）尿氮（N）排出量，提高了 N 保留和体氮质量。综上所述，仔猪简单饲粮的可消化能和净能含量低于复杂饲粮。SUP Thr 可以提高氮利用和体蛋白质沉积，与饲粮复杂程度无关。
