Department of Poultry Science, University of Arkansas at Fayetteville, AR 72701, USA.
Department of Poultry Science, Auburn University, Auburn, AL 36849, USA.
Poult Sci. 2024 Oct;103(10):104037. doi: 10.1016/j.psj.2024.104037. Epub 2024 Jun 27.
Three experiments were conducted to evaluate P utilization in soybean meal (SBM), canola meal (CM), distillers dried grains with solubles (DDGS), corn fermented protein (CFP), and wheat middlings (WM) using different assays. In Experiment 1, phytic acid disappearance (myo-inositol 1,2,3,4,5,6-hexakis; InsPD) and inositol phosphate disappearance (InsP-PD) were determined using precision-fed cecectomized Leghorn roosters. Roosters were precision-fed 20 to 25 g of SBM, CM, DDGS, CFP, and WM. In Experiment 2, InsPD, InsP-PD, and standardized ileal digestibility (SID) of P at different Ca levels were determined using ad libitum-fed broiler chickens. Semi-purified cornstarch-dextrose-based diets containing SBM, CM, DDGS, CFP, and WM as the sole source of P were fed. All diets contained 0.21% P and limestone was added at the expense of dextrose to provide 0.30, 0.45, 0.60, and 0.75% Ca. In Experiment 3, P bioavailability relative to KHPO was determined based on tibia bone ash. Experiments contained 5 to 6 replicates per treatment. In Experiment 1 with precision-fed roosters, InsPD and InsP-PD ranged from 8 to 71% among feedstuffs, with the lowest (P < 0.05) disappearance being observed in SBM. In Experiment 2 with ad libitum-fed chickens, there was a Ca × ingredient interaction (P < 0.05) whereby increasing Ca linearly decreased (P < 0.05) InsPD, InsP-PD, and SID of P for all feedstuffs, excluding CFP. Estimated P digestibility calculated using InsPD in Experiment 1 was in good agreement with SID in Experiment 2 determined at 0.75% Ca, except for SBM. In Experiment 3, regression of bone ash content (mg/tibia) on supplemental P intake yielded P bioavailability values ranging from 30 to 81% among feedstuffs relative to KHPO, with the highest (P < 0.05) bioavailability being observed for DDGS and CFP. In conclusion, 1) InsPD in precision-fed roosters can provide preliminary indications of P digestibility in plant-based feedstuffs, 2) SID determined at 0.75% Ca was in good agreement with other bioassays, and 3) P in DDGS and CFP was highly available compared with other feedstuffs.
进行了三项实验，以使用不同的测定方法评估大豆粉（SBM）、菜粕（CM）、酒糟干物质（DDGS）、玉米发酵蛋白（CFP）和小麦麸皮（WM）中的磷利用率。在实验 1 中，使用精准喂食去盲肠的来航公鸡测定植酸消失率（肌醇 1,2,3,4,5,6-六磷酸；InsPD）和肌醇磷酸盐消失率（InsP-PD）。公鸡被精准喂食 20 到 25 克的 SBM、CM、DDGS、CFP 和 WM。在实验 2 中，使用自由采食的肉鸡测定不同钙水平下的 InsPD、InsP-PD 和磷的标准回肠可消化性（SID）。以 SBM、CM、DDGS、CFP 和 WM 为唯一磷源的半纯化玉米淀粉-葡萄糖基础日粮进行饲喂。所有日粮均含有 0.21%的磷，添加石粉以牺牲葡萄糖的方式提供 0.30%、0.45%、0.60%和 0.75%的钙。在实验 3 中，基于胫骨灰分测定相对于 KHPO 的磷生物利用率。每个处理组包含 5 到 6 个重复。在使用精准喂食公鸡的实验 1 中，饲料中 InsPD 和 InsP-PD 的范围为 8 到 71%，其中 SBM 的消失率最低（P < 0.05）。在使用自由采食鸡的实验 2 中，钙与成分之间存在交互作用（P < 0.05），即随着钙含量的线性增加，所有饲料的 InsPD、InsP-PD 和磷的 SID 均降低（P < 0.05），但 CFP 除外。使用实验 1 中的 InsPD 计算得到的磷消化率与实验 2 中在 0.75%钙下确定的 SID 吻合良好，除了 SBM。在实验 3 中，根据补充磷摄入量对胫骨灰分含量（mg/胫骨）进行回归，得到相对于 KHPO 的磷生物利用率值在 30 到 81%之间，其中 DDGS 和 CFP 的生物利用率最高（P < 0.05）。总之，1）精准喂食公鸡中的 InsPD 可初步反映植物性饲料中磷的消化率，2）在 0.75%钙下确定的 SID 与其他生物测定方法吻合良好，3）DDGS 和 CFP 中的磷与其他饲料相比具有较高的生物有效性。
