Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, China; Key Laboratory for Animal Disease-Resistance Nutrition, Ministry of Education, Ministry of Agriculture and Rural Affaires, Sichuan Province, China, 611130.
Department of Poultry Science, University of Georgia, 110 Cedar St. Athens, GA, 30602, USA.
Poult Sci. 2020 Feb;99(2):1001-1009. doi: 10.1016/j.psj.2019.10.012. Epub 2019 Dec 10.
This study was conducted to determine whether protein solubility (PS) of rapeseed meals (RSM) can affect standardized ileal amino acid digestibility (SIDAA) in meat ducks. A total of 1,168, 14-days-old ducks were randomly allotted to 23 treatments (6 cages per diet, 8 ducks per cage) and 1 nitrogen-free diet treatment (8 cages, 8 ducks per cage) based on body weight. The 23 experimental diets consisted of a corn-soybean meal basal diet, and 22 diets containing 15% RSM: 85% basal diet. Titanium dioxide (0.5%) was included in all diets as an indigestible marker. On day 18, all ducks were euthanized by carbon dioxide asphyxiation and digesta samples from the ileum. The contents of PS, ether extract (EE), glucosinolate, isothiocyanate, and oxazolidine were significantly different (P < 0.05) in the 22 RSM, with the CV being 52.62, 49.23, 86.84, 90.19, and 81.98%, respectively. The content of lysine (Lys) and methionine in the 22 RSM samples ranged from 1.03 to 2.71% (CV 24.19%) and from 0.33 to 0.65% (CV 15.17%), respectively. The SIDAA, except for leucine (Leu) and tyrosine, of the 22 RSM samples varied significantly (P < 0.05). A positive correlation was observed (P < 0.05) between PS and standardized ileal digestibility (SID) of Lys, isoleucine, valine, phenylalanine, histidine, serine, cysteine, and tyrosine. The R value of multiple linear regression equations for predicting the SID of amino acids (AA) was best for Lys (R = 0.958 using dry matter, crude protein, EE, crude fiber, acid detergent fiber, and PS) and least significant for Leu (R = 0.348 using crude fiber and ash) with intermediate values for other AA (R = 0.359-0.837, P < 0.05). These results suggest that PS varying from 15.06 to 98.08%, also varied considerably in the proximate nutrient content, AA composition, and antinutritional factor content, which was reflected in considerable differences in the duck's SID of AA in RSM. Therefore, PS value can partly reflect the quality of RSM.
本研究旨在探讨菜籽粕（RSM）的蛋白质溶解度（PS）是否会影响肉鸭的标准回肠氨基酸消化率（SIDAA）。将 1168 只 14 日龄的鸭子随机分为 23 个处理组（每饲料 6 个笼，每个笼 8 只鸭子）和 1 个无氮饲料处理组（8 个笼，每个笼 8 只鸭子），基于体重。23 种实验饲料包括玉米-豆粕基础饲料和 22 种含 15%RSM 的饲料：85%基础饲料。所有饲料中均添加 0.5%二氧化钛作为不可消化标记物。在第 18 天，所有鸭子均通过二氧化碳窒息法安乐死，并从回肠中采集食糜样本。22 种 RSM 的 PS、乙醚提取物（EE）、硫代葡萄糖苷、异硫氰酸酯和恶唑烷的含量存在显著差异（P<0.05），变异系数分别为 52.62%、49.23%、86.84%、90.19%和 81.98%。22 种 RSM 样品中赖氨酸（Lys）和蛋氨酸的含量范围为 1.03-2.71%（变异系数 24.19%）和 0.33-0.65%（变异系数 15.17%）。22 种 RSM 样品的 SIDAA 除亮氨酸（Leu）和酪氨酸外，差异均有统计学意义（P<0.05）。PS 与 Lys、异亮氨酸、缬氨酸、苯丙氨酸、组氨酸、丝氨酸、半胱氨酸和酪氨酸的 SID 呈正相关（P<0.05）。预测氨基酸（AA）SID 的多元线性回归方程的 R 值对 Lys（用干物质、粗蛋白、EE、粗纤维、酸性洗涤纤维和 PS 预测，R=0.958）的预测最佳，对 Leu（用粗纤维和灰分预测，R=0.348）的预测最不显著，对其他 AA（R=0.359-0.837，P<0.05）的预测值介于两者之间。这些结果表明，PS 值在 15.06%至 98.08%之间变化，其近似营养成分、AA 组成和抗营养因子含量也有很大差异，这反映在 RSM 中鸭 AA 的 SID 存在很大差异。因此，PS 值可以部分反映 RSM 的质量。
