Song Mingqiang, Ren Cong, Liu Youyou, Ye Xiaomeng, Wang Yuming, Xie Jingjing, Zhao Feng
The State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
The State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Poult Sci. 2024 Dec;103(12):104417. doi: 10.1016/j.psj.2024.104417. Epub 2024 Oct 12.
The objective of this study was to compare the properties of small intestinal fluid (SIF) from white- and yellow-feathered broilers fed variable dietary CP to test the hypothesis that digestive enzymes sourced from the SIF of yellow-feathered broilers could serve as a viable alternative for preparing in vitro SIF specifically for white-feathered broilers. Ten Arbor Acres Plus broilers (32 days of age) and 20 Chinese yellow chickens (51 days of age) were fitted with jejunal cannulas and assigned to dietary treatments as follows: 1) white-feathered broilers (BW of 4.08 ± 0.39 kg) fed diet 1 with CP of 19.88 %, 2) yellow-feathered broilers (BW of 2.89 ± 0.27 kg) fed diet 1, and 3) yellow-feathered broilers (BW of 2.84 ± 0.20 kg) fed diet 2 with CP of 16.32 %. Each treatment contained 10 replicates with 1 broiler in each replicate. Digestive enzyme activities, ion concentrations, pH, 16 amino acid (AA, excluding Tyr and Trp) contents, molecular weight distribution (MWD) of protein, hydrolysis rates on wheat starch, corn starch, casein, and soybean protein concentrate, and in vitro digestible energy of corn, soybean meal, and corn gluten meal were evaluated for SIF. Activities of chymotrypsin and amylase, pH, concentrations (mg/mL) of total amino acid (TAA) and 13 AA (excluding Pro, Cys, and Glu), and hydrolysis rates in casein or soybean protein concentrate were greater (P < 0.05), whereas MWD of protein from 19 to 23 kDa was lower (P < 0.05) in the SIF of yellow compared to white-feathered broilers fed diet 1. Furthermore, activities of chymotrypsin and amylase, concentrations of Na, and Cl, MWD of protein from 15 to 18 kDa were greater, while concentrations of K were lower in the SIF of yellow-feathered broilers fed diet 2 compared to white feathered broilers fed diet 1. Activities of chymotrypsin and amylase, K concentration, pH, TAA and 13 AA (excluding Pro, Cys, and Glu), hydrolysis rates in casein or soybean protein concentrate increased (P < 0.05), while concentrations of Na and Cl (P < 0.05) decreased with dietary CP in SIF from yellow-feathered broilers. This experiment demonstrated diet composition and breed modulate digestive enzyme activities, ions (Na, K, Cl), pH, and AA concentrations in the SIF. Our findings revealed no substantial difference in the hydrolytic characteristics of SIF from white-feathered broilers fed diet 1 and yellow-feathered broilers fed diet 2. Consequently, it is feasible to use digestive enzymes extracted from the SIF of yellow-feathered broilers to prepare simulated SIF for in vitro digestion of white-feathered broilers.
本研究的目的是比较饲喂不同粗蛋白（CP）日粮的白羽肉鸡和黄羽肉鸡小肠液（SIF）的特性，以验证以下假设：源自黄羽肉鸡SIF的消化酶可作为一种可行的替代物，用于专门为白羽肉鸡制备体外SIF。将10只爱拔益加优质肉鸡（32日龄）和20只中国黄羽鸡（51日龄）安装空肠插管，并分配到以下日粮处理组：1）饲喂CP含量为19.88%的日粮1的白羽肉鸡（体重4.08±0.39千克）；2）饲喂日粮1的黄羽肉鸡（体重2.89±0.27千克）；3）饲喂CP含量为16.32%的日粮2的黄羽肉鸡（体重2.84±0.20千克）。每个处理组有10个重复，每个重复1只肉鸡。对SIF评估了消化酶活性、离子浓度、pH值、16种氨基酸（AA，不包括酪氨酸和色氨酸）含量、蛋白质分子量分布（MWD）、对小麦淀粉、玉米淀粉、酪蛋白和大豆浓缩蛋白的水解率，以及玉米、豆粕和玉米蛋白粉的体外可消化能量。与饲喂日粮1的白羽肉鸡相比，黄羽肉鸡SIF中的胰凝乳蛋白酶和淀粉酶活性、pH值、总氨基酸（TAA）和13种AA（不包括脯氨酸、半胱氨酸和谷氨酸）的浓度（毫克/毫升）以及在酪蛋白或大豆浓缩蛋白中的水解率更高（P<0.05），而19至23千道尔顿的蛋白质MWD更低（P<0.05）。此外，与饲喂日粮1的白羽肉鸡相比，饲喂日粮2的黄羽肉鸡SIF中的胰凝乳蛋白酶和淀粉酶活性、钠和氯的浓度、15至18千道尔顿的蛋白质MWD更高，而钾的浓度更低。黄羽肉鸡SIF中，胰凝乳蛋白酶和淀粉酶活性、钾浓度、pH值、TAA和13种AA（不包括脯氨酸、半胱氨酸和谷氨酸）、在酪蛋白或大豆浓缩蛋白中的水解率随日粮CP增加而升高（P<0.05），而钠和氯的浓度（P<0.05）降低。本实验表明日粮组成和品种可调节SIF中的消化酶活性、离子（钠、钾、氯）、pH值和AA浓度。我们的研究结果显示，饲喂日粮1的白羽肉鸡和饲喂日粮2的黄羽肉鸡SIF的水解特性没有实质性差异。因此，利用从黄羽肉鸡SIF中提取的消化酶制备模拟SIF用于白羽肉鸡的体外消化是可行的。
