Xu Huimin, Dai Shujun, Zhang Keying, Ding Xuemei, Bai Shiping, Wang Jianping, Peng Huanwei, Zeng Qiufeng
Institute of Animal Nutrition, Key Laboratory for Animal Disease-Resistance Nutrition of China, Ministry of Education, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
Asian-Australas J Anim Sci. 2019 Dec 1;32(12):1897-1906. doi: 10.5713/ajas.18.0683. Epub 2019 Apr 15.
An experiment was conducted to investigate the effects of dietary non-phytate phosphorus (nPP) deficiency on intestinal pH value, digestive enzyme activity, morphology, nutrient utilization, and gene expression of NaPi-IIb in meat ducks from 1 to 21 d of age.
525 one-d-old Cherry Valley ducklings were fed diets (with 7 pens of 15 ducklings, or 105 total ducklings, on each diet) with five levels of nPP (0.22, 0.34, 0.40, 0.46 or 0.58%) for 21 d in a completely randomized design. Five experimental diets contained a constant calcium (Ca) content of approximately 0.9%. Body weight (BW), body weight gain (BWG), feed intake (FI), and feed to gain ratio (F: G) were measured at 14 and 21 d of age. Ducks were sampled for duodenum and jejunum digestion and absorption function on 14 and 21 d. Nutrient utilization was assessed using 25- to 27-d-old ducks.
The results showed ducks fed 0.22% nPP had lower (P<0.05) growth performance and nutrient utilization and higher (P<0.05) serum Ca content and alkaline phosphatase (ALP) activity. When dietary nPP levels were increased, BW(d 14 and 21), BWG and FI (all intervals), and the serum phosphorus (P) content linearly and quadratically increased (P<0.05); and the jejunal pH value (d 14), duodenal muscle layer thickness (d 14), excreta dry matter, crude protein, energy, Ca and total P utilization linearly increased (P<0.05); however, the serum alkaline phosphatase (ALP) activity, jejunal Na+-K+-ATPase activity, and duodenal NaPi-IIb mRNA level (d 21) linearly decreased (P<0.05).
The results indicated that ducks aged from 1 to 21d fed diets with 0.22% nPP had poor growth performance related to poor intestinal digestion and absorption ability; but when fed diets with 0.40%, 0.46% and 0.58% nPP, ducks presented a better growth performance, intestinal digestion and absorption function.
进行一项实验，以研究日粮非植酸磷（nPP）缺乏对1至21日龄肉鸭肠道pH值、消化酶活性、形态、养分利用率以及NaPi-IIb基因表达的影响。
采用完全随机设计，将525只1日龄樱桃谷鸭雏鸭分为7组，每组15只（或每种日粮共105只），分别饲喂含5种nPP水平（0.22%、0.34%、0.40%、0.46%或0.58%）的日粮21天。5种实验日粮的钙（Ca）含量均恒定在约0.9%。在14日龄和21日龄时测量体重（BW）、体重增加量（BWG）、采食量（FI）和料重比（F:G）。在14日龄和21日龄时对鸭的十二指肠和空肠进行采样，以评估消化吸收功能。使用25至27日龄的鸭评估养分利用率。
结果显示，饲喂0.22% nPP日粮的鸭生长性能和养分利用率较低（P<0.05），血清钙含量和碱性磷酸酶（ALP）活性较高（P<0.05）。当日粮nPP水平升高时，14日龄和21日龄的BW、BWG和FI（各阶段）以及血清磷（P）含量呈线性和二次曲线增加（P<0.05）；空肠pH值（14日龄）、十二指肠肌层厚度（14日龄）、排泄物干物质、粗蛋白、能量、钙和总磷利用率呈线性增加（P<0.05）；然而，血清碱性磷酸酶（ALP）活性、空肠Na+-K+-ATP酶活性和十二指肠NaPi-IIb mRNA水平（21日龄）呈线性下降（P<0.05）。
结果表明，1至21日龄的鸭饲喂含0.22% nPP日粮时，生长性能较差，与肠道消化吸收能力差有关；但饲喂含0.40%、0.46%和0.58% nPP日粮时，鸭的生长性能、肠道消化吸收功能较好。
