Kim Eunjoo, Morgan Natalie K, Moss Amy F, Li Lily, Ader Peter, Choct Mingan
School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia.
BASF, South East Asia, 038987, Singapore.
Anim Nutr. 2022 Mar;8(1):153-159. doi: 10.1016/j.aninu.2021.09.011. Epub 2021 Oct 20.
This study was to characterise the undigested nutrients present along the gastrointestinal tract of birds offered common wheat- or maize-based diets, with the goal of optimising utilisation of enzymes to enhance digestive efficiency. Wheat- and maize-based diets were offered to 240 mixed-sex broilers (10 birds/pen; = 12) from 1 to 35 d post-hatch. Digestibility of dry matter, starch, crude protein and non-starch polysaccharides (NSP) were measured in the crop, gizzard, duodenum, jejunum, ileum, caeca and excreta at d 12 and 35 post-hatch. Analysis of nutrient levels in the excreta presented that more than 30% of nutrients provided in the feed was wasted, irrespective of wheat or maize diet type. On average, 92 g/kg crude protein, 92 g/kg insoluble NSP and 14 g/kg oligosaccharides were not utilised by birds at d 12 post-hatch. The quantity of water-insoluble NSP in the small intestine at d 12 was lower in birds offered the wheat-based diet compared to those fed the maize-based diet ( < 0.05), with the reverse being true for water-soluble NSP ( < 0.001). On average, 84 g/kg crude protein, 79 g/kg insoluble NSP and 9 g/kg oligosaccharides remained in the excreta at 35 d of age. At this time period, accumulation of feed in the gizzard was noted for birds offered both diets, but was more pronounced in those offered the maize-based diet ( < 0.001). Birds offered the maize-based diet demonstrated improved utilisation of oligosaccharides compared to those fed the wheat-based diet at both d 12 and 35 ( = 0.087 and = 0.047, respectively). Protein utilisation in the jejunum and ileum was greater in birds offered the wheat-based diet compared to those fed the maize-based diet ( = 0.004 and < 0.001, respectively). Thus, while both diets supported standard growth performance of birds, the degree and flow of nutrient disappearance along the gastrointestinal tract was influenced by cereal type and bird age.
本研究旨在表征以普通小麦或玉米为基础日粮的鸟类胃肠道中存在的未消化营养物质，目的是优化酶的利用以提高消化效率。从孵化后1至35天，给240只混合性别的肉鸡（每栏10只；共12栏）投喂以小麦和玉米为基础的日粮。在孵化后第12天和第35天，测定嗉囊、砂囊、十二指肠、空肠、回肠、盲肠和排泄物中干物质、淀粉、粗蛋白和非淀粉多糖（NSP）的消化率。排泄物中营养水平分析表明，无论日粮类型是小麦还是玉米，饲料中提供的营养物质超过30%被浪费。平均而言，孵化后第12天，鸟类未利用92 g/kg粗蛋白、92 g/kg不溶性NSP和14 g/kg寡糖。与饲喂玉米基础日粮的鸟类相比，饲喂小麦基础日粮的鸟类在第12天小肠中水溶性NSP的含量较低（P<0.05），而水溶性NSP的情况则相反（P<0.001）。平均而言，35日龄时，排泄物中仍有84 g/kg粗蛋白、79 g/kg不溶性NSP和9 g/kg寡糖。在此期间，两种日粮的鸟类砂囊中均有饲料积累，但以玉米为基础日粮的鸟类更为明显（P<0.001）。与饲喂小麦基础日粮的鸟类相比，饲喂玉米基础日粮的鸟类在第12天和第35天对寡糖的利用率均有所提高（分别为P=0.087和P=0.047）。与饲喂玉米基础日粮的鸟类相比，饲喂小麦基础日粮的鸟类空肠和回肠中的蛋白质利用率更高（分别为P=0.004和P<0.001）。因此，虽然两种日粮都能支持鸟类的标准生长性能，但营养物质在胃肠道中的消失程度和流动受谷物类型和鸟类年龄的影响。
