Abstract

Two trials were conducted to investigate the effects of different corn conditioning temperature and enzyme supplementation on nutrient utilisation, growth performance, and small intestine morphology in broiler chickens. In trial one, nutrient utilisation were determined in basal diets. These diets contained unconditioned or conditioned corn (temperatures 55, 70 and 85 °C) supplemented with enzyme (Rovabio^®) at the levels of 0 and 0.5‌ g/kg. Total excreta collection was performed with 144 chicks in 8 treatments with 6 replicates and 3 birds each, during 7–9 d. In trial two, 576 day-old broilers were distributed in 8 treatments, 6 pens and 12 chicks each. Birds were fed with diets containing conditioned corn in aforementioned temperatures and enzyme levels. A completely randomised design with 4 × 2 factorial arrangement was used in both trials. Conditioning of corn and enzyme supplementation had no significant effects on apparent metabolisable energy (AME) of corn and apparent total tract retention (ATTR) of corn nitrogen (N). In second trial, no significant differences were observed in growth performance of broilers during 1–24 d. Feed conversion ratio (FCR) in birds fed diets containing conditioned corn at 85 °C was significantly higher than that of 55 and 70 °C during 1–10 d. Corn conditioning significantly increased villus width (VW) and crypt depth (CD) but decreased VW:CD ratio. Enzyme supplementation increased jejunum villus height (VH), VW and ileal lactobacillus count and decreased pancreas weight at 24 ‌d (p‌ <‌ .05). Generally, corn conditioning and enzyme supplementation did not significantly affect growth performance and carcase traits of broilers during 1–24 d, but improved histology and microbial population of small intestine.

• HIGHLIGHTS

• Conditioning of corn used in mash diets of broiler chickens increased the population of bifidobacteria.

• Enzyme supplementation to the diets of broilers increased the height and width of intestinal villi.

• Enzyme supplementation to the diets of broilers decreased relative weight of pancreas.

摘要

进行了两项试验以研究不同玉米调理温度和酶补充剂对肉鸡营养利用、生长性能和小肠形态的影响。在试验一中，在基础日粮中测定营养利用。这些日粮包含未调理或调理的玉米（温度 55、70 和 85 °C），并辅以酶 (Rovabio ^®) 的水平为 0 和 0.5 克/千克。在 7-9 天期间，对 144 只小鸡进行了 8 个处理，每个处理 6 个重复和 3 只鸡的总排泄物收集。在试验二中，576 头日龄肉鸡被分配到 8 个处理组，每个处理组 6 个围栏和 12 只小鸡。在上述温度和酶水平下，用含有调理玉米的饲料喂养鸟类。两项试验均使用具有 4 × 2 析因排列的完全随机设计。玉米调理和酶补充剂对玉米的表观代谢能（AME）和玉米氮（N）的表观全道保留率（ATTR）没有显着影响。在第二次试验中，肉鸡在 1-24 天的生长性能没有显着差异。在 1-10 天期间，饲喂含有 85 °C 条件玉米的日粮的鸟类的饲料转化率 (FCR) 显着高于 55 和 70 °C。玉米调理显着增加了绒毛宽度 (VW) 和隐窝深度 (CD)，但降低了 VW:CD 比率。酶补充剂增加了空肠绒毛高度 (VH)、VW 和回肠乳酸菌计数，并在 24 d 时降低了胰腺重量（p‌ <‌ .05）。一般来说，玉米调理和酶补充剂在 1-24 d 期间对肉鸡的生长性能和胴体性状没有显着影响，但改善了小肠的组织学和微生物种群。

• 强调

• 肉鸡饲料中使用的玉米调理增加了双歧杆菌的数量。

• 肉鸡日粮中的酶补充剂增加了肠绒毛的高度和宽度。

• 在肉鸡日粮中添加酶可降低胰腺的相对重量。