School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, Southwell, NG25 0QF, United Kingdom.
School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, Southwell, NG25 0QF, United Kingdom.
Poult Sci. 2023 Oct;102(10):102979. doi: 10.1016/j.psj.2023.102979. Epub 2023 Jul 28.
Dietary fibres with increased particle size may develop foregut more efficiently in meat poultry fed diets moderately low in crude protein. The study investigated the performance of broilers fed low-density crude protein diets with the inclusion of oat hulls increasing in particle size. Ross 308 male broiler chicks (n = 336) were divided into 48 pens, 12 pens per treatment (7 chicks per pen). Pens were allocated to 4 dietary treatments in mash form; positive control (PC), a standard crude protein diet, negative control (NC), around 5% lower in protein with 5% celite as an inert material, OH400: 5% lower protein diet with 5% oat hulls of geometric mean diameter (GMD) 400 µm, OH850: 5% lower protein diet with 5% oat hulls of GMD 850µm. Birds were fed ad libitum from d 1 to 35 in 3 phases; starter: d 0 to 10, grower: d 10 to 24 and finisher: d 24 to 35. Growth performance was calculated at the end of the trial. Two birds per pen were sampled on d 24 and 35 to collect data on proventriculus and gizzard weights and pooled ileal digesta. Apparent ileal digestibility of amino acids on d 24, and metabolizable energy on d 24 and 35 were recorded for each pen. Litter was sampled from each pen on d 34 to analyze litter N and moisture content. Footpad dermatitis scores of all birds per pen were recorded on d 35. Overall, no difference (P > 0.05) in body weight gain and feed intake was found between the treatments. However, NC and OH400 showed poorer FCR than PC, whereas FCR on PC and OH850 was similar (P > 0.05). Gizzard absolute weight and relative to body weight, and gizzard to proventriculus ratio were higher (P < 0.05) on OH850 compared to PC and NC on d 24 and 35. Gizzard digesta particle size was reduced (P < 0.05) on OH850 compared to all other diets on d 24 and 35. Amino acids digestibility coefficients for aspartic acid and valine increased (P < 0.05) in birds fed OH850 compared to PC, whereas coefficients for several other amino acids were improved compared to NC and OH400. The apparent ileal digestibility of metabolizable energy was similar (P > 0.05) between PC and OH850. Litter moisture and nitrogen, and footpad dermatitis scores were reduced (P < 0.05) on OH850 compared to PC. In conclusion, the inclusion of coarse oat hulls of GMD 850 µm in low-density crude protein diets can be beneficial for the broilers in developing the foregut, utilizing the nutrients efficiently and reducing litter nitrogen and moisture, and footpad scores.
在粗蛋白水平适中降低的日粮中添加粒径增大的膳食纤维可能更有效地促进肉禽前胃的发育。本研究探讨了在添加粒径增大的燕麦壳的低蛋白密度日粮中饲养肉鸡的性能。罗斯 308 雄性肉鸡（n=336）分为 48 个围栏，每个处理 12 个围栏（每个围栏 7 只鸡）。围栏以 4 种日粮处理形式分配；阳性对照（PC），标准粗蛋白日粮，阴性对照（NC），蛋白水平低约 5%，并用 5%硅灰石作为惰性物质，OH400：蛋白水平低 5%的日粮，含有 5%的燕麦壳，平均粒径（GMD）为 400µm，OH850：蛋白水平低 5%的日粮，含有 5%的燕麦壳，GMD 为 850µm。从第 1 天到第 35 天，鸡群以自由采食的方式分 3 个阶段饲养：开始：第 0 天至第 10 天，生长：第 10 天至第 24 天，育肥：第 24 天至第 35 天。试验结束时计算生长性能。每个围栏随机选择 2 只鸡，于第 24 天和第 35 天收集前胃和肌胃重量和回肠食糜数据。每个围栏记录第 24 天的氨基酸表观回肠消化率和代谢能，第 24 天和第 35 天的代谢能。于第 34 天从每个围栏中采集垫料样本，以分析垫料中的氮和水分含量。于第 35 天记录每个围栏中所有鸡的脚垫皮炎评分。总的来说，处理之间的体重增重和采食量没有差异（P＞0.05）。然而，NC 和 OH400 的 FCR 低于 PC，而 PC 和 OH850 的 FCR 相似（P＞0.05）。第 24 天和第 35 天，OH850 组的肌胃绝对重量和相对体重以及肌胃与前胃的比例高于 PC 和 NC 组（P＜0.05）。第 24 天和第 35 天，与其他所有日粮相比，OH850 组的肌胃食糜粒径减小（P＜0.05）。与 PC 相比，饲喂 OH850 的鸡的天冬氨酸和缬氨酸的氨基酸消化率系数增加（P＜0.05），而与 NC 和 OH400 相比，其他几种氨基酸的系数也有所提高。PC 和 OH850 的代谢能表观回肠消化率相似（P＞0.05）。与 PC 相比，OH850 组的垫料水分和氮含量以及脚垫皮炎评分降低（P＜0.05）。综上所述，在低蛋白密度日粮中添加平均粒径为 850µm 的粗燕麦壳，可促进肉鸡前胃发育，提高养分利用率，降低垫料氮和水分含量，减少脚垫评分。
