Monogastric Research Centre, School of Agriculture and Environment, Massey University, Palmerston North 4442, New Zealand.
Poult Sci. 2019 Nov 1;98(11):5504-5513. doi: 10.3382/ps/pez206.
The interaction between bird type (broilers and layers) and corn particle size (fine, medium, and coarse) on the coefficient of apparent ileal digestibility (CAID) of DM, nitrogen (N), starch, fat, gross energy (GE), calcium (Ca) and phosphorus (P), and AMEn was investigated in a 2 by 3 factorial study of 6 dietary treatments. Whole corn was ground in a hammer mill to pass through screen sizes of 2.0, 5.0, and 8.0 mm for fine, medium, and coarse grades, respectively. A corn-soybean meal diet, mixed using the same batch of ingredients, was fed to both bird types. Titanium dioxide was included in all diets for digestibility measurements. 35-day-old Ross 308 male broilers and 59-wk-old Hy-Line Brown layers were used in this study. For each bird type, 108 birds of uniform body weights were accommodated in 18 replicates (6 replicates per particle size and 6 birds per replicate). The treatment diets were offered ad libitum for 7 d prior to the collection of ileal digesta. A bird type by particle size interaction was observed (P < 0.001) for the CAID of DM, starch and GE. In broilers, CAID of DM, starch and GE was unaffected by particle size, whilst in layers, increasing the corn particle size to medium and coarse resulted in a greater (P < 0.05) CAID for DM, starch and GE compared to fine particles. The CAID of N and fat was greater (P < 0.05) in broilers than layers and the opposite was observed (P < 0.05) for Ca and P. Regardless of bird type, coarse and medium-ground corn resulted in a greater (P < 0.05) Ca digestibility compared to finely-ground corn. Overall, broilers had a greater digestibility of nutrients than layers, except for Ca and P. Feeding medium and coarse corn particles benefited the CAID of DM, starch and GE in layers, suggesting that digestive system in these birds is probably more sensitive to feed particle size than broilers.
本试验采用 2×3 因子设计，研究了饲粮玉米粒度（细、中、粗）和鸡类型（肉鸡和蛋鸡）对肉鸡和蛋鸡表观回肠可消化率（CAID）、DM、氮（N）、淀粉、脂肪、总能（GE）、钙（Ca）、磷（P）和代谢能（AME）的影响。将整粒玉米用锤片式粉碎机粉碎，通过 2.0、5.0 和 8.0mm 的筛片，分别得到细、中、粗 3 个等级的玉米。使用同一批原料配制玉米-豆粕型饲粮，分别饲喂 2 种鸡类型。所有饲粮中均添加 TiO2 以进行消化率测定。试验选用 35 日龄的罗斯 308 雄性肉鸡和 59 周龄的海兰褐蛋鸡。每种鸡类型选用体质量均匀的 108 只鸡，设 18 个重复（每个粒度 6 个重复，每个重复 6 只鸡）。在收集回肠食糜前，2 种鸡类型的鸡自由采食试验饲粮 7d。鸡类型和粒度间存在互作（P＜0.001），对 DM、淀粉和 GE 的 CAID 有影响。肉鸡的 DM、淀粉和 GE 的 CAID 不受粒度影响，而蛋鸡中，随着玉米粒度从中粒和大粒增加，DM、淀粉和 GE 的 CAID 比细粒玉米更高（P＜0.05）。肉鸡的 N 和脂肪的 CAID 高于蛋鸡（P＜0.05），而 Ca 和 P 的情况则相反（P＜0.05）。不论鸡类型如何，粗粒和中粒玉米的 Ca 消化率均高于细粒玉米（P＜0.05）。总的来说，除了 Ca 和 P，肉鸡对营养素的消化率高于蛋鸡。对于蛋鸡，中粒和大粒玉米有利于 DM、淀粉和 GE 的 CAID，表明这些鸡的消化系统对饲料粒度可能比肉鸡更敏感。
