Limitations in beak size of newly hatched chicks have led the majority of broiler integrators in the United States to feed crumbles during the starter period. Previous research has reported improved growth performance on birds fed micro pellets during the starter period. However, research evaluating the effects of feeding micro pellets in the grower and finisher periods of broilers is sparse. Two experiments were conducted to determine the effects of feeding varying feed forms on growth performance and carcass characteristics of broilers during the starter, grower and finisher periods. In experiment 1, birds were fed diets with 3 feed forms: mash, crumbles, and 3.3 mm micro pellets during the starter period from 1 to 14 d (25 birds/pen; 8 replicate pens/treatment). In experiment 2, a 3 × 2 factorial arrangement of 3 feed forms (mash, 4.4 mm pellets, and 3.3 mm micro pellets) and 2 amino acid (AA) densities (88% and 96% of Aviagen recommendations Ross® 708 2014) were provided from 1 to 42 d (24 birds/pen; 7 replicate pens/treatment). In both experiments, birds fed 3.3 mm micro pellets during the starter period had lower feed conversion ratio compared with those that received mash and crumbles from 1 to 14 d (P< 0.05). In experiment 2, birds fed diets with 96% of AA recommendations had higher body weight, carcass yield, carcass and breast meat weight, and lower FCR than birds fed diets with 88% (P< 0.05). These data indicated that broilers can be fed 3.3 mm micro pellets during the starter and/or during the whole production period of broilers.

新孵出的雏鸟喙尺寸的局限性导致美国大多数肉鸡生产商在起步阶段喂碎肉。先前的研究已经报道了在开始阶段饲喂微颗粒的禽类的生长性能得到改善。但是，评估在肉鸡的生长期和育肥期饲喂微颗粒效果的研究很少。进行了两个实验，以确定在饲喂期，成长期和育肥期饲喂不同饲料形式对肉鸡生长性能和car体特性的影响。在实验1中，在开始阶段的1至14天（25只禽/笔； 8个重复的围栏/处理）中，以三种饲料形式给禽饲喂了饲料：，碎和3.3毫米的微丸。在实验2中，将3种饲料形式的3×2因式排列方式（饲料，4种 1至42天（24只/笔； 7支重复笔/处理）提供了4毫米颗粒和3.3毫米微颗粒）和2种氨基酸（AA）密度（Aviagen建议使用的Ross®708 2014为88％和96％） ）。在这两个实验中，在开始阶段喂食3.3毫米微丸的禽类的饲料转化率均低于在1到14 d内喂入捣碎和粉碎的禽类的饲料转化率（P <0.05）。在实验2中，与饲喂88％的鸟类相比，饲喂建议的AA含量为96％的鸟类具有更高的体重，car体产量，and体和胸肉重量，且FCR更低（P <0.05）。这些数据表明，在起子和/或整个生产过程中，可向肉鸡饲喂3.3毫米的微丸。