1. Changes in feather length and weight and daily losses of down, contour feathers, remiges and retrices were studied in two commercial broiler strains to determine feather growth and moult in broilers up to 112 d of age.

2. Ten pens of 20 chicks for each sex x strain were fed adequate amounts of dietary protein in a four-phase feeding programme. Ten birds were sampled per genotype at 14, 28, 42, 56, 70, 84, 98 and 112 d. Feather loss was determined for individual birds caged within a nylon net.

3. All feathers were dry-plucked from each of seven tracts, with representative feathers from the capital-cervical, dorsopelvic and interscapular, pectoral and femoral tracts being randomly selected. Three rectrices of the dorsocaudal tract and three primaries and secondaries of the humeral-alar tract of the right wing were evaluated.

4. The length of the selected feathers was measured, and the feathers from each tract and from the whole bird were weighed.

5. A wide range of rates of maturing (0.0250–0.0907/d) and mature weights (9.62–52.9 g) were evident between sampled tracts.

6. Feather weight failed to predict some moults which were detected by the measurement of feather losses. From the weight data, moulting was evident only in the humeral-alar and dorsocaudal tracts, whereas, when daily losses were measured, contour feathers accounted for over 0.7 proportion of feather losses. Logistic equations adequately described the cumulative losses of down, contour feathers and remiges.

7. Feather loss needs to be considered when feather growth is determined from feather weight at different ages.

8. The rate of maturing (B) of feathers was numerically higher in Ross males and females than in the Cobb strain. In females, B was higher than in males (0.0483 vs. 0335/d) but the mature weight was lower (162 vs. 230 g).

1.在两种商业肉鸡品系中研究了羽毛长度和重量的变化以及羽绒，轮廓羽毛，迁移和and丝的每日损失，以确定不超过11​​2天龄的肉鸡的羽毛生长和换羽。

2.在四个阶段的饲喂程序中，给每种性别x品系的20只小鸡的十只钢笔饲喂足够量的饮食蛋白。每个基因型在第14、28、42、56、70、84、98和112天取样了10只鸡。确定笼养在尼龙网中的个体禽的羽毛损失。

3.从七个道中的每一个拔干所有羽毛，并随机选择来自首都子宫颈，背盆腔和肩inter间，胸和股骨的代表性羽毛。评估了三个尾鳍的直肠和右翼的肱骨-鼻道的三个原发和继发。

4.测量所选羽毛的长度，并称重各道和整只鸡的羽毛。

5.样品之间的成熟率（0.0250–0.0907 / d）和成熟体重（9.62–52.9 g）的范围很广。

6.羽毛重量无法预测通过测量羽毛损失而检测到的换羽现象。从重量数据来看，换羽仅在肱骨和背尾部明显，而当测量每日损失时，轮廓羽毛占羽毛损失的0.7％以上。Logistic方程充分描述了羽绒，轮廓羽毛和迁移的累积损失。

7.根据不同年龄的羽毛重量确定羽毛的生长时，需要考虑羽毛损失。

8.在罗斯雄性和雌性中，羽毛的成熟率（B）在数值上高于科布氏菌株。女性中的B高于男性（0.0483 vs. 0335 / d），但成熟体重较低（162 vs. 230 g）。