MEASUREMENT OF THE COMPONENTS OF THE CASHMERE GROWTH-CYCLE IN AUSTRALIAN CASHMERE GOATS
MEASUREMENT OF THE COMPONENTS OF THE CASHMERE GROWTH-CYCLE IN AUSTRALIAN CASHMERE GOATS
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DOI：
10.1016/0921-4488(95)00660-d
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发表时间：
1995-08-01
影响因子：
1.8
通讯作者：
KLOREN, WRL
中科院分区：
文献类型：
--
作者：
NORTON, BW;KLOREN, WRL
羊绒纤维的季节性生长和脱落使得羊毛总重量测量难以解释与环境和实验变量的关系。在研究营养和光周期对山羊绒生长的影响时，我们发展了一种技术，它提供了山羊绒生长速率、最大纤维长度、生长期长度、开始和停止生长日期等可供统计分析的数值。该方法要求每月在山羊的三个部位（肩部、中侧和臀部）测量羊绒长度。该模型假设，一旦启动，羊绒长度的增长率是线性的，直到停止，并开始生长发生在一个固定的时间由光周期控制。本文提供了一种定量估计纤维生长开始和停止日期以及测定山羊绒和毛纤维线性生长速率的方法。该方法包括在整个生长期内每隔28天测量羊绒纤维长度，并从与长度和取样日期相关的曲线图的线性部分计算羊绒生长速率。将该线外推至时间0提供了开始日期的估计值。然后将停止日期计算为观察到的最大长度与该线性图相交的日期，并将生长期估计为开始和停止日期之间的差值。这个简单的模型被发现密切配合观察到的数据从个人或群体的山羊，并与适当的措施的变化，允许这些值的统计比较个人或群体之间。
Seasonal growth and shedding of cashmere fibre makes total fleece weight measurements difficult to interpret in relation to environmental and experimental variables. In studies of the effects of nutrition and photoperiod on cashmere growth, a technique has been developed which provides statistically analysable values for growth rates, maximum fibre length, length of growing period, and for dates of initiation and cessation of cashmere fibre growth. This method requires the measurement of cashmere length at monthly intervals at three sites (shoulder, midside and hip) on the goat. The model assumes that once initiated, the rate of cashmere length increase was linear until cessation, and that the initiation of growth occurs at a fixed time controlled by photoperiod. This paper provides a method for quantitative estimation of the dates of initiation and cessation of fibre growth, and for determining the linear rates of cashmere and hair fibre growth. The method involves the measurement of cashmere fibre length at 28 day intervals over the period of growth, and calculation of rate of cashmere growth from the linear portion of the graph relating length and date of sampling. Extrapolation of this line to time 0 provides an estimate of initiation date. Cessation date is then calculated as the date where maximum length observed intersects this linear plot, and the period of growth estimated as the difference between initiation and cessation dates. This simple model was found to closely fit observed data from individuals or groups of goats and, with the appropriate measures of variation, permits statistical comparisons of these values between individuals or groups.