PRINCIPAL DESCRIPTORS OF BODY CONDITION SCORE IN HOLSTEIN COWS
PRINCIPAL DESCRIPTORS OF BODY CONDITION SCORE IN HOLSTEIN COWS
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DOI：
10.3168/jds.s0022-0302(94)77212-x
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发表时间：
1994-09-01
影响因子：
3.5
通讯作者：
THOMSEN, N
中科院分区：
文献类型：
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作者：
FERGUSON, JD;GALLIGAN, DT;THOMSEN, N
这项研究的目的是客观地评估观察者评估奶牛身体状况的能力。四名观察者独立分配了一个身体状况评分(5分制，0.25分增量)，并描述了225头荷斯坦奶牛的七个身体区域的外观。所描述的区域包括瑟尔区、坐骨结节和回肠结节、回肠和坐骨尾韧带、腰椎横突和腰椎棘突。根据所有观察者的模式身体状况分数，为每头奶牛指定绝对身体状况分数。如果没有模式身体状况评分，则使用平均分作为绝对身体状况评分。采用主成分分析检验身体部位描述与绝对身体状况评分之间的关系。对身体区域的描述在所有绝对身体状况评分中都高度相关。4个主成分向量解释了人体区域相关矩阵变异的83.6%。第一主潜伏向量解释了55%的变异，并且与所有身体区域一致相关。以第一主潜伏向量为因变量，以绝对身体状况评分为分类变量的方差分析表明，身体状况在2.5~4.0之间可分为0.25个单位。在2.5和4.0以下，身体状况只能相差0.5个单位。特定身体区域的明显变化与绝对身体状况评分的变化有关。观察者在58.1%的时间内同意绝对分数，在32.6%的时间内偏离0.25个单位。可以根据2.5和4.0之间的特定身体区域的主要描述符乘以0.25个单位来给奶牛身体状况评分。
The objective of this study was to assess objectively the ability of observers to assess body condition of dairy cows. Four observers independently assigned a body condition score (five-point scale, .25 increments) and described the appearance of seven body regions of 225 Holstein cows. Areas described were the thurl region, ischial and ileal tuberosities, ilio-sacral and ischio-coccygeal ligaments, transverse processes of the lumbar vertebrae, and spinous processes of the lumbar vertebrae. An absolute body condition score was designated for each cow based on the modal body condition score for all observers. If there was no modal body condition score, the mean score was used for the absolute body condition score. Statistical analysis of principal components was used to examine the relationship between body region description and absolute body condition score. Descriptions of body regions were highly correlated across all absolute body condition scores. Four principal component vectors explained 83.6% of the variation of the body region correlation matrix. The first principal latent vector accounted for 55% of the variation and was uniformly correlated with all body regions. Analysis of variance of first principal latent vector as the dependent variable and absolute body condition score as the class variable indicated that body condition could be separated into .25 units between 2.5 and 4.0, inclusively. Below 2.5 and >4.0, body condition could only be separated by .5 units. Distinct changes in specific body regions were associated with change in absolute body condition score. Observers agreed with the absolute score 58.1% of the time, deviating by .25 units 32.6% of the time. A body condition score can be given to a cow based on principal descriptors of specific body regions between 2.5 and 4.0 by .25 units.