Development of black pigmented skin spots and pigmented wool fibres in a Merino flock - causes, field observations, and wool measurement
Development of black pigmented skin spots and pigmented wool fibres in a Merino flock - causes, field observations, and wool measurement
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DOI：
10.1071/ar05032
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发表时间：
2006-01-01
影响因子：
--
通讯作者：
Fleet, M. R.
中科院分区：
文献类型：
--
作者：
Fleet, M. R.
对成年美利奴羊在三年内黑灰色色素皮肤斑点和色素羊毛纤维的发展情况进行了评估。研究了长期放牧雌激素牧草和多次剪毛的影响。患病羊的数量和患病羊身上色素斑的数量随着年龄的增长而增加，以8.5岁时增加最多。放牧雌激素牧场没有效果，但每年两次剪毛会增加治疗两年后色素斑的形成。对没有明显色素斑点的绵羊羊毛和上衣的测量表明，这种羊毛通常不含色素纤维。相比之下，受影响个体的羊毛通常含有高浓度的有色羊毛纤维，有大量的有色长度（平均20-40毫米）并且颜色加深，这与黑灰色有色皮肤斑点的现场记录有关。在受影响羊毛的加工毛条中发现的深色纤维含量在 262 至 1293/kg 之间。根据这些发现，绵羊年龄是纳入决策系统的一个重要因素，提醒羊毛购买者注意隐藏的深色纤维的风险。然而，如果在剪羊毛过程中对绵羊进行充分的检查，以将羊毛与羊毛区域有黑灰色色素皮肤斑点的羊分开，那么对于未受影响的羊的羊毛，可以降低或消除所应用的风险水平。
The development of black-grey pigmented skin spots and pigmented wool fibres on adult Merino sheep over a 3-year period was assessed. Effects of long-term grazing of oestrogenic pasture and multiple shearing were studied. The number of affected sheep and number of pigmented spots on affected sheep increased with age, with the greatest increase at 8.5 years age. Grazing of oestrogenic pastures had no effect but twice yearly shearing increased the development of pigmented spots after 2 years of treatment. Measurements on fleeces and top from sheep with no apparent pigmented spots showed that this wool was generally free of pigmented fibres. In contrast, wool from affected individuals generally had high concentrations of pigmented wool fibres, with substantial pigmented lengths (means 20-40 mm) and intensely darkened, which related to the field records of black-grey pigmented skin spots. The amounts of dark pigmented fibres found in the processed top from affected fleeces ranged between 262 and 1293/kg. Based on these findings, sheep age is an important factor for inclusion in decision systems alerting wool buyers to the risk of hidden dark fibres. However, if adequate inspection of sheep during shearing is practical to isolate fleeces from sheep with black-grey pigmented skin spots in the fleece areas, then the risk level applied could be lowered or removed for the wool from the unaffected sheep.