Interest in reducing labour costs due to shearing has led to development of breed types that shed their wool naturally. Selection at young ages can facilitate response. Reliability of predictions of adult from lamb wool shedding (WS) is thus key in the design of breeding programmes to increase shedding. Our objectives were to estimate heritabilities and genetic relationships between WS measured once in lambs and repeatedly in ewes and to assess the accuracy of lamb WS EBV to predict ewe WS EBV based on a multi-trait threshold or a repeatability model. Data were 4,971 lamb and 3,335 ewe WS records on a Romanov, White Dorper and Katahdin composite flock. For the multivariate model, WS heritability ranged from 0.47 ± 0.03 in lambs to 0.59 ± 0.04 at 1 year of age. For the repeatability model, WS in adult ewes was moderately heritable (0.50 ± 0.03) and repeatable (0.60 ± 0.02). Genetic correlations were 0.72 ± 0.04, 0.65 ± 0.05, 0.50 ± 0.09 and 0.51 ± 0.09 between lamb WS and 1st through 4th record, respectively. Given the moderately high heritability and high correlations between WS performance in lambs and ewes, selecting animals early in life would effectively increase WS in crossbred flocks.

中文翻译：

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羔羊毛脱落是母羊羊毛脱落的良好预测指标

由于剪毛而降低劳动力成本的兴趣导致了自然脱落羊毛的品种类型的发展。年轻时的选择可以促进反应。因此，从羔羊毛脱落 (WS) 预测成虫的可靠性是设计育种计划以增加脱落的关键。我们的目标是估计在羔羊中测量一次和在母羊中重复测量的 WS 之间的遗传力和遗传关系，并评估羔羊 WS EBV 基于多性状阈值或可重复性模型预测母羊 WS EBV 的准确性。数据是罗曼诺夫、白杜泊和卡塔丁复合群的 4,971 只羔羊和 3,335 只母羊 WS 记录。对于多变量模型，WS 遗传力范围从羔羊的 0.47 ± 0.03 到 1 岁时的 0.59 ± 0.04。对于可重复性模型，成年母羊的 WS 具有中等遗传性 (0.50 ± 0. 03) 和可重复性 (0.60 ± 0.02)。羔羊 WS 与第 1 至第 4 条记录之间的遗传相关性分别为 0.72 ± 0.04、0.65 ± 0.05、0.50 ± 0.09 和 0.51 ± 0.09。鉴于羔羊和母羊的 WS 表现之间具有适度的高遗传力和高度相关性，在生命早期选择动物将有效地增加杂交羊群的 WS。