放牧条件下绒山羊绒毛季节性生长变化规律的研究

STUDY ON DYNAMIC CHANGE OF CASHMERE GROWTH OF GRAZING CASHMERE GOATS

本试验研究放牧条件下绒山羊绒毛季节性生长变化的规律。选择体重及产绒性能相近的2.5岁内蒙古白绒山羊羯羊10只,随机均分为2组,分别接受自然光照和短光照处理,短光照组每天的光照时间比自然光照组减少2小时,两组试羊在同一草场放牧。结果表明,放牧条件下,随牧草营养值下降(CP含量13.9%～6.0%)和光照递减(14.6～9.4h/d),绒毛生长呈慢—快—慢增长模式,主要的生长期在9月下旬～12月上旬,11月份为高峰期;减少光照可刺激绒毛生长,使快速生长的时间提前至8月下旬,绒毛长度增加10.9%,但生长模式不变。绒毛细度(14.6～14.9μm)和强度(6.9～5.9g)不受季节影响,但绒毛伸度下降54.3%;减少光照不改变绒毛强度和伸度,但绒毛细度增加5.6%、产绒量提高12.5%。

An experiment was conducted to study on dynamic change of cashmere grow th of grazing Inner Mongolian White Cashmere goats.The goats,aged two and half y ears old,were randomly divided into 2 groups and treated with the natural photop eriod and short photoperiod which was 2 hours less lighting time than natural ph otoperiod.All goats were grazed on the same grassland and given same supplement. The results showed that grass nutritive value(CP content 13.9～6.0%)and lighting time(14.6～9.4h/d)were decreased from July to December.Cashmere length performe d as slow-quick-slow growing model;the main growing period was from November to December;the fastest period was October(3.5cm).Cashmere growth was proceeded 1 m onth and cashmere length was improved 10.9% when photoperiod was shortened,but c ashmere growth model remained the same.There was no significant difference both cashmere diameter(14.6～14.9μm) and cashmere strength(6.9～5.9g) among the mont hs(P>0.05),but cashmere strected length was significantly decreased 54.3% from July to December(P<0.05).Cashmere strength and cashmere strected length were not changed,but cashmere diameter and cashmere yield were increased 5.6%,12.5% resp ectively when photoperiod was shortened.