光照控制、通风设计对绒山羊绒毛生长和圈舍氨气浓度的影响

本试验通过人为控制光照，探讨光照控制和通风设计对绒山羊在非产绒期绒毛生长和羊舍氨气（NH₃）浓度的影响，为非产绒期绒山羊高效生态养殖提供理论依据。选取年龄、体重、胎次相近的56只3~4岁陕北白绒山羊空怀母羊作为试验动物，随机分为3组。Ⅰ组为对照组，采用自然光照，试验羊12只；Ⅱ组为试验组，采用控制光照，试验羊22只；Ⅲ组在同等控制光照条件下，粗饲料饲喂量相同，精料水平饲喂量增加15%，试验羊22只。对照组采用完全自然光照；试验Ⅱ、Ⅲ组每日进行光照7 h（09：30~16：30），其余17 h（16：30~次日09：30）进入光控舍内进行光控处理，并设置不同的通风换气方案，测定试验羊绒毛生长性状和羊舍NH₃浓度。结果显示，与Ⅰ组相比，Ⅱ、Ⅲ组试验羊末重和日增重差异均不显著（P>0.05），平均日增重略高于Ⅰ组（P>0.05）。与Ⅰ组相比，Ⅱ、Ⅲ组可极显著增加绒毛混合重（P<0.01）、显著提高绒毛比（P<0.05）、极显著增加绒重（P<0.01），分别较Ⅰ组提高了68.40%和78.78%。Ⅱ、Ⅲ组绒毛混合重、绒毛比及绒重差异均不显著（P>0.05）。光照控制组可极显著增加绒纤维伸直长度（P<0.01），但在控制光照条件下增加精料摄入量对绒纤维伸直长度无显著影响（P>0.05）。与Ⅰ组相比，Ⅱ、Ⅲ组显著增加了绒纤维细度（P<0.05），但对绒纤维断裂强度无显著影响（P>0.05）。在每日清粪的基础上，在白天非光控时间（09：30~16：30）同时开启4个风机，可有效降低光控羊舍内NH₃浓度。结果提示，在绒山羊非产绒期，通过光照控制可增加羊绒产量，但应适当降低日粮中营养素浓度，以保证绒纤维品质。同时，应根据圈舍空间大小，选择合适的风机数量和功率及清粪间隔，以保障圈舍内空气质量和试验羊健康。

Effect of Light Controlling and Ventilation Design on Cashmere Growth and Ammonia Concentration of Cashmere Goat

This research was conducted to investigate the effect of light controlling and ventilation design on cashmere growth and ammonia concentration of cashmere goat,which would provide theoretical basis for high efficient and ecological feeding of cashmere goat during the cashmere non-growing period.A total of 56 non-pregnant Shaanbei White cashmere goat with similar age,weight and parity were selected and randomly divided into 3 groups.Group I was received natural light,group Ⅱ was received controlling (illumination at 09:30 to 16:30,and light control at 16:30 to 09:30 of next day),and group Ⅲ was received same light condition except for additional 15% concentrate feed supplemented.Different ventilation schemes of goat house under the light-controlled condition were set and cashmere wool growth traits and barn NH₃ concentrations were determined.The results showed that illumination condition had no significant effects on body weight of Shaanbei White cashmere goat (P>0.05),but average daily gain of groups Ⅱ and Ⅲwere slightly higher than group Ⅰ.Compared with group Ⅰ,the fluff mixtures weight of groups Ⅱ and Ⅲ were extremely significantly increased (P<0.01),the fluff ratio were significantly increased (P<0.05),and the weight of cashmere wool,which were increased by 68.40% and 78.78%,respectively,were extremely significantly increased (P<0.01).Less illumination resulted in longer cashmere fiber stretched length,while it caused an increasing fiber fineness of cashmere by increasing illumination.No significant differences were observed between groups Ⅱ and Ⅲ (P>0.05).Under light-controlled conditions,using four mechanical ventilators during non-light controlled time (09:30 to 16:30) could significantly reduce the concentration of NH₃ (P<0.05).The results indicated that light controlling could increase cashmere production during the cashmere non-growing period of cashmere goat,however,less nutrients intake should be done to prevent the increasing of fiber diameter.Proper ventilation and clearance rate should be considered to keep air quality and goat health according to feeding density and house space.