共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
3.
4.
5.
刈割次数对光叶紫花苕产草量和产种量的影响 总被引:3,自引:0,他引:3
针对凉山光叶紫花苕再生能力强的特点,研究了在西昌安宁河流域不同刈割次数对凉山光叶紫花苕生长状况、生产性能的影响。结果表明,秋播后80-100d可刈割利用鲜草一次,开春可刈割利用2次,也可直接利用其产种,但不宜再刈割。 相似文献
6.
7.
通过对6个不同产区凉山光叶紫花苕Vicia benghalensis综合性状分析,凉山光叶紫花苕存在明显的类型划分,盐源产区生育期最短,刈割后再生能力最差,平均每株分枝数最少,其以分枝长度长、叶量大、茎秆粗壮而获得较大生物量,而昭觉产区则相反;在植株植物学性状聚类分析中,盐源、昭觉产区独自各为一类,布拖、普格、小兴场、云南并为一类,可将盐源产区凉山光叶紫花苕划分为早熟类型,昭觉产区为晚熟类型,其他4个产区性状介于二者之间,属中熟类型。通过性状相关通径分析,影响凉山光叶紫花苕生物量的主要性状是叶量和分枝长度。 相似文献
8.
9.
光叶紫花苕的营养价值与饲用价值研究 总被引:10,自引:4,他引:6
研究测定了光叶紫花苕Vicia villosa routh var.的营养成分含量和消化能(牛、猪)、代谢能(鸡)能值,并进行了饲养试验.结果表明,紫花苕干物质中粗蛋白含量在20%以上,氨基酸、矿物质、维生素比较丰富,消化能分别为DE(牛)12.4 MJ/kg,DE(猪)11.9 MJ/kg,ME(鸡)10.7 MJ/kg;在肉牛精料中用紫花苕草粉代替全部麦麸,平均日增重增加92 g/d(P<0.05),饲料利用率提高9.5%;在肉猪日粮中用紫花苕草粉代替20%配合饲料,平均日增重增加81 g/d(P<0.05),饲料利用率提高13.16%;在肉鸡日粮中用紫花苕草粉代替10%~15%配合饲料,平均每只增重提高252 g/只(P<0.05),饲料利用率提高12.8%.从而认为紫花苕草粉且有较高的饲用价值. 相似文献
10.
为了给牧草栽培和推广提供科学参考,试验以毛苕子、光叶紫花苕、白车轴草、紫云英、紫花苜蓿种子为材料,设置6个恒温条件(5,10,15,20,25,30℃),测定发芽率、发芽势、发芽指数、萌发历期、萌发时滞、萌发速率指数等指标,研究了5种豆科牧草种子萌发特性对温度的响应。结果表明:5种豆科牧草种子的发芽率、发芽势及发芽指数均随温度的升高呈先增大后减小的趋势,且在15~25℃范围内处于相对较高水平;毛苕子和光叶紫花苕种子在低温(5℃)和高温(30℃)时,其发芽率、发芽势和发芽指数优于其他3种豆科牧草;随温度的升高5种豆科牧草种子的萌发时滞均逐渐减小并趋于稳定,萌发速率指数呈先增大后减小的趋势;白车轴草、紫云英和紫花苜蓿种子在温度为15~25℃范围内比毛苕子和光叶紫花苕种子具有更长的萌发历期;5种豆科牧草种子萌发值与温度间的关系均为三次曲线模型,整体拟合效果较好。通过模型预测5种豆科牧草种子的最适萌发温度在20.01~22.36℃之间。 相似文献
11.
12.
13.
14.
15.
17.
18.
19.
20.
Analysis of growth curves of fowl. I. Chickens. 总被引:4,自引:0,他引:4
1. The Richards function was used to describe the growth curves (n = 989) of 9 broiler lines. Chickens were fed ad libitum and body weight was recorded every second week from hatching to 26 weeks of age. 2. The accuracy of curve fit measured by the coefficient of determination (R2) was better for males than for females (0.9986-0.9995 vs 0.9972-0.9988, respectively). 3. The estimation of the asymptotic final weight (A) for different lines enabled the degree of maturity (ut = yt/A) to be determined at any fixed point of the curve. At the age of 7 weeks this had a value of 0.318-0.369 for cockerels and 0.325-0.377 for pullets and represented the slaughter maturity of individual lines. The ratio of inflection/asymptotic weight (y+/A = 0.370-0.388) indicated that in some cases chicken growth can be described approximately by the Gompertz function (y+/A = 0.368). 4. It was found that the age at the inflection point of curves (t+ 48.2-55.7 d for cockerels and t+ = 47.8-52.8 d for pullets) roughly corresponds to the slaughter age of the chickens. 5. The interline differences in the parameters of maturation rate for weight (y+/A, k, t+, u7) are low in comparison with the differences in body weight (A, y+, y7) and absolute growth rate (v, v+). 6. The intragroup phenotypic correlation among growth parameters and the importance of the mathematical models are discussed. 相似文献