青藏高原天然草场放牧家畜的采食量动态研究

用4N盐酸不溶灰份法测定牦牛和高山细毛羊的采食量季节动态,结果发现:在夏季、秋季和冬季,牦牛的采食量随年龄增大而增大(5岁前:P<0.01;5～6岁之间:P<0.05),6岁以后规律不明显;在春季,5岁、6岁和7岁牦牛的采食量间无显著差异(P>0.05)。在任何季节,6岁和7岁牦牛的采食量间无显著差异(P>0.05)。一岁牦牛的采食量在冬季最高,夏季次之,其它所有年龄组的牦牛的采食量在春季最高,冬季次之;所有牦牛的秋季采食量最低。高山细毛羊的采食量季节波动与牦牛类似,除1岁高山细毛羊的采食量在冬季和夏季最高,其它所有年龄组的高山细毛羊的采食量在春季最高,冬季次之;所有试羊的秋季采食量最低。用二次方程预测了牦牛从1岁起的累计牧草消耗量(AFC)与牦牛年龄间的关系,拟合度很高,R2均大于99.9%。牦牛的牧草消耗量随年龄而上升的速率远高于高山细毛羊,但相同年龄的牦牛和高山细毛羊,高山细毛羊每公斤体重所消耗的牧草量高于牦牛。

Feed Intake Dynamic of Grazing Livestock in Nature Grassland in Qinghai-Tibetan Plateau

The seasoral dynamic of feed intake of yak and Gansu Alpine sheep were compared using HCl-insoluble ash (AIA) by the total feces collection method. Results showed that the feed intake of yak increased (P<0.01 before 5 years old and P<0.05 between 5 and 6 years old) with age in summer, autumn, and winter, but such trend ceased after 6 years old. There were no significant differences on feed intake among 5-, 6-and 7-year-old yaks (P>0.05) in spring, and there were no significant differences on feed intake between 6-and 7-year-old yaks (P>0.05) in any seasons. Feed intake of yak in any age group was highest in spring and followed by winter and summer, with the exclusion of one-year-old yak, whose highest feed intake happened in winter and followed by summer. Seasonal dynamic of feed intake of Gansu Alpine Sheep was similar to that of yak. Feed intake of Gansu Alpine Sheep in any age group was highest in spring and followed by winter, with the exclusion of one-year-old Gansu Alpine Sheep, whose highest feed intake happened in winter and summer. For all the livestock, the lowest feed intake was always happened in autumn. Quadratic equation was used to predict the relationship between accumulated forage consumption (AFC) and age of yak, with high fitness (R~2>99.9%). With the age increase, the velocity of AFC increased more rapidly in yak than in Gansu Alpine Sheep. But the AFC of per kilogram body weight was lower in yak than in Gansu Alpine Sheep at the same age.