不同季节牧草营养成分与牦牛血液激素含量变化的研究

Studies on nutritious compositions of herbage and yak blood hormone content in different seasons

对青海环湖地区三角城种羊场暖季(6月份)和冷季翌年(2月份)天然牧草营养成分和牦牛血液中生长激素(GH)、胰岛素(Ins)、三碘甲状腺素(T3)、四碘甲状腺素(T4)水平变化进行了分析,结果为:暖季牦牛血液中Ins、T3、T4的含量高于冷季,呈季节性动态变化(P<0.01=,GH变化不明显;Ins与T3、T4间表现出显著正相关(P<0.01,r =0.735 2;P<0.05,r =0.354 4)。天然草场牧草中粗蛋白含量冷季(4.74 %)比暖季(15.22 %)损失68.9 %,粗脂肪冷季(2.85 %)比暖季(3.83 %)下降34.4 %;而干物质、粗纤维、无氮浸出物、灰分和Ca的含量暖季低于冷季。

The content of growth hormone (GH) and insulin (Ins), three iodine thyroxine (T3), four iodine thyroxine (T4) in yak blood and the defferences of nutritious compositions of natural forages between warm season (June) and cold season next year (February) in Shanjiaocheng Sheep Farm of Qinghai Province were tested and analysed. The results showed that Ins, T3 and T4 content of yak blood in warm season were higher than in cold season, assuming a seasonal change (P<0.01), but GH had no significant difference; Ins was positively correlated to T3 and T4(P<0.01,r=0.735 2; P<0.05,r=0. 354 4). In the natural grassland, the rough protein content of withered forage in cold season (4.74 %) decreased by 68.9 % of that of fresh forage in warm season (15.22 %), the rough fat content of forage in cold season (2.85 %) decreased by 34.4 % of that in warm season (3.83 %), and the contents of dry matter, coarse fiber, nitrogenless entraction, ash and calcium of forages in warm season were lower than in cold season