| The experiments were carried out on a deer farm in Tianzhu country of Gansu province from April to October in 2007, where the altitude is 2494m above sea level. Twenty-four varieties of oats were used as experimental materials, including 4601, 4609, 4677, 424, Ronald, Chudao, yellow oats, Baiyan No.2, 118, 4628, Qingyongjiu444, 478, 709, 409, 4616, Baiyan No.5, 4641, 316, 4666, 4617, 473, 94, 440 and 343. The experiment was carried out in 3 randomized blocks with three replicates. The growth characteristics, productivity and nutritive value od different oat varieties were studied. Artificial ruminal gas production in vitro was used to evaluate nutritive value of 4 superior varieties sekected from the experiment. The results showed as follows:(1) In alpine region of Qinghai-Tibet Plateau, varieties with long days to maturity should be selected for quality hay production, such as 709, 118, 343, 409, 440, etc; if the production objective is for grain yield, then Baiyan No.5, Qingyongjiu 444 and Ronald should be used.(2) Plant height is one of the main factors affecting forage yield. Among 24 tested varieties, 709,316, 440 and 343 were higher than the control; RGR is a indicator of biomass accumulation, during booting stage, 424, Ronald, 709, Baiyan No. 2, Baiyan No. 5 had higher RGR, which established a basis for hay and grain yield improvement.(3) Dry to fresh matter ratio increased with prolonging of plant growth, among 24 varieties, 709, 94, Baiyan No.2 and 4628 had higher dry to fresh matter ratio than the control and their hay yield were accordingly higher.(4) Hay yield is key to oat production in alpine region of Qinghai-Tibet Plateau, and is an important base for variety selection. To produce high quality hay, Baiyan No.5, 473, 709, Baiyan No.2, 409 and 440 should be selected, apart from Qingyongjiu 444.(5) Grain yield components include effective tillering, panicle length, spike numer, grains per panicle, grain weight per panicle and thousand grain weight, among which, grains per panicle, thousand grain weight and effective tillering are the most important for grain yield. Tillering number was negatively correlated to grain yield, while grains per panicle, thousand grain weight and effective tillering were positively correlated to oat grain yield significantly. In alpine region of Qinghai-Tibet Plateau, varieties with earlier mature and higher grain yield should be selected for seed production, such as 478, Ronald and 424.(6) DM digestbility and gas production of 4 oat varieties at 4 growth stages were determined by means of in vitro gas production method. The result indicated that gas volume reached the greatest at 0-24h, and declined after 36h. Accumulated gas production reached its peak at booting stage, declined at anthesis and grain filling stage, and came to the lowest when plant matured. Qingyongjiu 444 had significant higher gas accumulation than Baiyan No.5.(7) CP contents at anthesis, grain filling and mature stages were significantly different. Qingyongjiu 444 had the highest CP content at every growth stages, Baiyan No.5 had the highest ADF content. The digestibility of oats declined with the prolonging og plant growth. Among 4 varieties, Qingyongjiu 444 had the highest digestibility at each growth stage, while Baiyan No.5 was the lowest. Ronald and Baiyan No.2 were moderate. |
