【作者】 牟锦毅；

【导师】 荣廷昭；

【作者基本信息】 四川农业大学 ， 作物遗传育种学， 2008， 博士

【摘要】 针对农区发展草食性畜牧业饲草严重缺乏的现状，四川农业大学荣廷昭院士等根据西南地区的生态特点和目前农区主要推广牧草墨西哥玉米、高丹草等存在的优缺点，提出了发展营养体农业的思路，并成功选育了玉草1号和玉草2号等饲草玉米新品种（2007年7月通过省级鉴定，2007年10月通过四川省品种审定委员会审定）。本研究以墨西哥大刍草、高丹草和新选饲草组合玉草1号、玉草2号为主要研究材料，对它们的产量和品质及其构成进行了研究，同时还对影响产量和品质的主要因素进行了分析，探讨了在四川发展农区牧草的主要生产技术，提出了四川农区牧草的产业发展思路。主要研究结果如下：1．对高丹草、墨西哥玉米和新选饲草玉米组合比较研究表明，饲草玉米玉草1号产量优于其他组合。其鲜、干物质产量分别为174045kg·hm^-2和22208 kg·hm^-2，比高丹草和墨西哥玉米分别高出26900 kg·hm^-2、29200 kg·hm^-2，高18．3％、20．2％；干物质产量分别高出3300 kg·hm^-2、6100 kg·hm^-2，高17．5％、37．9％。2004年以来在四川的雅安、西充、雁江区、洪雅县、南江县、武胜县、东兴区、泸定县、金川县等县和云南、重庆、甘肃、广东等地进行了示范种植，结果表明饲草玉米比对照的鲜草产量普遍高50％以上。饲草玉米生长动态研究表明，其生长曲线符合Logistic模型，拟合方程为y=2983/1+25.6e^-0.05x （y为草长、x为发育天数，r=0．995）。2．饲草玉米第1次刈割（孕穗期）粗蛋白质（CP）和无氮浸出物（NFE）含量最高，分别为17．57％、48．73％，粗纤维（CF）含量最低，为21．65％，粗脂肪（EE）和粗灰分（CA）含量分别为4．30％和7．75％。饲草玉米CP和CF产量分别为2788．2kg·hm^-2和4713．3 kg·hm^-2，高于高丹草(2211．2 kg·hm^-2和3952．3 kg·hm^-2)和墨西哥玉米(2128．4 kg·hm^-2和2813．9 kg·hm^-2)。饲草玉米全年共刈割4次，各茬次平均营养成分含量为15．1％（CP）、25．6％（CF）、3．1％（EE）、8．9％（CA）、47．3％（NFE），营养品质优于对照高丹草（CP：14．6％、CF：26．2％、EE：4．0％、CA：8．6％、NFE：46．6％）。饲草玉米第1次刈割可溶性糖含量为9．8％，氨基酸总量为3．1％，其中赖氨酸含量（0．41％）高于对照高丹草（0．39％）和墨西哥玉米（0．39％）。总能（GE）、消化能（DE）、代谢能（ME）和可消化养分总量（TDN）在孕穗期或抽雄始期最高，抽雄始期鲜草产量和干物质产量分别达101400 kg·hm^-2和18350kg·hm^-2，粗蛋白（CP）、粗纤维（CF）、粗脂肪（EE）、粗灰分（CA）和无氮浸出物（NFE）含量分别为14．2％、24.3%、3．9％、6．3％和51．3％。3．留茬高度试验结果表明，草长220cm刈割的鲜草产量、干草产量和CP产量均显著高于草长190cm时刈割，但其CP含量和RFV较低，NDF含量较高。草长160cm时刈割的鲜、干草产量和CP产量均显著低于草长190cm时刈割，但CP含量和RFV较高。研究表明，留茬25cm、草长190cm刈割适用于青饲利用，留茬15cm、草长220cm刈割适用于青贮利用。密度试验结果表明，在密度37500株·hm^-2下的分蘖数、总茎粗、干物率均为最高，密度45000株·hm^-2次之，52500株·hm^-2最低。处理间各品质指标总体表现为：37500株·hm^-2的CP含量、CP产量以及RFV均为最高，45000株·hm^-2次之，52500株·hm^-2最低；37500株·hm^-2的NDF含量最低，52500株·hm^-2最高。研究表明，种植密度为45000株·hm^-2时产草量较高，饲用品质较优。施氮量和刈割间隔时间对玉草1号产量、品质均有显著影响，但施氮量和刈割间隔时间的互作效应对产量、品质的影响不显著。不施氮的处理总鲜草产量、干草产量、CP含量、CP产量和RFV均为最低，显著低于施氮量为2．2g／株的处理，而施氮量为2．2g/株的处理又显著低于施氮量为3．8g／株和5．4g/株的处理，后两者的总鲜干、草产量、CP含量、CP产量、NDF含量和RFV差异均不显著。刈割间隔时间为65d的处理总鲜草产量、总干草产量、NDF含量和CP产量均为最高，显著高于刈割间隔时间为55d和45d的处理，但是其CP含量和RFV却要显著低于刈割间隔时间为45d的处理。研究表明，施氮量为3．8g／株，刈割间隔时间为45d刈割的植株适宜于青饲利用，刈割间隔时间为65d的植株适宜于青贮利用。4．2007年在洪雅县进行的饲草玉米与牛鞭草饲喂奶牛试验结果表明，奶牛在饲喂饲草玉米后日产奶量平均值为16．58 kg，比饲喂牛鞭草的对照组每头奶牛日产奶量增加1．18 kg，增7．66％，表明给奶牛饲喂饲草玉米可明显增加其日产奶量。在南江县进行的南江黄羊在圈养、放牧喂养模式及其与常规饲喂模式下饲草玉米与自然野草对其体重等生育指标的影响试验结果表明，在圈养条件下，配合饲喂40％和60％的饲草玉米玉草1号，黄羊体重增加值（4．9 kg／只）均比饲喂自然野草时（2．00 kg／只）的增加值高；在放牧情况下，配合饲喂饲草玉米玉草1号对黄羊的生长发育作用与自然野草相比差异不显著；无论是圈养（4．9 kg、3．8 kg）或是放牧条件（4．6 kg、4．5 kg）下，饲喂玉草1号后，黄羊体重的增加值均大于对照组（2．5 kg）即常规饲养方法。5．本文研究结果表明，饲草玉米具有产量高，品质优等优点，适于西南区广泛种植。为使该成果迅速地转化为现实生产力，本文提出了饲草玉米产业发展思路、目标和主要措施。更多还原

【Abstract】 As forage grass of herbivorous stockbreeding in agricultural areas was very short, academician Rong Tingzhao of Sichuan Agricultural University presented the idea for development of nutritive agriculture according to ecological characteristics in the southwestern areas and advantages or disadvantages of Euchlaena mexicana and Gaodan grass in agricultural areas at present, and then successfully selected and bred new forage maize variety-Yucao No.1 and Yucao No.2, which passed the provincial appraisal in July 2007, and were certified by Crop Authorization Committee of Sichuan province in October 2007. With the main materials of Zea Mexican Schard, Gaodan grass and newly bred forage maize Yucao No. 1 and Yucao No.2, the study on the yield and the quality of them were carried out, and the main factors which had an impact on them were also investigated. Then the key technologies of forage maize grown in Sichuan were discussed and ideas for industry development of forage maize were also presented. The main results were as follows:1. The results of study on Gaodan-grass、Zea mexicana and newly bred forage maize combination showed that the yield of Yucao No. 1 was better than other combinations. Its fresh matter and dry matter yield were 174045 kg·ha^-1 and 22208 kg·ha^-1 respectively, which were 26900 kg·ha^-1（18.3%） and 29200 kg·ha^-1（20.2%） higher than that of Gaodan-grass and Zea mexicana separately. And the dry matter yield of Sicao No.l was 3300 kg·ha^-1（17.5%） and 6100 kg·ha^-1（37.9%） higher than that of Gaodan-grass and Zea mexicana separately. Since 2004, forage maize were planted in some areas of Sichuan such as Ya’an, Xichong, Yanjiang, Hongya, Nanjiang, Wusheng, Dongxing, Luding, Jinchuan, and also in Yunnan, Chongqing, Gansu, Guangdong. From the results above all these place, the fresh yield of forage maize was 50% higher than that of CK. Furthermore, results from growth dynamic of forage maize indicated that its growth rate conformed to a logistic model, fitting equation was y=2983/1+25.6e^-0.05x （y means grass length, x means growth days,r=0.995）.2. The crude protein （CP） and nitrogen-free extract （NFE） content of forage maize were 17.57% and 48.73% respectively, which reached the highest at booting stage of the first harvest; the content of crude fiber （CF） was the lowest 21.65%; the content of ether extract （EE） and crude ashes （CA） were 4.30% and 7.75%. The crude protein （CP） and crude fiber （CF） yield of forage maize were 2788.2 kg·ha^-1 and 4713.3 kg·ha^-1 separately, which were higher than that of Gaodan-grass(2211.2 kg·ha^-1和3952.3 kg·ha^-1) and Zea mexicana (2128.4 kg·ha^-1 and 2813.9 kg·ha^-1) . The forage maize harvested four times in a year, and its average nutrition composition at each time were 15.1% （CP）, 25.6% （CF）, 3.1% （EE）, 8.9% （CA）, 47.3% （NFE）, which were better than Gaodan-grass （CP: 14.6%, CF: 26.2%, EE: 4.0%, CA: 8.6%, NFE: 46.6%）. The dissolvable sugar and amino-acid content of forage maize at the booting stage of the first harvest were 9.8% and 3.1% respectively. The Lysine content of forage maize （0.41%） was higher than Gaodan-grass （0.39%） and Zea mexicana （0.39%）. Gross energy （GE）, digestible energy （DE）, metabolize energy （ME） and total digestible nutrient （TDN） were highest at booting stage or initial tasseling stage. Fresh and dry matter yield at initial tasseling stage were 101400 kg·ha^-1 and 18350 kg·ha^-1, and the content of crude protein （CP）, crude fiber （CF）, ether extract （EE）, crude ashes （CA） and nitrogen-free extract （NFE） were 14.2%, 24.3%, 3.9%, 6.3% and 51.3%, respectively.3. The results of mowed height indicated that fresh yield, dry yield and CP yield of forage maize harvested at 220cm grass length were all significantly higher than that at 190cm grass length. NDF content was also larger, but CP and RFV content were lower. Fresh yield, dry yield and CP yield of forage maize harvested at 160cm grass length were all significantly lower than at 190cm, while CP and RFV content were higher. Accordingly, it was useful for green forage when mowed height was 25cm and grass length was 190cm, and it was useful for green silage when mowed height was 15cm and grass length was 220cm.The results of plant density showed that tillering number, culm diameter and dry matter content with plant density of 37500 plant/ha^-1 reached the highest, 45000 plant/ha^-1 followed and 52500 plant/ha^-1 was the lowest. CP content, CP yield and RFV with plant density of 37500 plant/ha^-1 were the largest, 45000 plant/ha^-1 followed and 52500 plant/ha^-1 was the lowest; NDF content with plant density of 37500 plant/ha^-1 was the lowest while 52500 plant/ha^-1 was the highest. Therefore, grass yield and forage nutritive value were better with the plant density of 45000 plant/ha^-1.Nitrogen fertilizer amount and cutting interval time had a significant effect on yield and quality of Yucao No.1, but their interaction showed no significant effect on yield and quality of Yucao No.1. The gross fresh yield, dry yield, CP content, CP yield and RFV without nitrogen fertilizer were the lowest, which significantly lower than that with nitrogen fertilizer of 2.2 g/plant; while the gross fresh yield, dry yield, CP content, CP yield and RFV with nitrogen fertilizer of 2.2 g/plant was significantly lower than that with nitrogen fertilizer of 3.8 g/plant and 5.4 g/plant, whose gross fresh yield, dry yield, CP content, CP yield, NDF content and FRV were not significant. The gross fresh yield, dry yield, NDF content and CP yield with 65d cutting interval time were the highest, which were significantly higher than that with 55d and 45d; while the CP content and RFV with 65d were significantly lower than that with 45d. Therefore, it was useful for green forage when nitrogen fertilizer amount was 3.8 g/plant and cutting interval time was 45d, and it was useful for green silage when cutting interval time was 65d with the same nitrogen fertilizer amount.4. Dairy cows were bred by forage maize and hemarthriacompressa in Hongya in 2007, and the results showed that after breeding dairy cows with forage maize, the average of daily milk yield was 16.58 kg, and increased by 1.18 kg（7.66%） comparing with the CK which breeding dairy cows with hemarthriacompressa. Accordingly, the daily milk yield could obviously improved by breeding dairy cows with forage maize. In Nanjiang, the effect of forage maize and wild grass on the growing indexes such as weight of Nanjiang yellow cows by different feeding modes such as captive, grazing and conventional feeding were investigated. The results suggested that under captive feeding, the weight value-added of cows raised by 40% and 60% forage maize-Yucao No.1 （4.9kg/each） was higher than that by wild grass （2.00g/each）; under grazing feeding, the effect of Yucao No.1 on the growth and development of yellow cows was not significant with that of wild grass. However, no matter captive feeding （4.9 kg、3.8 kg） or grazing feeding （4.6kg、4.5 kg） , the weight value-added of yellow cows raised by Yucao No.l was larger than that by conventional feeding, the CK （2.5kg）.5. All above results indicated that forage maize with high yield and good quality was fit for planting in the southwestern areas. The study presented ideas for industry development, objectives and main measures of forage maize to put research findings into real productivity rapidly.更多还原