不同收获时期的玉米饲用生物学产量和营养价值的比较研究

Comparative study on feeding biological yield and nutritional value of maize in different harvest periods

试验旨在分析比较常规玉米收获、活秆收获和全株时玉米青贮收获玉米生物学产量、营养成分、单位面积营养总量及48 h瘤胃体外营养物质降解效果。采用随机区组设计,设3个不同的收获期,分别为常规收获、活秆收获、全株玉米青贮收获,每个收获期(区)设3个重复小区。结果显示:在全株玉米青贮收获干物质(DM)为33.76%时,生物学产量最大(21.78 t/hm^(2)),显著高于常规收获和活秆收获(19.22、20.13 t/hm^(2))(P<0.05)。常规收获玉米籽粒的粗蛋白(CP)含量显著高于玉米秸秆和玉米芯(P<0.05)。全株玉米青贮收获CP产量显著高于常规收获和活秆收获(P<0.05),全株玉米青贮收获粗纤维(CF)产量显著高于常规收获和活秆收获(P<0.05),全株玉米青贮收获总能(GE)显著高于常规收获和活秆收获(P<0.05);全株玉米青贮收获的DM、CP体外降解率显著高于常规收获和活秆收获(P<0.05)。全株玉米青贮收获单位面积瘤胃体外48 h可降解DM和中性洗涤纤维(NDF)总量显著高于常规收获和活秆收获(P<0.05)。研究表明,收获期对全株玉米饲用生物学产量、营养成分和可消化营养产量具有明显影响,全株玉米青贮收获可获得较好的单位面积可消化营养转化效率,延长籽粒收获期会降低生物学产量和可消化营养量。

The experiment was to analyze and compare the biological yield,nutrient composition,total nutrient per unit area and nutrient degradation effect of 48 h rumen in vitro among conventional maize harvest,live stalk harvest and whole plant maize silage harvest.A randomized block design was used,with three different harvest periods,namely conventional harvest,live stalk harvest and whole corn silage harvest,and three replicate plots were set up for each harvest period.The results showed that when the dry matter(DM)of whole plant maize silage was 33.76%,the biological yield was the highest(21.78 t/hm^(2)),which was significantly higher than that of conventional harvest and live stem harvest(19.22、20.13 t/hm^(2))(P<0.05).The crude protein(CP)content of conventionally harvested corn grains was significantly higher than that of corn stover and corn cob(P<0.05).The CP yield of whole plant corn silage harvest was significantly higher than that of conventional harvest and live culm harvest(P<0.05),the crude fiber(CF)yield of whole plant corn silage harvest was significantly higher than that of conventional harvest and live culm harvest(P<0.05),and the total energy(GE)of whole plant corn silage harvest was significantly higher than that of conventional harvest and live culm harvest(P<0.05).The in vitro degradation rates of DM and CP of whole corn silage harvest were significantly higher than those of conventional harvest and live stalk harvest(P<0.05).The total amount of biodegradable DM and neutral detergent fiber(NDF)per unit area of rumen in vitro at 48 h after whole corn silage harvest was significantly higher than that after conventional harvest and live stem harvest(P<0.05).The experiment indicates that of the whole plant corn harvest forage production of biological yield,nutrition composition and digestible nutrition has significant influence,whole plant corn silage harvest can get the best digest nutrient efficiency,prolong the grain harvest can reduce the biological yield and the amount of digestible nutrients.