摘要
Abstract
The aim of the experiment was to investigate the effects of different harvest periods on the yield,silage quality,and rumen degradation characteristics of whole-plant maize,and to determine the best harvest period of whole-plant maize.Long silage No.1 was selected as the experimental material,and whole-plant maize was harvested at 1/2 milk line,2/3 milk line and 3/4 milk line stages,respectively.The yield,silage quality,and rumen degradation characteristics of whole-plant maize at different harvest stages were determined.The results showed that there were significant differences in whole-plant maize yield at different harvest periods.The highest yield was 4 721.95 kg/667 m2 at 3/4 milk line stage,which was significantly higher than that at 2/3 milk line stage and 1/2 milk line stage(P<0.05).The concentrations of neutral detergent fiber and acid detergent lignin in silage at 2/3 and 3/4 milk line stage were significantly lower than those at 1/2 milk line stage(P<0.05),but the concentrations of dry matter,starch and water-soluble carbohydrate were significantly increased at 2/3 and 3/4 milk line stage(P<0.05).The acid detergent fiber content of whole-plant maize silage at 2/3 milk line stage was significantly lower than that at 1/2 and 3/4 milk line stage(P<0.05).The crude protein content of whole-plant maize silage at 1/2 milk line stage and 2/3 milk line stage was significantly higher than that at 3/4 milk line stage(P<0.05),pH value was significantly lower than that in 3/4 milk line stage(P<0.05),lactic acid content was significantly higher than that in 3/4 milk line stage(P<0.05).The acetic acid content of whole-plant maize silage at 2/3 milk line stage and 3/4 milk line stage was significantly lower than that at 1/2 milk line stage(P<0.05).When the whole-plant maize was harvested at 2/3 milk line stage,the in vitro rumen dry matter degradation rate of silage was significantly higher than that at 1/2 milk line stage(P<0.05),and the crude protein degradation rate was significantly higher than that at 1/2 milk line stage and 3/4 milk line stage(P<0.05).The degradation rates of neutral detergent fiber and acid detergent fiber were significantly higher at 1/2 milk line stage and 2/3 milk line stage than that at 3/4 milk line stage(P<0.05).The results show that the silage nutrition quality,fermentation quality and in vitro nutrient degradation rate of rumen are better when whole-plant maize is harvested at 2/3 milk line stage.关键词
不同收获期/全株玉米青贮/产量/发酵品质/瘤胃降解特性Key words
different harvest period/whole-plant maize silage/yield/fermentation quality/rumen degradation characteristics分类
畜牧业
