不同添加剂对薯渣与玉米秸秆混贮饲料发酵品质及牛瘤胃降解率的影响

研究4种不同添加剂对薯渣与玉米秸秆混贮饲料发酵品质以及牛瘤胃降解率的影响,并筛选出适宜的添加剂。试验采用密封塑料桶进行混贮,薯渣和玉米秸秆混贮水分含量控制在70%(混贮比例为1∶2),设置了对照组(CK)、微贮博士组(处理1)、青贮邦组(处理2)、拉巴克思复合添加剂组(处理3)以及亚芯组(处理4)5个处理,每个处理3个重复,贮存期60 d。采用实验室化学分析法及半体内试验测定第60天发酵品质、有氧稳定性、瘤胃降解率。结果表明各处理组和对照组(CK组)的感官评定结果无明显差异;经过发酵品质分析测定,4种添加剂处理均改善了薯渣饲料的发酵品质,其中处理4组的乳酸含量最高(P<0.01),pH和氨态氮含量最低(P<0.05);各添加剂处理均提高了薯渣混贮饲料的有氧稳定性,其中以处理4组效果最佳(P<0.01),有氧稳定时间为162 h,比CK组延长50 h,其次是处理2组(P<0.01)、处理3组(P<0.01),处理1组改善效果不明显;在瘤胃中培养48 h后,处理组干物质(DM)瘤胃降解率显著高于CK组(P<0.05),粗蛋白质(CP)瘤胃降解率极显著高于CK组(P<0.01);处理4组的NDF瘤胃降解率最高,显著高于处理3(P<0.05),但与其他处理组的NDF瘤胃降解率差异不显著(P>0.05);处理4组的ADF瘤胃降解率显著高于3组和CK组(P<0.05),与处理1组和处理2组差异不显著(P>0.05)。处理1组的淀粉瘤胃降解率比CK提高2.83%(P<0.01),其他各处理组间淀粉的牛瘤胃降解率无显著差异(P>0.05)。综上,添加剂处理对薯渣与玉米秸秆混贮饲料的发酵品质、有氧稳定性、瘤胃降解率等均有改善作用,其中以亚芯组处理效果最好。

Effect of additives on fermentation quality and cattle rumen degradability of mixed potato pulp and corn straw silage

The purpose of this experiment was to investigate the effect of different additives on fermentation quality and cattle rumen degradability of a mixed silage made with potato pulp and corn straw, and to screen for suitable additives. The sealed bucket storage method was used in the experiment. The mixed storage ratio of sweet potato pulp and corn straw was 1∶2 and the moisture content was 70%. Five different treatments were assessed: a control (CK), Weizhu group (treatment 1), silage-help group (treatment 2), LaBaX composite additive group (treatment 3) and Yaxin group (treatment 4); each treatment was replicated 3 times and the storage period was 60 days. Laboratory chemical analysis and in situ technology were used to determine the fermentation quality, aerobic stability and rumen degradation rate on the 60th day.There were no differences between treatments in the sensory evaluation; fermentation quality of the missed silage was improved by the additive treatments; lactic acid content in treatment 4 was the highest (P<0.01) whereas the pH and ammonia nitrogen content in treatment 4 were the lowest (P<0.05). Aerobic stability was increased by all additive treatments with treatment 4 (162 hours) again the best (P<0.01). Rumen degradability of dry matter (DM) in the treatment groups was significantly higher than that the CK group (P<0.05); crude protein (CP) rumen degradation rate was also significantly higher than that in the CK group (P<0.01).The neutral detergent fiber (NDF) rumen degradation rate in treatment 4 was the highest, significantly higher than that of treatment 3 (P<0.05), but was not different to other treatment groups (P>0.05).The acid detergent fiber (ADF) rumen degradation rate of treatment 4 was significantly higher than that of treatment 3 and CK (P<0.05), but was not different from treatment 1 and treatment 2 (P>0.05).The rumen degradability of starch in treatment 1 was 2.83% (P<0.01) higher than that of CK. The rumen degradation rate of starch in other treatment groups were not different (P>0.05). In conclusion, the additives used in this study improved fermentation quality, aerobic stability and rumen degradability of mixed potato pulp and corn straw but the Yaxin treament produced the best quality silage.