乳酸菌制剂对饲用油菜与全株玉米或玉米秸秆混合青贮品质的影响

Effects of Lactic Acid Bacteria Preparation on Quality of Mixed Silage of Forage Rape with Whole-Crop Corn or Corn Stalk

本试验旨在研究乳酸菌制剂对饲用油菜与全株玉米或玉米秸秆混合青贮的营养物质含量、发酵品质和有氧稳定性的影响,为乳酸菌制剂在饲用油菜混合青贮中的开发利用提供参考依据。试验设4个组,每组3个重复。4个组分别为饲用油菜+全株玉米混合青贮组(CR组)、饲用油菜+全株玉米+乳酸菌制剂混合青贮组(CR+LAB组)、饲用油菜+玉米秸秆混合青贮组(SR组)、饲用油菜+玉米秸秆+乳酸菌制剂混合青贮组(SR+LAB组)。饲用油菜与全株玉米的混合比例为5∶5(干物质基础),饲用油菜与玉米秸秆的混合比例为7∶3(干物质基础)。CR+LAB组和SR+LAB组中乳酸菌制剂添加量为5 g/t(溶于2 kg蒸馏水中),CR组和SR组添加等量的蒸馏水。取1 kg混合好的原料,切短为2~3 cm,装于袋中抽真空后密封,室温贮藏60 d。测定青贮样品的营养物质含量、pH、有机酸含量和有氧稳定性。结果表明:1)青贮60 d后,CR+LAB组和SR+LAB组的干物质含量显著高于CR组和SR组(P<0.05);CR+LAB组的粗蛋白质含量显著高于其他3组(P<0.05),SR组的粗蛋白质含量显著低于其他3组(P<0.05);SR组和SR+LAB组的中性洗涤纤维和酸性洗涤纤维含量显著高于CR组和CR+LAB组(P<0.05)。2)各组之间pH和乙酸含量无显著差异(P>0.05)。CR组和CR+LAB组的乳酸和丙酸含量显著高于SR组和SR+LAB组(P<0.05)。3)CR组和SR组的有氧稳定性显著低于CR+LAB组和SR+LAB组(P<0.05)。综上所述,饲用油菜与全株玉米混合青贮的营养价值高于饲用油菜与玉米秸秆混合青贮。青贮中添加乳酸菌制剂提高了青贮饲料的粗蛋白质含量,能够有效延长饲用油菜与全株玉米混合青贮的有氧稳定性。

This experiment was conducted to study the effects of lactic acid bacteria preparation on nutrient contents,fermentation quality and aerobic stability of mixed silage of forage rape with whole-crop corn or corn stalk,so as to provide reference for the development and utilization of lactic acid bacteria in mixed silage of forage rape.There were 4 groups with 3 replicates in each group.The four groups were forage rape+whole-crop corn mixed silage group(CR group),forage rape+whole-crop corn+lactic acid bacteria preparation mixed silage group(CR+LAB group),forage rape+corn stalk mixed silage group(SR group)and forage rape+corn stalk+lactic acid bacteria preparation mixed silage group(SR+LAB group).The mixed ratio of forage rape and whole-crop corn was 5∶5(dry matter basis),and the mixed ratio of forage rape and corn stalk was 7∶3(dry matter basis).The lactic acid bacteria preparation additive amount of CR+LAB group and SR+LAB group was 5 g/t(dissolved in 2 kg distilled water),and the CR group and SR group were added the same amount of distilled water.1 kg mixed feedstuffs were cut into 2 to 3 cm and packed in bags,vacuum sealed and stored at room temperature for 60 days.The nutrient contents,pH,organic acid contents and aerobic stability of silage samples were measured.The results showed as follows:1)after 60 days of ensiling,the dry matter content of CR+LAB group and SR+LAB group was significantly higher than that of CR group and SR group(P<0.05);the crude protein content of CR+LAB group was significantly higher than that of other 3 groups(P<0.05),and the crude protein content of SR group was significantly lower than that of other 3 groups(P<0.05);the neutral detergent fiber and acid detergent fiber contents of SR group and SR+LAB group were significantly higher than those of CR group and CR+LAB group(P<0.05).2)There were no significant differences in pH and acetic acid content among all groups(P>0.05).The lactic acid and propionic acid contents of CR group and CR+LAB group were significantly higher than those of SR group and SR+LAB group(P<0.05).3)The aerobic stability of CR group and SR group was significantly lower than that of CR+LAB group and SR+LAB group(P<0.05).In general,the nutritive value of mixed silage of forage rape with whole-crop corn was higher than that of mixed silage of forage rape with corn stalk.The addition of lactic acid bacteria preparation in ensiling increases the crude protein content of silage,and effectively prolonged the aerobic stability of mixed silage of forage rape with whole-crop corn.