摘要
本试验旨在利用体外发酵法评价棉秆与甜菜渣混合发酵产物的产气特性和营养品质并筛选出最佳发酵组合。甜菜渣的添加比例分别为10%、30%和50%,尿素添加比例分别为0.1%、0.2%和0.3%,菌液添加比例分别为0.05%、0.1%和0.2%,食盐添加量为0.2%的三因素三水平的正交试验设计,研究各组发酵产物的营养品质,筛选出最佳的发酵条件。结果表明,48 h累积产气量I组与K组差异极显著(P<0.01),与A、D、F组差异显著(P<0.05);G组显著高于K组56.03%(P<0.05);其他组间差异不显著(P>0.05);I组可消化有机物(DOM)和代谢能(ME)最高,分别为722.40 g·kg^-1和9.75 MJ·kg^-1;各组慢速降解参数(b),I组与K组差异极显著(P<0.01),与A、D、F组差异显著(P<0.05);G、H组与K组差异显著(P<0.05);各组快速降解参数(a)、产气速率(c)差异不显著;H组氨态氮浓度与其他各组差异显著(P<0.05),K组与D和F组差异不显著(P>0.05);H、I组可溶性糖与其他各组差异显著(P<0.05),H组显著高于B组44.06%、K组31.23%,K组与其他各组差异显著;pH值、乳酸和微生物蛋白则均无显著性差异(P>0.05);H组的总挥发性脂肪酸(VFA)浓度最高,为100.31 mmol·L^-1,显著高于除G组外的其他各组(P<0.05);乙酸和丁酸浓度也最高,显著高于除G和I组外的其他各组(P<0.05);丙酸浓度则为G组最高,显著高于除H组外的其他各组(P<0.05);同时,其乙酸/丙酸(A/P)最低,显著低于A、B、C和K组(P<0.05)。通过对棉秆与甜菜渣混合发酵产物隶属函数分析及综合价值排序得出各组隶属函数平均值分别为I组(0.719)>H组(0.692)>F组(0.595)>G组(0.591)>C组(0.407)>E组(0.400)>B组(0.395)>K组(0.374)>D组(0.307)>A组(0.243)。综上,以干物质基础棉秆与甜菜渣比例50∶50,添加尿素0.1%,复合菌液0.2%,食盐0.2%的I组,其混合发酵产物的体外产气量最高,可消化有机物和代谢能最大,乙酸和丁酸浓度较高,发酵组合综合价值排序最高,为最佳发酵组合,可作为饲喂反刍动物的粗饲料。
This experiment evaluated the nutritional quality,gas production characteristics and the fermentation products of mixed feedstuffs comprising cotton stalk and beet pulp.A three-factor,three-level orthogonal treatment combination and an in vitro fermentation method were used,in order to identify the optimal fermentation conditions.Beet pulp was added to cotton stalk in proportions of 10%,30%or 50%,with 0.1%,0.2%or 0.3%added urea,and 0.05%,0.1%or 0.2%added bacterial liquid(lactic acid bacteria and yeast are the main components),with salt added 0.2%in all cases.From the 27 available combinations,9 were chosen for inclusion in the experiment,designated A-I,and a control,K,as follows:A)10%beet pulp,90%cotton stalk,0.1%urea,0.05%bacterial liquid,0.2%salt;B)10%beet pulp,90%cotton stalk,0.2%urea,0.1%bacterial liquid,0.2%salt;C)10%beet pulp,90%cotton stalk,0.3%urea,0.2%bacterial liquid,0.2%salt;D)30%beet pulp,70%cotton stalk,0.3%urea,0.05%bacterial liquid,0.2%salt;E)30%beet pulp,70%cotton stalk,0.1%urea,0.1%bacterial liquid,0.2%salt;F)30%beet pulp,70%cotton stalk,0.2%urea,0.2%bacterial liquid,0.2%salt;G)50%beet pulp,50%cotton stalk,0.2%urea,0.05%bacterial liquid,0.2%salt;H)50%beet pulp,50%cotton stalk,0.3%urea,0.1%bacterial liquid,0.2%salt;I)50%beet pulp,50%cotton stalk,0.1%urea,0.2%bacterial liquid,0.2%salt and control group K(100%cotton stalk,0 urea,0 bacterial liquid,0.2%salt).It was found that for gas production at 48 hours,Group I was significantly higher than groups A,D,F(P<0.05),and group K(P<0.01),while,there were no significant difference between the other groups(P>0.05).Group I had the highest organic matter digestibility and metabolizable energy:722.40 g·kg^-1 and 9.75 MJ·kg^-1,respectively.The slow degradation parameter,b,was significantly higher in group I than in groups A,D,F(P<0.05),and group K(P<0.01).Groups G and H,were also significantly higher than group K(P<0.05),while there were no significant differences between the other groups(P>0.05).The rapid degradation parameter(a),and the gas production rate(c),did not differ significantly between any of the groups.The concentration of ammonia nitrogen in group H was significantly lower(P<0.05)than in other groups,and group K was significantly lower than groups A,B,C and E.Soluble sugar was significantly higher(P<0.05)in groups H and I than other groups,and in group H was 44.06%and 31.23%higher than the lowest groups,B and K,respectively.No significant differences between groups for pH,lactic acid and microbial protein were detected(P>0.05).The highest total volatile fatty acid(VFA)concentrations occurred in groups was group H and G(100.31 and 99.73 mmol·L^-1,respectively),and these values were which was significantly(P<0.05)higher than those of other groups.For the volatile fatty acids,acetate and butyrate were highest in Groups G,H,and I and propionate was highest in Groups G and H,while acetate:propionate ratio was lowest in groups G,H,and I.Using a membership function analysis for multivariate ranking of the mixed fermentation products of cotton stalk and beet pulp,the average membership function values of each group were I(0.719)>H(0.692)>F(0.595)>G(0.591)>C(0.407)>E(0.400)>B(0.395)>K(0.374)>D(0.307)>A(0.243).In conclusion,a dry matter-based ratio of cotton stalk to beet pulp of 50∶50,with 0.1%urea,0.2%bacterial liquid,and 0.2%salt(group I)is recommended based on this research.The mixed fermentation product of this mixture has the highest in vitro gas production,the highest digestible organic matter and metabolic energy content,the higher concentration of acetic acid and butyric acid,and the highest multivariate score of the fermentation products.It is the best among the fermentation combinations tested and is suitable as a roughage for ruminants.
作者
芦岩
张伶俐
罗远琴
魏利
薛雪
孙新文
向春和
毛胜勇
王新峰
张文举
LU Yan;ZHANG Ling-li;LUO Yuan-qin;WEI Li;XUE Xue;SUN Xin-wen;XIANG Chun-he;MAO Sheng-yong;WANG Xin-feng;ZHANG Wen-ju(College of Animal Science & Technology, Shihezi University, Shihezi 832003, China;Medical College, Shantou University, Shantou 515041, China;College of Animal Science & Technology, Nanjing Agricultural University, Nanjing 210095, China)
出处
《草业学报》
CSCD
北大核心
2020年第5期58-66,共9页
Acta Prataculturae Sinica
基金
国家自然科学基金(31360558)
广东省创新强校工程项目青年创新人才项目(2018KQNCX083)
动物消化道营养国际联合研究中心开放课题和国家重点研发计划子课题(2018YFD0502101)资助。
关键词
棉秆
甜菜渣
产气特性
发酵参数
cotton straw
beet pulp
gas production characteristics
fermentation parameters