| 摘要: |
| 【目的】通过体外产气法评价全株水稻青贮替代不同比例全株玉米青贮对奶牛瘤胃发酵特性的影响，筛选全株水稻青贮替代饲粮中全株玉米青贮的最佳比例，为全株水稻青贮在奶牛生产中的应用提供参考数据。【方法】采用体外产气法单因素试验，设Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ共5组，分别用全株水稻青贮替代各组饲粮中0%，25%，50%，75%和100%的全株玉米青贮（风干基础），每组5个重复，同时设2个空白（即只有瘤胃液或只有培养液而无底物）作为产气量矫正，筛选全株水稻青贮替代饲粮中全株玉米青贮的最佳比例；动物试验选用26 头产奶量、胎次、泌乳时间相近的健康荷斯坦奶牛，随机分为对照组（粗饲料由全株玉米青贮组成）和试验组（采用最佳替代比例，即用全株水稻青贮替代基础饲粮中50％的全株玉米青贮）2组，每组13 个重复，每个重复1 头奶牛。预试期14 d，正试期106 d，探究全株水稻青贮替代基础饲粮50％全株玉米青贮对奶牛生产性能、血清生化指标、养分表观消化率及瘤胃发酵参数的影响。【结果】体外产气法单因素试验表明，试验Ⅲ组的48 h累积产气量、Ⅱ组的干物质消失率、Ⅴ组的NH3-N质量浓度均高于其他各组，但相互间并无显著差异（P＞0.05）；试验Ⅲ组的微生物蛋白质量浓度（(3.19±0.37) mg/mL）显著高于Ⅰ、Ⅱ及Ⅳ组（P0.05），但与Ⅴ组差异不显著（P＞0.05）；所有试验组乙酸、丙酸、丁酸、总挥发性酸浓度差异均不显著（P＞0.05），但试验Ⅲ组的戊酸浓度（（1.33±0.39） mmol/L）显著高于Ⅳ和Ⅴ组，试验组Ⅰ和Ⅱ组显著高于试验Ⅴ组（P＜0.05），而Ⅰ、Ⅱ、Ⅲ组间差异不显著（P>0.05）。动物试验表明，与对照组相比，试验组奶牛生产性能指标（干物质采食量、产奶量、乳蛋白率、乳脂率、乳糖率、乳尿素氮质量浓度、乳体细胞数、总固体物质量分数）、血清生化指标（总蛋白、葡萄糖、总胆固醇、甘油三脂、白蛋白、尿素氮、谷丙转氨酶、谷草转氨酶）及养分表观消化率指标（粗蛋白、中性洗涤纤维、酸性洗涤纤维、干物质）均无显著差异（P＞0.05）；奶牛瘤胃发酵参数中，除对照组的NH3-N质量浓度（（9.89±4.85）mg/dL）、总挥发性脂肪酸浓度（（95.25±12.82） mmol/L）和丙酸体积分数（17.12%±3.44%）极显著（P＜0.01)或显著（P＜0.05)高于试验组外，其他参数间均无显著差异(P＞0.05)。【结论】以全株水稻青贮替代奶牛饲粮中50%的全株玉米青贮是可行的。 |
| 关键词: 全株水稻青贮；全株玉米青贮；发酵特性 生产性能；奶牛；替代比例 |
| DOI： |
| 分类号: |
| 基金项目:国家现代农业技术体系四川肉牛创新团队建设项目（sccxtd-2020-13） |
|
| Effect of whole plant rice silage on production performance of dairy cows |
|
SONG Hejian,PENG Zhongli,LIAO Yupeng,et al
|
| Abstract: |
| 【Objective】This study evaluated the effects of replacing different proportions of whole plant corn silage with whole plant rice silage on rumen fermentation characteristics of dairy cows through in vitro gas production method and screened the optimal proportion of whole plant corn silage in replacement diet of whole plant rice silage to provide reference for the application of whole plant rice silage in dairy cow production.【Method】Single factor experiments were conducted using in vitro gas production method in 5 groups of Ⅰ,Ⅱ,Ⅲ,Ⅳ and Ⅴ with 0%,25%,50%,75% and 100% of whole plant corn silage in the diet (air dried basis) replaced by whole plant rice silage.There were 5 replicates in each group and 2 blanks with only rumen liquid or culture medium without substrate were set for gas production correction.The optimal replacement ratio of whole plant rice silage in the diet was determined.In the animal testing,26 healthy Holstein cows with similar milk yield,parity and lactation time were randomly divided into two groups of control (whole plant corn silage) and test (50% of the whole plant corn silage in the basic diet was replaced),with 13 replicates in each group and one cow in each replicate.A preliminary trial period of 14 days and a trial period of 106 days were used to investigate the effects of replacing 50% whole plant corn silage on production performance,serum biochemical indicators,nutrient apparent digestibility and rumen fermentation parameters of dairy cows.【Result】The single factor experiment using in vitro gas production method showed that the cumulative gas production at 48 hours in group Ⅲ,dry matter disappearance rate in group Ⅱ and ammonia nitrogen mass concentration in group Ⅴ were higher than those in other groups without significant difference (P>0.05).The microbial protein mass concentration ((3.19±0.37) mg/mL) in group Ⅲ was significantly higher than those in groups Ⅰ,Ⅱ and Ⅳ (P<0.05),but there was no significant difference compared to group Ⅴ (P>0.05).There was no significant difference in concentrations of acetic acid,propionic acid,butyric acid and total volatile acids among all experimental groups (P>0.05).However,the concentration of valeric acid in group Ⅲ((1.33±0.39)mmol/L) was significantly higher than that in groups Ⅳ and Ⅴ.Its concentrations in groups Ⅰ and Ⅱ were significantly higher than that in group Ⅴ (P<0.05),and the differences in groups Ⅰ,Ⅱ and Ⅲ were insignificant (P>0.05).The animal testing showed that there were no significant differences in cow production performance indicators (dry matter intake,milk production,milk protein rate,milk fat rate,lactose rate,milk blood urea nitrogen mass concentration,milk somatic cell count and total solids mass fraction),serum biochemical indicators (TP,GLU,TC,TG,ALB,urea nitrogen,ALT and AST) and nutrient apparent digestibility indicators (crude protein,neutral detergent fiber,acidic detergent fiber and dry matter) among the control and test groups (P>0.05).Ammonia nitrogen mass concentration ((9.89±4.85 )mg/dL),total volatile fatty acid concentration ((95.25±12.82) mmol/L) and propionic acid volume fraction (17.12%±3.44%) of the control group were extremely significant (P<0.01) or significant (P<0.05) higher than the test group,while there were no significant differences in other rumen fermentation parameters (P>0.05).【Conclusion】It is feasible to replace 50% whole plant corn silage in cow feed with whole plant rice silage. |
| Key words: whole plant rice silage whole plant corn silage fermentation characteristics production performance cow substitution ratio |
