不同无机磷添加水平对混合瘤胃微生物体外发酵的影响

Effects of different inorganic phosphorus on in vitro fermentation of mixed ruminal microorganisms

采用体外法研究无机磷添加浓度对瘤胃发酵的影响。培养液中设0mg/L、30mg/L、60mg/L、90mg/L、120mg/L、150mg/L、200mg/L、250mg/L、300mg/L、350mg/L共10个无机磷水平。体外发酵48h后终止培养,测定培养液的产气量、pH值、挥发性脂肪酸、干物质降解率、NDF降解率。结果表明:无机磷添加水平对48h总产气量和DM降解率影响显著(P<0.05),随着无机磷添加水平的提高,48h总产气量和DM降解率显著提高,添加水平为200mg/L时达到最大值,分别为44.30mL和54.80%,随后下降。瘤胃培养液pH值随无机磷添加水平的增加而显著降低(P<0.05),无机磷添加水平为200mg/L时达到最小值6.35,随后又上升。不同无机磷添加水平对乙酸、丙酸、丁酸和总VFA产量影响显著(P<0.05),无机磷添加水平为200mg/L时,乙酸、丙酸、丁酸及总VFA产量最高,随后下降。

The effects of rumen fermentation by adding inorganic P in vitro were studied, concentration of inorganic phosphorus were 0mg/L, 30mg/L, 60mg/L, 90mg/L, 120mg/L, 150mg/L, 200mg/L, 250mg/L, 300mg/L and 350mg/L. The gas production, pH, VFA, dry matter and NDF degradation of 48h fermentation in vitro were measured. The results as follow： different inorganic P levels significantly influenced the gas production and DM digestibility by 48h fermentation in vitro （P〈0.05）. The gas production and DM digestibility increased and reached its maximum when inorganic P was 200mg/L and then declining, pH was significantly influenced by different inorganic phosphorus levels（P 〈 0.05）. pH decreased when inorganic P levels increased（P 〈 0.05）and reached its minimum when inorganic P was 200mg/L. Acetate, propionate, butyrate acid and total VFA production were significantly effected by the concentration of inorganic phosphorus（P〈0.05）.Acetate, propionate, butyrate acid and total VFA production were the highest when the concentration of inorganic phosphorus was 200mg/L.