硬核油对瘤胃体外发酵及脂肪酸组成的影响

摘要

In order to find the optimal supplemental level of Scleropyrum wallichianum oil,the effects of adding 1％,2％,3％ or 4％ (dry matter basis) of Scleropyrum wallichianum oil in diet on 24 h rumen fermentation parameters,gas production parameters and composition of fatty acids were investigated using in vitro gas production method.The results showed as follows:1) there were no significant effects of adding Scleropyrum wallichianum oil in diet on 24 h gas production,theoretical maximum gas production and the rate of gas production (P＞0.05).2) The concentrations of ammonia nitrogen (P =0.044),total volatile fatty acid (P＜ 0.001),acetate (P＜0.001),propionate (P=0.047) and butyrate (P=0.017) quadratically increased as the level of Scleropyrum wallichianum oil increased,besides,the concentrations of total volatile fatty acid and acetate of 1％,2％ and 3％ groups were significantly higher than those in control group and 4％ group (P＜0.05);there were no significant effects of adding Scleropyrum wallichianum oil on pH,microbe protein concentration,dry matter degradation rate,neutral detergent fiber degradation rate and acid detergent fiber degradation rate (P＞0.05).3) The content of saturated fatty acid was linearly (P =0.008) and quadratically decreased (P =0.028) as the level of Scleropyrum wallichianum oil increased,and C18∶0 content was linearly decreased (P=0.030),too;the content of unsaturated fatty acid was linearly (P=0.008) and quadratically increased (P=0.028) as the level of Scleropyrum wallichianum oil increased,t9-C18∶1 content was linearly (P=0.002),t11-C18∶1 content was quadratically (P＜0.001) and c9-C18∶1 was linearly (P=0.028) and quadratically increased (P=0.005),and t9-C18∶land c9-C18∶1 reached maximum values under the adding level of 3％.Under the conditions of the present study,the levels of 1％,2％ and 3％ Scleropyrum wallichianum oil can increase the contents of unsaturated fatty acids and the concentrations of volatile fatty acids,and the level of 3％ has the best effect.%本研究利用体外产气法,探究饲粮中分别添加1％、2％、3％及4％(干物质基础)的硬核油对瘤胃体外发酵24 h产气参数、发酵参数及脂肪酸组成的影响,旨在确定硬核油在瘤胃发酵中的最适添加水平.结果表明:1)饲粮中添加硬核油对24 h产气量、理论最大产气量及产气速率无显著影响(P＞0.05).2)氨氮(P=0.044)、总挥发性脂肪酸(P＜0.001)、乙酸(P＜0.001)、丙酸(P=0.047)及丁酸浓度(P=0.017)随硬核油添加水平的增加呈二次曲线升高,且总挥发性脂肪酸及乙酸浓度在1％、2％及3％组显著高于对照组及4％组(P＜0.05);pH、微生物蛋白浓度、干物质降解率、中性洗涤纤维降解率及酸性洗涤纤维降解率未受硬核油添加的影响(P＞0.05).3)饱和脂肪酸的含量随硬核油添加水平的增加呈线性(P=0.008)及二次(P=0.028)降低,其中C18∶0的含量也呈线性降低(P=0.030);不饱和脂肪酸的含量随硬核油添加水平的增加呈线性(P=0.008)及二次(P=0.028)升高,其中t9-C18∶1含量呈线性(P=0.002)、tll-C18∶1含量呈二次(P＜0.001)、c9-C18∶1含量呈线性(P=0.028)和二次(P=0.005)升高,且t9-C18∶1及c9-C18∶1含量均在3％添加水平下出现最大值.在本试验条件下,1％、2％及3％添加水平的硬核油可提高瘤胃体外发酵不饱和脂肪酸含量,同时增加挥发性脂肪酸的浓度,3％添加水平效果最佳.