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本试验通过体外发酵法,探讨皇竹草和精料以不同比例配制成的全混合日粮(TMR)对雷州山羊体外瘤胃发酵的影响。试验采用精料与皇竹草按干物质0∶100(Ⅰ组)、10∶90(Ⅱ组)、20∶80(Ⅲ组)、30∶70(Ⅳ组)和40∶60(V组)比例配制日粮,在体外发酵的第4、8、12、24和48h取样分析其发酵参数的变化,为皇竹草在雷州山羊TMR中的应用提供参考。结果显示,(1)随着精粗比的提高,粗蛋白质含量逐渐增高,纤维物质、粗灰分含量逐渐降低,且4、8、24、48h累积产气量呈现极显著增长(P<0.01)。(2)随着发酵时间和精料添加比例的增加,瘤胃pH呈下降趋势,同一时间点,Ⅳ、Ⅴ组pH均显著低于Ⅰ、Ⅱ组(P<0.05);干物质降解率呈上升趋势,同一时间点,Ⅳ、Ⅴ组的降解率均极显著高于Ⅰ、Ⅱ组(P<0.01);48h的氨态氮浓度均高于4h,4、24h时各组间均无显著差异(P>0.05)。(3)pH与累积产气量和干物质降解率呈显著或极显著的负相关,累积产气量与干物质降解率呈显著或极显著的正相关(P<0.05;P<0.01);各个发酵时间pH与干物质、粗灰分、粗纤维、中性洗涤纤维和酸性洗涤纤维呈显著或极显著正相关,与粗蛋白质呈显著或极显著负相关(P<0.05;P<0.01);累积产气量和干物质降解率与TMR日粮粗蛋白质含量呈显著或极显著正相关,与干物质、粗灰分、粗纤维、中性洗涤纤维和酸性洗涤纤维呈显著或极显著负相关(P<0.05;P<0.01)。综上,在本试验条件下,精料和皇竹草的比例为30∶70时,可获得较好的发酵效果,且可节约成本。
In this study, we investigated the effect of TMR on rumen fermentation of Leizhou goats in vitro by using in vitro fermentation method. The experiment was conducted on the basis of dry matter 0:100 (group Ⅰ), 10:90 (group Ⅱ), 20:80 (group Ⅲ), 30:70 (group Ⅳ) and 40:60 (group V) Proportion of rationally formulated diets, sampling and analyzing the changes of fermentation parameters on the 4th, 8th, 12th, 24th and 48th hour of in vitro fermentations, provided the reference for the application of imperial bamboo in TMR of Leizhou goat. The results showed that: (1) The crude protein content increased gradually with the increase of the ratio of fine to coarse, the content of fiber and crude ash gradually decreased, and the accumulated gas production increased significantly at 4, 8, 24, 48 h (P <0.01). (2) The rumen pH decreased with the increase of fermentation time and the proportion of concentrate, and at the same time point, the pH values in groups Ⅳ and Ⅴ were significantly lower than those in groups Ⅰ and Ⅱ (P <0.05); the degradation rate of dry matter increased At the same time point, the degradation rates in groups Ⅳ and Ⅴ were significantly higher than those in groups Ⅰ and Ⅱ (P <0.01). The concentrations of ammonia nitrogen in 48h were all higher than 4h, and there was no significant difference between 4 and 24 hours (P> 0.05). (3) There was a significant or extremely significant negative correlation between pH and cumulative gas production and dry matter degradation rate, with a significant positive correlation (P <0.05; P <0.01) between cumulative gas production and dry matter degradation rate The time pH was significantly or very significantly positively correlated with dry matter, crude ash, crude fiber, neutral detergent fiber and acid detergent fiber, but negatively correlated with crude protein (P <0.05; P <0.01) The gas and dry matter degradation rates were significantly or very significantly positively correlated with the crude protein content of TMR diet and negatively or significantly correlated with dry matter, crude ash, crude fiber, neutral detergent fiber and acid detergent fiber (P <0.05 ; P <0.01). In summary, under the test conditions, the ratio of concentrate to imperial bamboo is 30:70, the better fermentation effect can be obtained, and the cost can be saved.