The relationship between proportion of fodder beet root (FB: Beta vulgaris subsp. vulgaris L.) in a perennial ryegrass (Lolium perenne) diet and gas production was investigated in vitro. Cumulative gas production and fermentation products were measured in calibrated glass syringes using a factorial arrangement (4 x 6), of dry matter proportion of FB (0, 15, 35 and 50% DM: 0FB, 15FB, 35FB and 50FB, respectively), and incubation time (0, 2, 4, 8, 12 and 24 h). Concentrations of methane (CH₄) and carbon dioxide (CO₂) produced both in fermentation and from bicarbonate buffering of volatile fatty acid, were also calculated. The proportion of FB root linearly increased volume of gas (mL) produced per g dry matter (DM) and per g organic matter (OM) with gas accumulation 14.8% greater for 50FB compared to 0FB at 24-hours of incubation (P<0.001). The concentration of propionic and butyric acids also increased relative to the proportion of FB (P < 0.001). Stoichiometric calculations indicate that FB increased CO₂ released from both buffering and fermentation processes but reduced the fractions of methane in gas (17.6, 17.4, 17.0 and 16.8 ± 0.4% for 0FB, 15FB, 35FB, and 50FB, respectively, P< 0.001). However, the greater OM content of FB increased the total volume of both CO₂ and CH₄ produced. Results suggest that FB altered the thermodynamics of fermentation early in digestion by increasing formation of propionate which acted as a hydrogen sink to reduce formation of methane. However, as fermentation progressed, butyrate forming pathways became more favourable. The greater OM content of FB compared to ryegrass increased absolute volumes of CO₂ and CH₄ from fermentation, resulting in greater emission of gasses per kg DM of substrate. Further investigation in vivo is required to determine potential effects of microbial protein synthesis on gas production and further verify these results.

饲料甜菜根的比例之间的关系：（FB甜菜亚种。寻常在多年生黑麦草L.）（黑麦草）饮食和天然气生产在体外研究。气体累积量和发酵产物的测定是使用校正后的玻璃注射器（4 x 6）对FB的干物质比例（分别为0％，15％，35％和50％DM：0FB，15FB，35FB和50FB）进行的，孵育时间（0、2、4、8、12和24小时）。甲烷（CH ₄）和二氧化碳（CO ₂）的浓度还计算了发酵中和挥发性脂肪酸的碳酸氢盐缓冲液中产生的α）。孵化24小时时，FB根的比例线性增加，每克干物质（DM）和每克有机物质（OM）产生的气体量（mL），与50FB相比，50FB的气体积累高14.8％（P <0.001 ）。丙酸和丁酸的浓度也相对于FB的比例增加（P <0.001）。化学计量计算表明，FB增加了缓冲和发酵过程中释放的CO ₂，但减少了气体中甲烷的含量（对于0FB，15FB，35FB和50FB，分别为17.6、17.4、17.0和16.8±0.4％，P<0.001）。但是，FB的较大OM含量增加了所产生的CO ₂和CH ₄的总体积。结果表明，FB通过增加丙酸酯的形成来改变消化早期发酵的热力学，而丙酸酯的作用是减少氢的形成，减少甲烷的形成。然而，随着发酵的进行，丁酸酯形成途径变得越来越有利。与黑麦草相比，FB中更大的OM含量增加了发酵中CO ₂和CH _4的绝对体积，从而导致每千克DM底物的气体排放量增加。需要进一步的体内研究以确定微生物蛋白质合成对产气的潜在影响并进一步验证这些结果。