Departament Producció Animal, ETSEA, Alcalde Rovira Roure 191, 25198 Lleida, Spain.
J Anim Sci. 2012 Dec;90(13):4975-84. doi: 10.2527/jas.2011-4955. Epub 2012 Jul 24.
To study the effects of an extract of plant flavonoids [Bioflavex (FL)] in cattle fed high-concentrate diets, 2 experiments were designed. In the first experiment, the effects of Bioflavex on the development of rumen acidosis was evaluated in 8 Holstein-Friesian crossbreed heifers (451 kg; SEM 14.3 kg of BW) using a crossover design. Each experimental period lasted 22 d; from d 1 to 20, the animals were fed rye grass, on d 21 the animals were fasted, and on d 22, rumen acidosis was induced by applying 5 kg of wheat without [
(CTR) heifers who did not receive Bioflavex] or with flavonoids [heifers who received FL; 300 mg/kg DM] through a rumen cannula. Rumen pH was recorded continuously (from d 19 to d 22). On d 22, average rumen pH was significantly (P < 0.01) higher in the FL animals (6.29; SEM = 0.031) than it was in the CTR heifers (5.98; SEM = 0.029). After the wheat application, the rumen VFA concentration increased (P < 0.01), the proportion of acetic acid decreased (P < 0.01), and lactate concentration (mmol/L) increased, but the increase was not as great (P = 0.09) in the FL as it was in the CTR heifers (0.41 to 1.35 mmol/L; SEM = 0.24). On d 22, Streptococcus bovis and Selenomonas ruminantium titers increased after the wheat application, but Megasphaera elsdenii titers increased (P < 0.05) only in the FL heifers. In the second experiment, the effect of Bioflavex on the performance and rumen fermentation in finishing heifers was evaluated. Forty-eight Fleckvieh heifers (initial BW = 317 kg; SEM = 5.34) were used in a completely randomized design. Heifers were assigned to 1 of 4 blocks based on their BW and, within each block, assigned to 1 of 2 pens (6 heifers/pen). In addition, 16 heifers (2/pen) were rumen cannulated. Individual BW and group consumption of concentrate and straw were recorded weekly until the animals reached the target slaughter weight. Supplementation with FL did not affect ADG, feed consumption, or feed conversion ratio. Rumen pH and molar proportions of propionate were greater (P < 0.01) and acetate proportion was less in the FL (P < 0.01) than they were in the CTR heifers. Flavonoid supplementation might be effective in improving rumen fermentation and reducing the incidence of rumen acidosis. This effect of flavonoids may be partially explained by increasing the numbers of lactate-consuming microorganisms (e.g., M. elsdenii) in the rumen.
研究植物类黄酮提取物[Bioflavex（FL）]对高浓度日粮下牛的影响，设计了 2 个实验。在第一个实验中，采用交叉设计，用 8 头荷斯坦-弗里斯奶牛（451 kg；体重 BW 的 SEM 为 14.3 kg）评估 FL 对瘤胃酸中毒发展的影响。每个实验期持续 22 d；从第 1 天到第 20 天，动物饲喂黑麦草，第 21 天动物禁食，第 22 天通过瘤胃套管应用 5 kg 小麦（[对照：（CTR）未接受 FL 的牛]或含黄酮[接受 FL 的牛；DM 中 300 mg/kg]）诱导瘤胃酸中毒。连续记录瘤胃 pH 值（从第 19 天到第 22 天）。第 22 天，FL 动物的平均瘤胃 pH 值（6.29；SEM=0.031）显著高于 CTR 牛（5.98；SEM=0.029）（P<0.01）。小麦应用后，瘤胃 VFA 浓度增加（P<0.01），乙酸比例降低（P<0.01），乳酸浓度（mmol/L）升高，但 FL 牛的升高幅度（P=0.09）不如 CTR 牛（0.41 至 1.35 mmol/L；SEM=0.24）大。第 22 天，小麦应用后，链球菌和反刍月形单胞菌的滴度增加，但仅在 FL 牛中，巨球形菌的滴度增加（P<0.05）。在第二个实验中，评估了 Bioflavex 对育肥小公牛的性能和瘤胃发酵的影响。采用完全随机设计，使用 48 头弗莱维赫小公牛（初始 BW=317 kg；SEM=5.34）。根据 BW 将小公牛分为 1 个 4 个块，每个块内，将小公牛分为 2 个栏（6 头/栏）。此外，16 头小公牛（每栏 2 头）通过瘤胃套管进行了处理。每周记录个体 BW 和精料和秸秆的组消耗，直到动物达到目标屠宰体重。FL 的补充不影响 ADG、饲料消耗或饲料转化率。FL 牛的瘤胃 pH 值和丙酸摩尔比例更高（P<0.01），乙酸比例更低（P<0.01）。黄酮类化合物的补充可能有效改善瘤胃发酵，降低瘤胃酸中毒的发生率。黄酮类化合物的这种作用可能部分归因于增加了瘤胃中乳酸消耗微生物（如 M. elsdenii）的数量。
