Supplements investigated throughout the present study are produced by fermenting lactose that is present in whey to lactate, yielding products differing in ammonium relative to lactate concentrations and in physical form (liquid or dry). Trials 1 and 2 investigated Lacto-Whey (LW; Fermented Nutrition Corp., Luxemburg, WI) and GlucoBoost (GB; Fermented Nutrition Corp.), respectively, using dual-flow continuous culture systems (n = 4), each with a 4 × 4 Latin square design. A greater proportion of nonprotein nitrogen was present in GB than in LW. In trial 1, the treatment with LW was isonitrogenously dosed against soybean meal (SBM) as a control (no LW) and factorialized with either a wheat- or corn-based concentrate (55% inclusion rate, dry matter basis). We hypothesized that LW would increase propionate production and that the combination of +LW with wheat would increase bacterial assimilation of NH₃-N into cellular N. No differences were observed for total volatile fatty acid (VFA) production per day. However, treatment × time interactions revealed that +LW increased lactate concentration at 0, 0.5, and 1 h and tended to increase molar percentage of propionate at 1 and 1.5 h postfeeding, documenting the immediate availability of lactate converted to propionate in the +LW treatments. The main effect of corn increased the proportion of bacterial N derived from NH₃-N. Trial 2 was designed to investigate GB; isonitrogenous treatments included an SBM control, crystal GB, liquid GB (LGB), and LGB with yeast culture, which were dosed twice daily. We hypothesized that GB would increase propionate production and bacterial assimilation of NH₃-N; the combination of LGB and yeast culture was expected to have a positive additive effect, yielding the greatest VFA production and bacterial NH₃-N assimilation. No differences were observed for total VFA production; however, LGB decreased molar percentage of acetate and increased propionate and butyrate molar percentages. There were no differences in non-NH₃-N flow or microbial N flow. Under the conditions of our studies, lactate in LW and GB was fermented extensively to propionate, and microbial protein synthesis in these treatments was comparable with that in SBM controls.

通过将乳清中存在的乳糖发酵成乳酸，生产出在铵中相对于乳酸浓度和物理形式（液体或干燥形式）不同的产品，从而生产出贯穿本研究的补充食品。试验1和2使用双流连续培养系统（n = 4）分别研究了Lacto-Whey（LW; Fermented Nutrition Corp.，Luxemburg，WI）和GlucoBoost（GB; Fermented Nutrition Corp.），每个系统均采用4倍连续流培养系统（n = 4）。 ×4拉丁方形设计。更大比例的非蛋白质氮在GB中比在LW中存在。在试验1中，将LW的处理同等剂量地以大豆粉（SBM）为对照（无LW），并以小麦或玉米为基础的浓缩物（包含率为55％，以干物质为基础）进行因子分解。我们假设LW会增加丙酸的产生，+ LW与小麦的结合会增加NH _3的细菌同化作用-N进入细胞N。每天的总挥发性脂肪酸（VFA）产量未见差异。然而，处理×时间相互作用表明，+ LW在喂食后1、0和1.5 h时，乳酸浓度在0、0.5和1 h升高，并且倾向于增加丙酸酯的摩尔百分比，从而证明+ LW处理中乳酸可立即转化为丙酸酯。 。玉米的主要作用是增加源自NH ₃ -N的细菌N的比例。试验2旨在调查GB；等氮处理包括SBM对照，结晶GB，液体GB（LGB）和带有酵母培养物的LGB，每天两次。我们假设GB会增加丙酸酯的产生和NH _3的细菌同化作用-N; LGB和酵母培养物的组合有望产生积极的累加作用，产生最大的VFA产量和细菌NH ₃ -N同化作用。VFA的总产量未见差异。然而，LGB降低了乙酸盐的摩尔百分数，并增加了丙酸酯和丁酸酯的摩尔百分数。非NH ₃ -N流量或微生物氮流量无差异。在我们的研究条件下，LW和GB中的乳酸广泛发酵为丙酸，这些处理中的微生物蛋白质合成与SBM对照相当。