Department of Animal and Fish Production, Faculty of Agriculture, University of Alexandria, Aflaton St., El-Shatby, P.O. Box 21545, Alexandria, Egypt.
Animal Production Research Institute, Agricultural Research Center, Giza, Egypt.
Trop Anim Health Prod. 2023 Jul 11;55(4):265. doi: 10.1007/s11250-023-03672-7.
In vitro and in vivo experiments were carried out to investigate the effects of the supplementation of different levels of humic and fulvic acids alone or their combination (2:1 ratio) on ruminal fermentation constituents, and nutrients digestibility in goats. The treatments in Exp. 1 were the following: (1) basal substrate (50% concentrate: 50% forage) was incubated humic at 0, 2, 4, and 6 g/kg DM; (2) fulvic at 0, 1, 2, and 3 g/kg DM; and (3) a combination of humic and fulvic (in a 2:1 ratio) at 0, 3, 6, and 9 g/kg DM" of treatments. The results of Exp. 1 revealed that methane (CH) production was linearly decreased (P < 0.001) upon increasing humic doses. Whereas, the combination of fulvic acid with humic acid resulted in a quadratic decrease (P < 0.001) in net CH production. Supplementing humic and fulvic acids, either separately or in combination, resulted in reduced (P < 0.05) ammonia nitrogen (NH-N) and total volatile fatty acid (VFA) concentrations. In Exp. 2 to further examine the findings obtained in Exp. 1, forty Damascus non-lactating goats (2-3 years of age and body weight 29 ± 1.5 kg) were fed the same basal diet as in Exp. 1, plus one of four treatments. Treatments were the following: (1) control (no supplement); (2) basal diet plus 5 g humic alone; (3) basal diet plus 2.5 g fulvic alone, and (4) basal diet plus 7.5 g their combination. Goats fed diets supplemented with humic acid, fulvic acid, either alone or in combination, increased concentrations of butyrate (P = 0.003), total VFA (P < 0.001), and improved (P < 0.001) digestibility of nutrients, but reduced (P < 0.001) ruminal NH-N concentrations. In conclusion, applying humic and fulvic acids alone or in combination attenuated in vitro CH production, while improved intake and diet digestibility without adverse effect on rumen fermentation profiles in Damascus goats.
进行了体外和体内实验，以研究单独或组合（2:1 比例）添加不同水平的腐殖酸和富里酸对山羊瘤胃发酵成分和养分消化率的影响。实验 1 的处理如下：（1）基础底物（50%浓缩物：50%草料）以 0、2、4 和 6 g/kg DM 的剂量添加腐殖酸；（2）以 0、1、2 和 3 g/kg DM 的剂量添加富里酸；（3）以 0、3、6 和 9 g/kg DM 的剂量添加腐殖酸和富里酸的组合。实验 1 的结果表明，随着腐殖酸剂量的增加，甲烷（CH）的产生呈线性减少（P<0.001）。然而，富里酸与腐殖酸的组合导致净 CH 产量呈二次下降（P<0.001）。单独或组合添加腐殖酸和富里酸会降低（P<0.05）氨氮（NH-N）和总挥发性脂肪酸（VFA）浓度。在实验 2 中，为了进一步检验实验 1 中的发现，给 40 只大马士革非泌乳山羊（2-3 岁，体重 29±1.5 公斤）喂食与实验 1 相同的基础日粮，并添加四种处理中的一种。处理如下：（1）对照（无补充）；（2）基础日粮加 5 g 腐殖酸；（3）基础日粮加 2.5 g 富里酸；（4）基础日粮加 7.5 g 组合。单独或组合添加腐殖酸、富里酸的日粮，提高了丁酸（P=0.003）、总 VFA（P<0.001）浓度，改善（P<0.001）了养分消化率，但降低了（P<0.001）瘤胃 NH-N 浓度。综上所述，单独或组合应用腐殖酸和富里酸可减少体外 CH 产量，同时提高摄入和日粮消化率，而对大马士革山羊瘤胃发酵谱无不良影响。
