摘要
The objective of the study was to determine whether feeding a diet supplemented with 3-nitrooxypropanol (3-NOP) affects feeding behavior altering intake and rumen fermentation. Two experiments were conducted with 9 rumen-cannulated beef steers in a replicated 3 × 3 Latin square design where animals received a high-forage or high-grain diet. Treatments were 1) a basal diet (CON), the CON diet supplemented with 3-NOP (dNOP; 100 mg/kg in dietary DM or 1 g/d), or the CON diet with 3-NOP (1 g/d) infused into the rumen (infNOP). Each experimental period consisted of 14-d diet adaptation and 7-d sample collection. A 7-d washout period was provided between experiment periods. All data were analyzed as a Latin square design using Mixed Procedure of SAS. In Exp. 1 (high-forage diet), methane yield (measured by the Greenfeed system) was lowered by 18% (18.6 vs. 22.7 g/kg DMI; P < 0.01) by dNOP compared with CON. Rumen fermentation was altered similarly by both NOP treatments compared with CON where dNOP and infNOP increased (P < 0.01) rumen pH at 3 h and decreased (P < 0.01) proportion of acetate in total VFA. However, DMI, feed consumption rate (0 to 3, 3 to 6, 6 to 12, and 12 to 24 h after feeding), particle size distribution of orts, and feeding behavior (videotaped for individual animals over 48 h) were not affected by dNOP and infNOP compared with CON. In Exp. 2 (high-grain diet), methane production was not affected by dNOP or infNOP compared with CON. Dry matter intake, feed consumption rate, particle size distribution of orts, and feeding behavior were not altered by dNOP and infNOP compared with CON. However, both dNOP and infNOP affected rumen fermentation where total VFA decreased (P = 0.04) and acetate proportion in total VFA tended to decrease (P = 0.07) compared with CON. In conclusion, dietary supplementation of 3-NOP did not affect feeding behavior of beef steers fed a high-forage or high-grain diet. However, rumen fermentation was similarly changed when 3-NOP was provided in the diet or directly infused in the rumen. Thus, observed changes in rumen fermentation with 3-NOP were not due to changes in feeding behavior indicating no effects on the organoleptic property of the diets. In addition, according to small or no changes in DMI in both experiments and relatively small changes in rumen fermentation in Exp. 2, a greater dosage level of 3-NOP than 100 mg/kg (dietary DM) may need further examination of its effects on feeding behavior of beef cattle.
摘要译文
本研究的目的是确定饲喂补充了3-硝基氧丙醇（3-NOP）的饮食是否会影响采食行为，从而改变摄入量和瘤胃发酵。在重复的3×3拉丁方形设计中，使用9个瘤胃空心牛肉ste牛进行了两个实验，其中动物接受了高饲草或高谷物饮食。治疗方法是：1）基础饮食（CON），在CON饮食中补充3-NOP（dNOP）；日粮DM中100 mg / kg或1 g / d），或瘤胃中注入3-NOP（1 g / d）的CON饮食（infNOP）。每个实验阶段包括14天的饮食适应和7天的样本收集。在实验期间之间提供了7天的清除期。使用SAS的混合程序将所有数据分析为拉丁方形设计。在实验中1（高饲草日粮），甲烷产量（通过绿色饲料系统测得）降低了18％（18.6 vs. 22.7 g / kg DMI）； dNOP与CON相比，P <0.01）。与CON相比，NOP处理均改变了瘤胃发酵，其中dNOP和infNOP在3 h时瘤胃pH值升高（P <0.01），乙酸盐在总VFA中的比例降低（P <0.01）。然而，DMI，饲料消耗率（喂食后0至3、3至6、6至12和12至24小时），矿粒的粒径分布以及喂食行为（对48小时以上的动物进行录像）均不受影响。通过dNOP和infNOP与CON进行比较。在实验中2（高谷物饮食），与CON相比，dNOP或infNOP不会影响甲烷的产生。与CON相比，dNOP和infNOP不会改变干物质的摄入量，饲料消耗率，矿点的粒度分布和喂养行为。然而，与CON相比，dNOP和infNOP均影响瘤胃发酵，总VFA降低（P = 0.04），乙酸盐在总VFA中的比例倾向于降低（P = 0.07）。总之，饲料中添加3-NOP不会影响饲喂高饲粮或高谷物饮食的beef牛的饲喂行为。但是，当日粮中添加3-NOP或直接注入瘤胃中时，瘤胃发酵也发生了类似的变化。因此，观察到的3-NOP的瘤胃发酵变化不是由于进食行为的变化，表明对日粮的感官特性没有影响。此外，根据两个实验中DMI的变化很小或没有变化，以及Exp中瘤胃发酵的变化相对较小。 2，高于100 mg / kg（饮食DM）的3-NOP剂量水平可能需要进一步检查其对肉牛摄食行为的影响。
Seon-Ho Kim[1];Chanhee Lee[1];Heather A Pechtl[1];Jade M Hettick[1];Magnus R Campler[2];Monique D Pairis-Garcia[2];Karen A Beauchemin[3];Pietro Celi[4];Stephane M Duval[4]. Effects of 3-nitrooxypropanol on enteric methane production, rumen fermentation, and feeding behavior in beef cattle fed a high-forage or high-grain diet[J]. Journal of Animal Science, 2019,97(7): 2687-2699