摘要
Six ruminally fistulated steers (550 kg) and 24 heifers (315 kg) were used to determine the effect of source and amount of ruminal-escape lipid in a supplement on forage intake and digestion. Steers were used in a 6 × 6 Latin square digestion study to evaluate six supplementation treatments: 1) negative control (NC), no supplement; 2) positive control (PC), soybean meal:grain sorghum supplement; 3) low-Megalac® (calcium salts of fatty acids; LM) supplement; 4) high-Megalac (HM) supplement; 5) low-Alifet® (crystallized natural animal fat, LA) supplement; and 6) high-Alifet (HA) supplement. Supplements were fed at .30% of BW on a DM basis and were isoenergetic within fat levels (high vs low). Steers were fed mature brome hay (7.2% CP) at 1.5% of BW on a DM basis. In the forage intake trial, heifers were assigned randomly to the same supplement treatments. Prairie hay (4.4% CP) was offered at 130% of ad libitum intake. Dry matter and NDF digestibility, ruminal DM fill, indigestible ADF passage rate, and fluid dilution and flow rates were not different (P > .10) among treatments. Total VFA concentrations were greater (P < .01) and acetate-to-propionate ratio (Ac: Pr) was less (P < .01) in supplemented groups; however, neither source nor level of escape lipid influenced either total VFA or Ac:Pr. Forage intake was greater (P < .01) for supplemented groups than for the NC. At the high level of fat inclusion, heifers supplemented with Alifet ate slightly more (P < .05) forage than those supplemented with Megalac.(ABSTRACT TRUNCATED AT 250 WORDS)
摘要译文
使用六个瘤胃瘘管阉牛（550kg）和24个小母牛（315kg）来确定补充物中瘤胃逃逸脂质的来源和量对饲料摄入和消化的影响。在6×6拉丁方消化研究中使用转向来评估六种补充治疗：1）阴性对照（NC），无补充; 2）阳性对照（PC），豆粕：谷物高粱补充; 3）低Megalac®（脂肪酸的钙盐; LM）补充; 4）高Megalac（HM）补充; 5）低Alifet®（结晶天然动物脂肪，LA）补充剂;和6）高Alifet（HA）补充剂。补充剂以DM为基础以0.3％的BW喂养，并且在脂肪水平（高与低）之间是等能量的。在DM的基础上，以1.5％的BW饲喂成熟的菠萝干（7.2％CP）。在饲料摄入试验中，小母牛被随机分配到相同的补充治疗中。草原干草（4.4％CP）以130％的自由采食量提供。干物质和NDF消化率，瘤胃DM填充，难消化的ADF通过率，液体稀释和流速在处理之间没有差异（P> .10）。补充组总VFA浓度较高（P <.01），醋酸盐与丙酸的比例（Ac：Pr）较低（P <.01）;然而，逃逸脂质的来源和水平都不影响总VFA或Ac：Pr。补充组的饲料摄入量（NC <0.01）大于NC。在脂肪含量较高的情况下，添加Alifet的小母牛比添加Megalac的小母牛吃更多（P <.05）草料。（摘要截止250字）
R. B. Hightshoe;R. C. Cochran;L. R. Corah;D. L. Harmon;E. S. Vanzant. Influence of source and level of ruminal-escape lipid in supplements on forage intake, digestibility, digesta flow, and fermentation characteristics in beef cattle[J]. Journal of Animal Science, 1991,69(12): 4974-4982