Elizalde J C, Aldrich C G, LaCount D W, Drackley J K, Merchen N R
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
J Anim Sci. 1999 Jul;77(7):1930-9. doi: 10.2527/1999.7771930x.
We studied the effects of the addition of liquefied vs prilled mostly saturated fatty acids (FA) to the concentrate portion of total mixed diets on ruminal and total tract digestibilities. Four Holstein steers (270 +/- 23 kg) fitted with ruminal and duodenal cannulas were used in a 4 x 4 Latin square design with 21-d periods. Diets contained (DM basis) 30.0% corn silage, 22.2% chopped alfalfa hay, 25.0% ground shelled corn, 12.5% soybean meal, and 5% of one of the following fat sources: 1) prilled FA (PFA), 2) choice white grease (triglycerides) added in liquid form (LTG), 3) 2.5% PFA + 2.5% LTG, or 4) 2.5% liquefied PFA (LFA) + 2.5% LTG. Ad libitum OM intake was not different (P > .10) among diets (mean 7.8 kg/d). Ruminal digestibilities of OM (35.7, 39.9, 42.2, and 37.3% for Diets 1 to 4, respectively) were greatest (P < .10) for the combination of PFA + LTG and lowest for PFA alone. Ruminal digestibilities of NDF, ADF, and starch did not differ (P > .10) among diets. Total tract digestibilities of OM, NDF, and ADF were greater (P < .10) for the diet containing LTG alone than for the diet containing LFA + LTG because of trends for greater postruminal digestibilities. The LFA + LTG diet resulted in a greater proportion of acetate and lower proportion of propionate in ruminal fluid than PFA alone (P < .10). The acetate:propionate ratio (3.53, 2.96, 3.10, and 2.89 for Diets 1 to 4, respectively) was lower (P < .05) for LFA + LTG or LTG alone than for PFA alone. Postruminal and total tract digestibilities of total FA (66.0, 76.0, 71.2, and 68.9% for Diets 1 to 4, respectively) were lower (P < .05) for PFA than for other diets. Addition of saturated FA in liquid form resulted in digestibilities and ruminal effects similar to the same saturated FA added in prilled form.
我们研究了在全混合日粮的精料部分添加液化与颗粒状的主要饱和脂肪酸（FA）对瘤胃和全消化道消化率的影响。选用4头装有瘤胃和十二指肠瘘管的荷斯坦公牛（体重270±23千克），采用4×4拉丁方设计，每期21天。日粮（以干物质计）包含30.0%的玉米青贮、22.2%的苜蓿干草切碎物、25.0%的去壳玉米粉、12.5%的豆粕，以及5%的以下脂肪来源之一：1）颗粒状FA（PFA），2）以液体形式添加的精选白色油脂（甘油三酯）（LTG），3）2.5% PFA + 2.5% LTG，或4）2.5%液化PFA（LFA）+ 2.5% LTG。各日粮间随意采食量的有机物质摄入量无差异（P>.10）（平均7.8千克/天）。瘤胃有机物质消化率（日粮1至4分别为35.7%、39.9%、42.2%和37.3%）在PFA + LTG组合时最高（P<.10），单独PFA时最低。日粮间中性洗涤纤维、酸性洗涤纤维和淀粉的瘤胃消化率无差异（P>.10）。由于瘤胃后消化率有提高趋势，单独含LTG的日粮的全消化道有机物质、中性洗涤纤维和酸性洗涤纤维消化率高于含LFA + LTG的日粮（P<.10）。与单独PFA相比，LFA + LTG日粮使瘤胃液中乙酸比例更高，丙酸比例更低（P<.10）。LFA + LTG或单独LTG的乙酸:丙酸比率（日粮1至4分别为3.53、2.96、3.10和2.89）低于单独PFA（P<.05）。PFA的瘤胃后和全消化道总脂肪酸消化率（日粮1至4分别为66.0%、76.0%、71.2%和68.9%）低于其他日粮（P<. .05）。添加液体形式的饱和脂肪酸产生的消化率和瘤胃效应与添加颗粒状形式的相同饱和脂肪酸相似。
