Faculty of Veterinary Science, The University of Sydney, Sydney, NSW 2006, Australia.
J Anim Sci. 2013 Feb;91(2):829-37. doi: 10.2527/jas.2012-5215. Epub 2012 Nov 12.
Two experiments were conducted to evaluate the effects of increasing concentrations of glycerol in concentrate diets on total tract digestibility, methane (CH4) emissions, growth, fatty acid profiles, and carcass traits of lambs. In both experiments, the control diet contained 57% barley grain, 14.5% wheat dried distillers grain with solubles (WDDGS), 13% sunflower hulls, 6.5% beet pulp, 6.3% alfalfa, and 3% mineral-vitamin mix. Increasing concentrations (7, 14, and 21% dietary DM) of glycerol in the dietary DM were replaced for barley grain. As glycerol was added, alfalfa meal and WDDGS were increased to maintain similar concentrations of CP and NDF among diets. In Exp.1, nutrient digestibility and CH4 emissions from 12 ram lambs were measured in a replicated 4 × 4 Latin square experiment. In Exp. 2, lamb performance was evaluated in 60 weaned lambs that were blocked by BW and randomly assigned to 1 of the 4 dietary treatments and fed to slaughter weight. In Exp. 1, nutrient digestibility and CH4 emissions were not altered (P = 0.15) by inclusion of glycerol in the diets. In Exp.2, increasing glycerol in the diet linearly decreased DMI (P < 0.01) and tended (P = 0.06) to reduce ADG, resulting in a linearly decreased final BW. Feed efficiency was not affected by glycerol inclusion in the diets. Carcass traits and total SFA or total MUFA proportions of subcutaneous fat were not affected (P = 0.77) by inclusion of glycerol, but PUFA were linearly decreased (P < 0.01). Proportions of 16:0, 10t-18:1, linoleic acid (18:2 n-6) and the n-6/n-3 ratio were linearly reduced (P < 0.01) and those of 18:0 (stearic acid), 9c-18:1 (oleic acid), linearly increased (P < 0.01) by glycerol. When included up to 21% of diet DM, glycerol did not affect nutrient digestibility or CH4 emissions of lambs fed barley based finishing diets. Glycerol may improve backfat fatty acid profiles by increasing 18:0 and 9c-18:1 and reducing 10t-18:1 and the n-6/n-3 ratio.
进行了两项实验，以评估浓缩饲料中甘油浓度增加对绵羊全肠道消化率、甲烷（CH4）排放、生长、脂肪酸谱和胴体特性的影响。在这两项实验中，对照日粮含有 57%的大麦粒、14.5%的小麦干酒糟及其可溶物（WDDGS）、13%的葵花粕、6.5%的甜菜浆、6.3%的紫花苜蓿和 3%的矿物质-维生素混合物。日粮干物质中甘油的浓度增加了（7、14 和 21%的日粮 DM），取代了大麦粒。随着甘油的添加，苜蓿粉和 WDDGS 的添加量增加，以保持日粮中 CP 和 NDF 的浓度相似。在实验 1 中，12 只公羊绵羊的养分消化率和 CH4 排放量在重复的 4×4 拉丁方实验中进行了测量。在实验 2 中，将 60 只断奶羔羊按体重分组，随机分配到 4 种日粮处理之一，并饲养到屠宰体重，评估羔羊的生产性能。在实验 1 中，日粮中添加甘油并未改变养分消化率和 CH4 排放量（P=0.15）。在实验 2 中，日粮中甘油的添加量线性降低了 DMI（P<0.01），并趋于降低 ADG，从而导致最终 BW 线性降低。甘油的添加对饲料效率没有影响。甘油的添加对胴体特性和皮下脂肪的总 SFA 或总 MUFA 比例没有影响（P=0.77），但 PUFA 线性降低（P<0.01）。16:0、10t-18:1、亚油酸（18:2 n-6）和 n-6/n-3 比值线性降低（P<0.01），18:0（硬脂酸）、9c-18:1（油酸）比值线性增加（P<0.01）。当添加到日粮 DM 的 21%时，甘油对饲喂基于大麦的育肥日粮的绵羊的养分消化率或 CH4 排放没有影响。甘油可以通过增加 18:0 和 9c-18:1 并降低 10t-18:1 和 n-6/n-3 比值来改善背脂脂肪酸谱。
