Ueda K, Ferlay A, Chabrot J, Loor J J, Chilliard Y, Doreau M
Unité de Recherches sur les Herbivores, Institut National de la Recherche Agronomique, Theix, 63122 Saint-Genès-Champanelle, France.
J Dairy Sci. 2003 Dec;86(12):3999-4007. doi: 10.3168/jds.S0022-0302(03)74011-9.
The effect of linseed oil (LSO) supplementation on total-tract and ruminal nutrient digestibility, N metabolism, and ruminal fluid characteristics was investigated in dairy cows fed diets containing different forage to concentrate ratios (F:C). The experimental design was a 4 x 4 Latin square with 2 x 2 factorial arrangement of treatments. Four lactating Holstein cows were fed a forage-rich diet without LSO (F; F:C = 65:35, dry matter basis), a forage-rich diet with LSO (FO; F:C = 65:32, 3% LSO), a concentrate-rich diet without LSO (C; F:C = 35:65), or a concentrate-rich diet with LSO (CO; F:C = 35:62, 3% LSO). Total-tract digestibility of DM and OM was greater with supplemental LSO. A tendency for greater total-tract digestibility of NDF and ADF also was observed in cows fed LSO. Ruminal digestibility of NDF or ADF decreased when CO was fed compared with C. In contrast, feeding FO increased NDF or ADF digestibility compared with F. Although ruminal starch digestion was nearly complete with all diets, digestibility was greater when cows were fed C or CO compared with F or FO. Bacterial N flow to the duodenum decreased when FO was fed compared with F. In contrast, feeding CO increased bacterial-N flow compared with C. Neither F:C nor LSO supplementation affected ruminal pH or total VFA concentration in ruminal fluid. However, molar proportion of propionate was greater with C or CO compared with F or FO and increased with LSO supplementation regardless of F:C. Molar proportion of n-butyrate decreased with LSO supplementation. Total protozoal numbers in ruminal fluid decreased markedly only when CO was fed. Overall, data show that feeding LSO had no negative effects on total-tract digestion in dairy cows but may decrease ruminal fiber digestibility when fed with high-concentrate diets. The widely spread idea that LSO decreases digestibility, arising from studies with sheep, did not seem to apply to lactating cows fed 3% LSO.
研究了在饲喂不同粗饲料与精饲料比例（F:C）日粮的奶牛中，添加亚麻籽油（LSO）对全消化道和瘤胃养分消化率、氮代谢及瘤胃液特性的影响。试验设计为4×4拉丁方，采用2×2析因处理安排。四头泌乳荷斯坦奶牛分别饲喂不添加LSO的高粗饲料日粮（F；F:C = 65:35，干物质基础）、添加LSO的高粗饲料日粮（FO；F:C = 65:32，3% LSO）、不添加LSO的高精饲料日粮（C；F:C = 35:65）或添加LSO的高精饲料日粮（CO；F:C = 35:62，3% LSO）。添加LSO时，干物质和有机物的全消化道消化率更高。在饲喂LSO的奶牛中，中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）的全消化道消化率也有提高的趋势。与C组相比，饲喂CO组时瘤胃中NDF或ADF的消化率降低。相反，与F组相比，饲喂FO组提高了NDF或ADF的消化率。尽管所有日粮的瘤胃淀粉消化几乎都很完全，但与F组或FO组相比，饲喂C组或CO组时奶牛的淀粉消化率更高。与F组相比，饲喂FO组时十二指肠细菌氮流量减少。相反，与C组相比，饲喂CO组增加了细菌氮流量。F:C比例和LSO添加均未影响瘤胃液的pH值或总挥发性脂肪酸（VFA）浓度。然而，与F组或FO组相比，C组或CO组的丙酸摩尔比例更高，且无论F:C比例如何，添加LSO后丙酸摩尔比例均增加。添加LSO后丁酸摩尔比例降低。仅在饲喂CO组时，瘤胃液中原虫总数显著减少。总体而言，数据表明，饲喂LSO对奶牛的全消化道消化没有负面影响，但在与高精饲料日粮一起饲喂时，可能会降低瘤胃纤维消化率。源于对绵羊研究的LSO会降低消化率这一广泛观点，似乎不适用于饲喂3% LSO的泌乳奶牛。
