Martin C, Ferlay A, Mosoni P, Rochette Y, Chilliard Y, Doreau M
INRA, UMR1213 Herbivores, F-63122 Saint-Genès-Champanelle, France; Clermont Université, VetAgro Sup, UMR Herbivores, BP 10448 F-63000 Clermont-Ferrand, France.
INRA, UMR1213 Herbivores, F-63122 Saint-Genès-Champanelle, France; Clermont Université, VetAgro Sup, UMR Herbivores, BP 10448 F-63000 Clermont-Ferrand, France.
J Dairy Sci. 2016 May;99(5):3445-3456. doi: 10.3168/jds.2015-10110.
We investigated the effects of increasing extruded linseed supply in diets based on hay (H; experiment 1) or corn silage (CS; experiment 2) on enteric methane (CH4) emission, rumen microbial and fermentation parameters, and rumen and total-tract digestibility. In each experiment, 4 lactating Holstein cows fitted with cannulas at the rumen and proximal duodenum were used in a 4×4 Latin square design (28-d periods). Cows were fed ad libitum a diet [50:50 and 60:40 forage:concentrate on a dry matter (DM) basis for experiments 1 and 2, respectively] without supplementation (H0, CS0) or supplemented with extruded linseed at 5% (H5, CS5), 10% (H10, CS10), and 15% (H15, CS15) of dietary DM (i.e., 1.8, 3.6 and 5.4% total fatty acids added, respectively). All measurements were carried out during the last 8 d of each period. Linseed supply linearly decreased daily CH4 emission in cows fed H diets (from 486 to 289g/d for H0 to H15, on average) and CS diets (from 354 to 207g/d for CS0 to CS15, on average). The average decrease in CH4 per kilogram of DM intake was, respectively, -7, -15, and -38% for H5, H10, H15 compared with the H0 diet, and -4, -8, and -34% for CS5, CS10, and CS15 compared with the CS0 diet. The same dose-response effect was observed on CH4 emission in percent of gross energy intake, per kilogram of nutrient digested, and per kilogram of 4% fat- and 3.3% protein-corrected milk (FPCM) in both experiments. Changes in the composition of rumen volatile fatty acids in response to increasing linseed supply resulted in a moderate or marked linear decrease in acetate:propionate ratio for H or CS diets, respectively. The depressive effect of linseed on total protozoa concentration was linear for H diets (-15 to -40%, on average, for H5 to H15 compared with H0) and quadratic for CS diets (-17 to -83%, on average, for CS5 to CS15 compared with CS0). Concentration of methanogens was similar among H or CS diets. The energetic benefits from the decreased CH4 emission with linseed supply in diets based on hay or corn silage did not improve digestibility or milk yield. Milk efficiency (kg of FPCM/kg of DM intake) was improved with linseed supply up to H10 in H diets and was unchanged in CS diets. Lower CH4 enteric emission from dairy cows fed linseed helps limit the environmental footprint of ruminant livestock.
我们研究了在以干草（H；实验1）或玉米青贮料（CS；实验2）为基础的日粮中增加挤压亚麻籽供应量，对肠道甲烷（CH₄）排放、瘤胃微生物和发酵参数以及瘤胃和全消化道消化率的影响。在每个实验中，选用4头在瘤胃和十二指肠近端安装了瘘管的泌乳荷斯坦奶牛，采用4×4拉丁方设计（每期28天）。奶牛自由采食日粮（实验1和实验2中，干物质基础上的粗饲料:精饲料比例分别为50:50和60:40），不添加（H0、CS0）或添加5%（H5、CS5）、10%（H10、CS10）和15%（H15、CS15）日粮干物质的挤压亚麻籽（即分别添加1.8%、3.6%和5.4%的总脂肪酸）。所有测量均在每期的最后8天进行。亚麻籽供应使采食H日粮的奶牛每日CH₄排放量呈线性下降（H0至H15平均从486克/天降至289克/天），采食CS日粮的奶牛也是如此（CS0至CS15平均从354克/天降至207克/天）。与H0日粮相比，H日粮中每千克干物质摄入量的CH₄平均减少量，H5、H10、H15分别为-7%、-15%和-38%；与CS0日粮相比，CS日粮中CS5、CS10和CS15分别为-4%、-8%和-34%。在两个实验中，对于占总能摄入量百分比、每千克消化养分以及每千克4%脂肪和3.3%蛋白质校正乳（FPCM）的CH₄排放，也观察到了相同的剂量反应效应。随着亚麻籽供应量增加，瘤胃挥发性脂肪酸组成的变化导致H或CS日粮的乙酸:丙酸比例分别呈中度或显著线性下降。亚麻籽对总原生动物浓度的抑制作用，对于H日粮呈线性（H5至H15与H0相比平均为-15%至-40%），对于CS日粮呈二次曲线关系（CS5至CS15与CS0相比平均为-17%至-83%）。H或CS日粮中甲烷菌的浓度相似。基于干草或玉米青贮料的日粮中，亚麻籽供应使CH₄排放减少带来的能量效益，并未提高消化率或产奶量。H日粮中，亚麻籽供应使FPCM效率（每千克干物质摄入量的FPCM千克数）提高至H10，而CS日粮中则无变化。饲喂亚麻籽的奶牛较低的肠道CH₄排放有助于限制反刍家畜的环境足迹。
