Soita H W, Meier J A, Fehr M, Yu P, Christensen D A, McKinon J J, Mustafa A F
Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Arch Tierernahr. 2003 Apr;57(2):107-16. doi: 10.1080/0003942031000107334.
Twelve multiparous Holstein cows at 72 +/- 20 days in milk were used in a switch-back design with 14-d periods to determine the effect of replacing barley grain into a dairy total mixed ration with micronized or raw flaxseed on nutrient digestibility, milk yield, milk composition. Total mixed diets were (DM basis) 50% barley silage, 50% concentrate mix mainly rolled barley grain and canola meal. Diets were supplemented with 1 kg raw (RF) or micronized (MF) flaxseed to substitute 1 kg of rolled barley grain (C). Neutral detergent fibre, ADF and CP digestibility of the diets were not significantly affected by supplementation; however, calcium digestibility was reduced by 62% and 46% when raw and micronized flax were fed, respectively. Milk yield (38.3, 39.6, and 38.4 kg/d for diets C, RF and MF, respectively) was similar for all diets. Milk fat (3.50, 3.48, and 3.52%) and protein (3.31, 3.34, and 3.31%) for diets C, RF and MF, respectively, were not affected by treatment diets. Concentrations of c9, t11 conjugated linoleic acid (CLA; 0.51, 0.72 and 0.76 g/100 g fatty acids) in milk fat increased (P<0.05) similarly among the two flaxseed supplemented diets. The RF and MF diets significantly increased the C18:1, C18:1 trans-11, C18:2 cis-9, cis-12 and C18:3 in milk fat however, C12:0, C14:0 and C16:0 were significantly reduced compared with control. Replacing barley grain with flaxseed in the diet of lactating cows increased the beneficial fatty acids in milk without depressing nutrient digestibility. Micronization of flaxseed did not reveal any advantage over raw flaxseed.
选用12头经产荷斯坦奶牛，泌乳期为72±20天，采用14天周期的折返式设计，以确定用微粉化或生亚麻籽替代奶牛全混合日粮中的大麦谷物对养分消化率、产奶量和牛奶成分的影响。全混合日粮（以干物质计）为50%大麦青贮、50%精料混合料，精料混合料主要为压片大麦谷物和油菜籽粕。日粮中添加1千克生亚麻籽（RF）或微粉化亚麻籽（MF）以替代1千克压片大麦谷物（C）。日粮的中性洗涤纤维、酸性洗涤纤维和粗蛋白消化率不受添加物的显著影响；然而，饲喂生亚麻籽和微粉化亚麻籽时，钙消化率分别降低了62%和46%。所有日粮的产奶量相似（日粮C、RF和MF的产奶量分别为38.3、39.6和38.4千克/天）。日粮C、RF和MF的乳脂率（分别为3.50%、3.48%和3.52%）和乳蛋白率（分别为3.31%、3.34%和3.31%）不受处理日粮的影响。两种添加亚麻籽的日粮中，乳脂中c9,t11-共轭亚油酸（CLA；0.51、0.72和0.76克/100克脂肪酸）的浓度均显著增加（P<0.05）。RF和MF日粮显著增加了乳脂中的C18:1、反式-11 C18:1、顺式-9,顺式-12 C18:2和C18:3；然而，与对照组相比，C12:0、C14:0和C16:0显著降低。在泌乳奶牛日粮中用亚麻籽替代大麦谷物可增加牛奶中有益脂肪酸的含量，且不降低养分消化率。亚麻籽微粉化与生亚麻籽相比未显示出任何优势。
