Khorasani G R, Kennelly J J
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada.
J Dairy Sci. 1998 Sep;81(9):2459-68. doi: 10.3168/jds.S0022-0302(98)70137-7.
Effects of supplemental Jet-Sploded canola seed in the diets of dairy cows on milk yield and composition and blood metabolite concentrations were investigated. Twenty multiparous and 5 primiparous midlactation Holstein cows were assigned to treatments following a 3-wk covariate period; cows were then on the treatments for 70 d. Ten of the cows had previously been fitted with rumen cannulas. Five concentrate mixtures containing 0, 7.5, 15, 22, or 29% Jet-Sploded canola seed (Simons Feed Co., Quimby, IA) (equivalent to 0, 2.66, 5.33, 7.81, and 10.30% added fat, respectively) were formulated by substituting Jet-Sploded canola seed for barley and canola meal. Diets consisted of 25% alfalfa silage, 25% whole-crop oat silage, and 50% of one of the concentrate mixtures (dry matter basis). An increase in the amount of dietary fat from Jet-Sploded canola seed did not influence feed intake, milk yield or composition, or milk component yields. The inclusion of Jet-Sploded canola seed in the diet increased long-chain fatty acids and inhibited de novo synthesis of medium-chain fatty acids in milk. Mean total volatile fatty acids in the rumen and propionate concentration were reduced in a linear fashion by treatment. The inclusion of Jet-Sploded canola seed in the diets of mid-lactation cows altered rumen and blood metabolite concentrations; however, these changes had minimal effects on yield responses with the exception of milk fatty acid composition and milk protein content.
研究了在奶牛日粮中添加爆裂油菜籽对产奶量、奶成分及血液代谢物浓度的影响。在为期3周的协变量期后，将20头经产和5头初产的泌乳中期荷斯坦奶牛分配至各处理组；奶牛随后接受各处理70天。其中10头奶牛此前已安装瘤胃瘘管。通过用爆裂油菜籽替代大麦和油菜粕，配制了5种浓缩混合料，分别含有0%、7.5%、15%、22%或29%的爆裂油菜籽（西蒙斯饲料公司，爱荷华州昆比）（分别相当于添加0%脂肪、2.66%脂肪、5.33%脂肪、7.81%脂肪和10.30%脂肪）。日粮由25%苜蓿青贮、25%全株燕麦青贮和50%的一种浓缩混合料（干物质基础）组成。来自爆裂油菜籽的日粮脂肪量增加并未影响采食量、产奶量或奶成分，也未影响奶成分产量。日粮中添加爆裂油菜籽增加了长链脂肪酸含量，并抑制了牛奶中中链脂肪酸的从头合成。瘤胃中总挥发性脂肪酸的平均值和丙酸浓度随处理呈线性降低。在泌乳中期奶牛的日粮中添加爆裂油菜籽改变了瘤胃和血液代谢物浓度；然而，除了牛奶脂肪酸组成和牛奶蛋白质含量外，这些变化对产量反应的影响极小。
