Chelikani Prasanth K, Bell John A, Kennelly John J
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5.
J Dairy Res. 2004 Aug;71(3):279-87. doi: 10.1017/s0022029904000287.
We determined the effects of feeding canola oil or infusing it into the abomasum on rumen fermentation, nutrient digestibility, duodenal flows of fatty acids, and milk composition in Holstein cows. Five ruminally and duodenally cannulated Holstein cows in late lactation were used in a 3 x 5 incomplete Latin square design. Treatments were 1) CONTROL: basal diet (CON), 2) CONTROL+supplementation of canola oil at 1 kg/d in the feed (FED), and 3) CONTROL+abomasal infusion of canola oil at 1 kg/d (INF). Compared with CON, feed intake, ruminal fermentation characteristics, ruminal and total tract digestibilities of nutrients were not significantly affected by FED treatment but duodenal flows and milk concentrations of fatty acids (FA) such as trans-11 18:1 and cis-9 trans-11 18:2 (conjugated linoleic acid, CLA) were increased. In contrast to the effects of FED, INF reduced feed intake, total VFA production, intestinal flows of nutrients, FA digestibility and yields of milk and milk fat. Both FED and INF significantly reduced the proportions of saturated and medium-chain FA, and increased cis 18:1 in milk. Concentrations of 18:2n-6 and 18:3n-3 in milk were increased nearly 2-fold with INF relative to CON. Dietary or postruminal supplementation of canola oil to late-lactation cows reduced saturated FA and increased unsaturated C18 in milk but nutrient digestion was adversely affected with abomasal infusion of canola oil.
我们测定了给荷斯坦奶牛饲喂菜籽油或将其注入皱胃对瘤胃发酵、养分消化率、十二指肠脂肪酸流量和牛奶成分的影响。选用5头处于泌乳后期、安装了瘤胃和十二指肠瘘管的荷斯坦奶牛，采用3×5不完全拉丁方设计。处理方式如下：1）对照：基础日粮（CON）；2）对照+在饲料中添加1千克/天的菜籽油（FED）；3）对照+向皱胃注入1千克/天的菜籽油（INF）。与CON相比，FED处理对采食量、瘤胃发酵特征、瘤胃和全消化道养分消化率没有显著影响，但十二指肠脂肪酸流量以及反式11 18:1和顺式9反式11 18:2（共轭亚油酸，CLA）等脂肪酸的牛奶浓度增加。与FED的效果相反，INF降低了采食量、总挥发性脂肪酸产量、养分的肠道流量、脂肪酸消化率以及牛奶和乳脂产量。FED和INF均显著降低了牛奶中饱和脂肪酸和中链脂肪酸的比例，并增加了顺式18:1的含量。与CON相比，INF使牛奶中18:2n-6和18:3n-3的浓度增加了近2倍。给泌乳后期奶牛进行日粮或瘤胃后补充菜籽油可降低牛奶中的饱和脂肪酸并增加不饱和C18脂肪酸，但向皱胃注入菜籽油会对养分消化产生不利影响。
