Jenkins T C, Thompson C E, Bridges W C
Department of Animal and Veterinary Sciences, Clemson University, SC 29634, USA.
J Anim Sci. 2000 Oct;78(10):2745-53. doi: 10.2527/2000.78102745x.
Two experiments were conducted to determine effects of oleamide on feed intake and ruminal fatty acids when the oleamide was introduced in the feed vs through a ruminal fistula (Exp. 1) or the oleamide was fed for an extended (9-wk) length of time (Exp. 2). In Exp. 1, four nonlactating Holstein cows, each fitted with a ruminal cannula, were fed four diets in a 4 x 4 Latin square design. Each period lasted 2 wk. Diets consisted of 48% corn silage and 52% concentrate on a DM basis. One diet contained no added fat (control) and a second diet contained 4.2% oleic acid. The remaining two diets were designed to expose cows to 4.2% amide (as oleamide) either through the feed (AF) or by administering oleamide into the rumen (AR) each day through the ruminal cannula. The AF diet reduced DMI similarly to results reported previously for lactating dairy cows and sheep. Intake of the oleic acid diet was intermediate between the control and AF diets. Dry matter intake was reduced by AR similarly to the AF diet. The acetate:propionate ratio in samples of ruminal contents was reduced by oleic acid but not by AF or AR. In Exp. 2, 12 steers were divided into three equal groups of two Angus and two Simmental x Angus crosses, and each group was assigned a diet containing either no added fat (control), 4% oleamide, or 4% high-oleic canola oil. All steers had ad libitum access to feed and water. Dry matter intake by steers fed the canola oil diet was not different from that by steers fed the control diet when averaged over the first 3 wk, the last 3 wk, or over the entire 9-wk study. Oleamide reduced DMI 4 kg/d over the first 3 wk of the study. However, DMI of the oleamide diet consistently increased over the 9-wk study, resulting in wk 7 to 9 DMI that was not different from that of steers fed the control diet. These results show that the reduction in feed intake when oleamide is added to cattle rations can be attributed more to physiological responses than to an undesirable unique taste or odor of the oleamide. In finishing beef steers, the decreased intake induced by oleamide was most severe during the first 1 or 2 wk of feeding but gradually lessened over time until it nearly returned to normal by wk 9.
进行了两项试验，以确定在饲料中添加油酸酰胺与通过瘤胃瘘管添加（试验1），或长时间（9周）饲喂油酸酰胺（试验2）时，油酸酰胺对采食量和瘤胃脂肪酸的影响。在试验1中，4头装有瘤胃瘘管的非泌乳荷斯坦奶牛，按照4×4拉丁方设计饲喂4种日粮。每个阶段持续2周。日粮以干物质计，由48%的玉米青贮和52%的精料组成。一种日粮不添加脂肪（对照），另一种日粮添加4.2%的油酸。其余两种日粮旨在使奶牛通过饲料接触4.2%的酰胺（以油酸酰胺形式）（AF），或每天通过瘤胃瘘管向瘤胃内注入油酸酰胺（AR）。AF日粮使干物质采食量降低，与先前报道的泌乳奶牛和绵羊的结果相似。油酸日粮的采食量介于对照日粮和AF日粮之间。AR使干物质采食量降低，与AF日粮相似。瘤胃内容物样本中的乙酸:丙酸比值因油酸而降低，但不受AF或AR的影响。在试验2中，12头阉牛被分为3组，每组2头安格斯牛和2头西门塔尔×安格斯杂交牛，每组饲喂一种日粮，分别为不添加脂肪（对照）、4%油酸酰胺或4%高油酸菜籽油。所有阉牛均可自由采食和饮水。在前3周、后3周或整个9周的研究期间，饲喂菜籽油日粮的阉牛的干物质采食量与饲喂对照日粮的阉牛没有差异。在研究的前3周，油酸酰胺使干物质采食量降低4 kg/d。然而，在9周的研究期间，油酸酰胺日粮的干物质采食量持续增加，导致第7至9周的干物质采食量与饲喂对照日粮的阉牛没有差异。这些结果表明，在牛日粮中添加油酸酰胺时采食量的降低，更多地可归因于生理反应，而非油酸酰胺不良的独特味道或气味。在育肥牛阉牛中，油酸酰胺引起的采食量下降在饲喂的第1或2周最为严重，但随着时间的推移逐渐减轻，到第9周时几乎恢复正常。
