Colin-Schoellen O, Laurent F, Vignon B, Robert J C, Sloan B
Ecole Nationale Supérieure d'Agronomie et des Industries Alimentaires, Laboratoire de Sciences Animales, Institut National de la Recherche Agronomique, Vandoeuvre les Nancy, France.
J Dairy Sci. 1995 Dec;78(12):2807-18. doi: 10.3168/jds.S0022-0302(95)76911-9.
Interactions between supplementation with ruminally protected Met and Lys and the nature of protein or energy concentration of the diet were studied using 16 and 12 multiparous lactating dairy cows in two trials of 8 and 12 wk, respectively, commencing on approximately d 40 of lactation. In trial 1, cows received a semicomplete diet plus concentrates. The diet consisted of 62 to 63% corn silage, 2.2% corn gluten meal, .4% urea, 11% soybean meal (untreated or treated with formaldehyde), and 23 to 24% barley. In trial 2, cows received a complete diet with corn silage, untreated and formaldehyde-treated soybean meal, and barley in the ratio 78:12:9:0 or 49:13:4:33. All treatments were replicated in a 4 x 4 Latin square design. In both trials, Met plus Lys (10 g/d of intestinally available Met and 30 g/d of Lys) has no significant effect on DMI, milk yield, fat content, casein as a percentage of true protein, or urea content of the milk. Mean increase of milk protein yield was 46 g/d with Met plus Lys, and mean increase of true protein content was 1.1 g/kg of milk. The increase in content of milk true protein was greater for cows receiving the low energy diet. Protein source had no effect on milk yield or composition. Glucose, urea, NEFA, BHBA, and total free AA in plasma were unaffected by supplementation of ruminally protected Met plus Lys. However, concentrations of Met and Lys in blood were slightly, but not significantly, higher in supplemented cows.
分别在泌乳约40天时开始的两项试验（8周和12周）中，使用16头和12头经产泌乳奶牛，研究了瘤胃保护性蛋氨酸和赖氨酸补充剂与日粮蛋白质或能量浓度性质之间的相互作用。在试验1中，奶牛接受半精料日粮加精料补充料。日粮由62%至63%的玉米青贮、2.2%的玉米蛋白粉、0.4%的尿素、11%的豆粕（未处理或经甲醛处理）以及23%至24%的大麦组成。在试验2中，奶牛接受全价日粮，其中玉米青贮、未处理和经甲醛处理的豆粕以及大麦的比例为78:12:9:0或49:13:4:33。所有处理均采用4×4拉丁方设计进行重复。在两项试验中，蛋氨酸加赖氨酸（10克/天的肠道可利用蛋氨酸和30克/天的赖氨酸）对干物质采食量、产奶量、脂肪含量、酪蛋白占真蛋白的百分比或牛奶尿素含量均无显著影响。蛋氨酸加赖氨酸使牛奶蛋白产量平均增加46克/天，真蛋白含量平均增加1.1克/千克牛奶。接受低能量日粮的奶牛，牛奶真蛋白含量的增加幅度更大。蛋白质来源对产奶量或奶成分没有影响。瘤胃保护性蛋氨酸加赖氨酸的补充对血浆中的葡萄糖、尿素、非酯化脂肪酸、β-羟基丁酸和总游离氨基酸没有影响。然而，补充组奶牛血液中蛋氨酸和赖氨酸的浓度略有升高，但不显著。
