EFFECT OF THE PROTEIN MATRIX ON THE DIGESTION OF CEREAL-GRAINS BY RUMINAL MICROORGANISMS
EFFECT OF THE PROTEIN MATRIX ON THE DIGESTION OF CEREAL-GRAINS BY RUMINAL MICROORGANISMS
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DOI：
10.2527/1993.711205x
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发表时间：
1993-01-01
影响因子：
3.3
通讯作者：
CHENG, KJ
中科院分区：
文献类型：
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作者：
MCALLISTER, TA;PHILLIPPE, RC;CHENG, KJ
本试验旨在研究蛋白质基质在瘤胃微生物消化大麦和玉米中的作用。颗粒，研磨和收集在筛子上作为两个颗粒馏分。25到。89 mm（小颗粒）和2.00 ~ 3.00 mm（大颗粒）以及分离的大麦和玉米淀粉颗粒用瘤胃疫苗孵育。两种谷物中，小颗粒的淀粉消化量均大于大颗粒（P < 0.001）。在16和24 h，大麦的淀粉消化量大于玉米粉（P < 0.01），无论颗粒大小。在任何孵育时间内，大麦淀粉颗粒的消化率与玉米淀粉颗粒的消化率无显著差异（P < 0.05）。小颗粒玉米和大麦用蛋白酶预孵育4 h后，16 h玉米中淀粉的微生物消化量增加（P < 0.001），但对大麦的消化没有影响。在4 × 4拉丁方试验中，4头瘤胃空心阉牛分别饲喂含有80%大麦、玉米或小麦或100%苜蓿干草的饲粮，饲喂谷物的阉牛瘤胃接种物的淀粉水解活性高于饲喂苜蓿的阉牛。然而，当以细菌总活菌数标准化时，不同饲粮处理的瘤胃解淀粉活性无显著差异（P < 0.05），但苜蓿饲粮的瘤胃蛋白水解活性高于谷物饲粮（P < 0.01）。饲喂苜蓿的肉牛瘤胃接种物中丝氨酸蛋白酶活性高于饲喂谷物的肉牛（P < 0.05）。蛋白质基质似乎是造成玉米和大麦籽粒瘤胃消化差异的主要因素。不同谷物间蛋白质基质性质的差异并没有改变瘤胃的淀粉水解或蛋白水解活性。
Experiments were conducted to investigate the role of the protein matrix in the digestion of barley and corn by ruminal microorganisms. Grains, ground and collected on sieves as two particle fractions .25 to .89 mm (small particles) and 2.00 to 3.00 mm (large particles), as well as isolated barley and com starch granules, were incubated with ruminal inocula. For both grains, digestion of starch in small particles was greater (P < .001) than that of large particles. At 16 and 24 h starch digestion was greater (P < .01) in barley than in com, for small and large particles. Digestion of barley starch granules did not differ (P > .05) from that of corn starch granules at any incubation time. A 4-h preincubation of small-particle corn and barley with protease increased (P < .001) microbial digestion of starch in corn at 16 h but did not affect digestion of barley. When four ruminally cannulated steers were fed diets containing 80% barley, corn, or wheat or 100% alfalfa hay in a 4 x 4 Latin square experiment, amylolytic activity of ruminal inoculum was higher for steers fed grains than for those fed alfalfa. However, when standardized for total viable counts of bacteria, ruminal amylolytic activity did not differ (P > .05) among diet treatments, but proteolytic activity of ruminal inoculum for steers fed alfalfa was higher (P < .01) than that for steers fed cereal grains. Activity of serine proteases in ruminal inoculum was higher (P < .05) for steers fed alfalfa than for steers fed grains. The protein matrix seemed to be the major factor responsible for differences in ruminal digestion of ground corn and barley. Differences in the properties of the protein matrix among cereal grains did not alter ruminal amylolytic or proteolytic activity.