Department of Animal Sciences, Faculty of Agricultural Sciences, University of Zanjan, Zanjan, 313-45195, Iran.
J Anim Sci Biotechnol. 2012 Jul 9;3(1):22. doi: 10.1186/2049-1891-3-22.
Barley grain (Hordeum vulgare L.) is characterized by a thick fibrous coat, a high level of ß-glucans and simply-arranged starch granules. World production of barley is about 30 % of that of corn. In comparison with corn, barley has more protein, methionine, lysine, cysteine and tryptophan. For ruminants, barley is the third most readily degradable cereal behind oats and wheat. Due to its more rapid starch fermentation rate compared with corn, barley also provides a more synchronous release of energy and nitrogen, thereby improving microbial nutrient assimilation. As a result, feeding barley can reduce the need for feeding protected protein sources. However, this benefit is only realized if rumen acidity is maintained within an optimal range (e.g., > 5.8 to 6.0); below this range, microbial maintenance requirements and wastage increase. With a low pH, microbial endotoxines cause pro-inflammatory responses that can weaken immunity and shorten animal longevity. Thus, mismanagement in barley processing and feeding may make a tragedy from this treasure or pearl of cereal grains. Steam-rolling of barley may improve feed efficiency and post-rumen starch digestion. However, it is doubtful if such processing can improve milk production and feed intake. Due to the need to process barley less extensively than other cereals (as long as the pericarp is broken), consistent and global standards for feeding and processing barley could be feasibly established. In high-starch diets, barley feeding reduces the need for capacious small intestinal starch assimilation, subsequently reducing hindgut starch use and fecal nutrient loss. With its nutritional exclusivities underlined, barley use will be a factual art that can either matchlessly profit or harm rumen microbes, cattle production, farm economics and the environment.
大麦（Hordeum vulgare L.）的特点是有一层厚厚的纤维状外壳，β-葡聚糖含量高，淀粉颗粒排列简单。世界大麦产量约为玉米的 30%。与玉米相比，大麦含有更多的蛋白质、蛋氨酸、赖氨酸、半胱氨酸和色氨酸。对于反刍动物来说，大麦是仅次于燕麦和小麦的第三易降解谷物。由于大麦的淀粉发酵速度比玉米快，因此能更同步地释放能量和氮，从而提高微生物对养分的吸收。因此，用大麦代替部分饲料可以减少对保护性蛋白质源的需求。然而，只有在瘤胃酸度维持在最佳范围内（例如，>5.8 至 6.0）时，才能实现这一益处；在此范围以下，微生物维持的需求和损耗会增加。在低 pH 值下，微生物内毒素会引起促炎反应，从而削弱免疫力并缩短动物寿命。因此，如果在大麦加工和饲养管理方面出现失误，可能会使这种谷物的宝藏或明珠变成悲剧。大麦蒸汽压片可以提高饲料效率和瘤胃后淀粉消化率。然而，目前还不清楚这种加工方法是否能提高产奶量和采食量。由于与其他谷物相比，大麦的加工不需要那么广泛（只要打破种皮即可），因此可以为大麦的饲养和加工制定可行的统一和全球标准。在高淀粉饮食中，大麦的喂养减少了对大量小肠淀粉吸收的需求，从而减少了后肠淀粉的利用和粪便养分的损失。大麦的使用具有独特的营养价值，它既能给瘤胃微生物、牛的生产、农场经济和环境带来无与伦比的好处，也能带来危害。
