英文文献：Economically Optimal Distiller Grain Inclusion in Beef Feedlot Rations: Recognition of Omitted Factors-经济上最优的酒糟纳入牛肉饲料:忽略因素的识别
英文文献作者：Jones, Crystal,Tonsor, Glynn T.,Black, J. Roy,Rust, Steven R.
英文文献摘要：
With the rapid expansion of the ethanol industry, the feeding landscape familiar to the feedlot industry is changing. While concerns regarding rising corn prices persist, many within the industry are looking at distiller's grains, a by-product of ethanol production, to serve as a feed substitute. The question remains as to what extent these two feed sources are substitutable. The purpose of this study is to identify the economically optimal inclusion rate of distiller's grains in beef feedlot rations, considering an array of often omitted factors. Most currently prevailing recommendation rates are strictly biologically based and frequently reference only one feeding trial. Unique economic factors considered in this research include the impact of by-product inclusion rates on animal performance (utilizing recently conducted meta-analysis from 17 relevant feeding trials), enhanced likelihood of death loss from heightened sulfur content, and manure disposal costs. Results indicate that excluding these factors can significantly impact optimal inclusion levels and that reliance on a single or few feeding trials may greatly bias results.

随着乙醇工业的迅速扩张，饲料业熟悉的饲料业格局正在发生变化。尽管对玉米价格上涨的担忧仍在持续，但业内许多人正考虑将酒糟(乙醇生产的副产品)作为饲料替代品。问题是这两种饲料源在多大程度上是可替代的。本研究的目的是确定经济上最优的包含率的酒糟在牛肉饲料，考虑到一系列经常被忽略的因素。目前大多数流行的推荐率是严格基于生物学的，并且经常只参考一个喂养试验。本研究中考虑的独特经济因素包括副产品包含率对动物性能的影响(利用最近从17个相关饲养试验中进行的荟萃分析)，硫含量升高导致死亡损失的可能性增加，以及粪便处理成本。结果表明，排除这些因素会显著影响最佳的纳入水平，而依赖单一或少数喂养试验可能会极大地偏斜结果。