The objectives of this study were to evaluate the effects of pretreating dairy cow rations with a fibrolytic enzyme derived from Trichoderma reesei (FETR; mixture of xylanase and cellulase; AB Vista, Wiltshire, UK) on lactation performance, digestibility, and feeding behavior in response to feeding a barley silage–based diet. Before starting the dairy trial, in vitro incubations were conducted to determine whether the addition of FETR would have an effect on these animal performance characteristics when applied to a barley silage–based diet for dairy cows. The dairy trial was performed using 8 Holstein dairy cows. The cows were blocked by parity and assigned randomly to 1 of 4 treatments: 0, 0.5, 0.75, and 1 mL of FETR/kg of dry matter (DM) diet in a replicated Latin square design. The pretreatment was applied to the complete diet during the mixing process. The experimental period continued for 22 d, with each experimental period consisting of a 16-d adaptation period and a 6-d sampling period. The daily feed intake of each individual cow was monitored using Insentec feed bins (RIC system, Insentec, Marknesse, the Netherlands). Feeding behavior characteristics were measured during the entire sampling period using the feed bin attendance data. Milk samples were collected in the last 3 d of each experimental period. The addition of FETR linearly increased the in vitro DM digestibility and tended to improve the in vitro digestibility of barley silage. There was a cubic effect of the enzyme levels on the total-tract DM and neutral detergent fiber digestibility. Maximal digestibility was reached at 0.75 mL of FETR/kg of TMR. The milk fat yield, fat-corrected milk, and energy-corrected milk quadratically responded to the incremental levels of FETR. The milk protein percentage linearly improved in response to FETR. Increasing FETR levels resulted in a quadratic effect on feed efficiency. There was no effect of FETR level on feeding behavior. In conclusion, pretreating dairy cow barley silage–based diet with 0.75 mL of FETR/kg of TMR increased the milk production efficiency of dairy cows fed diet containing 34% barley silage (DM basis). The positive effect of adding FETR could benefit the dairy industry in western Canada, where barley silage–based diets are common.

这项研究的目的是评估使用源自里氏木霉的纤溶酶对奶牛口粮进行预处理的效果。（FETR；木聚糖酶和纤维素酶的混合物；英国威尔特郡AB Vista）对饲喂大麦青贮饲料的泌乳性能，消化率和饲喂行为的影响。在开始乳品试验之前，进行了体外培养，以确定将FETR添加到大麦青贮饲料中是否会对这些动物的生产性能产生影响。奶牛试验是使用8头荷斯坦奶牛进行的。牛被均等性阻断，并随机分配到4种处理方法之一：0、0.5、0.75和1 mL FETR / kg干物质（DM）日粮，采用重复的拉丁方设计。在混合过程中将预处理应用于完全饮食。实验期持续了22 d，每个实验周期包括一个16天的适应期和一个6天的采样期。使用Insentec饲喂箱（RIC系统，Insentec，Marknesse，荷兰）监控每头母牛的日采食量。在整个采样期间，使用进料仓出勤数据测量进料行为特征。在每个实验期的最后3天收集牛奶样品。FETR的添加线性增加了大麦青贮饲料的体外DM消化率，并倾向于提高其体外消化率。酶水平对全干DM和中性洗涤剂纤维的消化率有立方影响。0.75 mL FETR / kg TMR时可达到最大消化率。牛奶的脂肪产量，脂肪校正过的牛奶和能量校正过的牛奶对FETR的增加水平有二次响应。牛奶蛋白质百分比响应于FETR线性改善。FETR水平的提高对饲料效率产生二次影响。FETR水平对进食行为没有影响。总之，以0.75毫升FETR / kg TMR预处理以大麦青贮饲料为基础的日粮，可以提高以34％大麦青贮饲料（以DM为基础）饲喂日粮的奶牛的产奶效率。添加FETR的积极作用可以使加拿大西部的乳制品业受益，那里以大麦青贮饲料为基础。75 mL FETR / kg TMR可提高饲喂含34％大麦青贮饲料（以DM为基础）日粮的奶牛的产奶效率。添加FETR的积极作用可以使加拿大西部的乳制品业受益，那里以大麦青贮饲料为基础。75 mL FETR / kg TMR可提高饲喂含34％大麦青贮饲料（以DM为基础）日粮的奶牛的产奶效率。添加FETR的积极作用可以使加拿大西部的乳制品业受益，那里以大麦青贮饲料为基础。