摘要
Feedlot and in vitro ruminal experiments were conducted to assess the effects of saponin-containing surfactant applied during tempering of barley grain on cattle growth performance and on ruminal fermentation. In the feedlot experiment, treatments with three barley grain/barley silage based diets were prepared using barley grain at 7.7% moisture (dry, D), after tempering to 18% moisture (M), or after tempering with a saponin-based surfactant included at 60 ml/t (MS). Each treatment was rolled at settings determined previously to yield optimally processed barley. A total of 180 newly weaned British${\times}$Charolais steers were fed three diets in 18 pens for a 63-d backgrounding period and 91-d finishing period to determine feed intake, growth rate and feed efficiency. Cattle were slaughtered at the end of the experiment to measure the carcass characteristics. Tempering reduced (p<0.001) volume weight and processing index, but processing characteristics were similar between MS and M. Tempering increased (p<0.05) growth during backgrounding only, compared with D, but did not affect feed intake in either phase. During backgrounding, feed efficiency was improved with tempering, but during finishing and overall this response was only observed with the surfactant. Tempering did not affect carcass weight, fat content or meat yield. Surfactant doubled the proportion of carcasses grading AAA. In the in vitro experiment, barley (500 mg; ground to <1.0 mm or steam-rolled) was incubated in buffered ruminal fluid (40 ml) without or with surfactant up to 20 ${\mu}l/g$ DM substrate for 24 h. Surfactant increased (p<0.05) apparent DM disappearance and starch digestibility but reduced productions of gas and the volatile fatty acid and acetate:propionate ratio, irrespective of barley particle size. Compared with feeding diets prepared with non-tempered barley, tempering with surfactant increased the feed efficiency of feedlot steers. This may have arisen from alteration in processing characteristics of barley grain by surfactant rather than its direct effect on rumen microbial fermentation.
摘要译文
和体外瘤胃进行实验，以评估含有皂素表面活性剂的大麦种子的牛生长性能及对瘤胃发酵回火过程中施加的影响。在饲养场试验中，有三个大麦/大麦青贮为主的饮食疗法使用大麦种子在7.7％的水分（干燥的，D）的制备，回火到18％的水分（M）的后，或具有皂苷系表面活性剂回火后包含在60毫升/吨（MS）。每个治疗轧在先前确定，以产生最佳的加工大麦设置。共有180刚断奶英国$ {\\倍} $夏洛莱肉牛饲喂三种饮食中18笔为63-D一个后台期和91-D整理期间确定的采食量，生长速度和饲料利用率。牛被屠宰在实验以测量胎体特征的末端。回火减少（P但加工特征是MS和M.回火之间的相似增加（p在一个后台，饲料效率与回火改善，但整理和总体这种反应只与表面活性剂观察期间。回火并未影响胴体重，脂肪含量和肉产量。表面活性剂增加了一倍的尸体AAA评级的比例。在体外实验中，大麦（500毫克;地面0毫米或蒸汽热轧）中没有或有表面活性剂的多达20个$ {\\亩}升/ 24小时克$ DM底孵育缓冲胃液（40毫升）中。表面活性剂的增加（p05）明显DM消失和淀粉的消化率，但天然气生产减少和挥发性脂肪酸和乙：丙酸比例，不论大麦颗粒大小。用料制备的非调质大麦日粮，与表面活性剂相比，回火提高肉牛饲养场的饲料效率。这可能已经出现了从以改变表面活性剂，而不是对瘤胃直接影响微生物发酵处理大麦的特性。
Wang, Y. ; Gibb, D. ; Greer, D. ; McAllister, T.A.. Effects of Moisture and a Saponin-based Surfactant during Barley Processing on Growth Performance and Carcass Quality of Feedlot Steers and on In vitro Ruminal Fermentation[J]. Asian-Australasian Journal of Animal Sciences, 2011,24(12): 1690-