Sindt J J, Drouillard J S, Montgomery S P, Loe E R
Department of Animal Sciences and Industry, Kansas State University, Manhattan, 66506-1600, USA.
J Anim Sci. 2006 Jan;84(1):154-61. doi: 10.2527/2006.841154x.
Three experiments were conducted to identify factors influencing steam-flaked corn (SFC) characteristics and feeding value. In Exp. 1, corn samples (n = 108) were tempered for 2 h using 6, 10, or 14% moisture containing 0 or 0.67 mL of surfactant/L. Samples were steamed for 20 or 40 min and flaked to 360, 335, or 310 g/L. Treatments were arranged in a 3 x 2 x 2 x 3 factorial. No interactions existed in Exp. 1. Increasing tempering moisture linearly (P < 0.001) increased corn moisture after tempering, steaming, and flaking; however, SFC moisture was not increased (quadratic; P < 0.001) greatly by applying more than 10% water during tempering. The surfactant, steam time, and flake density had no effect (P = 0.16 to 0.93) on corn moisture after tempering, steaming, or flaking, but adding a surfactant during tempering decreased (P = 0.05) moisture loss after flaking. Starch availability was unaffected (P = 0.31 to 0.84) by tempering moisture concentration, tempering with a surfactant, or steam time but was increased (linear; P < 0.01) by decreasing flake density. Flake durability was increased by increasing tempering moisture (linear; P < 0.001), tempering with a surfactant (P = 0.04), increasing steam time (P < 0.001), and decreasing flake density (linear; P = 0.02). In Exp. 2, 89 heifers (initial BW = 350 kg) were fed 75% SFC-based diets for 108 d to determine the effects of SFC particle size on performance and carcass traits. Treatments were SFC that was mixed for 0 (4,667 microm) or 15 min (3,330 microm) before addition of other ingredients. Heifers fed 3,330-microm SFC tended (P = 0.13) to eat less DM, but ADG and G:F did not differ (P = 0.58 to 0.65) between treatments. Carcass traits did not differ, except that heifers fed 3,330-microm SFC had less (P = 0.008) KPH. In Exp. 3, 96 heifers (initial BW = 389 kg) were fed for 82 d diets containing 73% SFC that was either 18 or 36% moisture. Heifers fed 36% moisture SFC ate less DM (P = 0.02) and gained slower (P = 0.05) than heifers fed 18% moisture SFC, but G:F did not differ (P = 0.93) with SFC moisture. Heifers fed 36% moisture SFC were fatter at the 12th rib (P = 0.009), but all other carcass traits did not differ. Methods that increase moisture of SFC improved durability, but extreme moisture levels negatively affected cattle performance. Flake particle size did not affect cattle performance. Flake density is the major factor affecting starch availability in SFC.
进行了三项试验以确定影响蒸汽压片玉米（SFC）特性和饲喂价值的因素。在试验1中，对108个玉米样本进行调质处理2小时，调质水分含量分别为6%、10%或14%，每升含0或0.67毫升表面活性剂。样本蒸20或40分钟，压片至360、335或310克/升。处理按3×2×2×3析因设计排列。试验1中不存在交互作用。调质水分线性增加（P<0.001）使调质、蒸煮和压片后的玉米水分增加；然而，调质时水分超过10%并不会大幅增加SFC水分（二次效应；P<0.001）。表面活性剂、蒸汽时间和压片密度对调质、蒸煮或压片后的玉米水分无影响（P=0.16至0.93），但调质时添加表面活性剂可降低（P=0.05）压片后的水分损失。调质水分浓度、添加表面活性剂调质或蒸汽时间对淀粉消化率无影响（P=0.31至0.84），但降低压片密度可使淀粉消化率增加（线性；P<0.01）。增加调质水分（线性；P<0.001）、添加表面活性剂调质（P=0.04）、增加蒸汽时间（P<0.001）和降低压片密度（线性；P=0.02）可提高压片耐久性。在试验2中，89头小母牛（初始体重=350千克）饲喂含75%SFC的日粮108天，以确定SFC粒度对生产性能和胴体性状的影响。处理为在添加其他成分前，SFC混合0（4667微米）或15分钟（3330微米）。饲喂3330微米SFC的小母牛采食量有降低趋势（P=0.13），但处理间平均日增重和料重比无差异（P=0.58至0.65）。胴体性状无差异，只是饲喂3330微米SFC的小母牛的肾周脂肪较少（P=0.008）。在试验3中，96头小母牛（初始体重=389千克）饲喂含73%SFC的日粮82天，SFC水分含量分别为18%或36%。饲喂36%水分SFC的小母牛采食量低于（P=0.02）饲喂18%水分SFC的小母牛，增重也较慢（P=0.05），但料重比不受SFC水分影响（P=0.93）。饲喂36%水分SFC的小母牛第12肋处更肥（P=0.009），但其他胴体性状无差异。提高SFC水分的方法可提高耐久性，但过高水分水平对牛的生产性能有负面影响。压片粒度不影响牛的生产性能。压片密度是影响SFC中淀粉消化率的主要因素。
