谷物加工程度对饲喂中等精料育成日粮的阉牛采食量、消化率、瘤胃发酵及生产性能特征的影响。

Effect of grain processing degree on intake, digestion, ruminal fermentation, and performance characteristics of steers fed medium-concentrate growing diets.

作者信息

Bengochea W L, Lardy G P, Bauer M L, Soto-Navarro S A

机构信息

Department of Animal and Range Sciences, North Dakota State University, Fargo, 58105, USA.

出版信息

J Anim Sci. 2005 Dec;83(12):2815-25. doi: 10.2527/2005.83122815x.

DOI:10.2527/2005.83122815x

PMID:16282620

Abstract

Three trials were conducted to evaluate the effects of degree of barley and corn processing on performance and digestion characteristics of steers fed growing diets. Trial 1 used 14 (328 +/- 43 kg initial BW) Holstein steers fitted with ruminal, duodenal, and ileal cannulas in a completely randomized design to evaluate intake, site of digestion, and ruminal fermentation. Treatments consisted of coarsely rolled barley (2,770 microm), moderately rolled barley (2,127 microm), and finely rolled barley (1,385 microm). Trial 2 used 141 crossbred beef steers (319 +/- 5.5 kg initial BW; 441 +/- 5.5 kg final BW) fed for 84 d in a 2 x 2 factorial arrangement to evaluate the effects of grain source (barley or corn) and extent of processing (coarse or fine) on steer performance. Trial 3 investigated four degrees of grain processing in barley-based growing diets and used 143 crossbred steers (277 +/- 19 kg initial BW; 396 +/- 19 kg final BW) fed for 93 d. Treatments were coarsely, moderately, and finely rolled barley and a mixture of coarsely and finely rolled barley to approximate moderately rolled barley. In Trial 1, total tract digestibilities of OM, CP, NDF, and ADF were not affected (P > or = 0.10) by barley processing; however, total tract starch digestibility increased linearly (P < 0.05), and fecal starch output decreased linearly (P < 0.05) with finer barley processing. In situ DM, CP, starch disappearance rate, starch soluble fraction, and extent of starch digestion increased linearly (P < 0.05) with finer processing. In Trial 2, final BW and ADG were not affected by degree of processing or type of grain (P > or = 0.13). Steers fed corn had greater DMI (P = 0.05) than those fed barley. In Trial 3, DMI decreased linearly with finer degree of processing (P = 0.003). Gain efficiency, apparent dietary NEm, and apparent dietary NEg increased (P < 0.001) with increased degree of processing. Finer processing of barley improved characteristics of starch digestion and feed efficiency, but finer processing of corn did not improve animal performance in medium-concentrate, growing diets.

摘要

进行了三项试验，以评估大麦和玉米加工程度对饲喂生长日粮的阉牛生产性能和消化特性的影响。试验1采用完全随机设计，选用14头（初始体重328±43千克）装有瘤胃、十二指肠和回肠瘘管的荷斯坦阉牛，以评估采食量、消化部位和瘤胃发酵情况。处理组包括粗轧大麦（2770微米）、中轧大麦（2127微米）和细轧大麦（1385微米）。试验2采用141头杂交肉牛阉牛（初始体重319±5.5千克；最终体重441±5.5千克），按2×2析因设计饲养84天，以评估谷物来源（大麦或玉米）和加工程度（粗或细）对阉牛生产性能的影响。试验3研究了以大麦为基础的生长日粮中四种谷物加工程度，并选用143头杂交阉牛（初始体重277±19千克；最终体重396±19千克）饲养93天。处理组包括粗轧、中轧和细轧大麦以及粗轧和细轧大麦的混合物，以近似中轧大麦。在试验1中，大麦加工对有机物、粗蛋白、中性洗涤纤维和酸性洗涤纤维的全消化道消化率没有影响（P≥0.10）；然而，随着大麦加工更细，全消化道淀粉消化率呈线性增加（P<0.05），粪便淀粉排出量呈线性减少（P<0.05）。随着加工更细，干物质、粗蛋白、淀粉原位消失率、淀粉可溶部分和淀粉消化程度呈线性增加（P<0.05）。在试验2中，最终体重和平均日增重不受加工程度或谷物类型的影响（P≥0.13）。饲喂玉米的阉牛干物质采食量（DMI）高于饲喂大麦的阉牛（P=0.05）。在试验3中，随着加工程度更细，DMI呈线性下降（P=0.003）。随着加工程度的提高，增重效率、表观日粮净能（NEm）和表观日粮净能（NEg）增加（P<0.001）。大麦的精细加工改善了淀粉消化特性和饲料效率，但玉米的精细加工在中等精料生长日粮中并未改善动物生产性能。