Burken D B, Nuttelman B L, Jolly-Briethaupt M J, Gramkow J L, Gardine S E, Klopfenstein T J, MacDonald J C, Erickson G E
Department of Animal Science, University of Nebraska, Lincoln 68583.
Transl Anim Sci. 2017 Sep 1;1(3):382-396. doi: 10.2527/tas2017.0046. eCollection 2017 Sep.
Two finishing and 1 digestibility experiment evaluated the partial substitution of corn with corn silage and corn modified distillers grains with solubles (MDGS). Steers were used in Exp. 1 (n = 295; 467 ± 52 kg) and Exp. 2 (n = 225; BW = 348 ± 27 kg) in a 2 × 2 + 1 factorial arrangement of treatments with factors including corn silage (15 or 45%) and MDGS (20 or 40%) plus a control diet consisting of 5% cornstalks and 40% MDGS. In Exp. 1, there were tendencies for a corn silage × MDGS interaction for ADG, final BW, and G:F ( ≤ 0.08). In the overall F-test for G:F, there were no differences between the control treatment and 15:20, 15:40, or 45:40 ( ≥ 0.15), however, steers fed the control treatment had increased G:F compared to steers fed 45:20 treatment diets ( = 0.03). In Exp. 2, there were no corn silage × MDGS interactions ( ≥ 0.12). As corn silage increased in the diet, ADG, final BW, and G:F decreased ( ≤ 0.01). As MDGS increased from 20 to 40%, ADG and G:F tended to improve ( ≤ 0.07). In the overall F-test, the control was not different for G:F from 15:20, 45:20, or 45:40 ( ≥ 0.15), but had a 4.8% poorer G:F compared to 15:40 ( < 0.01). In Exp. 3, ruminally fistulated steers (n = 6) were used in a 5 × 6 Latin rectangle design and fed 15 or 45% corn silage with 20 or 40% MDGS as a 2 × 2 factorial. An additional diet consisting of 95% corn silage and 5% supplement was fed. There were no corn silage × MDGS interactions for nutrient intake, total tract digestibility, ruminal pH measurements, acetate: propionate ratio (A:P), or in-situ disappearance data ( ≥ 0.31) for the 2 × 2 factorial. As corn silage increased in the diet, DMI, NDF intake, ruminal pH, A:P, in-situ NDF disappearance of corn bran, and DM disappearance of corn increased ( ≤ 0.09) with decreases in DM and OM digestibility ( ≤ 0.03). As MDGS increased in the diet, there was an increase in NDF intake, total volatile fatty acid concentration, and NDF disappearance of corn bran ( ≤ 0.03) with no differences for any other tested variables ( ≥ 0.13). In general, increasing corn silage in place of corn in finishing diets containing MDGS results in a modest reduction in ADG and G:F with increases in ruminal pH.
两项育肥试验和一项消化率试验评估了用玉米青贮料和玉米改性可溶物酒糟（MDGS）部分替代玉米的效果。试验1使用了阉牛（n = 295；体重467 ± 52千克），试验2使用了阉牛（n = 225；体重348 ± 27千克），采用2×2 + 1析因处理设计，处理因素包括玉米青贮料（15%或45%）和MDGS（20%或40%），再加上一种对照日粮，其由5%的玉米秸秆和40%的MDGS组成。在试验1中，平均日增重（ADG）、末重和料重比（G:F）存在玉米青贮料×MDGS互作趋势（P≤0.08）。在G:F的总体F检验中，对照处理与15:20、15:40或45:40处理之间无差异（P≥0.15），然而，与饲喂45:20处理日粮的阉牛相比，饲喂对照处理日粮的阉牛G:F有所提高（P = 0.03）。在试验2中，不存在玉米青贮料×MDGS互作（P≥0.12）。随着日粮中玉米青贮料增加，ADG、末重和G:F降低（P≤0.01）。随着MDGS从20%增加到40%，ADG和G:F有改善趋势（P≤0.07）。在总体F检验中，对照处理的G:F与15:20、45:20或45:40处理无差异（P≥0.15），但与15:40处理相比，其G:F低4.8%（P<0.01）。在试验3中，使用瘤胃瘘管阉牛（n = 6），采用5×6拉丁方设计，以2×2析因设计饲喂15%或45%的玉米青贮料与20%或40%的MDGS。另外还饲喂一种由95%玉米青贮料和5%补充料组成的日粮。对于2×2析因设计，在营养物质摄入量、全消化道消化率、瘤胃pH测量值、乙酸:丙酸比例（A:P）或原位消失数据方面，不存在玉米青贮料×MDGS互作（P≥0.31）。随着日粮中玉米青贮料增加，干物质采食量（DMI）、中性洗涤纤维摄入量、瘤胃pH、A:P、玉米麸皮原位中性洗涤纤维消失率以及玉米干物质消失率增加（P≤0.09），而干物质和有机物消化率降低（P≤0.03）。随着日粮中MDGS增加，中性洗涤纤维摄入量、总挥发性脂肪酸浓度和玉米麸皮中性洗涤纤维消失率增加（P≤0.03），其他任何测试变量均无差异（P≥0.13）。总体而言，在含有MDGS的育肥日粮中，用玉米青贮料替代玉米会使ADG和G:F略有降低，同时瘤胃pH升高。
