Lancaster Nicholas A, Muegge Chris R, Carvalho Jose R R, Lopes Rodrigo C, Narumiya Rafael S, Pinese Fabio, Baird Aubrey Nickie, Schoonmaker Jon P
Department of Animal Sciences, Purdue University, West Lafayette, IN.
Department of Animal Science, Universidade Federal de Lavras, Lavras, MG, Brazil.
Transl Anim Sci. 2020 Jun 30;4(3):txaa105. doi: 10.1093/tas/txaa105. eCollection 2020 Jul.
The objective of this study was to determine the effect of soybean hulls (SBH) and/or calcium oxide (CaO) on rumen pH, digestibility, and performance of steers fed diets containing dried distillers grains with solubles (DDGS). In experiment 1, Angus × Simmental steers ( = 112, body weight [BW] = 364 ± 7.8 kg) were allotted to 1 of 4 diets arranged as a 2 × 2 factorial and placed in 16 pens (7 steers/pen, 4 pens/treatment, and 28 steers/treatment). Factors were SBH (0% or 30% of diet dry matter [DM]) and CaO (0% or 1%) inclusion. Basal diets contained 20% corn stover, 30% DDGS, and 4% supplement. Diets with SBH contained 14.1% or 15.0% corn and diets without SBH contained 43.9% or 44.8% corn. In experiment two, four steers (BW = 510 ± 9.8 kg) were allotted to a 4 × 4 Latin square (21 d periods) to determine the effects of CaO and SBH on ruminal pH, volatile fatty acid (VFA), nutrient digestibility, and digestion kinetics. Statistical analyses were conducted using the MIXED procedure of SAS. In experiment 1, BW did not differ among treatments ( ≥ 0.46). Overall carcass-adjusted gain did not differ due to SBH or CaO inclusion ( ≥ 0.13); however, there was an interaction ( = 0.01) where CaO improved gain in steers fed no SBH, but not in steers fed SBH. Steers fed SBH consumed more DM than steers not fed SBH ( = 0.02) and an interaction tended to occur ( = 0.06) where CaO increased dry matter intake in steers fed no SBH, but not in steers fed SBH. Calcium oxide increased hot carcass weight and yield grade (interaction; ≤ 0.04) and tended to increase fat thickness (interaction; = 0.08) in steers fed no SBH, but not in steers fed SBH. Dressing percentage, longissimus muscle area, % kidney, pelvic, heart fat, and marbling score did not differ among treatments ( ≥ 0.14). Total VFA concentrations were greater with SBH inclusion and with CaO addition ( < 0.01). Digestibility of DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) was greater with CaO addition ( ≤ 0.04) and NDF and ADF digestibility were greater with SBH inclusion ( < 0.001). Inclusion of SBH did not affect ( ≥ 0.26) rate of digestion ( ) or passage ( ). Addition of CaO tended to increase mean retention time ( = 0.09). An interaction between SBH inclusion and CaO addition occurred for ( = 0.01), where CaO increased in steers fed SBH, but decreased when steers were fed no SBH. Total N excretion tended to be lower with SBH inclusion and CaO addition ( = 0.07). In conclusion, CaO enhances performance of cattle fed corn, DDGS, and corn stover diets, but not when corn is partially replaced by a fiber-based energy feed.
本研究的目的是确定大豆皮（SBH）和/或氧化钙（CaO）对饲喂含干酒糟及其可溶物（DDGS）日粮的阉牛瘤胃pH值、消化率和生产性能的影响。在实验1中，将安格斯×西门塔尔阉牛（n = 112，体重[BW]=364±7.8 kg）分配到4种日粮中的1种，采用2×2析因设计，置于16个栏中（每栏7头牛，每个处理4栏，每个处理28头牛）。因素为SBH（占日粮干物质[DM]的0%或30%）和CaO（0%或1%）的添加。基础日粮包含20%的玉米秸秆、30%的DDGS和4%的补充料。含SBH的日粮含有14.1%或15.0%的玉米，不含SBH的日粮含有43.9%或44.8%的玉米。在实验2中，将4头阉牛（BW = 510±9.8 kg）分配到一个4×4拉丁方设计（21天周期）中，以确定CaO和SBH对瘤胃pH值、挥发性脂肪酸（VFA）、养分消化率和消化动力学的影响。使用SAS的MIXED程序进行统计分析。在实验1中，各处理间的BW无差异（P≥0.46）。由于添加SBH或CaO，总体胴体校正增重无差异（P≥0.13）；然而，存在交互作用（P = 0.01），即CaO提高了未饲喂SBH阉牛的增重，但对饲喂SBH的阉牛没有影响。饲喂SBH的阉牛比未饲喂SBH的阉牛消耗更多的DM（P = 0.02），并且存在交互作用趋势（P = 0.06），即CaO增加了未饲喂SBH阉牛的干物质摄入量，但对饲喂SBH的阉牛没有影响。氧化钙增加了未饲喂SBH阉牛的热胴体重和产肉等级（交互作用；P≤0.04），并倾向于增加脂肪厚度（交互作用；P = 0.08），但对饲喂SBH的阉牛没有影响。屠宰率、背最长肌面积、肾、盆腔、心脏脂肪百分比和大理石花纹评分在各处理间无差异（P≥0.14）。添加SBH和CaO时，总VFA浓度更高（P < 0.01）。添加CaO时，DM、中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）的消化率更高（P≤0.04），添加SBH时，NDF和ADF的消化率更高（P < 0.001）。添加SBH不影响（P≥0.26）消化率（k）或通过率（c）。添加CaO倾向于增加平均滞留时间（P = 0.09）。添加SBH和CaO之间存在k的交互作用（P = 0.01），即CaO增加了饲喂SBH阉牛的k，但在未饲喂SBH的阉牛中降低了k。添加SBH和CaO时，总氮排泄量倾向于降低（P = 0.07）。总之，CaO提高了饲喂玉米、DDGS和玉米秸秆日粮的牛的生产性能，但当玉米部分被基于纤维的能量饲料替代时则不然。
