Chelkapally S C, Terrill T H, Ogunade I M, Estrada-Reyes Z M, Pech-Cervantes A A
Agricultural Research Station, Fort Valley State University, Fort Valley, GA 31030.
Division of Animal and Nutritional Science, West Virginia University, Morgantown, WV 26505.
JDS Commun. 2024 Dec 12;6(3):299-303. doi: 10.3168/jdsc.2024-0626. eCollection 2025 May.
Distillery byproducts such as brewers grains (BG) have been widely used in dairy cow diets for decades to reduce diet costs and improve nutrient efficiency. Thus, the objective of this study was to evaluate the magnitude of the effects of dietary supplementation with BG on feed intake (DMI), digestibility, milk yield (MY), and feed efficiency (FE) of lactating dairy cows. A total of 12 peer-reviewed articles (n = 472 dairy cows) from 1983 to 2021 were collected systematically with the PRISMA method. The weighted raw mean differences (RMD) between dietary BG and control treatments were estimated with a robust variance estimation. Likewise, diet characteristics, such as CP content, NDF content, type of BG (wet = 1 and dry = 2), DIM, and BG inclusion rate (0 to 75%) were used as covariates in a meta-regression, subset, and dose-response analysis. Compared with the control, dietary BG decreased DMI (19.7 vs. 20.2 kg/d) and tended to increase MY (28.9 vs. 28.4 kg/d), but no effects were observed on FCM yield (29.1 vs. 28.8 kg/d), milk fat (3.8 vs. 3.7%), and milk protein (3.2 vs. 3.2%) concentrations. However, dietary BG increased FE (1.45 vs. 1.34 FCM/DMI) without influencing total-tract DM (61.9 vs. 55.7%) and NDF (49.7 vs. 54.5%) digestibility. Increasing the inclusion rate of BG linearly increased (R = 0. 554) dietary NDF. Thus, the dose-response analysis revealed that feeding up to 20% BG (dietary NDF = 39%) to lactating dairy cows increased MY and FE. Overall, this meta-analysis supports the hypothesis that dietary BG improved FE in lactating dairy cows.
几十年来，酿酒厂副产品如啤酒糟（BG）已广泛用于奶牛日粮中，以降低日粮成本并提高养分利用效率。因此，本研究的目的是评估日粮中添加BG对泌乳奶牛采食量（DMI）、消化率、产奶量（MY）和饲料效率（FE）的影响程度。采用PRISMA方法系统收集了1983年至2021年的12篇同行评议文章（n = 472头奶牛）。采用稳健方差估计法估计日粮BG与对照处理之间的加权原始均值差（RMD）。同样，日粮特性，如粗蛋白（CP）含量、中性洗涤纤维（NDF）含量、BG类型（湿=1，干=2）、泌乳天数（DIM）和BG添加率（0至75%）在荟萃回归、子集和剂量反应分析中用作协变量。与对照相比，日粮BG降低了DMI（19.7对20.2千克/天），并倾向于提高MY（28.9对28.4千克/天），但对乳脂校正乳产量（29.1对28.8千克/天）、乳脂率（3.8对3.7%）和乳蛋白率（3.2对3.2%）没有影响。然而，日粮BG提高了FE（1.45对1.34乳脂校正乳/DMI），而不影响全消化道干物质（61.9对55.7%）和NDF（49.7对54.5%）消化率。增加BG添加率使日粮NDF呈线性增加（R = 0.554）。因此，剂量反应分析表明，给泌乳奶牛饲喂高达20%的BG（日粮NDF = 39%）可提高MY和FE。总体而言，这项荟萃分析支持日粮BG可提高泌乳奶牛FE的假设。
