Department of Veterinary Medicine, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan 069-8501.
Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5.
J Dairy Sci. 2020 Apr;103(4):3656-3667. doi: 10.3168/jds.2019-17677. Epub 2020 Feb 20.
The objective of this study was to evaluate effects of butyrate supplementation on plasma concentration of glucagon-like peptide-2 (GLP-2), apparent total-tract digestibility, and responses to a grain challenge of lactating dairy cows fed diets differing in starch content. Eight Holstein cows averaging 58.6 ± 9.96 d in milk (4 primiparous cows fitted with rumen cannula and 4 multiparous intact cows) were blocked by parity and assigned to one of two 4 × 4 Latin squares balanced for carryover effects with a 2 × 2 factorial arrangement of treatments. Treatments were dietary starch content [20.6 vs. 27.5%, respectively, for low starch (LS) and high starch (HS)] and butyrate supplementation (butyrate vs. control) with 21-d periods. Butyrate was provided as Gustor BP70 WS (Norel, S.A., Madrid, Spain), containing 70% sodium butyrate and 30% fatty acid mixture, at 2% of dietary dry matter (providing butyrate at 1.1% of dietary dry matter), and control premix contained 70% wheat bran and 30% fatty acid mixture. Feeds, orts, and fecal samples were collected from d 17 to 19 to determine apparent total-tract nutrient digestibility. Blood and rumen fluid samples were collected on d 19. The baseline of dry matter intake (DMI) was determined as average DMI from d 17 to 19 for each cow, and cows were feed-restricted at 60% of the baseline DMI on d 20, and a grain challenge was conducted by providing steam-flaked corn grain at 0.6% of body weight, on an as-fed basis, in addition to each treatment diet on d 21, and blood and ruminal fluid samples were collected. The interaction of dietary starch content by butyrate supplementation was significant for plasma GLP-2 concentration, being greater for cows fed butyrate with the HS diet than those fed the other 3 diets. Cows fed butyrate increased n-butyrate concentration in the ruminal fluid and tended to increase dry matter and organic matter digestibility compared with the control. During the grain challenge, rumen endotoxin concentration increased over time and was higher for cows fed the HS diets compared with those fed LS diets. However, response variables related to inflammation were not affected by the grain challenge. However, serum haptoglobin, lipopolysaccharide-binding protein, and serum amyloid-A concentrations were greater for cows fed butyrate with the LS diet, but not for those fed the HS diet. These results indicate that butyrate supplementation may increase plasma GLP-2 concentration for cows fed HS diets, and total-tract digestibility regardless of dietary starch content. However, butyrate supplementation did not mitigate inflammation in this study.
本研究旨在评估丁酸盐补充对泌乳奶牛血浆胰高血糖素样肽-2（GLP-2）浓度、表观全肠道消化率和谷物挑战反应的影响，这些奶牛分别饲喂不同淀粉含量的日粮。8 头荷斯坦奶牛，泌乳天数平均为 58.6±9.96d（4 头带有瘤胃瘘管的初产奶牛和 4 头经产完整奶牛），根据胎次进行分组，并按 2×2 因子设计的处理进行 4×4 拉丁方平衡，具有残留效应。处理为日粮淀粉含量[分别为 20.6%和 27.5%，低淀粉（LS）和高淀粉（HS）]和丁酸盐补充（丁酸盐与对照），周期为 21d。丁酸盐作为 Gustor BP70 WS（Norel，S.A.，马德里，西班牙）提供，含有 70%的丁酸钠和 30%的脂肪酸混合物，占日粮干物质的 2%（提供日粮干物质 1.1%的丁酸钠），对照预混料含有 70%的小麦麸皮和 30%的脂肪酸混合物。在 d17 至 19 期间收集饲料、残渣和粪便样品，以确定表观全肠道养分消化率。在 d19 收集血液和瘤胃液样品。干物质采食量（DMI）的基线是根据每头奶牛在 d17 至 19 期间的平均 DMI 确定的，在 d20 时奶牛的 DMI 被限制在基线 DMI 的 60%，在 d21 时，每头奶牛在饲喂基础上额外饲喂蒸汽压片玉米谷物 0.6%，作为谷物挑战，同时还饲喂每一种处理日粮，并收集血液和瘤胃液样品。丁酸盐补充对血浆 GLP-2 浓度的影响与日粮淀粉含量的互作显著，与其他 3 种日粮相比，饲喂丁酸盐和 HS 日粮的奶牛的血浆 GLP-2 浓度更高。与对照组相比，饲喂丁酸盐的奶牛瘤胃液中 n-丁酸浓度增加，且干物质和有机物消化率呈增加趋势。在谷物挑战期间，瘤胃内毒素浓度随时间增加，且饲喂 HS 日粮的奶牛高于饲喂 LS 日粮的奶牛。然而，与炎症相关的反应变量不受谷物挑战的影响。然而，血清结合珠蛋白、脂多糖结合蛋白和血清淀粉样蛋白 A 的浓度在饲喂 LS 日粮但不是 HS 日粮的奶牛中更高。这些结果表明，丁酸盐补充可以增加饲喂 HS 日粮奶牛的血浆 GLP-2 浓度和全肠道消化率，而与日粮淀粉含量无关。然而，在本研究中，丁酸盐补充并没有减轻炎症。
