Goetz B M, Abeyta M A, Rodriguez-Jimenez S, Opgenorth J, McGill J L, Bryan K A, Baumgard L H
Department of Animal Science, Iowa State University, Ames, IA 50011.
Department of Veterinary Microbiology and Preventative Medicine, Iowa State University, Ames, IA 50011.
JDS Commun. 2023 Nov 17;5(2):167-171. doi: 10.3168/jdsc.2023-0402. eCollection 2024 Mar.
The objectives were to evaluate the effects of a 4-strain direct-fed microbial (DFM) on gastrointestinal tract (GIT) permeability and inflammation during feed restriction (FR) in heifers. Holstein heifers (n = 32; mean ± standard deviation; 295 ± 25 kg body weight; 287 ± 17 d of age) were used in an experiment conducted in 2 replicates (16/replicate). Heifers were randomly assigned to 1 of 2 top-dressed dietary treatments: (1) control (CON; 10 g/d dried lactose; n = 16) or (2) DFM containing a commercial blend of , , , and at 11.8 × 10 cfu/d (PRO; 10 g/d 4-strain DFM; n = 16). The trial consisted of 2 experimental periods (P): P1 (14 d) served as baseline for P2 (5 d), when all heifers were restricted to 40% of their P1 dry matter intake (DMI). On P1 d 12 and P2 d 2 and 5, GIT permeability was evaluated using oral chromium (Cr)-EDTA. By design, FR decreased DMI (60%) and body weight (∼18 kg) in all heifers. Regardless of treatment, during FR, all heifers had decreased circulating glucose, β-hydroxybutyrate, insulin, and l-lactate (4, 14, 45, and 19%, respectively), but increased nonesterified fatty acids, serum amyloid A, and haptoglobin (3.0-, 1.7-, and 5.0-fold, respectively). Circulating white blood cells, neutrophils, lymphocytes, and basophils decreased (4, 7, 5, and 6%, respectively), whereas eosinophils increased (41%) during P2 irrespective of dietary treatment. Circulating IFN-γ inducible protein-10 increased (23%) during FR compared with P1 regardless of treatment. Plasma Cr area under the curve increased in all heifers on d 2 and 5 (10 and 14%, respectively) of P2 relative to P1, but this was unaltered by dietary treatment. In summary, FR compromised GIT barrier function and stimulated an inflammatory response, but this did not appear to be ameliorated by PRO.
本研究旨在评估一种四菌株直接投喂微生物（DFM）对育成母牛限饲（FR）期间胃肠道（GIT）通透性和炎症的影响。选用荷斯坦育成母牛（n = 32；平均值±标准差；体重295±25 kg；年龄287±17 d）进行试验，试验分2个重复组（每组16头）。将育成母牛随机分为2种撒施日粮处理组中的1组：（1）对照组（CON；10 g/d干乳糖；n = 16）或（2）DFM组，日粮中含有商业混合的[此处原文缺失四种菌的具体名称]，剂量为11.8×10 cfu/d（PRO；10 g/d四菌株DFM；n = 16）。试验包括2个试验期（P）：第1期（P1，14 d）作为第2期（P2，5 d）的基线期，在此期间所有育成母牛的干物质摄入量（DMI）限制为P1期的40%。在P1期第12天以及P2期第2天和第5天，通过口服铬（Cr）-乙二胺四乙酸（EDTA）评估GIT通透性。按照设计，限饲使所有育成母牛的DMI降低（60%），体重下降（约18 kg）。无论处理方式如何，在限饲期间，所有育成母牛的循环葡萄糖、β-羟基丁酸、胰岛素和L-乳酸均下降（分别下降4%、14%、45%和19%），但非酯化脂肪酸、血清淀粉样蛋白A和触珠蛋白增加（分别增加3.0倍、1.7倍和5.0倍）。无论日粮处理如何，在P2期循环白细胞、中性粒细胞、淋巴细胞和嗜碱性粒细胞均减少（分别减少4%、7%、5%和6%），而嗜酸性粒细胞增加（41%）。与P1期相比，无论处理方式如何，限饲期间循环γ-干扰素诱导蛋白10均增加（23%）。与P1期相比，所有育成母牛在P2期第2天和第5天的血浆Cr曲线下面积均增加（分别增加10%和14%），但日粮处理对此无影响。总之，限饲损害了GIT屏障功能并引发了炎症反应，但PRO似乎并未改善这种情况。
