Salfer I J, Crawford C E, Rottman L W, Harvatine K J
Department of Animal Science, University of Minnesota, St. Paul 55108.
Department of Animal Science, The Pennsylvania State University, University Park 16802.
JDS Commun. 2021 Aug 26;2(6):334-339. doi: 10.3168/jds.2021-0099. eCollection 2021 Nov.
The effect of feeding a single TMR versus multiple rations across the day that differ in concentrations of neutral detergent fiber (NDF) and starch on the daily pattern of rumen microbial populations was characterized. Diets included a control total mixed ration (CON; 33.3% NDF), a low-fiber diet (LF; 29.6% NDF), and a high-fiber diet (HF; 34.8% NDF). Nine cannulated Holstein cows were assigned to 1 of 3 treatment sequences in a 3 × 3 Latin square design. Treatments included feeding CON ad libitum at 0900 h, feeding HF at 70% of daily offering at 0900 h and LF at 30% of daily offering at 2200 h (H/L), and feeding LF at 30% of daily offering at 0900 h and HF at 70% of daily offering at 1300 h (L/H). Rumen digesta was collected to represent every 3 h across the day, microbial DNA was extracted, and real-time quantitative PCR was used to determine the relative abundances of total bacteria, total fungi, total protozoa, , , , , , , , and . The relative abundances of total bacteria, total ciliated protozoa, , , , , and were affected by time of day. Additionally, treatment affected the relative abundance of certain microbial groups at specific times of day. Notably, H/L treatment dramatically increased the relative abundances of , , and at 0900 h, by 2.5-, 5.4-, and 4.4-fold, respectively. Furthermore, the relative abundances of (3.9-fold), (3.9-fold), (1.3-fold), (1.3-fold), and (4.5-fold) were greatly increased by L/H at 0900 h. At 0600 h, the relative abundance of was 58% greater in L/H than H/L and the relative abundance of was 49% greater in H/L than L/H. Results suggest that there is a daily pattern of selected microbial populations that is altered by feeding rations that differ in NDF and starch within a day, with the greatest difference occurring before morning feeding.
研究了全天饲喂单一全混合日粮（TMR）与饲喂中性洗涤纤维（NDF）和淀粉浓度不同的多种日粮对瘤胃微生物种群日模式的影响。日粮包括对照全混合日粮（CON；33.3%NDF）、低纤维日粮（LF；29.6%NDF）和高纤维日粮（HF；34.8%NDF）。采用3×3拉丁方设计，将9头安装了瘤胃瘘管的荷斯坦奶牛分配到3种处理顺序中的1种。处理包括在09:00自由采食CON，在09:00以每日供应量的70%饲喂HF，在22:00以每日供应量的30%饲喂LF（H/L），以及在09:00以每日供应量的30%饲喂LF，在13:00以每日供应量的70%饲喂HF（L/H）。全天每隔3小时采集瘤胃消化物，提取微生物DNA，并使用实时定量PCR测定总细菌、总真菌、总原生动物、……、……、……、……、……和……的相对丰度。总细菌、总纤毛虫原生动物、……、……、……和……的相对丰度受一天中时间的影响。此外，处理在一天中的特定时间影响某些微生物组的相对丰度。值得注意的是，H/L处理在09:00时分别使……、……和……的相对丰度显著增加了2.5倍、5.4倍和4.4倍。此外，L/H在09:00时使……（3.9倍）、……（3.9倍）、……（1.3倍）、……（1.3倍）和……（4.5倍）的相对丰度大幅增加。在06:00时，L/H处理中……的相对丰度比H/L处理高58%，而H/L处理中……的相对丰度比L/H处理高49%。结果表明，特定微生物种群存在日模式，且在一天内通过饲喂NDF和淀粉含量不同的日粮会改变这种模式，其中最大差异出现在晨饲前。
