Wu H M, Zhang J, Wang C, Liu Q, Guo G, Huo W J, Chen L, Zhang Y L, Pei C X, Zhang S L
College of Animal Sciences, Shanxi Agricultural University, Taigu, 030801, Shanxi, People's Republic of China.
Br J Nutr. 2021 Nov 14;126(9):1288-1295. doi: 10.1017/S0007114520005243. Epub 2021 Jan 8.
To investigate the influences of dietary riboflavin (RF) addition on nutrient digestion and rumen fermentation, eight rumen cannulated Holstein bulls were randomly allocated into four treatments in a repeated 4 × 4 Latin square design. Daily addition level of RF for each bull in control, low RF, medium RF and high RF was 0, 300, 600 and 900 mg, respectively. Increasing the addition level of RF, DM intake was not affected, average daily gain tended to be increased linearly and feed conversion ratio decreased linearly. Total tract digestibilities of DM, organic matter, crude protein (CP) and neutral-detergent fibre (NDF) increased linearly. Rumen pH decreased quadratically, and total volatile fatty acids (VFA) increased quadratically. Acetate molar percentage and acetate:propionate ratio increased linearly, but propionate molar percentage and ammonia-N content decreased linearly. Rumen effective degradability of DM increased linearly, NDF increased quadratically but CP was unaltered. Activity of cellulase and populations of total bacteria, protozoa, fungi, dominant cellulolytic bacteria, Prevotella ruminicola and Ruminobacter amylophilus increased linearly. Linear increase was observed for urinary total purine derivatives excretion. The data suggested that dietary RF addition was essential for rumen microbial growth, and no further increase in performance and rumen total VFA concentration was observed when increasing RF level from 600 to 900 mg/d in dairy bulls.
为研究日粮添加核黄素（RF）对养分消化和瘤胃发酵的影响，采用4×4重复拉丁方设计，将8头安装了瘤胃瘘管的荷斯坦公牛随机分为4组。对照组、低RF组、中RF组和高RF组每头公牛的RF日添加水平分别为0、300、600和900毫克。随着RF添加水平的提高，干物质采食量未受影响，平均日增重呈线性增加趋势，饲料转化率呈线性下降。干物质、有机物、粗蛋白（CP）和中性洗涤纤维（NDF）的全消化道消化率呈线性增加。瘤胃pH值呈二次下降，总挥发性脂肪酸（VFA）呈二次增加。乙酸摩尔百分比和乙酸:丙酸比值呈线性增加，但丙酸摩尔百分比和氨氮含量呈线性下降。干物质的瘤胃有效降解率呈线性增加，NDF呈二次增加，但CP不变。纤维素酶活性以及总细菌、原生动物、真菌、优势纤维素分解菌、瘤胃普雷沃氏菌和嗜淀粉瘤胃杆菌的数量呈线性增加。尿中总嘌呤衍生物排泄量呈线性增加。数据表明，日粮添加RF对瘤胃微生物生长至关重要，在奶牛中，当RF水平从600毫克/天提高到900毫克/天时，生产性能和瘤胃总VFA浓度未进一步增加。
