中文摘要：

选5头经产并装有永久性十二指肠瘘管的中国荷斯坦奶牛,采用5×5拉丁方试验设计,分为对照组（烟酸和核黄素,0g/d）、烟酸组（烟酸,3g/d）、核黄素组（核黄素,0.3g/d）、烟酸＋核黄素组（烟酸3g/d＋核黄素0.3g/d）、VB混合物组（烟酸3g/d＋核黄素0.3g/d＋硫胺素0.03g/d＋泛酸0.42g/d＋吡哆醇0.03g/d＋生物素0.04g/d＋叶酸0.04g/d）,以研究十二指肠灌注烟酸、核黄素、烟酸＋核黄素、VB混合物对奶牛生产性能、血液参数及牛奶风味的影响。结果表明,奶牛干物质采食量和产奶量在烟酸＋核黄素组、VB混合物组中增加（P〈0.05）,在烟酸组、核黄素组中无显著改变（P〉0.05）;外周血红细胞数和血红蛋白含量在VB混合物组中增加（P〈0.05）,在烟酸＋核黄素组中降低（P〈0.05）,在烟酸组中无显著变化（P〉0.05）,核黄素组外周血红细胞数降低（P〈0.05）,血红蛋白含量无显著改变（P〉0.05）,处理组间其余外周血红细胞参数、血小板参数及牛奶风味均无显著差异（P〉0.05）。因此,泌乳奶牛十二指肠灌注烟酸＋核黄素、VB混合物可以提高奶牛生产性能,且VB混合物对外周血红细胞数量和血红蛋白含量具有提高作用,经十二指肠灌注烟酸、核黄素、烟酸＋核黄素、VB混合物对牛奶风味无副作用,且烟酸＋核黄素、VB混合物组牛奶风味较对照组更佳。

英文摘要：

In order to research the effects of nicotinic acid and riboflavin duodenal infulsion on dry matter intake,milk production and blood parameters in dairy cows,five primiparous Chinese Holstein cows fitted with duodenal cannulas were arranged in a 5×5 Latin square design for five groups as control check（water,5 L/d）,nicotinic acid（3 g/d）,riboflavin（0.3 g/d）,nicotinic acid and riboflavin blend（nicotinic acid 3 g/d ＋ riboflavin 0.3 g/d）and B-vitamin blend（nicotinic acid 3 g/d ＋ riboflavin 0.3 g/d＋thiamine 0.03 g/d ＋pantothenic acid 0.42 g/d ＋pyridoxine 0.03 g/d ＋biotin 0.04 g/d ＋folic Acid 0.04 g/d）.The results showed that the dry matter intake and milk production were improved significantly by nicotinic acid and riboflavin blend and B-vitamin blend（P0.05）,but with no effect of nicotinic acid or riboflavin（P0.05）.There were no effects of nicotinic acid on red blood cells and hemoglobin（P0.05）,as well as riboflavin on hemoglobin,but red blood cells were decreased by riboflavin.For nicotinic acid and riboflavin blend,both of red blood cells and hemoglobin were decreased（P0.05）,inversely improved by B-vitamin blend（P0.05）.All the vitamin treatments had no effects on other red blood cells parameters and platelet parameters（P0.05）,but the platelet tended to increase.It suggested that nicotinic acid and riboflavin supplement at the same time can improve performance,and red blood cells and hemoglobin may be improved by B-vitamin blend.Duodenal infusion of nicotinic acid,riboflavin,nicotinic acid and riboflavin blend,B-vitamin had no adverse effect on milk flavor.Milk from cows infused nicotinic acid and riboflavin blend,B-vitamin blend into duodenum had better flavor than milk from control cows.