Effects Of Dietary Dihydromyricetin Supplementation On Intestinal Morphology, Intestinal Microflora And Immune Function Of Broilers

Three experiments were conducted in the present study to investigate effects of dietary dihydromyriectin(DMY) supplementation on intestinal morphology, intestinal microflora and immune function of broilers. The results were as followed:In experiment 1, DMY antibacterial ability was studied. The results indicated that the 0.1% DMY could suppress the growth of escherichia coil,staphylococcus aureus and salmonella significantly. Antibacterial action of addition of 0.2% DMY on escherichia coil was higher than that of addition of 0.075% terramycin, and there was no difference between the addition of 0.2% DMY and the 0.075% terramycin on antibacterial action to salmonella.In experiment 2, 360 AA broilers of either sex were randomly assigned to each of the 5 dietary groups, that were blank control group, 0.025%, 0.05%, 0.1% and 0.2% DMY group, every group had 6 replications. At the 7d, the 14d and the 21d of age, two broilers in each replication were killed for the cultivation of the bacteria in jejunum and cecum and the microscopic section making of duodenum and jejunum at the 21d age. The results indicated that the addition of 0.05% DMY significantly increased the height of villous (P<0.05) in jejunum, and significantly reduced the depth of intestinal gland in duodenum. The addition of 0.2% DMY significantly shortened the height of villous in duodenum. The addition of 0.025%~0.2% DMY had no significant influence on the growth of escherichia coil, staphylococcus aureus and salmonella .In experiment 3, 300 AA male broilers were randomly assigned to each of the 5 dietary groups, that were blank control group, 0.025%, 0.05%, 0.1% and 0.2% DMY group, every group had 6 replications. At the 21d and the 42d, the relative weight (%BW) of thymus, bursa and spleen were estimated. Meanwhile, all of the above organs were made the microscopic section respectively. And serum antibody titres to Newscastle Disease virus, serum IL-1 and serum IL-2 were estimated. At the 42d age carcass quality of broilers in each replication were determined. From Id to 42d, the body weight gain and feed intake of each replication were recorded weekly. The results indicated that the addition of 0.025%~0.05% DMY significantly increased the index of thymus and bursa and serum antibody titres to Newscastle Disease virus-And the addition of 0.025%~0.05% DMY could promote the development of immune organs. On the contrary, the addition of 0.1%~0.2% DMY could inhibited the development of immune organs. At the 21d age, broilers received the diets added with the 0.2% DMY had a lower serum IL-1 P than that of the control group and the 0.05% group (P<0.05), the addition of 0.1% DMY had a significant lower (P<0.05) serum IL-2 than that of the control group. The addition of 0.025% DMY and 0.05% DMY group had a significant lower (P<0.05) serum IL-1 than that of the control and the 0.2% DMY group at the 42d age. The addition of 0.025% DMY could improve average daily gain (P<0.05), feed intake, the feed conversion ratio, carcass quality of the male chicks-percentage of thigh muscle increased by 15.6% (PO.05).