The Effects Of Exogenous Nucleic Acid On Growth Performance And Intestinal Mucosa Structure Of Broilers

Yeast nucleic acid was added to the feed of Avian broilers in order to study the effects of exogenous nucleic acid on the growth performance, muscle composition and intestinal mucosa structure.One hundred and twenty-five healthy Avian broilers were allotted to five groups randomly with five duplicates each group which include one corn-soybean basal diet or supplemented with 0.1%, 0.2%, 0.3%, 0.4% yeast nucleic acid .The broilers were fed for four weeks. At the end of second week and the end of feeding experiment, five broilers were selected each group and then killed to determine the growth performance, carcass composition, muscle nutrients content, serum bio-chemical parameters and intestinal mucosa structure. The results were summarized as follows:Growth performance: Yeast nucleic acid was potential to increase the average daily gain and average feed intake. In the first two weeks, adding 0.3%, 0.4% yeast nucleic acid increased the average daily gain significantly compared to control group (P<0.05) , while adding 0.1%, 0.2% yeast nucleic acid had no significant difference compared to control group (P>0.05) .In the last two weeks, all the trial groups had significant increase on average daily gain compared to the control group (P<0.05) . In the first two weeks, compared to control group ,adding 0.4% yeast nucleic acid group had significant increase on average feed intake (P<0.05) while the other trial groups had no significant difference; In the last two weeks, the 0.2% nucleic acid group had significant increase on average feed intake (P<0.05) while the other groups had no significant difference compared to control group. In the first two weeks, all the groups had no significant difference with regard to feed conversation between each other (P>0.05) .In the last two weeks ,0.3%, 0.4% nucleic acid group had significant increase on feed conversion compared to control group (P<0.05) .Slaughter performance: Yeast nucleic acid increased the live weight significantly in all the trial groups in the experiment period (P<0.05) . In the first two weeks, 0.2% yeast nucleic acid group increased the eviscerated carcass rate and the semi-eviscerated carcass rate significantly compared to the control group (P<0.05) .In the last two weeks, 0.3%, 0.4% yeast nucleic acid group increased the eviscerated carcass rate and the percentage of breast muscle significantly compared to control group (P<0.05) .In the first two weeks, compared to control group ,0.2% yeast nucleic acid group had significant effects on the percentage of gizzard weight and liver weight (P<0.05) , while had no significant effect on other organs (P>0.05) . In the last two weeks, compared to control group ,0.2% yeast nucleic acid increased the percentage of liver weight significantly (P<0.05) while had no significant effect on other organs (P>0.05) .Immune organs: In the first two weeks, adding 0.1%, 0.2% yeast nucleic acid...