Effect Of Compound Culture Of Lactic Acid Bacteria And Yeast On Performance And Immune Characteristics Of Broilers

To screen the optimal amount of compound culture including Lactic acid bacteria cultures and yeast culture added to broiler feed, this experiment according to the laboratory screening of lactic acid bacteria cultures the optimal adding amount of 1.6 ‰ and yeast culture the optimal adding amount of 1.8 ‰, the tow adding amount are respectively reduced to form 4 gradient respectively, 4×4 two-factor test. 608 one day old AA broilers that had the same weight evenly in basic health were assigned to 19 treatment diets in a completely randomized experimental design, at the same time set up 1.6 ‰ lactic acid bacteria cultures diet control group(17), containing 1.8 ‰ yeast culture diet control group(18), and blank control group(19), each treatment had 4 replicates with 8 birds per replicate, the experiment was last to 42 d. On 42 d, two Average body condition of broilers per replicate were randomly selected and slaughtered for blood biochemical test. Through the determination of growth performance, metabolic functions,blood biochemical indicators, immune performance and VFA content in the cecum chyme, for the purpose of compound microbial cultures in production process broiler providing certain theoretical basis of science. The results are as follows:(1)The effect of compound cultures on broilers’ performance. The results showed that group 1, 2, 3, 4, 5, 6, 8, 11, 13, 14 and 15 of average daily gai n of broilers had a certain growth at the early stage of the breeding. Group 8and group 11 can significantly higher improve average daily gain of broilers days than the blank control group(P<0.05). The average daily gain of the tw o groups of broilers were increased by 12.55% and 12.85%. In the late breedi ng, group 1, 4, 6, 8, 11, 15, 16, 17 and 18 of average daily gain of broilers had a certain growth at the early stage of the breeding,and group 8 and grou p 11 were best, the average daily gain of the two groups of broilers were incr eased by 9.31% and 8.35%. Both Lactic acid bacteria culture and yeast culture have interaction on average daily gain in the later(P<0.05) and feed weight ratio in the later and the whole raising stage(P<0.05).(2) The effect of compound cultures on broilers’ nutrient digestibility and blood index. The results showed that most of treatments plans can improve the nutrient digestibility of broilers.The nutrient digestibility of 8 and 11 groups was highest at 7 to 21 days, but no significant difference was found the control group(group 19)(P >0.05).The digestibility of protein, fat, Ca and P of group 8 respectively increased by 24.00%、20.70%、11.63% and 10.35%;while group 11 respectively increased by 18.01%、18.33%、9.39%、11.96%.The effect of group 8 and group 11 were better at 22 to 42 days. Group 8 significantly improved glucose and total protein(P>0.05). Aspertate aminotransferase and third transaminase content in the two groups were the lowest, but the difference between them group 8 and group 19 was not significant(P>0.05). Both Lactic acid bacteria culture and yeast culture did not have interaction on nutrient digestibility and blood index significant(P>0.05).(3) The effect of compound cultures on broilers’ VFA content of cecum and immune index. The results showed that acetic acid,propionic acid content in cecum at group 8 and group 11 were significantly higher than that of control group at 42d(P<0.05).The spleen indexes of broilers of group 8 and group 11 were significantly higher than that of control group(P<0.05). Bursa of fabricius index of group 11 was extremely significantly higher than that of control group(p<0.01).IgA in serum of group 8 and group 11 were extremely significantly higher than that of control group(p<0.01). IgG in serum of group 8 and group 11 were significantly higher than that of control group(P<0.05). Both Lactic acid bacteria culture and yeast culture had a significant effect of interaction on acetic acid and IgA in secum(P<0.05), and a extremely significant effect on propionic acid(P<0.01).In summary, compound culture in group 8 and group 11 improved performance and immune function of broilers,illustrating that the ratio of lactic acid bacteria culture and yeast culture in both groups was optimal.