Effects Of Lactobacillus On Growth Performance, Immune Function And Intestinal Microflora In Broilers

The present experiment was conducted to study the effects of dietary Lactobacillus fermentum F-6 and Lactobacillus casei-Zhang on growth performance, immune function, antioxidative activity,and to elucidate its mechanism according to volatile fatty acid contents, population and diversity of intestinal microflora in Broilers. The basal diet was mainly composed of corn and soybean. In the experiment, a total of 480 1-day-old AA mixed-sex broilers with similar body weight were randomLy allotted into 8 treatments with 6 replicates in each treatment, with 10 broilers in each replicate. Group 1 was the control that didn't add Lactobacillus in drinking water, Group 2,3 and 4 were fed individually 3 levels of L.fermentum F6 ( 2×10~5cfu/mL,L.F1, 2×10~6 cfu/mL,L.F2 and 1×107 cfu/mL ,(L.F3)). Group 5 and 6 were fed individually 2 levels of levels of L.casei Zhang (2×10~5cfu/mL,L.C1 and 2×10~6 cfu/mL,L.C2). Group 7 and 8 were fed individually 2 levels of mixture of L.fermentum F6 and L.casei Zhang ((1+1)×10~5cfu/mL,L.C1 and (1+1)×10~6 cfu/mL ,L.C2). Lactobacillus liquids were fed twice a day and limited to finish this drink in an hour each time.The trial period was 42d.The results showed as follows under the present experimental conditions:1. Adding the L.fermentum F-6, L. casei Zhang or the mixture of both could significantly improve growth performance and nutrients digestability in broilers, especially, the dosage of 2×10~6cfu/mL or (1+1)×10~6 cfu/mL had a better effect; and they had no significant effects on meat quality in broilers.2. Adding the L.fermentum F-6, L. casei Zhang or the mixture of both could significantly improve immune function and antioxidative activity in broilers, the dosage of 2×10~6cfu/mL L.casei Zhang or (1+1)×10~6 cfu/mL mixture of both Lactobacillus had a better effect.3. Adding the L.fermentum F-6, L. casei Zhang or the mixture of both could benefit Intestinal microflora balance , and significantly improve population of beneficial bacteria, and reduce population of harmful bacteria in ileum and cecal in broilers, the dosage of 2×10~6cfu/mL or (1+1)×10~6 cfu/mL drinking water had a better effect. 4. Adding the L.fermentum F-6, L. casei Zhang or the mixture of both could significantly improve contents of VFA in ileum and cecal of broilers; and the dosage of (1+1)×10~6 cfu/mL mixture of both Lactobacillus had the best effect; and the dosage of 2×10~6cfu/mL L.fermentum F-6 or L.casei Zhang had a better effect.5. Adding the L.fermentum F-6, L. casei Zhang or the mixture of both could significantly improve diversity of bacteria and lactobacillus in intestinal of broilers; and change dominant strain of lactobacillus in intestinal of broilers. Feeding L. casei Zhang could improve population of L. casei Zhang in intestinal of broilers.6. In conclusion, the addition of 2×10~6cfu/mL L.fermentum F-6 in drinking water would have the best effect in the growth performance and economic benifits for broilers, and the addition of (1+1)×10~6 cfu/mL mixture of both Lactobacillus or 2×10~6cfu/mL L. casei Zhang would be also better.