| To evaluate the effects of probiotics on growth, apparent digestibility, immunity function, activities of digestive enzyme and intestinal microflora of Allogynogenetic crucian carp, we divided diferent levels of single probiotics preparations into the same basic dietary to provide a theoretical basis for a reasonable match between the strains.Exp. one Effects of probiotics on growth and apparent digestibility of Allogynogenetic crucian carpIn the experiment 720 carps were divided into 9 groups randomly, with 4 replicates and each replicates contained 20 carps.Three kinds of single probiotics preparations of the Brewers yeast (6.40×109cfu/kg,9.60×109cfu/kg,1.28×1010cfu/kg),the Lactobacillus acidophilus (1.60×109cfu/kg,3.20×109cfu/kg,4.80×109cfu/kg) and the Bacillus subtilis (3.50×109cfu/kg,1.05×1010cfu/kg,1.75×1010cfu/kg) were added into the feed and mixed for compound probiotics by L9 (34)design. The test lasted 60 days.The growth performance and apparent digestibility were determined. The results showed that:(1) the influence of three kinds of single probiotics preparations on growth of the carp in order was Brewers yeast>Bacillus subtilis > Lactobacillus acidophilus, and Brewers yeast achieved a significant level (P<0.01), and when the dosage of 1.28×1010cfu/kg, the weight gain and specific growth rate was significantly higher than the other two test levels (P<0.05). (2) the influence of three kinds of single probiotics preparations on feed conversion rate of the carp in order was Brewers yeast>Bacillus subtilis > Lactobacillus acidophilus, and Brewers yeast, Bacillus subtilis achieved a significant level (P<0.01) or (P<0.05), and When the Brewers yeast dosage of 1.28×1010cfu/kg, Bacillus subtilis of 3.50×109cfu/kg, the feed conversion rate was lower than other test levels. (3) the influence of three kinds of single probiotics preparations on protein digestibility and dry matter digestibility of the carp in order was Brewers yeast> Lactobacillus acidophilus > Bacillus subtilis,on apparent digestibility of phosphorus in order was Brewers yeast> Bacillus subtilis> Lactobacillus acidophilus, and Brewers yeast on phosphorus digestibility and apparent digestibility of dry matter was significantly (P<0.01 or P <0.05).Exp.two Effects of probiotics on part of the immune indicators in blood of Allogynogenetic crucian carpExperiment diet and treatments were same to Exp.one, and parts of the immune indicators in blood were measured. The results showed that Brewers yeast had a significantly effects on serum lysozyme (P <0.01), and Bacillus subtilis had a significantly effects on lysozyme (P <0.01). The three kinds of single probiotics preparations had no significant effect on the superoxide dismutase, and Lactobacillus acidophilu, Bacillus subtilis had a significantly effects on serum alkaline phosphatase (P<0.01). Experiment diet and treatments were same to Exp.one,and the activities of amylase , lipase and protease in intestine were measured. The results showed that (1) in different segments of intestine, the amylase activity in midgut was the strongest, the foregut weakest, while lipase was a front to back ranked in descending order, and midgut protease activity was the strongest, the hindgut weakest; (2) the three kinds of single probiotics preparations had different effects on digestive enzyme in different segments of intestine.Exp.four. Effects of probiotics on intestinal microflora of Allogynogenetic crucian carpThe control group was a natural stocking of fish, the experimental group same with the first test.The number of Yeast, Lactobacillus, Bacillus, Colon bacillus Aeromonas in the luminal contents.was determined.The results showed that probiotics can significantly increase the intestinal Yeast, Lactobacillus, Bacillus, and inhibit growth of Colon bacillus and Aeromonas. |
